bluuebunny/crossref_metadata_2025 huggingface dataset:
GROWTH OF POLLEN GRAIN NUCLEI OFTRADESCANTIA PALUDOSA
Authors: White R. L. , Davidson D.
Published: November 2014

Pollen grain nuclei of Tradescantia paludosa Anderson and Woodson had a mean volume of 122 μm3in early G1and 1,415 μm3in late G2. The distribution of nuclear volumes was not linear normal; however, it closely approximated a log normal distribution and probit plots yielded straight lines for the central 85-90% of the values. Most nuclei were spherical or nearly-spherical in early G1but their increase in volume was accompanied by a change to an ovaloid or elongate shape. Interphase in the pollen grain lasted about five days at 25 °C. In the first 3.5 days the rate of increase in mean nuclear volume was about 87 μm3per day. In the last 1.5 days of pollen grain interphase, nuclei increased at a mean rate of 658 μm3per day; nuclear growth was relatively slow in G1and rapid in G2. The largest nuclei tended to divide first; the result was that as the proportion of nuclei that have divided increased, mean nuclear volume decreased from 1415 μm3to 680 μm3. Nuclear volumes were also determined for diploid nuclei of root meristem and sporogenous cells; their mean volumes were smaller, 1,355 μm3and 1,018 μm3, than that of the G2haploid nuclei, 1,415 μm3.
ESTIMATION OF GENERAL AND SPECIFIC COMBINING ABILITIES IN POTATO
Authors: Tai G.C.C.
Published: November 2014

Seven quantitative traits of the cultivated potato (Solanum tuberosum L.) were studied in a partial diallel cross experiment. Large specific combining ability effects were observed for total and marketable yields, total number of tubers, and number of marketable tubers. Large general combining ability effects were obtained for average weight per tuber, average weight per marketable tuber, and specific gravity. The SCA effect for specific gravity was also significant. It is suggested that the difference of combining ability performance noted above for the two yield components was due to a long history of directional selection for high yield and stabilizing selection for tubers within the marketable size range. There were low frequencies of both GCA and SCA effects showing significant difference from the population mean. This is interpreted as an affirmation of the narrow genetic base which exists in the present gene pool in Solanum tuberosum. Heritability estimates based on GCA effects indicated that parents can be efficiently selected for average tuber weight and specific gravity.
CHROMOSOMAL CHARACTERISATION OF FIVE LEPIDOPTERAN CELL LINES OF MALACOSOMA DISSTRIA (LASIOCAMPIDAE) AND CHRISTONEURA FUMIFERANA (TORTRICIDAE)
Authors: Ennis T. J. , Sohi S. S.
Published: November 2014

Chromosome number and morphology have been examined in four established cell lines (Md63, Md66, Md108, and Md109) of the forest tent caterpillar, Malacosoma disstria Hübner, and one (Cf124) of the spruce budworm, Choristoneura fumiferana (Clemens). Chromosome number distributions of Md63 (mode = 112), Md108 (mode = 103), Md109 (mode = 103), and Cf124 (mode = 110) overlap sufficiently to prevent identification of individual lines by number alone. However, Md66 is exceptional in possessing a modal number of 157. One large chromosome occurs in cells of all lines. The presence of this chromosome, the lack of any distinct polyploid series among chromosome numbers encountered, and the general inverse relationship between number and size of chromosomes, suggest that the high level of heteroploidy characteristic of these and other lepidopteran cell lines reflects not only a possible polyploid origin but also extensive chromosomal rearrangement and fragmentation. Tolerance for such change is attributed to the holokinetic organisation of lepidopteran chromosomes. A distinct heteropycnotic body is present in about 10% of Cf124 cell nuclei, and can be used as a marker for this line. This body may represent the sex chromatin normally encountered in somatic cells of female C. fumiferana.
INDUCTION OF HOMOEOLOGOUS PAIRING IN WHEAT BY GENES OF RYE SUPPRESSING CHROMOSOME 5B EFFECT
Authors: Lelley Tamás
Published: November 2014

To test the effect of single rye chromosomes on the pairing of homoeologous wheat chromosomes, the seven wheat-rye addition lines of "Chinese Spring" and "Imperial" were crossed with Secale cereale L. and S. montanum L. In haploid triticale with 28 chromosomes (ABD R) no homoeologous pairing was induced. In the 29-chromosome hybrids, the two homologous rye chromosomes tended to form a rod bivalent indicating a suppressor effect of the wheat genome on chiasma formation between homologous rye chromosomes. Unequivocal evidence for homoeologous pairing of wheat chromosomes was found in several F1 plants. It is suggested that in the rye species Secale cereale and S. montanum the system which suppresses the activity of the Ph locus consists of more than two alleles which may act additively. They may be located on different chromosomes and may differ in number in the same genotype. Alleles effecting homoeologous pairing in wheat seem to be more frequent in S. montanum than in S. cereale. It is possible that in rye exceptionally strong alleles exist for homoeologous pairing.
BANDING ANALYSIS OF THE SOMATIC CHROMOSOMES OF THE DOMESTIC DOG (CANIS FAMILIARIS)
Authors: Manolache M. , Ross W. M. , Schmid M.
Published: November 2014

The chromosomes of the domestic dog (Beagle) were investigated by several different staining techniques. G-banding, Q-banding, and the bis-benzimidazol derivative Hoechst 33258, make possible the identification of all 39 chromosome pairs. Constitutive heterochromatin (C-bands) was present on a few chromosomes as distinctive, large stained areas; on the other autosomes there was little or no heterochromatin detectable.
THE GENETIC RELATIONSHIP BETWEEN THE Hbb LOCUS AND BODY SIZE IN A POPULATION OF MICE DIVERGENTLY SELECTED FOR SIX-WEEK BODY WEIGHT
Authors: Garnett I.
Published: November 2014

