bluuebunny/crossref_metadata_2025 huggingface dataset:
STUDIES ON THE REVERSAL OF 5-FLUORODEOXYURIDINE-INDUCED MITOTIC INHIBITION BY THYMIDINE AND THYMIDINE ANALOGUES
Authors: Hoffmann George R.
Published: November 2014

At concentrations of 10−7M and 10−8M, 5-fluorodeoxyuridine (FUDR) completely inhibits cell division in root tips of Vicia faba. Suppression of cell division by 10−8M FUDR is incomplete. In roots treated with 10−4M thymidine (TDR), the level of mitosis is unchanged. In 10−3M TDR, 10−4M 5-bromodeoxyuridine (BUDR), or 10−4M 5-iododeoxyuridine (IUDR), there is some decline in the mitotic index, particularly at later time periods.After a 2.5-hour treatment with 10−0M FUDR, roots do not recover for more than 2 days in water. Recovery is faster in TDR. There is a slight enhancement of recovery in 10−6M TDR and more rapid recovery at higher concentrations. The TDR analogues, BUDR and IUDR, are also somewhat effective in reversing FUDR-induced mitotic inhibition. TDR itself is most effective, followed by BUDR and IUDR, in that order. Renewed cell division, however, is often only temporary.When administered simultaneously with 10−3M FUDR, TDR, at higher concentrations, provides some protection from mitotic inhibition. The protection from 10−6M FUDR offered by simultaneous exposure to IUDR is slight. With simultaneous exposure to 10−6M FUDR and 10−4M BUDR, a decline in the level of mitosis is followed by partially synchronous cell divisions.
VARIATIONS IN CHROMOSOME NUMBER AND STRUCTURE IN PLANT CELLS GROWN IN SUSPENSION CULTURES
Authors: Kao K. N. , Miller R. A. , Gamborg O. L. , Harvey B. L.
Published: November 2014

Cell suspension cultures of Triticum monococcum, Triticiam aestivum, Glycine max, Melilotus alba, and Haplopappus gracilis, were examined to determine whether chromosomal changes had occurred during culture. All cultures except H. gracilis showed change in chromosome number and the two species of Triticum showed abnormal karyotypes.
CHROMOSOME ASSOCIATIONS IN THE FIRST MEIOTIC DIVISION IN THREE TETRAPLOID CLONES OF VACCINIUM CORYMBOSUM L
Authors: Jelenkovic G. , Hough L. F.
Published: November 2014

The analysis of chromosome pairing in three tetraploid cultivars of Vaccinium corymbosum L. revealed chat the great majority of bivalents were involved in pseudo-multivalent associations. The number of independent bivalents (not involved in formation of multivalents) increased from diakinesis to metaphase I.The pseudo-multivalents at diakinesis and at MI are the consequence of incomplete relaxation of the synizetic knot, a dense chromatic mass observed in early prophase. Factors that might affect the relaxation process are discussed.
GENETIC EVIDENCE FOR 'DARWINIAN' SELECTION AT THE MOLECULAR LEVEL. II. GENETIC ANALYSIS OF CYTOPLASMICALLY-INHERITED HIGH AND LOW SUPPRESSITIVITY IN SACCHAROMYCES CERVISIAE
Authors: Rank Gerald H.
Published: November 2014

A method was devised for the genetic analysis of cytoplasmically-inherited high and low suppressitivity in S. cervisiae thus enabling a test of the prediction, by the model of 'Darwinian' selection of mitochondrial DNA, that abnormal mitochondrial DNA of a high suppressitivity strain has a replicative advantage over abnormal mitochondrial DNA of a low suppressitivity strain. Support for the model was indicated by the ability of the suppressive factor resident in the high suppressitivity strain to control the phenotypic expression of suppressitivity in zygotes formed by crossing a low and high suppressitivity strain.
A NOTE ON KIDWELL'S CHROMOSOMAL ANALYSIS OF EGG PRODUCTION AND CHAETA NUMBER IN DROSOPHILA MELANOGASTER
Authors: Glaser P. , Kldwell J. F.
Published: November 2014

