DIAGNOSTIC GENES FOR TOXOPLASMOSIS

Abstract: Genetic material encoding p30 and B1 peptides of Toxoplasma gondii has been isolated and characterized. This genetic material allows the production of peptides for use in diagnostic or immunization or can itself be directly used in hybridization assays.

Description: DIAGNOSTIC GENES FOR TOXOPLASMOSIS BACKGROUND OF THE INVENTION Field of the Invention This invention relates to the field of genetic engineering and more particularly to the identification and preparation of polynucleotide sequences and polypep- tides useful for vaccine development and for detection of a toxoplasma infection by hybridization and immuno- logical assays. Description of the Background Toxoplasmosis is caused by the protozoan para- site £ondjΛ_. The disease is traditionally associated with the developing fetus in whom it can cause severe neurological problems manifesting as hydro- cephaly, mental retardation, or blindness. In healthy adults, the disease is typically mild producing few if any symptoms. Recently, the number of toxoplasmosis cases has dramatically increased as a result of an increase in persons who are in some way immunodeficient, such as resulting from post-transplantation therapy, neoplastic disease, or acquired immunodeficiency syndrome (AIDS). In such immunodeficient patients, the parasite can cause encephalitis, a potentially fatal form of the disease. The current means of diagnosing toxoplasmosis are costly, time consuming, of limited sensitivity, and associated with substantial risks to the patient. Con¬ ventional procedures involving serologic techniques are very often not reliable because of severe immune dis- function in AIDS patients and because of the recurrent nature of the disease. In pregnant women who are first tested for toxoplasmosis during pregnancy, it is criti- cal to differentiate between current and past infection (currently done by comparing IgG and IgM titers over a period of time) . One problem that currently exists is obtaining sufficient quantities of suitable antigens both for the preparation of vaccines and for use as standards in immunological assays. Current techniques for providing antigen require the growth of protozoa in mice and the continual reinfection of new mice. Availability of a genetically-engineered polypeptide antigen capable of being used either as a vaccine or an immunological stan¬ dard would alleviate numerous problems with the current source of antigen. Furthermore, the methods of treatment for pre- vention of toxoplasma infection are currently limited. There are no commercial vaccines available for the con¬ trol of toxoplasmosis. Treatment of the disease is generally initiated and maintained with a drug regimen involving a combination of pyrimethamine and sulfadiaz- ine. However, toxicity due to the drug treatment can be significant so that prophylactic drug therapy is not recommended except where cysts have actually been detected. Accordingly, there remains a need for the development of diagnostic assays that reliably detect low levels of toxoplasma infection and of materials useful for the production of vaccines. SUMMARY OF THE INVENTION The present invention provides genetic mater¬ ial encoding, among others, cell surface antigens of T_. gondii. The genetic material can be used to produce polypeptides or proteins for use as vaccines or diag¬ nostic reagents, or can be used themselves as probes in nucleic acid hybridization assays for the direct detec¬ tion of toxoplasma infections. Specific genetic mater¬ ial and analytical techniques are disclosed in the fol¬ lowing detailed description and the examples that follow. BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a graph plotting hydrophilicity versus position for the polypeptide encoded by the p30 genetic sequence of the invention. DESCRIPTION OF SPECIFIC EMBODIMENTS The present inventors have identified and obtained for the first time genetic material encoding specific proteins of the protozoan parasite Toxoplasma gondii. The specific antigens are the p30 and B1 anti¬ gens. The p30 antigen is a major surface antigen (see Kasper .et .al.., J. Imm. (1983) 130.-2*107-2412) and can be used for the production of vaccines or diagnostic stan- dards (the latter for use in immunoassays for detecting JT. gondii) . The function and location of the B1 anti¬ gen is unknown, but its multiple genomic nature makes it a particularly useful target for DNA hybridization assays. Accordingly, identification and isolation of the specified genetic material allows production of various biochemical components, such as antigens, diag¬ nostic nucleic acid probes, and systems for producing the same, which find use in a variety of useful biolo¬ gical applications. Since there is a known and definite correspon¬ dence between amino acids in a peptide and the DNA se¬ quence that codes for the peptide, the DNA sequence of a DNA or RNA molecule coding for natural _T. gondii pro¬ teins (or any of the modified peptides later discussed) will readily be understood as indicating particular amino acid sequences, and such exemplary sequences of nucleotides and amino acids are shown in Table 1. Table 1 Nucleotide sequences of one strand of DNA encoding various 7. gondii proteins and sequences of corresponding peptides. The numbers refer to the DNA se¬ quence beginning at the 5' terminus of the sequence. The DNA sequence will correspond to the mRNA sequence except that U replaces T in the mRNA. p30 Sequence 10 20 3 40 ■ SO S3 ε in n ciε si rεi sϊε ' -εs ιsτ sic sz «« •» BCB ε«e <sτ TBT STB sπ Bet SerUal 73 80 93 tαθ 110 123 * > < » * » ICB CIS CSC CϋC TTC BIT BIT TCI TCI ESI ITT IIS 8CS BBT BIG ITT CCE RHB KB £TE SΪΓ Leu His Hij Phs He He Ser Ser Sly P e Leu Ihr Ser M Phe Pro Lys Bla ϋal 120 140 ISO 160 170 1B0 * • • • « « mescsecETCBεεcaεεεsisinscεcscccSCBCTSBTBTCSTTCTTBεssTBT firg Brg Bla &1 Thr Bla Sly Ual Phe Bla Bla Pro ϊhr Leu (let Ser Phe Leu flrg Cys m 200 210 223 230 240 * . « • • « • 66CSIT BIBECBTCS BBTCCCCCT CTT SIT SCC BBT CBBSTI SICBCCTEC CCB EBI RBB SlyUalRetBlaSerBspPrsPro Leu ϋal Bla BenSinUal Ual Ihr CysPro BspLys 2S0 W 273 2B0 290 300 * « ~ » • « ■ mTCSBCBSCCECSSTCBIT CTC KB CCSACS BBSBBCCBC TTCBCTCTCBBS TECCCT LysSer IhrBlaBlaUallieLeuIhrProThr Slu fisnHis Phe Ihr LeuLysCysPro 310 32B 330 340 350 3S0 « t e e • • mseaSECεcicac msecmCBC TCTTECSTBΠCax nCBESCB mCTSCCC LysTie-Sly81aHis flrgfil»SerHisSerCysUal LeuThrSinSinBlaBsaLeuPre 378 3S8 390 WO 410 120 * ■ • < ■ • setSET BCΓBCBBSTSEC mBCBTCBBUSSCT STBBCBΠSBSCICCΠSBTTεπ m SerSlyIhrIlrSerSerSerThrSerLys BlaUal IhrLeuSerSerLeuliePreEli α m 4so w m m • • • • < ■ SCB Eflfi OT 8EC TEE TBS S3 ESS SBT TCT SCI SSI CTC SBC BCS ECB S6C BTC Bββ CTC 81a Slu Bsp Ser Trp Irp Ihr Sly Bsp Ser Bla Ser Leu Bsp Ihr Bla Ely He Lys Lea 490 SOS 510 S20 S3Q 510 • 1 * 1 « « BCBSIT OBBTCSBSBBSTICCCCSTEBCSBCSCSS SCSTTT SISSICEST ISCBTC IBS ThrUal PrelieSluLysPheProUal Thr ThrSinϊhrPheUal Ual SlyCysHeLys 50 Sβ S70 SSO S90 EDO • 1 » • I • E6B