Both pleiotropy and linkage were examined as possible explanations for the fixation of the Hbbs allele in the six Large lines of a population of mice divergently selected for six-week body weight (six replicates in each direction and six controls). A survey of over 1200 individuals in the lines still segregating at the Hbb locus excluded pleiotropy as a possible explanation. The results showed a nonsignificant effect of haemoglobin genotype on body weight. The linkage relationship of the Hbb locus was examined using a backcross mating system. The Hbbs c+ region (chromosome 7) of a Large line was backcrossed into its corresponding Small line (Hbbd c). The resultant difference in body weight between the two segregants (Hbbs c+/Hbbd c; Hbbd c/Hbbd c) was measured. The results suggested linkage as the most plausible explanation for the fixation of the Hbbs allele in the six Large lines.
A STUDY OF STERILOID CHARACTERS IN A MONOTELOSOMIC LINE OF CULTIVATED OATS, AVENA SATIVA
Authors: Chow M. T. C. , Gauthier F. M. , Dubuc J. P.
Published: November 2014

Three telosomic lines ST-20L of cultivated oats, Avena sativa L., were studied for their different expression of spikelet characters. An A sterilis type of spikelet was observed in one monotelosomic line in contrast to the A. sativa type (exception for one reduced twisted geniculate awn on the primary floret only) present in its monosomic counterpart. The genes responsible for cultivated vs. wild type spikelet characters were located on the short arm of ST-20, and the expression of the wild characters was found to be influenced by other suppressors located on chromosome(s) other than ST-20. It seems that the suppression of wild types of spikelet characters in cultivated oats is governed by more than one gene complex located on different chromosomes.
RELATIONSHIP TO POLYEMBRYONY, FREQUENCY, MORPHOLOGY, REPRODUCTIVE BEHAVIOR, AND CYTOLOGY OF AUTOTETRAPLOIDS IN PENNISETUM AMERICANUM
Authors: Hanna W. W. , Powell J. B. , Burton G. W.
Published: November 2014

Data were collected on the origin, frequency, morphology, reproductive behaviour, and cytology of spontaneously occurring autotetraploids in pearl millet, Pennisetum americanum (L.) K. Schum. Autotetraploids occurred at frequencies as high as 1 per 13 and 292 plants in poly-embryonic and non polyembryonic inbred 'Tift 239' material, respectively. Tetraploids could not be visually distinguished from diploids at the vegetative stage. However, at anthesis the tetraploids, in contrast to the diploids, has poor pollen shed and the inflorescence had a tufted appearance due to longer and more frequent stigmatic hairs on the pistil. Tetraploids exhibited less stainable pollen, greater variability in pollen size, and larger guard cell areas than the diploids. Seed set of selfed tetraploids was 1% that of selfed diploids. The mean numbers of chromosome configurations observed per microsporocyte at metaphase I were 2.64 univalents, 8.97 bivalents, 0.38 trivalents, and 1.49 quadrivalents. Polyembryony in Tift 239 pearl millet is apparently associated with tetraploidy. Lines giving high numbers of polyembryonic caryopses also give high numbers of tetraploids.
DIFFERENTIAL FLUORESCENCE OF SISTER CHROMATIDS WITH 4′-6-DIAMIDINO-2-PHENYLINDOLE
Authors: Lin M. S. , Alfi O. S. , Donnell G. N.
Published: November 2014

Differential fluorescence of sister chromatids and sister chromatid exchanges (SCE) in chromosomes from human lymphocytes grown two replication cycles in medium containing 5-bromodeoxyuridine can be detected by fluorescence microscopy after staining with 4′-6-diamidino-2-phenylindole (DAPI). The DAPI fluorescence appears to be more stable than that of the dye 33258 Hoechst and may provide a more sensitive method for the detection of SCE.
THE SIGNIFICANCE OF CHROMOSOME ASSOCIATION IN AN ADVANCED POPULATION OF TETRAPLOID RYE
Authors: Hossain M. Gul
Published: November 2014

Chromosome pairing was studied in a population of tetraploid spring rye (Secale cereale L.) 20 years after the chromosomes were doubled. Cytogenetically the population was heterogeneous as revealed by significant differences between plants for chiasma frequency, the proportions of regular MI cells and regular quartets. Compared to early C generations meiotic behavior in the population improved by an increase in quadrivalent frequency, mainly at the expense of trivalents and univalents. However, quadrivalent frequency failed to correlate with all other meiotic features; instead bivalent frequency had significant positive correlations with the features of meiotic regularity including chiasma frequency. Furthermore, the average quadrivalent frequency in the population was considerably less than that of inbred lines. These facts led to the conclusion that disomic association dominated the chromosome association pattern in this random mating population, whereas in inbred materials the chromosome association pattern is predominantly tetrasomic. This was further proved by a test against the theoretically expected chromosome association pattern in a true autotetaploid.
CYTOTAXONOMIC STUDIES ON THE GENUS BOONACRIS: I. The "eastern" taxa and a comparison with the related genera Dendrotettix and Appalachia (Orthoptera: Catantopidae: Podismini)
Authors: Fontana P. G. , Vickery V. R.
Published: November 2014

Thirteen populations of four distinct taxa in the wingless grasshopper genus Boonacris with an eastern distribution in Canada and the United States had a chromosome complement of 2n ♀; ♂ = 20A + XO;XX. A detailed analysis of chromosome lengths and of the heterochromatin content and distribution in the karyotypes of the populations sampled revealed extreme endophenotypic stability and conservatism. Two populations were found to contain heterochromatically variant karyomorphs, one being polymorphic with respect to a complex pattern of autosome and sex-chromosome heterochromatin expression, the other for the occurrence of a large heterochromatic supernumerary chromosome. The cytogenetic system of Boonacris species was compared with those of the related, largely sympatric species Appalachia arcana and Dendrotettix quercus. The last two species have 2n ♀; ♂ = 22A + XO;XX but their complements show structural differences. The available evidence from a number of podismine species suggests that the forms with the lower chromosome number (i.e. 21 ♀; 22 ♂) may have originated from a common 'proto-Podisma' ancestor with 23 chromosomes (♀) via evolutionary loss or elimination of a small, unstable megameric pair. This dichotomy of major phyletic lineages and other cytogenetic evidence is discussed in relation to a phenetic classification of the tribe.
MORPHOLOGY AND BREEDING BEHAVIOR OF COTTON HAPLOIDS
Authors: Chaudhari H. K.
Published: November 2014