An earlier paper (Kidwell, J.F., 1969, Can. J. Genet. Cytol 11: 547-557) has described partitioning of the genetic variance of egg production and chaeta number in Drosophila melanogaster, assuming equal frequencies of all chromosomes. Kidwell's data were analyzed again, and the new analyses were based on several panmictic populations with varying frequencies for each genotype. The importances of the several portions of the genetic variance were estimated for each population; several cases are presented. In most cases the ranges were substantial, especially those of the dominance and four-factor epistatic variances. The results of the present study generally support Kidwell's previous conclusions and suggest that epistatic variance should not routinely be assumed negligible.
PODOPHYLLIN AS A MITOTIC ARRESTOR IN KARYOTYPE STUDIES OF THE DOMESTIC FOWL
Authors: Ahmad M. Sharif , Hardin R. T.
Published: November 2014

White Rock chicks (1 day to 4 weeks old) were innoculated with a 0.05% solution of either colcemid (CIBA) or podophyllin. Feather follicle cells were squashed on slides and temporarily stained. Cells obtained after podophyllin pretreatment yielded mitotic plates comparable with those obtained after colcemid pretreatment. Also a larger mitotic index was observed in cells from chicks pretreated with podophyllin. The results suggest that in karyotype studies of the domestic fowl podophyllin may be used as an effective mitotic arrestor.
TOPOGRAPHY OF THEad-3REGION OFNEUROSPORA CRASSA
Authors: Griffiths A. J. F.
Published: November 2014

An analysis of prototroph frequencies in crosses between 7 ad-3A and 10 ad-3B mutants has demonstrated that where a linear order of ad-3B alleles can be specified, the order is consistent with that obtained from complementation maps. The data also provide a working estimate of the sizes of the components of the ad-3 region.
LINKAGE ANALYSIS OF CHROMOSOME I OFAEDES AEGYPTI
Authors: Bhalla Satish C. , Craig Jr. George B.
Published: November 2014

A tentative map of chromosome I of the yellow fever mosquito, Aedes aegypti has been proposed. The order of the genes ru (rust-eye), re (red-eye), m (sex), bz (bronze-body) and w (white-eye), has been definitively established. However, large variations in linkage distances were obtained in different experiments. The most representative values obtained from repeated tests are presented and possible reasons for heterogeneity of linkage data are discussed.
ESTIMATED GENETIC PARAMETERS OF CERTAIN BLOOD CONSTITUENTS AND ECONOMIC TRAITS OF TURKEYS
Authors: Mukherjee T. K. , Friars G. W. , Waghorne D.
Published: November 2014

Levels of plasma cholinesterase and blood glutathione were assayed at 13 and 26 weeks and three subsequent ages of the male and female breeders in two random bred control strains of turkeys and in the respective strains selected for 12-week body weight. The significant differences (P < 0.01) in plasma cholinesterase activity of the selected over the controls ranged from 0.020 ± 0.008 to 0.080 ± 0.005 ΔpH/hour and for glutathione from 2.80 ± 0.32 to 11.10 ± 0.62 mgm/100 ml. at 13 weeks of age. These differences tended to decrease for the measurements made at later ages and in certain cases during the reproductive phases control lines exhibited higher activity than the selected lines.Heritability estimates obtained by midparent-progeny regression in the four strains ranged from 0.15 ± 0.08 to 0.75 ± 0.28 for plasma cholinesterase activity. The estimates for blood glutathione levels in the control and selected strains of the Large White population ranged from 0.02 ± 0.07 to 0.20 ± 0.14 while negative estimates were obtained in both the Auburn lines.There were indications that a significant (P < 0.05) positive phenotypic correlation and a high positive genetic correlation exist between 12-week body weight and the levels of cholinesterase or glutathione at 13 weeks. Apart from this relationship, no significant (P < 0.05) associations were found between the levels of cholinesterase and glutathione at different ages and growth after 12 weeks of age or between the biochemical components and reproductive traits.
PERICENTRIC REARRANGEMENT POLYMORPHISM IN A NORTH AMERICAN DOLICHODERINE ANT (HYMENOPTERA: FORMICIDAE)
Authors: Crozier R. H.
Published: November 2014