SBCSBCECBCSS BET 1ST BTSSTC BCS STS BCB STBCBB SCCBSB ECC TCB TCS STC ElyBspBspBla ElαSerCysBetUal Ihr Ual Thr UalSinBla BrgBla Ser SerUal ence ( Cont 'd ) (10 S2S 630 S40 (SO BTC KIT ffflT STC ECB sεε Tsc TCC «ε ssi sea εsε BSC BCT CTT sεr CCI ETC røε TIE Ual Bsn Rs« Ual Bla Brg Cys Ser T y Slv a i; & » ier Thr Leu Ely Pro Ual Lys Leu 670 69Q TOO 710 720 TCT ECS EBB SER CCC BCT BCB BTE BCC CTC S!5 TEC EEE M EBT SSR STC BBB BIT CCT Ser Bla Slu Sly Pro Thr Thr tlet Thr Leu ϋal Cys Ely Lys Bsp Ely Ual Lys Ual Pro 730 740 750 760 770 780 CBB Sf Bfiε BBT CRS TBC 1ST TCC SEE BCS BCS CTS BCT SET T8C BBC BBS BBB TCB TIC Sin Bsp Bsn Bsn Sin Tyr Cys Ser Sly Thr Thr Leu Thr Sly Cys Bsn Slu Lys Ser Phe 790 810 820 830 BIO BOB SBI RTT IIS CCB RBB TTB ACT 6BS BBC CCS T66 CBS Bl BBC BCT TCS BST 6AT BBS Lys Bsp He Leu Pro Lys Leu Thr Slu Bsn Pro Trp Sin Ely Bsn Bla Ser Ser Bsp Lys 850 870 BT SCC BCS CTB DCS BTC MG BBB BBB SCR TIT CCB SCC SBE TCfl BBB BBC ETC BTT BTT Sly Rla Ihr Uu Thr He Lys Lys Elu Rla Phe Pre Bla Slu Ser Lys Ser Ual He He 910 920 930 940 9SQ 960 SSR TEC KB BE SO TCS CCT SBS BBS CAT CBC 1ST BCC SIS BBB CTE 8BE ITT BCC 888 Qy Cys Thr Sly Sly Ser Pro Elu Lys His His Cys Thr Ual Lys Leu Slu Phe Bla Ely * Cϊ KB 66E TCB ECB flflβ TCS BCT 6C6 SSB BCB SCC BST CBC BTT TCC BTT SCC BT6 Ht Bla Sly Ser Bla Lys Ser Bla Bla Sly Ilr βla Ser His Ual Ser He Phe Bla Met 1B30 1040 1OS0 t060 1070 1080 • t ~ * ~ a ereBTCessΠT BTTεεcΪCT BTCECB SCTιετETCεcειεsereBTT BCCεπεiεCTC 6B1 He Sly Leu He Ely Ser He Bla βla Cys Ual Bla — 1090 1100 1110 1120 1130 1140 * ( * CT TCT CBB BTC SK BBB B8B BBC BCB CTT CST SO) CB 1ST SCC CCB TTB TBB BBB BBC 1150 1160 1170 1180 1190 1200 1 1 « - • • TBB ETT BTT CCS CTE 188 CTT KB SST BIC KB TCC BCB BBB BCC SSC CBB CTC TBB BTR 1210 « EBB ETS TTT CSC nce 10 20 30 40 SO SO • • • • » * m TIC 6TT CBB CBS BBB 888 SEC BBS BST IS6 SBC TBB BTC SBB SCI SBS BIS CTC BBB E F U E Q X 6 S I S U 0 - I E B E H L K K S r O B K S S E U S T K S K L K C S t l E S T E R E Q E L B L K E S - O B Q S 70 SO 90 ISO 110 120 • • < 1 • * - STC SBC CSC SBB BIB CBC CCS CBS BBS BBS SSC T8B CTC SBS CCB ST STS CTB BBS SCS U B 1 E B H P Q K K 8 - L E P 0 U L I B S T B K C I B K B K B O S H O n C - ' B K E f I 0 B P R E E 8 L T E T R E B I S U 130 140 150 160 170 180 < « * ■ < < TCB πε crε TIC ιετ CCT BTC ECB BCB BBS TIC TIC CCB sac ETE EBT ITC CST isε TTC s L L F C P I B T E r F P 0 u D F a U F H C C S U L S Q E S S S Q T U I S U S S I fl U L S Ϋ 8 H S U L P 1 I 8 F P L U P 190 200 210 220 251 240 « • ■ » » « CSC CTC CΪΪ CST CCS ICE TBB TBT CSS 8CC TTC 181 TCT 8TT CSC 1ST CIS ΪΩ BSS ECS E L L E P S - Y Q B F C S U S C L S R B t S F U E E H I E P S B L F B U C L B H t t S S ϋ U I S 6 L L F C S L S 8 - S T 2S0 260 270 280 290 230 < * * 1 • * CCC TIB CTS CBft SBS BBS TBT ITS 866 TCB TBT CST CCC BIS RβS TCS BCC BCC 161 TIC P L L Q E I Y L R S Y S P R I S T I C F P Y C I R S I - S H I U P - S E P P U S L T R B E U F E U I S S 8 E V B H- L F P 310 320 330 340 350 360 • « « • a i CTC ΪCIrø CTS 10 CSTRCS flCRTCS C8T TCB 866 S8B 65 BTC CBS rø BTC TCS TTC L S S L S E T T S H S E I E I I) Q I S F S L R C H O E H E I Q S I E S S E S I S L F T U T Y Q I B F ϊ S E D P fi D L B R 370 380 390 400 410 420 • < • • • • CTS TBT TCS ra m ss BES TCC sec ccc scs sea ess ciε BBS BRi ES BCR TTC TIE β Y S E Q E R S B P I R E L Ϊ K R I F L c i E o i E ε p p Q o ε - t n Q H s c 0 F E I I E U 8 ? H I I fl E E C H I L U 430 440 450 460 470 480 « « « 2T - • * ιεc is TC ETC iα ιεε on sis CCB BBS EBB SEE IBC STS ITS εsr CBT BSC m use C C L S U Q H P E i i Y il ^ H B I s s a s s H ε r. c o i i s F •: ι i i ? - 1 ? P L X a - H ?. β 3 ?. ' j 2 ; j) : - j r ι_ ence (Cont'd) 490 53Q 510 515 550 540 • • > « » » 1ST fin ir CGC ISE CSS RIB CBS GTS RAfl TGT BCC TCC RSR Aflfi SCC BCC T36 IBI C5T C l S R U Q i g y R C t S R K R I - Y u r P fl 6 K Y a - n u P P E P P S I U Y r p L B H i ε E n Y L g K S H L U S C 550 560 570 580 590 600 « » » » • • 6CS ECB BT6 TBC CRC CTC SCC TCI TEE SR6 BBB BBS fiSS HR6 BSB CSC TSC CSC TBT TTI B 8 « C H L fl S U E I I 8 I I I C E C F 8 0 C R T S P L E R K B 6 B 0 fl R B U L 6 H U P P E L L S E K E E E T L P L F C 610 620 630 640 650 660 * » « » • « 6CR BBT ERR RRS SRI TCB TTI ICG CHS TBC RCC BEE R6T TBS BTT ITS TBS R6C ETC TCT B I E K 0 S F S Q Y T 8 S U I L - S U 5 8 n i a i H F a s T p s u ε r c a B S L l - I S F I F fl U H Q E L 0 F U E R L S 670 680 690 700 710 720 « » « • « • CTT Cflfl SCR SCS TBT IE! CSB 6TB EBT CAS Bflfl S8B RCT BCR TCC SIT CRT 8flS TRT BR8 L Q B fl Y C E U 0 Q I 6 T B S U H E Y I F I Q 8 I U E - I R I E L H P T H S I E S S S U L s s a s E a H C I a S - U - E 730 740 750 760 770 780 * » » « * • m m Riε τ» SBR TER BBS BSR εεc TRB TST STT TEC BIB EET TEC BST CRC TSB CSB i i n u E - i a a - c u c I s c s H - a l i C 8 H E 8 0 fl H U F fl - U fl U T 0 E I 1 « 6 II I E I L H C L H 8 L Q S L T S 790 Kffl 610 820 830 840 ■ * » • * ■ επ ccc CTC TEC TB CEB m εiε m TIC BTB BST BTC TBT εca BCT TIE EIS TBT TCE R P L C U B K O K F lt S I C fl T L U Y S L P S fl B E t - H S - U S U Q L U C I R S P L L fl I S E I H E Y L C H F 6 0 T R 650 660 870 880 890 900 r- ~ ~ • « « « CBS BTT BT C8C CTS Cflfl TCS flTfl ETT BBC CRC ERR CSC ITT Bflfl 6BR CA6 BBS flflS BR6 Q I E B L Q S I U Q H E 8 F K E Q E K K a L u fl c H a - L T i x B L I w a a a a 0 U 5 P 8 I 0 S - P a T L - B T 6 E E 0 910 920 930 940 950 960 • * • • • * BTC 515 RRS SBB TRC BRS RRS BE6 " i?G RT« 5RR STC BCT SCS SR6 BCB SCS RR5 i u r. E Y E K a • • ε i E U R A E T fl K s - < K T a a δ τ : ' - Ϊ s L a a 3 a a a E a i a ε E u •< J 3 a s a c s a s E o j 3 3 J H 3 5 H 3 ϊ X A X 0 " i 3 A d 1 S 3 d 1 1 D 0 j i 8 X 0 I X S S 6 ft S H 3 5111333D 113 BB3983311 B3B B5B SBB BB3 Bid BBB B31131583 B 3311B33D OKI OSH SZVl Oi»i 00*1 06ΣI S S 3 B 1 B 1 1 B 1 0 ft d 1 8 3 8 3 3 S ft J ft 5 S 3 H K 3 B d β B I 5 8 3 1 1 J 8 fl 8 - 1 3 6 D 1 X S d 3 H X 0 ft J H 3 133 ID 1339813139D SO 8839D 88833153333i 1833889833D Hi 383 ID * » » » < I D8ΣI 02EI 03ΣI 05£l OKI O∑∑l 1 0 ] J fl H 3 n J H 3 3 I 3 d d 3 s n a α s i j a s ft u s x a a κ x i i - 3 U 3 8 fl J J l β 3 0 I X 3 S X fi H H A 9 Q 8 8983D 11: Ul 33B 3D D918331888898993188888338338891989318389 ■ » t i l l OZΣl Ol∑l BO∑l 0621 05ZI OiZl 3 8 3 3 J A 3 S 8 1 X d 8 A ft I 8 9 8 3 a a a - j i i - 3 i x i a 3 s ii i 3 j a l X X 3 I ft ft 1 n 8 0 8 S 3 - 3 3 3 x 338388 SBB 311 ID ID ID 8133313BB BB3383331311381 KB 89339888338 0921 D5ZI mi OΣZl OZZl 0121 0 S fl S S 0 fl S S A H S ft 1 3 8 3 S 3 3 - n - fl j - a J δ i i i s H n x a i « 9 A u 1 a I 1 d fl 1 I H A δ 8 U X 0 8 o a 9D 9189D 193 ID 911333115 B3B HB 383181383833318 BBB 383133183338 » • * * » I oozi 06 u 08U oai 0311 0311 X a H S 1 3 II 8 3 1 3 6 3 3 3 1 A 3 I H 3 s d x B Λ H d fi o a i a a a A i i H 3 9 I 8 - a 3 8 8 8 8 X -B X X 0 I A A 1 9 B9531B 333BBi 333131833335193 B3B 98838B 583 SBB 5B3 BIB 1B11B1 B3B B53 » » t * • I Wit O∑li Oil! Oil! OGU 0501 3 3 3 3 S ft 3 I S X H U A 8 0 1 3 3 1 3 8 8 X 8 j 3 - λ I fi 3 λ 3 8 1 ϋ 3 3 d ti 3 * 3 3 a j a i 1 Λ l - " i ft s H a a - B O 