Haploids of two cotton species Gossypium barbadense L. andG. hirsutum L. were produced by using the semigametic strain VSg-7. They were identified by a genetic marker, Miniature stature, their small leaves and flowers, and anther indehiscence. Haploids and diploids differed significantly from each other in seven characteristics and the differences in four of them were close to 2:1, the same as the chromosome ratio. Haploids of G. hirsutum were completely sterile, while those of G. barbadense showed some fertility as evidenced by an apparent 2% diads in PMCs, 3% functional pollen, 6% crossing, and fruit-setting in 43% of the haploids.
DIALLEL CROSS ANALYSIS OF STOMATAL DENSITY AND LEAF-BLADE AREA IN GRAIN SORGHUM, SORGHUM BICOLOR
Authors: Suh H. W. , Dayton A. D. , Casady A. J. , Liang G. H.
Published: November 2014

Analysis of a 6-variety diallel revealed that general and specific combining abilities were highly significant for stomatal density and leaf-blade area in Sorghum bicolor (L,) Moench. Interactions of genotype × location were also highly significant for both characters. For stomatal density, overdominance was indicated and one gene (or one block of genes) was involved; heritability estimate was 51%. For leaf-blade area, again overdominance was indicated and at least one gene controlled that trait; estimate of heritability was 18%. Regression coefficients of Wr on Vr of both characters deviated slightly from unity which could be due to epistasis or correlated gene distribution, or both. Dominance order of the parents was KS 9, Redlan, Combine Kafir 60, KS 18, KS 24, and Martin for stomatal density and KS 9, Martin, Redlan, KS 18, KS 24, and Combine Kafir 60 for leaf-blade area. The significant interaction of general combining ability × location and the highly significant interaction of specific combining ability (sea) × location for stomatal density and the highly significant interaction of sea × location for leaf-blade area imply that the breeding program attempting to improve these characters should tend toward producing individual lines for each different environment.
INHERITANCE OF RESISTANCE TO PUCCINIA CORONATA AVENAE AND ITS ASSOCIATION WITH SEED CHARACTERISTICS IN FOUR ACCESSIONS OF AVENA STERILIS
Authors: Kiehn F. A. , McKenzie R. I. H. , Harder D. E.
Published: November 2014

The inheritance of resistance to oat crown rust Puccinia coronata Cda. f. sp. avenae Eriks. was studied in four accessions of Avena sterilis L. Three of the accessions, CAV 4963, CAV 1358 and CAV 1376, originated from Israel, and one, CAV 1964, from Algeria. Seedling rust tests on F2 backcross families indicated that a single recessive gene, Pc-55, in CAV 4963 conditioned seedling resistance to 10 of 12 crown rust isolates tested. In CAV 1964, a single dominant gene Pc-56 conferred resistance in both the adult and seedling stages to all crown rust isolates tested except race 239, while a second dominant gene conditioned resistance to only two of the twelve cultures used. From adult and seedling tests it appeared that the resistance in CAV 1358 and CAV 1376 was conditioned by a number of recessive minor additive genes. The genes Pc-55 and Pc-56 are not allelic with the A. sterilis derived genes Pc-35, Pc-38, Pc-40, Pc-45, Pc-46, Pc-47, Pc-48, and Pc-50. Genes Pc-39 and Pc-55 are either very closely linked or allelic and Pc-56 is not closely linked to either Pc-39 or Pc-55. The usefulness of genes Pc-55 and Pc-56 was demonstrated in tests which showed that both genes were effective against 99.8 and 94.5%, respectively, of all crown rust cultures isolated in Canada in 1974 and 1975. The genes for seed color and awn character did not appear to be linked to the crown rust resistance genes. In CAV 4963, CAV 1358 and CAV 1376 the genes for grey color and wild type awns appeared to be linked with recombination values of about 2, 23 and 18%, respectively.
CYTOGENETICS OF WIEBE'S 16 CHROMOSOME BARLEY
Authors: Fedak George
Published: November 2014

A cytogenetic study was made on Wiebe's stock of barley (H. vulgare L.) with 16 chromosomes in which the extra chromosome was derived from a shortened section of a T5-7a translocation. Predominantly 8 chromosome pairs (8″) were observed at MI. Transmission of the extra chromosome through both egg and pollen was regular. The absence of pairing between the extra and homologous segments of normal chromosomes was attributed to the presumed absence of terminal sections of the extra chromosomes. A low frequency of a quadrivalent involving normal chromosomes indicated the presence of a translocation.
INHERITANCE OF YIELD, YIELD COMPONENTS, AND FALL-FRUITING HABIT IN RED RASPBERRY DIALLEL CROSSES
Authors: Fejer S. O.
Published: November 2014

From a series of 4 × 4 diallel crosses in the red raspberry (Rubus idaeus L.), it was determined that inheritance was predominantly additive for fruit yield and weight, fall-fruiting habit, day of flowering and total soluble solid content. However, it was mainly nonadditive for numbers of cane branches and laterals. Inbreeding depression was found for the yield of seedlings from sib-crosses within individual diallels. Reciprocal differences were noted for some characters.
GENETIC STRUCTURE OFHORDEUM JUBATUM. I. OUTCROSSING RATES AND HETEROZYGOSITY LEVELS
Authors: Babbel G. R. , Wain R. P.
Published: November 2014