Tapinoma melanocephalum has a haploid number of 5, comprising four metacentrics and one acrocentric chromosome. T. sessile karyotypes (n = 8) comprise seven metacentric chromosomes and one that has acrocentric, subacrocentric and metacentric alternatives. In some haploid sessile preparations with acrocentric or subacrocentric chromosomes present, an acromatic gap, sometimes with an interstitial granule, is seen in the long arm of the non-metacentric.
THE CYTOGENETICS OF A DITELOTETRASOMIC LINE IN BARLEY
Authors: Fedak George , Helgason S. B.
Published: November 2014

A ditelotetrasomic line (14+2−1S) carrying two telocentric chromosomes in addition to the normal complement was isolated in the selfed progeny of a monotelotrisomic (14+1S) of barley. The plants were shorter and later maturing than the disomic, and highly sterile. In diakinesis and metaphase I cells at meiosis, the extra telos showed a high frequency of pairing with each other and with their normal homologues, resulting in 6″ + (t″ + 1″) and 7″ + t″ as the most frequent configurations. Regular meiotic behavior at subsequent stages resulted in a 42.2% frequency of pollen transmission of the extra telos. Selfed progenies gave rise to 7.1% diploids, 45.7% monotelotrisomics and 47.2% ditelotetrasomics.
IMMUNOFLUORESCENT STUDIES OF BASIC NUCLEAR PROTEINS
Authors: David L. A. , Corey Margaret J.
Published: November 2014

Histone antibodies were obtained by injecting salt extracted calf thymus basic nuclear proteins into chickens. Fluorescent globulins were prepared from chicken antisera with precipitating antibodies against a single electrophoretic fraction of the nuclear protein extract. The fluorescent antiserum was specific for nuclei and chromosomes but was neither organ nor species specific. It reacted specifically with nuclei of cell imprints of bovine and human leucocytes, with polytene chromosomes from Chironomus salivary gland cells, and with nuclei from lily and onion root tip cells. It did not react with chicken blood smears. A decrease in the intensity of fluorescence roughly proportional to the phylogenetic divergence of the tested species was observed.These studies indicate that this basic nuclear protein fraction has acquired remarkably little variation over a long evolutionary period.
INHERITANCE OF FRUIT HAIRINESS, FRUIT SKIN COLOUR AND LEAF LOBING IN OKRA, ABELMOSCHUS ESCULENTUS
Authors: Nath Prem , Dutta O. P.
Published: November 2014

Inheritance of fruit hairiness, fruit skin colour and leaf lobing was studied in intervarietal crosses of okra, Abelmoschus esculentus (L.) Moench. Fruit hairiness was found to be monogenically controlled, the alleles for prickly hairs and smooth hairs showing interaction. Fruit skin colour was controlled digenically. Light cream colour and pink shading were both dominant over green. The inheritance of leaf lobing was monogenic with incomplete dominance.
VIRUS-LIKE PARTICLES IN ABNORMAL CELLS OFSACCHAROMYCES CARLSBERGENSIS
Authors: Volkoff Olga , Walters Teresa
Published: November 2014

An electron microscope investigation of abnormal vegetative cells and asci of a strain of Saccharomyces carlsbergensis has revealed virus-like particles with a slightly elongated hexagonal head measuring 80 × 70 mμ and a tail of the same length or slightly shorter than the longitudinal axis of the head.
ETHYL METHANESULFONATE-INDUCED CHLOROPHYLL MUTATIONS INTRITICUM AESTIVUM
Authors: Washington W. J. , Sears E. R.
Published: November 2014