5B9585 BBS 333 ill 55B 311 BD iBB B3B B318115i533B 3B3 B5B S5B 5Bi 335185 » « * » • » OBOi ύiOl 0501 0501 0»0l KOI * U ϊ 1 5 «» 5 » I R ϊ 5 H 1 3 3 - X 8 B a 3 3 3 B B d 8 fl d 1 J 11 0 8 1 B3i BBB 838833353391983383839833 B338333D 3331383ii 383183 SB 138 ~ * » » I t (p, uoo) 9ouanθ9s La 00L80/68 OΛ ence ( Cont ' d ) 1450 1460 1470 1490 1490 ISOO « • « * * • TTC TIT TBB CCT CRR TRB CRS ERT 6RE SCC ICC CTC CTA TCT TTC RSC CBB CCC Btt BRA r r - P Q - Q D D fi S L L S F S Q P S K S F S L H s B fl I P P 5 Y L S R H P R H L L R S I B 6 - R L P P I F 0 P I 0 Q I 1510 1520 1S30 1540 1550 1560 • * • • • * CC C8B CBB CT CTC T8T BBB 8TB BCB BBB B6A B88 Cflfl BBC BCS CCfl TCB CSR BCB π H 8 8 I L ε 8 U I I E R 0 B B P S 8 T L I ■ 0 E L S U E - δ 8 E S I T 8 H H E H S P T K S L - S H t E K fl K 8 fl I I H T 8 1S70 15S0 1590 1600 1610 1620 • • • « • • SCR BBS flT6 RTR CRS RSB CST STC BTC B8S CR BSS TTS ETC SCI TRfl TTI TCT 8TR TftT R E n I Q 8 E U I 8 I 8 L U fl - F S U Y Q 8 - Y 8 0 U S S 6 I) S U S L H T L Y I 8 0 D I E I C H Q D K U 8 R L I F C I - 1630 1640 1650 1660 1670 1680 • * « • • « BEE BTT TIT m BIB CC CIT TCB 8C CTC BC 8C CST ECB Bflfl SEA TCS CO OT SET S 1 F 8 tl 8 L S 0 L H K R fl K S S P P 6 fl F L E ' C T F 8 1 S I T U Q I 0 8 B L 0 H F - N B P F E P Q Q P C r 8 I B T U C 1690 1700 1710 1720 1730 1740 > • « « ' « • ETC ϊπ TCS SEC ETC ABB CE RC TBT C1E TBT BTC TCT CBB EEB SEB H6 ttB BU ΪES B S S S « I ϊ H Y L Y I S Q S E L fl I U S L Q B S I E 1 I C I S L I E 0 U 0 P 6 L F K E 8 H E L S U Y L S B 8 T 8 H I I 1750 1760 1770 1780 1790 1100 • « • • * • IS! CSR CBB CR6 (fflC fSC IK RSI CCS Sffl ATR 6RR ffiC CRT δfi SCR D Cffl CK SCS C E Q Q II S C S P E I E S H E fl L Q 8 1 U D I E ϊ B fl U 8 I - I fl R 8 H S H 8 8 s T I E g L q s ε H E I p - ε I p T s E 1110 1820 1830 1B40 1850 I860 • • • « « • KT BEC CC TBB 68fl ERI BCB BC Ttt IBfl BCB STC CSS 8T8 Bflfl Cflfl Tffi RSI SIR H8 S S T - B 0 T H C - T U 8 U I 0 - a U L U B P E E I 0 T B I 8 S E - fl H 8 E Y U - H L 8 8 Y ϊ L L H E P S E T I E 5 T 8 1870 1880 1890 19(H) 1910 1320 « « • « • • csi sc esc TBC TK CCR SIT ETC BIS ccfl TCS Rcε TRS sec BS RRfl m εεc ε& E a a a Y c P u u n P s T - T o K - ε E H U R B T B 0 L S C H a a a P a H E fl a T S P L L P s ε H 8 I D U B P E n a a E nce (Cont'd) 1938 1940 1950 1960 1970 - I960 « • • • * « Bflfl TTB RTR ITS π β ETB BC CAT TCS ORB BET TCCEET CSB SB8 CT BBB CCS CRB fffiE K L I L L V I I S K S S S E E R K P q c R - Y C - - S I I I « P I E 1 L 1 W I S i « I u s i a r i i r i s r 6 - T T t u 1990 2800 2010 2820 2030 2040 • « • • • • Ttt RSt CCR IC ECB BCC BTC RC TIB RCB BBB 6C8 BIT SBI SRT EET TC CTC 8C TTC C I t C B fl I S L T I R I E B E C L i T R H H R Q F S B - Q K Q L U n V R S S S Q T H R S H Q L B K S S U - U L P R U P 20S0 2060 2070 2080 2090 2100 a • « • a a ΠT ΠS fififl ere SIT TC ΠC ETC RC EBS ccc αε is caε CAT επ TIC CCB εiε L L ϊ « D Y r I K E P T T 3 H R R F P U F - i u i i s s i s P P I 8 i n L s q c 5 E « 6 L L I' 3 a R H H 8 E S C r P S B 2110 2120 2130 2140 2150 2160 a a a a a a ΠBAREcsTncTUBBSIBBCCCBCSBTSess m msεεHTCECCTRCSIBECB L I E F • s s E T n E K B ( S I R Y U fl - S U S I tl R fl 3 C E fl L I S S P I - H I B r L l - P H II B E C - ε O E L E S T 2170 2180 2190 2200 2210 2220 a a a * a • HI SIT sis cπ cc ccc ccfl CT CST εcε πc BIT πε επ lεε TC εcε επ εaB TTC H 8 U P H P P fl R fl L I L L S C R fl E F H L C L I P Q L « 1 S F S F E fl E L K C C β S P P S S C R H S P F 8 E S - I Since the DNA sequence of the gene has been fully identified, it is possible to produce a DNA gene entirely by synthetic chemistry, after which the gene can be inserted into any of the many available DNA vectors using known techniques of recombinant DNA technology. Thus the present invention can be carried out using re¬ agents, plasmids, and microorganism which are freely available and in the public domain at the time of filing of this patent application. For example, nucleotide sequences greater than 100 bases long can be readily synthesized on an Applied Biosystems Model 380A DNA Synthesizer as evidenced by commercial advertising of the same (e.g., Genetic Engin¬ eering News, November/December 198-4, p. 3). Such oligo- nucleotides can readily be spliced using, among others, the technique of preparing overlapping complementary sequences (e.g, 1-100 of coding strand, 0-50 and 51-150 of complementary strand, 101-200 of coding strand, etc.) followed by hybridizing and ligating the strands. Furthermore, automated equipment is also avail¬ able that makes direct synthesis of any of the peptides disclosed herein readily available. In the same issue of Genetic Engineering News mentioned above, a commercially available automated peptide synthesizer having a coupling efficiency exceeding 99% is advertised (page 3 1 *). Such equipment provides ready access to the peptides of the invention, either by direct synthesis or by synthesis of a series of fragments that can be coupled using other known techniques. In addition to the specific polypeptide sequen¬ ces shown in Table 1 , peptide fragments based on these sequences and fragments representing minor variations thereof will have the biological activity of the various peptides. For example, fragments of the p30 peptide se- quence that are capable of being recognized by immuno- globulins specific for the p30 antigen itself can readily be prepared and screened. Peptide synthesizers can be used to prepare small polypeptide fragments (e.g., less than TOO amino acids) or techniques of genetic engineer¬ ing can be used to prepare larger fragments. A simple screening procedure that will identify suitable polypep- tide fragments consists of preparing monoclonal antibo¬ dies to the p30 antigen, attaching the antibodies to an affinity column, and capturing peptide fragments that are retained by the bound antibody. Polyclonal antisera can be used instead of monoclonal antibodies if desired. The suitability of this technique has been demonstrated ex¬ perimentally. A subsequence of the p30 sequence has been cloned and expressed as a β-galactosidase fusion product (Identified as p30.5). The polynucleotide sequence en¬ coding the p30.5 protein sequence begins at nucleotide number 582 in Figure 1 and ends at nucleotide 996. The p30.5 polypeptide is reactive with polyclonal anti-p30 serum. The ability to prepare and select appropriate immunologically active fragments from a larger protein is well known in the art and is described in a number of publications, including patents. See, for example, U.S. Patent No. ■4,629,783, which describes the preparation of immunologically active fragments of viral proteins. One common variation is the preparation of a polypeptide of the invention in the form of a fused poly¬ peptide. Such peptides are typically prepared by using the promoter region of a gene known to be expressed in a host and inserting nucleotides that encode all or a major portion of the amino acid sequence of the invention into the genetic sequence for the host protein. Examples of such