The inheritance patterns of four allozyme systems were studied in the tetraploid weed, Hordeum jubatum L. The allozymes are: two cathodal peroxidase systems, CPX-2 and CPX-6, one glutamate oxaloacetate transaminase system, GOT-2, and one esterase system, EST-4. Using these systems outcrossing rates in two populations were calculated to be 1 to 3%. Because of intensive inbreeding, there is little heterozygosity at any of the loci examined in three sample populations. In the GOT and EST systems, however, duplicated loci resulting from polyploidy produce high levels of fixed heterozygosity. In the EST system, both heterozygous and homozygous phenotypes can occur in high frequencies in a population. The underlying genotypic flexibility may be the result of duplicated loci segregating for the same alleles, or for null alleles. The combination of self-fertilization, polyploidy, and duplicated loci with genotypic flexibility may contribute to the successful weedy nature of H. jubatum.
THE G-BANDING PATTERN OF CHROMOSOMES IN EHRLICH LETTŕE ASCITES TUMOR CELLS
Authors: Evans W. L. , Welch D. L.
Published: November 2014

The trypsin digestion-Giemsa staining technique was used to produce distinctive banding patterns in chromosomes of Ehrlich Lettŕe ascites tumor cells derived from a frozen culture originally begun from the ELD line. The chromosome numbers most frequently encountered in cells were 44 and 45. Four large marker chromosomes were identified in the karyotype. One of these was a large submetacentric chromosome, the banding pattern of which indicated its probable origin was from a pair of telocentric chromosomes. Using banding patterns and lengths, the chromosomes were classified into four groups — marker, paired, unpaired, and minute chromosomes.
INFLUENCE OF AESTIVUM WHEAT CYTOPLASM ON HEXAPLOID TRITICALE
Authors: Gour V. K. , Singh C. B.
Published: November 2014

Hexaploid triticale × aestivum wheat crosses were compared with its reciprocals in the F1 generation for morphological characters, fertility, and meiotic instability. Use of wheat as the female parent resulted in considerable reduction in vigour and fertility. It was suggested that triticale be used as the female parent in triticale × wheat hybridization programs.
SOMATIC INSTABILITY IN THE BRAZILIAN SEMI-DWARF WHEAT IAS 54
Authors: Guerra M. dos Santos , Fernandes M. Irene B. De Moraes
Published: November 2014

The mitotic chromosome behavior of the Brazilian semi-dwarf wheat cultivar IAS 54 (Triticum aestivum L. em Tell) is described. In root tip cells dicentrics, fragments, isochromosomes, a satellite tandemly duplicated, chromatid exchanges, aneuploidy, ring chromosomes and breaks in almost all chromosomes of the complement were observed. Since anaphase cells that were not pretreated showed bridges, disorderly condensation and micronuclei, the possibility that pretreatment was responsible for the abnormalities was eliminated. Other possible genetic factors and virus infection as causal agents were discussed.
SEX AND CROSSING OVER IN LINKAGE GROUP III OFTRIBOLIUM CASTANEUM
Authors: Sokoloff Alexander
Published: November 2014

The relative position of the genes black (b), light ocular diaphragm (lod) and aureate (au) for the third linkage group of T. castaneum (Herbst) (Coleoptera, Tenebrionidae) has been determined as b – lod – au. The distances between the various genes vary, depending on the cross. The b++/+ lod au ♂ × + lod au/+ lod au ♀ crosses give the following recombination values: au – lod = 18.32 ± 1.21%; b – lod = 21.05 ± 1.51% and b – au = 37.43 ± 1.27%. The reciprocal crosses give au – lod = 27.67 ± 1.62%; b – lod = 13.97 ± 1.26% and b – au = 39.79 ± 1.78%. For the larger distances encompassed in the b – au region the recombination values in the two sexes were not significantly different. For the shorter b – lod region the recombination values were significantly larger in the females than in the males, while for the adjacent lod – au region the opposite was true. On the basis of the current literature it would appear that the main factors contributing to these sex differences in recombination are the modifiers which are different in the genetic background of the two sexes.
MALE-STERILITY AS A SOURCE OF HAPLOIDS AND POLYPLOIDS OF GLYCINE MAX
Authors: Beversdorf W. D. , Bingham E. T.
Published: November 2014

Haploids, diploids, triploids, tetraploids, pentaploids, and hexaploids were observed among the progeny of male-sterile (ms1/ms1) soybeans (Glycine max (L.) Merrill). Seedlings from 167 polyembryonic seeds included 5 haploids, 304 diploids, 15 triploids, and 3 tetraploids. Polyembryony occurred at a frequency of 2.3% among 7,206 viable seeds obtained from male-sterile soybean plants. Although diploid seedling combinations were most frequent from polyembryonic seeds (77%), haploid-haploid, haploid-diploid, diploid-triploid, diploid-tetraploid, and tetraploid-tetraploid combinations were observed. Seedlings from mono-embryonic seeds included a haploid, diploids, triploids, tetraploids, pentaploids, and hexaploids. Highly polyploid individuals resulted from mono-embryonic seeds that were shrivelled prior to germination. Male-sterile soybeans, homozygous for ms1, appear to be a valuable source of haploids and polyploids.
FUSION OF CHROMOCENTERS IN PREMEIOTIC INTERPHASE OFSECALE CEREALEAND ITS POSSIBLE RELATIONSHIP TO CHROMOSOME PAIRING
Authors: Bowman J. G. , Rajhathy Tibor
Published: November 2014

The premeiotic interphase of rye has been found to exhibit a synchronized fusion of chromocenters. This results in a solid knot of heterochromatin localized to one side of the nucleus. Colchicine injected into the immature inflorescence of diploid rye has been found to induce univalent and multivalent formation at metaphase I. The early premeiotic interphase was the phase of development most sensitive to colchicine. Colchicine was also found to have a similar disruptive effect on fusion of chromocenters in the premeiotic interphase. The relationship of these observations to chromosome pairing is discussed.
INHERITANCE OF LEAF RUST RESISTANCE IN WHEAT CULTIVARS RAFAELA AND EAP 26127 AND CHROMOSOME LOCATION.OF GENE Lr17
Authors: Dyck P. L. , Kerber E. R.
Published: November 2014