Seeds of hexaploid wheat variety Chinese Spring were treated with ethyl methanesulfonate (EMS). Two hundred and fifty-six plants were observed in the M1generation which had white, yellow or pale green longitudinal stripes in their leaves. Of four recessive, viable, simply inherited chlorophyll mutations obtained in M2, two were chlorina (pale yellow-green), one was virescent (white or nearly white as a seedling but later turning green), and one was also virescent but in some plantings had late leaves that were 'white banded'. An albino mutation was also recovered.The two chlorina mutants were located on chromosomes 7B and 7D, the homoeologues of chromosome 7A, which was already known to carry a similar mutation, chlorina-1. The mutants were located by the use of monosomics, taking advantage of the fact that when the chromosome carrying a chlorina gene was made monosomic, segregation of the gene then depended upon the male and female transmission of the monosome, with the result that all disomic offspring, and no others, were chlorina. Monosomic analysis also indicated that the viridis (white or nearly white as a seedling but later turning green) mutation is located on chromosome 3A, which was already known to carry a homoeologue of the normal allele of the gene determining a similar mutation, Neatby's virescent, on chromosome 3B.In crosses, similar mutants complemented each other only partially or not at all, showing that the mutant genes are functionally similar, although located on different chromosomes.
CORRELATED RESPONSE IN BROWNSARSON
Authors: Rao T. Swamy
Published: November 2014

The correlated response with changes in self-compatibility in three varieties of brown sarson subjected to gamma irradiation was examined. Selection for improved seed set in the irradiated populations showed that substantial correlated response can result for a constellation of other characters in which the self-compatible and self-incompatible forms differ. The correlated response was in a direction opposite to that of the previous history of selection.
A SUPPRESSOR OF THE HETEROKARYON- INCOMPATIBILITY ASSOCIATED WITH MATING TYPE INNEUROSPORA CRASSA
Authors: Newmeyer Dorothy
Published: November 2014

Neurospora crassa strains of opposite mating type are ordinarily heterokaryon-incompatible during vegetative growth. An unlinked mutant called tolerant (tol) is described, which suppresses the vegetative incompatibility of unlike mating types without affecting their ability to cross. The mutant tol was selected and studied by means of duplications heterozygous for mating type. Use of the duplication eliminates complications due to unlinked heterokaryon genes. The mode of action of tol has been confirmed by conventional heterokaryon tests. tol has been mapped in linkage group IV, close to tryp-4. A suppressor similar or identical to tolerant has been found in a wild strain from Panama, out of 14 different wild types which were tested. By using a different duplication which covers the unlinked heterokaryon-compatibility locus C, it was shown that tolerant does not suppress C/c incompatibility. The fact that tolerant suppresses only one of the two functions ascribed to mating type revives the question of whether 'mating-type' is one gene or two. However, the data strongly support Pittenger's (1957) conclusion that, if two genes are involved, they must be closely linked.
INCOMPLETE SYNCHRONY OF LABELLING IN HOMOLOGUES OF THE AUTOSOMAL PAIRS
Authors: Jan K. Y. , Boyes J. W.
Published: November 2014

The 10 autosomes of Musca domestica L. ocra strain are somatically paired and each pair is cytologically recognizable. Thymidine-methyl-H3 incorporation into the third instar larval brain cells and subsequent autoradiography revealed that the co-labelling index for the two homologues of a pair appears to be correlated to some extent with the labelling rate for that particular pair. The homologues are often but not always labelled at the same time, even when all the autosomal pairs have a high labelling rate. Thus, there does not seem to be strict synchrony of DNA replication for the two homologues of a pair.
HALF-CHROMATID ABERRATIONS AND CHROMOSOME STRANDEDNESS
Authors: Comings David E.
Published: November 2014