fused proteins include the β-galactosidase fused protein discussed above. Another technique for preparing immunologically active peptide fragments is to synthesize a series of amino acids of from 5-100 amino acids in length (or any intervening length, such as 10, 15, or any other multiple of 2, 3» or 5 in this range) and screen for immunological activity using an antiserum (or monoclonal antibody). The fragments would be selected along the entire length of the peptide to optimize cross-reactivity (e.g., a ser¬ ies of peptides 20 amino acids in length and comprising AA 1 -AA 2Q » AA5-AA25, AA 10 -AAg 0 , etc.). The selected frag¬ ment would then correspond to particularly useful corre¬ sponding nucleotide sequences that could be used to pro¬ duce large amounts of the peptide for use as described herein. In addition, minor variations of the previously mentioned peptides and DNA molecules are also contempla¬ ted as being equivalent to those peptides and DNA mole¬ cules that are set forth in more detail, as will be ap¬ preciated by those skilled in the art. For example, it is reasonable to expect that an isolated replacement of a leucine with an isoleucine or valine, an aspartate with a glutamate, a threonine with a serine, or a similar replace¬ ment of an amino acid with a structurally related amino acid (i.e., a conservative replacement) will not have a major effect on the biological activity of the resulting molecule, especially if the replacement does not involve an amino acid at a binding site or other site of biologic activity. Whether a change results in a functioning pep¬ tide can readily be determined by direct analysis for function in an immunization or in a diagnostic test that relies on immunogenic specificity. Examples of this pro¬ cess are described later in detail. Peptides in which more than one replacement has taken place can readily be tested in the same manner. Preferred peptides differ at no more than 12, more preferably no more than 5, amino acids in any contiguous group of 20 amino acids. Stan¬ dard conservative groups of amino acids are shown in parenthesis using the one-letter amino acid code: non- polar (A,V, L, I, P,M) ; aromatic (F,T,W); uncharged polar (G,S,T,C, N,Q) ; acidic (D,E); basic (K,R,H). The aromatic groups are sometimes considered to belong to the broader- defined nonpolar (F,W) or uncharged polar (T) groups. m Other DNA molecules that code for such pep¬ tides can readily be determined from the list of codons in Table 2 and are likewise contemplated as being equi¬ valent to the DNA sequence of Table 1. In fact, since there is a fixed relationship between DNA codons and amino acids in a peptide, any discussion in this appli¬ cation of a replacement or other change in a peptide is equally applicable to the corresponding DNA sequence or to the DNA molecule, recombinant vector, or transformed microorganism in which the sequence is located (and vice versa) . Table 2 Genetic Code Alanine(Ala) GCL Leucine(Leu XTY Arginine(Arg) WGZ Lysine(Lys) AAJ Asparagine(Asn) AAK Methionine(Met) ATG Aspartic acid(Asp) GAK Phenylalanine(Phe) TTK Cysteine(Cys) TGK Proline(Pro) CCL Glutamic acid(Glu) GAJ Serine(Ser) QRS Glutamine(Gln) CAJ Threonine(Thr) ACL Glycine(Gly) GGL Tryptophan(Trp) TGG Histidine(His) CAK Tyrosine(Tyr) TAK Isoleucine(Ile) ATM Valine(Val) GTL Termination signal TAJ Termination signal TGA Key: Each 3-letter triplet represents a trinucleotide of DNA having a 5' end on the left and a 3' end on the right. The letters stand for the purine or pyrimidine bases forming the nucleotide sequence. A ~~ adenine Y A, G, C, or T if X is C C - cytosine Y A or G if X is T G - guanine ¥ C or A if Z is C or T J = A or G W C if Z is C or T K = T or C Z A, G, C, or T if W is G L = A, T, C, or G z A or G if W is A M = A, C, or T QR TC if S is A, G, C, or T T = Thy ine QR AG if S is T or C X - T or C if Y is A or G S A, G, C, or T if QR is TC X - C if Y is C or T S T or C if QR is AG In addition to the specific nucleotides listed in Table 1, DNA (or corresponding RNA) molecules of the invention can have additional nucleotides preceeding or following those that are specifically listed. For ex- ample, poly A can be added to the 3'-terminal, short (e.g., fewer than 20 nucleotides) sequence can be added to either terminal to provide a terminal sequence cor¬ responding to a restriction endonuclease site, stop codons can follow the peptide sequence to terminate translation, and the like. Additionally, DNA molecules containing a promoter region or other control region upstream from the gene can be produced. All DNA mole¬ cules containing the sequences of the invention will be useful for at least one purpose since all can minimally be fragmented to produce oligonucleotide probes and be used in the isolation or detection of DNA from biologi¬ cal sources. Peptides of the invention can be prepared for the first time as homogeneous preparations, either by direct synthesis or by using a cloned gene or a frag¬ ment thereof as described herein. The p30 peptide was previously enriched by affinity chromatography, but the resulting material was not free of all other toxoplasma materials. By "homogeneous" is meant, when referring to a peptide or DNA sequence, that the primary molecu¬ lar structure (i.e., the sequence of amino acids or nucleotides) of substantially all molecules present in the composition under consideration is identical. The term "substantially" as used in the preceding sentence preferably means at least 95? by weight, more prefer¬ ably at least 99? by weight, and most preferably at least 99.8? by weight. The presence of fragments de¬ rived from entire molecules of the homogeneous peptide or DNA sequence, if present in no more than 5? by weight, preferably 1? by weight, and more preferably 0.2? by weight, is not to be considered in determining homogenity since the term "homogeneous" relates to the presence of entire moleucles (and fragments thereof) have a single defined structure as opposed to mixtures in which several molecules of similar molecular weight are present but which differ in their primary molecular structure. The term "isolated" as used herein refers to pure peptide, DNA, or RNA separated from other pep¬ tides, DNAs, or RNAs, respectively, and being found in the presence of (if anything) only a solvent, buffer, ion or other component normally present in a biochemi- cal solution of the same. "Isolated" does not encom¬ pass either natural materials in their native state or natural materials that have been separated into compo¬ nents (e.g., in an acylamide gel) but not obtained either as pure substances or as solutions. The term "pure" as used herein preferably has the same numerical limits as "substantially" immediately above. The phrase "replaced by" or "replacement" as used herein does not necessarily refer to any action that must take place but to the peptide that exists when an indicated "replacement" amino acid is present in the same posi¬ tion as the amino acid indicated