The inheritance of seedling resistance to leaf rust (Puccinia recondita) was studied in wheat (Triticum aestivum L.) cultivars Rafaela and EAP 26127. Rafaela has genes Lr14b and Lr17 while EAP 26127 has Lr17. Lr17 was located on chromosome 2A, possibly the short arm, and was independent of Lr11.
CHROMOSOME LOCATION OF GENE Sr29 FOR REACTION TO STEM RUST
Authors: Dyck P. L. , Kerber E. R.
Published: November 2014

A gene for stem rust resistance, previously designated SrEC and present in the wheat cultivar Etoile de Choisy, was located on the β arm of chromosome 6D. The gene, now designated Sr29, is independent of Sr5, known to be on chromosome 6D, and possibly independent of the 6D centromere.
INVITATION PAPER: THE INCIDENCE OF GENETIC DISEASE AND THE IMPACT ON MAN OF AN ALTERED MUTATION RATE
Authors: Trimble Benjamin K. , Smith Martha E.
Published: November 2014

In order to adequately assess the genetic risks to man of an altered mutation rate, it is necessary to know the naturally occurring frequency of mutation-maintained genetic ill-health and the burden that such defects impose. The relevant data that are available are largely inadequate to "determine the incidence of genetic disease that is maintained by mutation, and measures of various aspects of the social and personal burdens due to hereditary ill-health are almost wholly lacking. It is suggested that the creation of individual and family histories, using large scale automatic record linkage and existing files of vital and ill-health records, may be a useful approach to these kinds of problems. Using such linked individual health histories, new data are presented that relate to measures of the burden due to childhood dominant and recessive diseases and congenital malformations.
INHERITANCE OF Q AND C BAND POLYMORPHISMS
Authors: Phillips Ruth B.
Published: November 2014

Sequential Q and C banding of chromosomes from 36 individuals in three unrelated families revealed Q band variants on 6 different chromosomes and C band variants on 14 different chromosomes. These variants were inherited in Mendelian fashion with one exception in which a C band variant absent in the parents was found in a child. Although some of the Q band variants were also detected with C banding, there was no consistent correlation between the intensity of variant Q and C bands.
GROWTH OF NUCLEI IN METHYLXANTHINE INDUCED BINUCLEATE CELLS OFVICIA FABA
Authors: Wellwood C. A. , Davidson D.
Published: November 2014

Primary roots of Vicia faha L. were treated with solutions of two methylxanthines, 3-isobutyl-1-methylxanthine (IBMX) and 8-ethoxycaffeine (8-EOC). Binucleate cells were formed and, using this marked sub-population, nuclear growth was studied. In a 12 h period of interphase, nuclei did not grow, their mean volume decreased slightly, by 5.3% in IBMX induced binucleate cells and by 11.3% in 8-EOC induced binucleate cells. In the next 2 h, nuclear volume increased. By 15-17 h after IBMX treatment, about 75% of the binucleate cells had divided; none of the binucleate cells in 8-EOC treated roots had divided even by 21 h. Mean volume of prophase nuclei was lower in uni- and binucleate cells of IBMX treated roots than in normal roots. Sister nuclei of binucleate cells rarely had identical volumes. The difference between the mean volume of the larger and smaller nucleus of each pair of interphase nuclei ranged from 74 μm3, in a sample whose mean nuclear volume was 545 ± 131 μm3, to 178 μm3, when mean nuclear volume was 707 ± 284 μm3. The mean difference between prophase sister nuclei was 190 μm3and the overall mean volume was 1320 ± 297 μm3. In some way, sister nuclei of binucleate cells are unequal and the mitosis from which they were formed was differential. The results are discussed in terms of nucleo-cytoplasmic interactions.
TRISOMY 12 MOSAICISM IN AN INFERTILE MAN
Authors: Richer C.-L. , Bleau G. , Chapdelaine A.
Published: November 2014

Cytological studies of peripheral blood lymphocytes from an infertile man revealed the presence of a mosaic trisomy 12. To our knowledge this has not been previously reported in patients. The clinical manifestations in this case enhance the interest of the cytological findings.
FLUORESCENT PROBES OF CHROMOSOME STRUCTURE AND REPLICATION
Authors: Latt Samuel A.
Published: November 2014

Procedures employing fluorescent dyes or Giemsa stain have been utilized to differentiate metaphase chromosomes into longitudinal segments termed bands. In spite of the immense practical utility of chromosome banding, the chemical basis of banding patterns remains incompletely understood. Physical chemical studies have elucidated the modes and specificities of the interaction of fluorescent dyes such as quinacrine, 33258 Hoechst, daunomycin, chromomycin A3 and 7-aminoactinomycin D with DNA and chromatin. However, it is not clear that all aspects of chromosome staining are explainable in terms of the optical properties of soluble dye-DNA complexes. BrdU-dye techniques in which chromosome staining depends on the schedule of BrdU incorporation by cells, have been used for cytological studies of chromosome structure and replication. These procedures have revealed a close association between quinacrine or Giemsa bands and late replicating chromosomal regions. Biochemical studies on chromatin differentially labelled according to replication timing may thus prove useful for investigating the molecular basis of chromosome banding.
BANDING PATTERNS IN MITOTIC CHROMOSOMES OF THE RABBIT (ORYCTOLAGUS CUNICULUS)
Authors: Chan F. P. H. , Sergovich F. R. , Shaver E. L.
Published: November 2014

A detailed analysis of rabbit mitotic chromosomes stained with quinacrine and Trypsin-Giemsa methods to elucidate the Q and G bands is presented. Each of the 21 pairs of autosomes can be identified unequivocally. The sex chromosomes can also be distinguished from the autosomes. The X chromosome is a medium length submetacentric with its own distinctive banding pattern. The Y chromosome is the smallest acrocentric chromosome and fluoresces with a medium intensity.
THE INHERITANCE OF ROSE EYE, A SEX LINKED MUTANT IN THE MALARIA VECTOR ANOPHELES CULICIFACIES
Authors: Sakai R. K. , Ainsley R. W. , Baker R. H.
Published: November 2014