If cells are irradiated during prophase, at anaphase they may show a side-arm bridge type of configuration. These have usually been interpreted as half-chromatid aberrations and they have been used as evidence that chromosomes are multistranded. It is the purpose of this paper to emphasize that such a configuration may just as easily arise on the basis of a single-stranded chromosome, and that the data on the type of aberrations found at the next mitosis (M2) suggest that chromosomes are single-stranded.
MONOSOMIC ANALYSIS OF FERTILITY-RESTORING GENES IN TRITICUM AESTIVUM STRAIN P168
Authors: Tahir Ch. M. , Tsunewaki K.
Published: November 2014

Genes and chromosomes involved in fertility restoration mechanism in Triticum aestivum strain P168, an effective restorer for Aegilops ovata cytoplasm, were studied by conventional and monosomic analysis. The study revealed that chromosome 1C (or C-sat-2), which is a substitute for original chromosome 1D of Triticum aestivum var. erythrospermum, carries a dominant fertility-restoring gene, Rfc1. Chromosomes 2A, 2B, 2D, 4A, 5D and 7A of P168 were found to carry modifying genes which counteract the fertility-restoring gene, A possible homo-ancestral relationship of three fertility-restoring genes, Rf1, Rf2 and Rfc3, was suggested.
STUDIES ON DROSOPHILA PALLIDIPENNIS DOBZHANSKY AND PAVAN. I. INTRODUCTORY SURVEY. CHROMOSOMES
Authors: Pasteur Georges , Kastritsis Costas D.
Published: November 2014

Studies of the salivary gland chromosomes of many strains of Drosophila pallidipennis, with various cross-tests, has revealed that of the five rodlike chromosomes only one autosome (D) has undergone important inversions and the X chromosome exhibits special behavior (such as little variation of the strong parts and weaker pairing), and that the group is a complex rather than a single species. There are two separate Mendelian populations, the hybrids of which display more or less strong degrees of breakdown in gene coadaptedness (the minimum being complete F1 male sterility). Whether they are full species (through complete assortative mating when mixed) remains to be verified. One of these forms (centralis), occupying Central America and Colombia, is monomorphic for a CE gene arrangement of the D chromosome. In the other form (true pallidipennis) the CE gene arrangement occurs only in Peruvian populations and is completely lacking in Bolivia, Venezuela and Brazil, where local populations are mono- and polymorphic for rearrangements, each of which can only result from an inversion in the CE chromosome. It is suggested that selection is in the process of eliminating the CE arrangement in pallidipennis. This interesting situation, combined with the very high quality of breeding and chromosomal cytology of the flies, should prove valuable for studies in developmental and population genetics.
SOME FINE STRUCTURE FEATURES OF MEIOSIS IN THE YEASTSACCHAROMYCES CEREVISIAE
Authors: Rapport Ellen
Published: November 2014

Fine structure features of yeast cells in meiosis are reported. Cytoplasmic and nuclear organization are compared during budding, meiosis I and meiosis II. Spindle plaques previously reported in budding yeast are identified during meiosis and the morphology of the plaques in meiosis I and II is illustrated. The dimunition of the vacuole and the increase in the number of lipid, granules in sporulating yeast, known from light microscopy, is confirmed.
SPONTANEOUS MEIOTIC CHROMOSOME ABNORMALITIES IN MALE MICE (MUS MUSCULUS)
Authors: Lin Chyi-Chyang , Tsuchida W. S. , Morris S. A.
Published: November 2014