to be present in a different formula (e.g., when leueine is present at amino acid 3 of p30 instead of valine) . Salts of any of the peptides described herein will naturally occur when such peptides are present in (or isolated from) aqueous solutions of various pHs. All salts of peptides having the indicated biological activity are considered to be within the scope of the present invention. Examples include alkali, alkaline earth, and other metal salts of carboxylic acid resi¬ dues, acid addition salts (e.g., HC1) of amino resi¬ dues, and zwitter ions formed by reactions between carboxylic acid and amino residues within the same molecule. The invention has specifically contemplated each and every possible variation of polynucleotide that could be made by selecting combinations based on the possible codon choices listed in Table 1 and Table 2, and all such variations are to be considered as being specifically disclosed. Although genes and corresponding proteins can be prepared by the totally synthetic techniques dis¬ cussed above, in preferred embodiments of the invention genetic information is obtained from natural sources and identified as described herein. The genetic mater¬ ial is first obtained in the form of a gene library, using any of numerous existing techniques. The first of these is to randomly shear genomic DNA and insert this sheared material into expression vectors. If enough recombinants are generated, there is a good probability of having at least one recombinant in the population which is expressing a fusion protein corre¬ sponding to the antigen of interest. In practice, for a genome the size of _T. gondii (about 7x10' bp), at least 5x10 independent recombinants are needed. This allows for the entire genome to be represented by re- combinants where at least one insert will exist with one of its ends falling within any 10-base-pair region. Allowing for only 1 in 6 such insertions being in the correct orientation and reading frame, functional re¬ combinants should exist in such a library with fusions corresponding to every 60 base pairs. Such a library was generated in the laboratory of the inventors and screened with serum from an infec¬ ted mouse. Among the recombinants expressing determin¬ ants reactive with the serum was one which was found at above average frequency. This recombinant, arbitrarily termed B1 , has been characterized as follows. The B1 gene is 2.2 kilobases (kb) long and is tandemly repeated about thirty-five times in a head-to- tail manner. There are no extensive open reading frames based on the complete sequence of the gene. This suggests that either only a short polypeptide pro¬ duct is encoded or that there are introns in this gene. A B1 cDNA has been isolated which begins at nucleotide 411 and ends at nucleotide 1384, as shown in the fol¬ lowing sequence: 11 AAC ATT CTT GTG...GTG TTC GTC One intron is identified in the genomic sequence as beginning at nucleotide 456 and ending at nucleotide 843 as shown in the following sequence: 456 G ITA CGT GTT...GTG TAT TCG CAG Accordingly, an open reading frame is present that begins with the 5 '-end of the cDNA clone (frame 3), switches to frame 1 at the beginning of the new exon (thereby maintaining the ORF) , and ends at nucleotide 1020. A second strategy of preparing gene libraries is to make complementary DNA (cDNA) copies of the total mRNA population of the parasite and to clone these as recombinant molecules in expression vectors. Other investigations carried out by the present inventors indicated that introns were present within the coding regions of other JT. gondii genes. Although introns do not preclude use of sheared genomic DNA, they increase the number of recombinants which must be screened and make further analyses substantially complicated. Based on this result, use of a cDNA library to obtain T_. gon¬ dii genes is preferred. Polyclonal antisera to p30 can be used to screen a cDNA library in order to locate the p30 gene. Recombinants initially identified in this manner have been found to contain different genes, implying that at least some fortuitous cross-reaction with anti-p30 sera occurs. The true p30 gene can be obtained by preparing antisera against each of the fusion proteins obtained in the initial screening. These sera are then used in Western blot analyses against a lysate of JT. gondii. Only antisera from the fusion product of the p30 gene will show reactivity predominantly or exclusively to p30. A clone obtained in the manner described above has been fully sequenced. This sequence was used to isolate other cDNA clones. Together, these sequences can be used to predict the complete protein-coding se¬ quence of the gene as shown in Table 1. A hydrophobi- city analysis of the predicted amino acid sequence is set forth in Figure 1. The primary translation product has a predicted M r of 36,210 kD. It also has a prob- able hydrophobic signal peptide at its N-terminus, as expected for a surface antigen. It has one predicted N-glycosylation site (residue 267) consistent with in¬ vestigations of previous workers which have indicated that the p30 protein may be a glycoprotein. Finally, it has a hydrophobic C-terminus which is not followed by any charged residues. This is apparently diagnostic of a process originally reported in trypanosomes where¬ by the hydrophobic polypeptide segment is replaced by a glycolipid anchor. Such a process is now known to occur for major surface antigens of Leishmania and Plasmodium as well. The gene encoding the p30 antigen can be used for the production of full or modified peptides using standard techniques of manipulating and growing uni- cellular microorganisms. Antigens which are candidates for vaccine development and/or diagnostic reagents will include those recognized by serum from infected patients. Additionally, any of the genetic sequences can be used as probes in hybridization assays. Although the techniques set forth above, when used in combination with the knowledge of those skilled in the art of genetic engineering and the previously stated guidelines, will readily enable isolation of the desired gene and its use in recombinant DNA vectors now that- sufficient information is provided to locate the gene, other methods which lead to the same result are also known and may be used in the preparation of recom¬ binant DNA vectors of this invention. Expression of _T.. gondii protein can be enhanced by including multiple copies of the gene in a transformed host, by selecting a vector known to reproduce in the host, thereby producing large quantities of protein from exogeneous inserted DNA (such as pUCδ ; ptac12; pIN-III- ompA1 , 2, or 3; pOTS; pAS1 ; or pKK223-3h or by any other known means of enhancing peptide expression. In all cases, a _T. gondii protein will be ex- pressed when the DNA sequence is functionally inserted into the vector. By "functionally inserted" is meant in proper reading frame and orientation, as is well understood by those skilled in the