A mutant, rose eye (re) in which both the ocellus and compound eye are a bright rose, was discovered following treatment of Anopheles culicifacies Giles with 0.005 M ethyl methanesulfonate. In females this locus is sex linked and recessive, while males are hemizygous for this locus. The genetic results suggest that sex in this species is determined by a chromosome mechanism wherein the females are XX and the males XY.
ON THE POLYTENE MORPHOLOGY OF A DROSOPHILA MELANOGASTER CHROMOSOMAL INVERSION INCLUDING THE NUCLEOLUS ORGANIZER
Authors: Nash David , Vyse E. R.
Published: November 2014

In (1) 1625 inverts about 80% of the polytene X-chromosome of Drosophila melanogaster, including the nucleolus organizer. The nucleolus is found associated with the new nucleolus organizer position in polytene nuclei. In this respect, it appears that the nucleolus has a definitive association with a specific segment of the polytene X-chromosome. However, it is not possible to suggest an association with a specific chromomere; nor is polytene material generated from positions normally proximal to the nucleolus organizer routinely recognizable in the inverted chromosome. A single, exceptional nucleus containing uninverted basal polytene material (which, hence, should have its origin from a position proximal to the nucleolus organizer in a wild-type chromosome) suggests that polytenization in basal heterochromatin may occur, but rarely.
GIEMSA BANDING IN LOLIUM TEMULENTUM
Authors: Thomas H. M.
Published: November 2014

A Giemsa staining technique has been applied to the somatic chromosomes of the inbreeding diploid grass Lolium temulentum (2n = 14). Bands appear in six of the seven pairs and are associated either with the centromere or secondary constriction. An idiogram of the chromosomes with their banding patterns is presented.
RELATIVE POSITIONS OF CHROMOSOME 1 LOCI Fy, PGM1, Sc, UMPK, Rh, PGD AND ENO1 IN MAN
Authors: Lewis Marion , Kaita Hiroko , Chown Bruce , Giblett Eloise R. , Anderson Jeanne E.
Published: November 2014

Ongoing linkage studies of red cell antigens and enzymes in many families along with concentration on a large Mennonite kindred segregating for Sc have resulted in lods, recombinant: nonrecombinant counts and multi-point information which support an order with approximate recombination fractions as measured in the male as follows: Fy -.25 - PGM1 -.20 - Sc - <.05 - UMPK -.15 - Rh -.20 - PGD, with ENO1 close to PGD. The insertion of Sc and UMPK between PGM1 and Rh allows the recognition of double crossing-over between the latter pair; indications are that this is not a rare event in the female. In the male no evidence of double crossing-over was found in the similar distances PGM1 - Rh and Sc - PGD in 13 and 19 opportunities respectively.
THE GENETIC BASIS OF DISPERSAL BEHAVIOR IN THE FLOUR BEETLE TRIBOLIUM CASTANEUM
Authors: Ritte Uzi , Lavie Batia
Published: November 2014

Flour beetles of the genus Tribolium are suitable for the study of dispersal. In an attempt to gain an understanding of the genetic basis of this trait in T. castaneum, a two-way selection experiment was carried out, for 11 successive generations, in a stock derived from an Israeli wild population. When dispersants were defined as beetles that disperse more than once in several attempts, separation between the lines was achieved after one generation of selection. The difference between the lines remained more or less constant in subsequent generations of selection, and did not disappear when selection was relaxed. Reciprocal crosses between the lines suggest that the tendency to disperse is determined by the genotype at a single, sex-linked locus. The allele for dispersal is dominant. Males tend to disperse more readily than females of equivalent genotypes.
THE ANTHRANILATE SYNTHETASE ENZYME COMPLEX AND THE TRIFUNCTIONALtrpCGENE OFASPERGILLUS
Authors: Käfer Etta
Published: November 2014

In all fungi, anthranilate synthetase (AS) depends on two unlinked genes, one coding for a protein which has ammonia-dependent AS activity in vitro, the other providing glutamine-amido transferase (GAT) activity. In Aspergillus nidulans these proteins are part of a 10 S enzyme complex; the former is the trpA gene product and can be isolated as 4.5 S subunits, while the latter is one of three enzyme activities of the 7.5 S subunits coded for by the trpC gene or gene region. To investigate whether trpC represents a multi-functional gene or an operon-like gene cluster various trpC mutants were mapped by meiotic recombination, checked for complementation in diploids, assayed for residual enzyme activities and the size of their active proteins was estimated by sucrose gradient centrifugation. Three of the five types found each lacked one enzyme activity, produced 10 S complexes and complemented each other; mutants of the same type mapped in the same gene segment and presumably were missense mutations. The most extreme type lacked all three activities but several cases showed partial complementation, indicative of a one-gene trifunctional-polypeptide situation. However, the most interesting type retained GAT-function alone and produced AS-activity in 6-7 S complexes. These are proposed to contain trpC polypeptide fragments which fold normally in the GAT-domain and by combining with trpA+polypeptides form complexes of reduced but almost constant size due to protease activities, as demonstrated for the homologous proteins in Neurospora by Hulett and DeMoss (J. Biol. Chem. 250: 6648, 1975).
DETECTION OF ABERRANT 4:4 ASCI INASCOBOLUS IMMERSUS
Authors: Paquette N.
Published: November 2014

Ascopore and mycelium markers were used to detect the aberrant 4:4 asci of the mutation b2A4 of the b2 locus of Ascobolus immersus. Previous studies have shown that this mutation produces gene conversion events with many postmeiotic (30+:5 m and 5+:3 m) in addition to meiotic (2+:6 m and 6+:2 m) segregations. But the aberrant 4:4 asci could not be scored because the octads of this fungus are unordered. The asci were screened using round-spored and granular-spored mutants and confirmed with two mycelium markers, a brown mutant and a wave mutant. Very high frequencies of aberrant 4:4 asci were observed in each cross performed (more than 40% of the postmeiotic segregations). This suggested that both chromatids are very often implicated in the process of hybrid DNA formation at this site of the locus.
INHERITANCE OF RESISTANCE TO FRUIT FLY IN WATERMELON
Authors: Khandelwal R. C. , Nath Prem
Published: November 2014