Three types of spontaneous meiotic chromosome aberrations were described in mouse spermatocytes: (1) Precocious separation of XY chromosomes was observed in about 6% of cells in diakinesis and first metaphase; (2) chromosome degeneration appeared in 9.2 and 4.8% of cells at pachytene and at first metaphase, respectively; (3) polyploidy, in particular tetraploidy, occurred in 2.7 and 3.2% of cells at pachytene and first metaphase, respectively. These chromosome anomalies should be considered in cytological studies of the effect of noxious agents on chromosomes in mouse spermatocytes.
SATELLITE ASSOCIATION IN HUMAN LYMPHOCYTES AND SODIUM CITRATE CONCENTRATION OF HYPOTONIC (SPREADING) SOLUTION
Authors: Nankin Howard R.
Published: November 2014

The present investigation examined the relationship between satellite association in lymphocytes and sodium citrate concentration of the hypotonic solutions used to aid in spreading chromosomes. With reduction of sodium citrate from 0.9%, to 0.75%, and to 0.6%, the percentage of acrocentric chromosomes engaged in satellite association went from 32.7%, to 26.8%, and to 19.1% respectively. The reductions appeared to be equally divided between the D group and G group chromosomes.
AN INVESTIGATION OF GENOTYPE × ENVIRONMENT INTERACTION IN RELATION TO A SELECTION EXPERIMENT IN TRIBOLIUM CASTANEUM
Authors: Friars G. W. , Nayak B. N. , Jui P. Y. , Raktoe B. L.
Published: November 2014

An experiment involving the selection of certain lines of Tribolium castaneum for larva weight and others for offspring number in both wet and dry environments was carried out over nine generations. No apparent interactions of environment-selected-in × environment-tested-in was found. That is, the environment-selected-in did not condition response to selection for larva weight, although some slight tendency toward this type of effect was noted for offspring number. However, lines selected for high larva weight showed greater response over controls when tested in the wet as opposed to the dry environment.Crosses of the respective lines indicated that the hatchability of lines selected for larva weight was elevated when they were shifted from the dry to the wet environment. However, the reverse trend was apparent for the control lines. A cross of lines selected for offspring number in wet and dry environments respectively showed repeated superiority in hatchability over other lines and crosses to which it was compared.
RING-LIKE CONFIGURATIONS OF NONRING CHROMOSOMES IN DROSOPHILA MELANOGASTER
Authors: Moore Charleen M.
Published: November 2014

Metaphase figures in ganglia and ovary squashes of Drosophila melanogaster show ring-like configurations of X chromosomes, which have been shown through genetic tests to be linear. Displaced heterochromatin at the tips of these chromosomes tends to hold the ends together, while in the euchromatic regions the chromatids repel each other, creating the ring effect. Ring-like figures in human preparations are considered.
GENETIC CONTROL OF VIRULENCE IN USTILAGO HORDEI. II. SEGREGATIONS FOR HIGHER LEVELS OF VIRULENCE
Authors: Sidhu Gurmel , Person Clayton
Published: November 2014

Genetics of virulence of Ustilago hordei towards five barley cultivars (Excelsior, Vantage, Hannchen, Trebi and Lion) was investigated. Two genes, Uhv-1 and Uhv-2, were identified; Uhv-2 was effective on Excelsior, and Uhv-1 on both Hannchen and Vantage. The virulence genes were both recessive.
QUANTITATIVE INHERITANCE IN DURUM WHEAT
Authors: Kaltsikes P. J. , Lee J.
Published: November 2014

Little or no heterosis was found for height, yield and yield components in the F1's resulting from the diallel crossing of six geographically diverse cultivars of durum wheat. General combining ability effects were more pronounced than specific combining ability effects and average parental performance gave a good prediction of hybrid performance. Heritability for yield was 0.61. For the cultivars studied, a conventional pedigree breeding program probably offers the most hope for genetic advancement. No easily measured character could substitute for yield per plant as a selection criterion for yield.
PACHYTENE KARYOTYPES OF 2XHAPLOIDS DERIVED FROM TETRAPLOID ALFALFA (MEDICAGO SATIVA) — EVIDENCE FOR AUTOTETRAPLOIDY
Authors: Gillies C. B. , Bingham E. T.
Published: November 2014