art. Typically, a gene will be inserted downstream from a promoter and will be followed by a stop codon, although production as a hybrid protein (possibly followed by cleavage) may be used, If desired. In addition to the above general procedures which can be used for preparing recombinant DNA mole- cules and transformed unicellular organisms in accor¬ dance with the practices of this invention, other known techniques and modifications thereof can be used in carrying out the practice of the invention. In partic¬ ular, techniques relating to genetic engineering have recently undergone explosive growth and development. Many recent U.S. patents disclose plasmids, genetically engineering microorganisms, and methods of conducting genetic engineering which can be used in the practice of the present invention. For example, U.S. Patent 4,273,875 discloses a plasmid and a process of isolat¬ ing the same. U.S. Patent 4,304,863 discloses a pro- cess for producing bacteria by genetic engineering in which a hybrid plasmid is constructed and used to transform a bacterial host. U.S. Patent 4,419,450 discloses a plasmid useful as a cloning vehicle in re¬ combinant DNA work. U.S. Patent 4,362,867 discloses recombinant cDNA construction methods and hybrid nuc¬ leotides produced thereby which are useful in cloning processes. U.S. Patent 4,403,036 discloses genetic reagents for generating plasmids containing multiple copies of DNA segments. U.S. Patent 4,363,877 disclo- ses recombinant DNA transfer vectors. U.S. Patent 4,356,270 discloses a recombinant DNA cloning vehicle and is a particularly useful disclosure for those with limited experience in the area of genetic engineering since it defines many of the terms used in genetic engineering and the basic processes used therein. U.S. Patent 4,336,336 discloses a fused gene and a method of making the same. U.S. Patent 4,349,629 discloses plas¬ mid vectors and the production and use thereof. U.S. Patent 4,332,901 discloses a cloning vector useful in recombinant DNA. Although some of these patents are directed to the production of a particular gene product that is not within the scope of the present invention, the procedures described therein can easily be modified to the practice of the invention described in this specification by those skilled in the art of genetic engineering. The implications of the present invention are significant in that unlimited supplies of _T. gondii proteins and genetic material of the invention will become available for use in the development of hybridi¬ zation assays or in any other type of assay utilizing these materials as a reagent for use in diagnosis, immunization, therapeutics, and research. Methods of using genetic material in a hybridization assay are disclosed in U.S. Application Serial Number 080,479, filed July 31, 1987, and commonly assigned, which is herein incorporated by reference. Transferring the JT. gondii cDNA which has been isolated to other expression vectors will produce constructs which improve the ex¬ pression of a . gondii polypeptide in JE. coli or express the polypeptide in other hosts. Particularly contemplated is the isolation of genes from these and related organisms that express JT.. gondii protein using oligonucleotide probes based on the principal and variant nucleotide sequences dis¬ closed herein. Such probes can be considerably shorter than the entire sequence but should be at least 10, preferably at least 14, nucleotides in length. Inter¬ mediate oligonucleotides from 20 to 500, especially 30 to 200, nucleotides in length provide particularly spe¬ cific and rapid-acting probes. Longer oligonucleotides are also useful, up to the full length of the gene. Both RNA and DNA probes can be used. In use, the probes are typically labelled in a detectable manner (e.g., with ^ ?, ^ E. biotin, or avi- din) and are incubated with single-stranded DNA or RNA from the organism in which a gene is being sought. Hybridization is detected by means of the label after single-stranded and double-stranded (hybridized) DNA (or DNA/RNA) have been separated (typically using nitrocellulose paper). Hybridization techniques suit- able for use with oligonucleotides are well known. The B1 gene is a particularly desirable target of hybridi¬ zation, as it is already present in multiple copies. Although probes are normally used with a detectable label that allows easy identification, unlabeled oligonucleotides are also useful, both as precursors of labeled probes and for use in methods that provide for direct detection of double-stranded DNA (or DNA/RNA) , such as absorption onto nitrocellu¬ lose. Accordingly, the term "oligonucleotide probe" refers to both labeled and unlabeled forms. The invention now being generally described, the same will be better understood by reference to the following examples which are provided for purposes of illustration only and are not to be considered limiting of the invention unless so specified. EXAMPLES The genetic material having the sequences set forth in Table 1 were isolated as described below. Materials and Methods A. Parasite Material Most of the work described here uses the RH strain of Toxoplasma gondii which is the most commonly used laboratory strain amongst Toxoplasma researchers (Pfefferkorn _et..al.. , Exp. Parasitol. (1976) 39 :365- 376). Due to its long history of continuous passage in the laboratory, it is highly virulent in animals and grows rapidly in culture making it ideal for obtaining large amounts of material. However, it has lost the ability to go through the complete sexual cycle in cats. Accordingly, more recent isolates, "C" and "P" strains which retain full biological function but grow more slowly (Pfefferkorn t.^. , J. Parasitol. (1977) J53_:158-159 and Ware _et_ ιl.. , Infect. Immun. (1987) 5_:778-783) , were also used. Parasites were generally grown in vitro in monolayers of cultured human foreskin fibroblasts ( HFF) . Typically, using the RH strain, infected cultures were maintained by seeding uninfected monolayers at about a 1 :50 dilution every 48-72 hours. This yields about 10^ parasites from three T175 flasks of infected cultures. Parasites were harvested just as lysis occurred by pas¬ sage of trypsinized cells through a syringe and removal of HFF debris by column chromatography, as described in Hoshino-Shimizu .et..al. » J. Parasitol (1980) _66_:989-991. B, Gene Libraries Three gene libraries for _T. gondii were con¬ structed in the inventors' laboratory. Unless other¬ wise noted, all libraries comprise λgt11 recombinants constructed by adding EcoRI linkers to methylated in¬ serts and cloning into the EcoRI site of the vector. These are: 1. λRHgl, a library of needle-sheared genomic DNA from RH strain. 2. CRHgl , a library of partially Sau3A diges¬ ted RH genomic DNA inserted into the BamHI site of the cosmid vector c2XB (Bates .et__aχ. , Gene (1983) 26 :137- 146). 