Inheritance of resistance to the fruit fly Dacus cucurbitae Coq., was studied in intervarietal crosses of watermelon Citrullus lanatus (Thunb.) Mansf. Two sources of resistance J 18-1 and J 56-1 were used. The resistance of watermelon to the fruit fly was controlled by a single dominant gene. The symbol Fwr has been proposed to denote the resistant gene.
AN ANALYSIS OF GENETIC REPRESSION AT THE yg-6 LOCUS OF TURNIP RAPE
Authors: Stringam Gary R.
Published: November 2014

The inheritance of a repressor gene affecting chlorophyll synthesis at the yg-6 locus was studied in Brassica campestris L. Repression was determined by a partially dominant gene, r, with allelic expression ranging from the normal yg-6 phenotype through bright yellow-green to albino. This gene also reduced the viability of male gametophytes. The usefulness of this character in biochemical and genetic studies is discussed.
NUCLEOLAR ORGANIZER REGIONS IN THE RABBIT (ORYCTOLAGUS CUNICULUS) AS SHOWN BY SILVER STAINING
Authors: Martin-Deleon Patricia A. , Petrosky Dorene L. , Fleming M. Eileen
Published: November 2014

Nucleolar organizer regions (NOR's) were demonstrated in metaphase chromosomes of the domestic rabbit, Oryctolagus cuniculus (L.) (New Zealand white strain) using silver staining. Sequential quinacrine banding and a modification of the Ag-AS silver precipitation technique with duplicate photography allowed identification of silver staining NOR's on the short arms of chromosomes 13, 16, and 20, as well as the telomeric region of the long arms of number 21 in some cells. Chromosomes 13, 16 and 20 all have subterminal to terminal centromeres, often showed satellites and secondary constrictions, and were sometimes involved in associations.
MALE STERILITY-FERTILITY RESTORATION SYSTEMS IN TRITICUM DURUM
Authors: Sasakuma Tetsuo , Maan S. S.
Published: November 2014

Triticum durum Desf. selection 56-1 (2n = 28,AABB) genomes were introduced into the cytoplasms of six species of Triticum, 14 of Aegilops, and one each of Secale and Haynaldia by the backcross method. Of the 22 alloplasmic lines, 14 were completely male sterile, four were partially fertile, and the remaining four, having cytoplasms of T. dicoccoides Körn, Ae. kotschyi Boiss., Ae. variabilis, Eig. or H. villosa L., were of normal fertility. Eleven of these lines headed late and 14 had lower plant height than the control euplasmic T. durum. The 14 male-sterile lines were crossed with five R-lines derived from crosses involving T. nudiglumis Nabalek and T. durum, and male-fertility restoration in F1 hybrids was examined. All five R-lines restored male fertility to six of the male-sterile lines having cytoplasms of Ae. speltoides Tausch., Ae. bicornis Forsk., T. nudiglumis, T. araraticum Jakubz., T. timopheevi Zhuk., or T. zhukovskyi Men. &Er. The male fertility of the alloplasmic line having rye (secale cereale L.) cytoplasm was completely restored by RE 5 and partially by RE 2. Also, RE 5 restored plant vigor to durum plants having rye cytoplasm. None of the five R-lines restored male fertility or plant vigor to any of the six male-sterile lines having cytoplasms of T. boeoticum Boiss., Ae. caudata L., Ae. umbellulata Zhuk., Ae. heldreichii Holzm., Ae. sharonensis Eig., or Ae. triaristata Willd. In general, F2 data from crosses involving four of the male-sterile lines and five R-lines indicated that male fertility restoration was simply inherited.
AN ORANGE-EYE MUTANT OF THE SPRUCE BUDWORM CHORISTONEURA FUMIFERANA (LEPIDOPTERA; TORTRICIDAE)
Authors: Ennis T. J.
Published: November 2014

A mutant adult phenotype of the spruce budworm, Choristoneura fumiferana (Clemens), possesses orange eyes in place of the normal dark purple wild type. Larvae are paler than wild type, and testis pigment is orange instead of purple. The mutant phenotype is due to the expression of a recessive autosomal gene, designated or.
GENETIC CONTROL OF CHIASMA FREQUENCY AND DISTRIBUTION IN RYE SECALE CEREALE
Authors: Lelley T.
Published: November 2014

In inbred lines of rye (Secale cereale L.) a close negative correlation was found between mean chiasma number and their between-cell variance. No correlation was detected between mean chiasma number or chiasma variance and the positional distribution of chiasmata within the bivalents, that is, terminal or interstitial. It is concluded, therefore, that while the between-cell variance of chiasmata is a direct consequence of the mean chiasma frequency, the positional distribution of chiasmata within bivalents is probably subject to an independent control system.
EVIDENCE OF TWO CENTRIC FUSIONS IN CHROMOSOME COMPLEMENTS OF NODITERMES LAMANIANUS
Authors: Vincke P. P. , Tilquin J. P.
Published: November 2014

From a survey of chromosome numbers in Termitidae, it appears that Noditermes laminianus Sjöstedt (Isoptera, Termitidae) and Procubitermes sp. 1 have n = 19 instead of n = 21 as is usually found in the African members of the family. A detailed investigation on N. lamanianus demonstrates that this feature is constant in the area of distribution of this species. This change in the basic chromosome number is explained as the result of two centric fusions.
ESTIMATION OF HERITABILITY OF AN INDEX
Authors: Lin C. Y.
Published: November 2014

Two alternative ways of calculating heritability of an index are presented. The first method is the regression of genetic index on the selection index and the second method is the ordinary analysis of co-variance among relatives where the selection index is treated as a single trait measurement. It is shown that these two estimation methods are equivalent theoretically and yield similar estimates from experimental data.
DNA CONTENT, RIBOSOMAL-RNA GENE NUMBER, AND PROTEIN CONTENT IN SOYBEANS
Authors: Doerschug Earle B. , Miksche Jerome P. , Palmer Reid G.
Published: November 2014

Six cultivars and five plant introductions of Glycine max L. Merr. varied in picograms of DNA per cell from 1.84 to 2.61, and in number of ribosomal-RNA genes per 2 C nucleus from 960 to 2431 (Laboratory 1, Ames) and from 768 to 2095 (Laboratory 2, Rhinelander). The parameters did not correlate with seed protein content, which varied from 32.8% to 52.6%. With these materials, use of the rRNA locus size as a breeding tool for increasing percentage protein content by use of cytogenetic and genetic manipulations is not warranted.
AN ALTERNATIVE METHOD FOR ISOLATING HOMOZYGOTES OF AUTOSOMAL TRANSLOCATIONS IN THE MOSQUITO CULEX TARSALIS
Authors: McDonald P. T. , Asman S. M. , Terwedow Jr. H. A.
Published: November 2014

An alternative pseudolinkage procedure for isolating homozygotes of autosomal translocations has been developed with the mosquito Culex tarsalis (Coquillett). The first step was to induce a translocation heterozygote in a population that was marked with recessive mutants. Interbred translocation heterozygotes produced translocation homozygotes that were phenotypically different from their translocation heterozygote and normal siblings. Thus, a translocation homozygote line of this species was selected and established in shorter time and with less effort than by prior pseudolinkage procedure.
A GENETIC STUDY OF CRYPTORCHIDISM AND SCROTAL HERNIA IN PIGS
Authors: Mikami Hitoshi , Fredeen H. T.
Published: November 2014

The genetic parameters of cryptorchidism and scrotal hernia were estimated. The heritability of liability to cryptorchidism identified at birth was about 0.5 and that identified to be normal at birth, but recognized to be abnormal later was almost zero. The heritabilities of scrotal hernia estimated in two herds were 0.65 and 0.86. The genetic correlation between these two defects was 0.20. An equation for calculating selection differentials for family selection was derived and expected changes of incidence resulting from individual, full-sib and half-sib family selection calculated. Practical culling plans were discussed from the aspect of selection response and possible culling rate.
THE CHROMOSOMES OF THE CANADIAN BEAVER CASTOR CANADENSIS
Authors: Genest Fernande B. , Morisset Pierre , Patenaude Robert P.
Published: November 2014

A chromosome analysis of 24 Canadian beavers, Castor canadensis Kuhl (12 males and 12 females), captured in Laurentides Park, Québec, has been performed from preparations of blood lymphocyte and skin cultures. The chromosome number was found to be 2n = 40. Measurements were made to determine relative lengths and arm ratios of chromosomes, which are metacentric or submetacentric. Results are in agreement with those already published regarding the chromosome number, but differ in the identification of the X chromosome, and in the morphology of the Y and some autosomes. C- and G-banding techniques allowed the precise identification of individual chromosome pairs. A detailed idiogram of G-bands is presented.
A AND B GENOME HOMOEOLOGIES IN TETRAPLOID AND OCTOPLOID CYTOTYPES OFBROMUS INERMIS
Authors: Armstrong K. C.
Published: November 2014

Homoeology between the A and B genomes of allotetraploid (2n = 4x = 28) AiAiBiBiand autoallooctoploid (2n = 8x = 56) AIAIAIAIBIBIBIBIcytotypes of B. inermis Leyss. was studied in a tetraploid F1hybrid (AeAeAiBi) from 4x B. erectus × 4x B. inermis and in a haplo-triploid (AIeAIeBI) which occurred spontaneously in the F2from open-pollination among plants of the hexaploid F1hybrid (AeAeAIAIBIBI) from 4x B. erectus × 8x B. inermis. Chromosome pairing at metaphase I in both the tetraploid (AeAeAiBi) and haplo-triploid (AIeAIeBI) indicated that for each A genome chromosome there was a corresponding B genome homoeologue. There was no convincing evidence of gross structural differences between the two homoeologous genomes. The frequency of trivalent formation in the haplo-triploid was approximately one-half that found in two pentaploids (2n = 5x = 35) AIeAIeAIBIBI. This indicates that the pairing affinity between the A and B genomes is one-half that between homologues as expressed by trivalent formation in triploids of the type AAB and AAA. Homoeologous chromosome pairing (A with B) may be controlled by a gene which is hemizygous ineffective.
THE USE OF THE SALMONELLA/MICROSOMAL ASSAY TO DETERMINE MUTAGENICITY IN PAIRED CHEMICAL MIXTURES
Authors: Salamone M. F. , Heddle J. A. , Katz M.
Published: November 2014

The mutagenicities of two sets of chemicals acting singly and in pairwise combinations were determined by use of the Salmonella/microsomal assay. The first set consisted of the promutagens of benzo(a)pyrene and benzo(rst)pentaphene. The second set contained the direct-acting mutagens methyl-nitro-nitroso-guanidine and ethyl methane sulfonate. In the tests with the promutagens, the quantities of S-9 mix were varied over the range of 0.05 ml to 1.0 ml with increasing quantities of each chemical. The mutagenic responses or production of revertant colonies of the promutagens, acting singly and in pairwise combinations failed to show an additive effect. Excess quantities of S-9 mix appeared to inhibit partially or totally the mutagenic activity of each chemical, although for each particular dose there was an optimal quantity of S-9 mix to induce maximum activity. However, the direct-acting mutagens produced, individually, almost linear dose responses with increasing concentrations. In pairwise combinations, these chemicals also showed linear responses that closely approximated the theoretical additivity indicating that the mutagenicity of the mixtures was the sum of the activities of each component.