3- λRHc2, a cDNA library of RH strain tachy- zoite mRNA prepared in the inventors' laboratory. Libraries were constructed and manipulated as described in Huynh et al. , In D.M. Glover (ed): DNA Cloning, Oxford: IRL Press (1985) pp. 49-78. C. Antibodies 1. Monoclonal Anti-Toxoplasma Monoclonal antibodies to two polypeptide anti¬ gens of the RH strain of _T. gondii were used. Together with their specificities, these are: a. 7B8: against p30, the major surface anti¬ gen of about 30 kD (Kasper _et__ . , J. Im . (1983) 130 : 2407-2412). 2. Polyclonal Anti-Toxoplasma In addition to antisera raised by the inven¬ tors, collaborators provided the following antisera: a. HC1...HC10: human sera from infants con- genitally infected with _T. gondii. b. HA: human sera from infected human adults. c. Rp30 : rabbit antisera to purified p30 (prepared by immunoadsorption to mcAb 7B8). d. RTL1 and RTL2: rabbit antisera to lysates of T. gondii RH strain tachyzoites. Results A. Surface Antigen p30 We used polyclonal antisera to p30 (Rp30) to screen our cDNA library, λRHc2. Several recombinants were identified on the first screen, and of these, three were chosen for further examination based on the strength and reproducibility of the positive signal. The three recombinants were compared by isolating the inserts and using each as a hybridization probe against the other and in Southern blot analyses of digested genomic DNA. From this, it became clear that the three recombinants represent different genes, implying that at least two were due to fortuitous cross-reaction with the anti-p30 sera. Sequence and Southern blot analyses confirmed their distinct coding functions. To deter¬ mine which was the true p30 gene, rabbit antisera was prepared to each fusion protein by excising the appro¬ priate band from an acryla ide gel and injecting this into a rabbit. These sera were then used in Western blot analyses against a lysate of 7_. gondii. Only anti¬ sera to one clone, λTc30.5, showed reactivity to p30. This sera also showed reactivity to no other material in the lysate. That this was indeed p30, rather than a comigrating material, is evident from the reactivity of the antisera with purified p30. The other two clones are clearly distinct genes and presumably only fortui¬ tously cross-reactive. The λTc30.5 clone was fully sequenced and used to isolate other cDNA clones which have also been se- quenced. From these, a complete sequence for the p30 coding region has been derived (see Table 1). Figure 1 shows a hydrophobicity analysis of the predicted amino acid sequence. The primary translation product has a predicted M r of 36,210 kD although the precise amino terminus cannot be determined without direct protein sequencing. It also has a probable hydrophobic signal peptide at its N-terminus, as expected for a surface antigen. It has one predicted N-glycosylation site (residue 267) consistent with prior results indicating that p30 may be a glycoprotein. Finally, it has a hydrophobic C-terminus which Is not followed by any charged residues. This is apparently diagnostic of the process originally reported in trypanosomes whereby the hydrophobic polypeptide segment is replaced by a glyco- lipid anchor. Such a process is now known to occur for major surface antigens of Leishmania and Plasmodium. Using the predicted amino acid sequence, the sizes of cyanogen bromide fragments can be predicted. The data indicate two large fragments, one of which has a tyrosine. Using ' 5 ι_ι a bele p30, cyanogen bromide generates a single large fragment (by polyacrylamide gel electrophoresis) of the predicted size (11 kD) along with several small fragments. Moreover, the poly¬ peptide sequence predicts substantial hydrophobicity for the protein as a whole as previously indicated for p30 by charge-shift immunoelectrophoresis. These re- suits further confirm that the recombinant encodes p30. The presumptive p30 gene is present in one copy per haploid genome and encodes a mRNA of 1.5kb. Based on the signal intensity of the Northern analyses (the band is readily apparent in 0.25 hr) and abundance of cDNAs for this gene in the cDNA library (at least 20 plaques per 10,000 recombinant phage) , it is an abun¬ dant message as would be expected of a protein present at about 3? of total cellular protein. B. Repeat Gene B1 A mouse antisera raised against a lysate of J. ' gondii was used to screen the sheared genomic lib¬ rary λRHgl as a means of identifying possible antigen- encoding genes prior to the availability of the poly¬ clonal antisera. Several recombinants were identified, most of which, it transpired, represented the same gene (here, arbitrarily referred to as B1 ) , which exists as a 2.2 kb tandem repeat in the _T. gondii genome. A par- tial cDNA clone (including poly A tail) has been iden¬ tified from the λRHc2 library and sequenced. A part of the complete open reading frame has been identified (at least one intron is so far apparent from comparing the genomic and cDNA sequence); the transcriptional orien- tation and approximate end points of transcription unit are indicated. Despite repeated attempts, we have been unable to identify the product of the recombinant phage which is responsible for the reactivity to antisera (such reactivity is easily reproducible on phage lifts but has never been observed in Western blots of the induced lysogen) . This lack of reactivity has preclu¬ ded identifying the in vivo antigen because no bacter¬ ial product can be identified for purification and "antibody selection" has been unsuccessful (presumably because of insufficient avidity and/or titer of the anti-B1 antibodies in the serum. Significantly, the gene is conserved (as judged by Southern blot analyses of EcoRI digests) in the genome of all four other T_. gondii strains analyzed, including a recent isolate from an AIDS patient. The repeated nature of this gene enhances its utility as a target for direct diagnosis by hybridiza¬ tion assays, such as those described in prior applica¬ tion, Serial Number 080,479, filed July 31, 1987. All publications and patent applications mentioned in this specification are indicative of the level of skill of those skilled in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. The invention now being fully described, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the appended claims.

Claims: WHAT IS CLAIMED IS: 1. A DNA or RNA molecule, which comprises a nucleotide sequence coding for a p30 or Bl peptide of Toxoplasma gondii 2. The molecule of Claim 1, wherein said molecule comprises a sequence selected from a p30 sequence: ATG QRS GTL QRS XTY CAK CAK TTK ATM ATM χo QRS QRS GGL TTK XTY ACL QRS ATG TTK CCL 20 AAJ GCL GTL WGZ WGZ GCL GTL ACL GCL GGL 3Q GTL TTK GCL GCL CCL ACL XTY ATG QRS TTK 4Q XTY WGZ TGK GGL GTL ATG GCL QRS GAK CCL 50 CCL XTY GTL GCL AAK CAJ GTL GTL ACL TGKg 0 CCL GAK AAJ AAJ QRS ACL GCL GCL GTL ATM ?0 XTY ACL CCL ACL GAJ AAK CAK TTK ACL XTY QQ AAJ TGK CCL AAJ ACL GGL GCL CAK WGZ GCL 9Q QRS CAK QRS TGK GTL XTY ACL CAJ CAJ GCL 10Q AAK XTY CCL QTS GGL ACL ACL QRS QRS QRS 11Q ACL QRS AAJ GCL GTL ACL XTY QRS QRS Y 120 ATM CCL GAJ GCL GAJ GAK QRS TGG TGG ACL 13() GGL GAK QRS GCL QRS XTY GAK ACL GCL GGL 14Q ATM AAJ XTY ACL GTL CCL ATM GAJ AAJ TTK 15Q CCL GTL ACL ACL CAJ ACL TTK GTL GTL GGL 16Q TGK ATM AAJ GGL GAK GAK GCL CAJ QRS TGK 17Q ATG GTL ACL GTL ACL GTL CAJ GCL WGZ GCL 180 QRS QRS GTL GTL AAK AAK GTL GCL WGZ TGK 190 QRS TAK GGL GCL GAK QRS ACL XTY GGL CCL 200 GTL AAJ XTY QRS GCL GAJ GGL CCL ACL ACL 210 ATG ACL XTY GTL TGK GGL AAJ GAK GGL GTL 22Q AAJ GTL CCL CAJ GAK AAK AAK CAJ TAK TGK 230 QRS GGL ACL ACL XTY ACL GGL TGK AAK GAK 240 AAJ QRS TTK AAJ GAK ATM XTY CCL AAJ Y 25Q ACL GGL AAK CCL TGG CAJ GGL AAK GCL QRS 26Q QRS GAK AAJ GGL GCL ACL XTY ACL ATM AAJ 27Q AAJ GAJ GCL TTK CCL GCL GAJ QRS AAJ QRS 280 GTL ATM. ATM GGL TGK ACL GGL GGL QRS CCL 290 GAJ AAJ CAK CAK TGK ACL GTL AAJ XTY GAJ 300 TTK GCL GGL GCL GCL GGL QRS GCL AAJ Q S 310 GCL GCL GGL ACL GCL QRS CAK GTL QRS ATM 320 TTK GCL ATG GTL ATM GGL XTY ATM GGL QRS 330 ATM GCL GCL TGK GTL GCL; or a Bl sequence : GAATTCGTTCGA CAGAAAGGGAGC AAGAGTTGGGAC TAAATCGAAGCT GAGATGCTCAAA 6 ° GTCGACCGCGAG ATGCACCCGCAG AAGAAGGGCTGA CTCGAACCAGAT GTGCTAAAGGCG 12 0 TCATTGCTGTTC TGTCCTATCGCA ACGGAGTTCTTC CCAGACGTGGAT TTCCGTTGGTTC 180 CGCCTCCTTCGT CCGTCGTAATAT CAGCGGTTCTGT TCTGTTCGCTGT CTGTCTAGGGCA 24 ° CCCTTACTGCAA GAGAAGTATTTG AGGTCATATCGT CCCATGAAGTCG ACCACCTGTTTC 30 0 CTCTCTTCACTG TCACGTACGACA TCGCATTCAAGG GAAGAGATCCAG CAGATCTCGTTC 360 GTGTATTCGAGA CAAGAGAGGTCC GCCCCCACAAGA CGGCTGAAGAAT GCAACATTCTTG 2 ° TGCTGCCTCCTC TCATGGCAAATG CCAGAAGAAGGG TACGTGTTGCAT CATAACAAGAGC 48 0 TGTATTTCCCGC TGGCAAATACAG GTGAAATGTACC TCCAGAAAAGCC ACCTAGTATCGT 540 GCGGCAATGTGC CACCTCGCCTCT TGGGAGAAAAAG AGGAAGAGACGC TGCCGCTGTTTT 60 0 GCAAATGAAAAG GATTCATTTTCG CAGTACACCAGG AGTTGGATTTTG TAGAGCCTCTCT 660 CTTCAAGCAGCG TATTGTCGAGTA GATCAGAAAGGA ACTGCATCCGTT CATGAGTATAAG 720 AAAAAAATGTGG GAATGAAAGAGA CGCTAATGTGTT TGCATAGGTTGC AGTCACTGACGA 78 0 GCTCCCCTCTGC TGGCGAAAAGTG AAATTCATGAGT ATCTGTGCAACT TTGGTGTATTCG 840 CAGATTGGTCGC CTGCAATCGATA GTTGACCACGAA CGCTTTAAAGAA CAGGAGAAGAAG 900 ATCGTGAAAGAA TACGAGAAGAAG TACACAGAGATA GAAGTCGCTGCG GAGACAGCGAAG 96 ° ACTGCGGATGAC TTCACTCCCGTC GCACCAGCAGCA GAGGAGTGCCGG GCAAGAAAATGA 1020 GATGCCTAGAGG AGACACAGCGTG TTATGAACAAAT CTATTGAGGTTT CGCGAAGAGGAG 1080 GGAACATATTAT ATACAGAAGAAG AACAAGAGACGT GCCGCATGTCGC TAAGCCATCGGA 1140 AGGGATGCTCAG AAAATGGCACAG TATCACATTACA GTTCCGTTGATT CGTCTGATGGTG 1200 ACGAAAGGGGAA GAATAGTTGTCG CACCAAAACTGG CTAGTTGTTATT TTGAAGAAGRCG 1260 AGAGATGGAGTG AACCACCAAAAA TCGGAGAAAATC GATGGTGTCACG TTTTTTGTCAGA 132 ° CTTCACTTTGTG CAGAAGCATTGC CCGTCCAAACTG CAACAACTGCTC TAGCGTGTTCGT 138 0 CTCCATTCCGTA CAGTCTTCAAAA ATACAAAAGAGA ACATTCCAGCAA CTTCTGCCTTTG 1440 TTCTTTTAGCCT CAATAGCAGGAT GACGCCICCCTC CTATCTTTCAGC CAACCCAGCAAA 150 0 CACCGACGAACT CTCTGTAGAGTA ACAAAGAGAAGG CAAAACGCGCCA TCACGAACACTC 1560 GCAGAGATGATA CAGAGACGTGTC ATCAGGACAAGG TTGGTCGCTTAA TTTTCTGTATAT 1620 AGCATTTTTAGA ATGCACCTTTCG GACCTCAACAAC CGTGCAAAAGGA TCGCCACCTGGT 1680 GTCTCTTCAAGC GTCAAAACGAAC TATCTGTATATC TCTCAAGGAGGA CTGGCAACCTGG 17 40 TGTCGACAACAG AACAGCTGCAGT CCGGAAATAGAA AGCCATGAGGCA CTCCAACGGGCG 1800 AGTAGCACCTGA GGAGATACAAAC TGCTAAACGGTC CGGGTGAAACAA TAGAGAGTACTG 1860 GAACGTCGCCGC TACTGCCCAGTT GTCATGCCATCG ACGTAGACCCAG AAATGAGGCGAG 1920 AAATTAATATTG TTAGTAAAGCAT TCAAAAAGTTCC GGTCGAGAGGCT AAACCACAAAAG 1980 TGCAAACCATGC GCAGCCATCAGC TTAACAAAAGCR GTTGGTGATGGT TGCCTCGAGTTC 20 0 CTTCTGAAAATG GATTACTTCATC AACGAGCCCACC ACGCAGAATCAT GCTTTCCCAGTG 2100 CTAAAGCGTTTC TAAAGTAGCCGC ACAATGCGGAAT GCTAAGGGGATC GCCTACGTAGCA 2160 CATGTTGTGCCT CACCCCCCAGCT CGTGCGCTCATT CTCCTTTCGTGC GCGGCTGAATTC 2220 wherein: A is deoxyadenyl; G is dexoyguanyl; C is deoxycytosyl; T is deoxythymidyl; J is A or G; K is T or C; L is A, T, C, or G; M is A, C or T; X is T or C, if the succeeding Y is A or G, and C if the succeeding Y is C or T; Y is A, G, C or T, if the preceding X is C, and A or G if the preceding X is T; W is C or A, if the succeeding Z is G or A, and C if the succeeding Z is C or T; Z is A, G, C or T, if the preceding W is C, and A or G if the preceding W is A; QR is TC, if the succeeding S is A, G, C or T, and AG if the succeeding S is T or C; S is A, G, C or T, if the preceding QR is TC, and T or C if the preceding QR is AG; subscript numerals refer to the amino acid position in a peptide sequence for which the nucleotide sequence corresponds according to the genetic code, the amino acid positions being numbered from the amino end; and superscript numerals refer to the nucleotide position measured from the 5' end. 3 . The molecule of Claim 2 , wherein said molecule has a p30 sequence : G TCTCTTCTCGGT TGTGTCACATGT GTCATTGTCGTG TAAAC CACGGT TGTATGTCGGTT 61 TCGCTGCACCAC TTCATTATTTCT TCTGGTTTTTTG ACGAGTATGTTT CCGAAGGCAGTG 12 AGACGCGCCGTC ACGGCAGGGGTG TTTGCCGCGCCC ACACTGATGTCG TTCTTGCGATGT 18 GGCGTTATGGCA TCGGATCCCCCT CTTGTTGCCAAT CAAGTTGTCACC TGCCCAGATAAA 24 AAATCGACAGCC GCGGTCATTCTC ACACCGACGGAG AACCACTTCACT CTCAAGTGCCCT 30 AAAACAGGCGCT CACAGAGCCTCC CACTCTTGCGTA CTCACCCAACAG GCAAATCTGCCC 36 AGCGGTACTACA AGTAGCAGTACA TCAAAGGCTGTA ACATTGAGCTCC TTGATTCCTGAA 42 GCAGAAGATAGC TGGTGGACGGGG GATTCTGCTAGT CTCGACACGGCA GGCATCAAACTC 48 ACAGTTCCAATC GAGAAGTTCCCC GTGACAACGCAG ACGTTTGTGGTC GGTTGCATCAAG 5 GGAGACGACGCA CAGAGTTGTATG GTCACGGTGACA GTACAAGCCAGA GCCTCATCGGTC 60 GTCAATAATGTC GCAAGGTGCTCC TACGGTGCAGAC AGCACTCTTGGT CCTGTCAAGTTG 66 TCTGCGGAAGGA CCCACTACAATG ACCCTCGTGTGC GGGAAAGATGGA GTCAAAGTTCCT 7 CAAGACAACAAT CAGTACTGTTCC GGGACGACGCTG ACTGGTTGCAAC GAGAAATCGTTC 7 AAAGATATTTTG CCAAAATTAACT GAGAACCCGTGG CAGGGTAACGCT TCGAGTGATAAG 8 GGTGCCACGCTA ACGATCAAGAAG GAAGCATTTCCA GCCGAGTCAAAA AGCGTCATTATT 9 GGATGCACAGGG GGATCGCCTGAG AAGCATCTCTGT ACCGTGAAACTG GAGTTTGCCGGG 9 GCTGCAGGGTCA GCRAAATCGGCT GCGGGAACAGCC AGTCACGTTTCC ATTTTTGCCATG 1 GTGATCGGACTT ATTGGCTCTATC GCAGCTTGTGTC GCGTGAGTGATT ACCGTTGTGCTC 1 ACTTCTCAAATC GACAAAGGAAAC ACACTTCGTGCA GCATGTGCCCCA TTATAAAGAAAC 1 TGAGTTGTTCCG CTGTGGCTTGCA GGTGTCACATCC ACAAAAACCGGC CGACTCTAAATA 1 GGAGTGTTTCGC 4. The molecule of Claim 2 , wherein said molecule has said Bl sequence . 5 . The molecule of Claim 1, wherein at least one copy of said sequence is present in a functioning re¬ combinant DNA vector . 6 . A genetically engineered microorganism, wherein said microorganism comprises the vector of Claim 5 . 35 7. An isolated oligonucleotide, comprising at least 10 consecutive nucleotides selected from nucle¬ otide sequences of Claim 2. 8. A genetically engineered peptide encoded by a nucleotide sequence of Claim 1. 9. The peptide of Claim 8, wherein said peptide is non-glycosylated. 10. A genetically engineered peptide encoded by a nucleotide sequence of Claim 2, wherein said peptide is immunologically cross-reactive with an antigen of Toxoplasma gondii.

Inventors: BOOTHROYD JOHN C, BURG JAMES L, KASPER LLOYD H, BOOTHROYD, JOHN, C., BURG, JAMES, L., KASPER, LLOYD, H.
Applicants: UNIV LELAND STANFORD JUNIOR, THE BOARD OF TRUSTEES OF THE LELAND STANFORD JUNIO
Application year: 1989
Main classification: C12N1
IPC codes: A61K39, A61P33, C07K14, C12N1, C12N15, C12Q1, C12R1, G01N33