Five 2x haploid plants derived from three different tetraploid Mediaago sativa L. plants all had normal pachytene pairing, and their karyotypes were very similar to that of diploid M. sativa. A hybrid of one 2x haploid with diploid M. falcata L. also had a normal karyotype. The pachytene chromosome lengths of the 2x haploids were shorter than those of diploid M. sativa and M. falcata but close to values for tetraploid M. sativa and autotetraploid M. falcata. The results presented support an autotetraploid origin of the parental tetraploid alfalfa.
CONSTANCY OF THE DURATION OF DNA SYNTHESIS AND PER CENT G+C IN WHITE SPRUCE FROM SEVERAL PROVENANCES
Authors: Miksche Jerome P. , Rollins James A.
Published: November 2014

In white spruce seedlings from four provenances, the period of DNA synthesis was found to be independent of the quantity of DNA per cell, and lasted 11.1 hours on the average. The per cent G+C (guanine plus cytosine) averaged 37.5 for seven provenances.
INHERITANCE OF RESISTANCE TO BLACK SHANK IN NICOTIANA TABACUM L.
Authors: Collins G. B. , Legg Paul D. , Litton C. C. , Kasperbauer M. J.
Published: November 2014

Resistance to race 0 of black shank (Phytophthora parasitica var. Nicotianae) derived from Nicotians longiflora Cav. and transferred to the burley tobacco breeding line L8 appears to be conditioned by a single dominant gene. However, on the basis of expected ratios for a single dominant gene, a deficiency of resistant progeny was observed in the F2 and backcross generations. Haploid plants extracted from F1 individuals heterozygous for black shank resistance substantiated the deficiency in the resistance class. The haploid segregation with reduced recovery of the resistant genotype rules out preferential pollination as the cause for the altered ratios. The mechanism responsible for impaired function of the gamete carrying the allele for resistance is not known.
STIMULATION OF RABBIT LYMPHOCYTES IN VITRO BY A PROTOZOAN FACTOR
Authors: Beckert William H. , Davis John , Sharkey Sr. Margaret M.
Published: November 2014

A substance extracted from the growth medium of Colpidium can cause blastogenesis with subsequent mitosis of rabbit peripheral blood lymphocytes in vitro. This substance, termed a probiotic, is also capable of influencing the growth rate of various species of protozoa.
INBRED LINE × TESTER ANALYSIS AND THE POTENTIAL OF INBREEDING IN STRAWBERRY BREEDING
Authors: Spangelo L. P. S. , Hsu C. S. , Fejer S. O. , Watkins R.
Published: November 2014

The performance in fruit yield characteristics and fruit appearance of seven Premier S5inbred selections was studied in their crosses with four tester varieties, Redcoat, Senga Sengana, Sparkle and Jerseybelle. Some of the progenies produced by crossing Premier S5, inbreds with testers were superior in a number of yield characters to those produced when Premier was crossed to the same testers. This suggests that inbreeding, although expensive and time consuming, may be a useful step in one type of approach to breeding for higher yield in the cultivated strawberry.General combining abilities of the inbred selections and of the testers were both significant for all but one character, while specific combining ability of inbreds × testers was significant for six of the eight characters. The estimates of general combining ability effects of the inbreds and the testers were found to be of limited value in predicting the most desirable single crosses. The significance of this is discussed together with a proposed procedure for exploiting inbreeding in strawberry breeding.
GENETIC, PHENOTYPIC AND ENVIRONMENTAL CORRELATIONS AMONG 28 FRUIT AND PLANT CHARACTERS IN THE CULTIVATED STRAWBERRY
Authors: Bedard P. R. , Hsu C. S. , Spangelo L. P. S. , Fejer S. O. , Rousselle G. L.
Published: November 2014

Generic, phenorypic and environmental correlations and coheritabibties between 28 fruit and plant characters were estimated in 64 progenies produced among 31 North American strawberry clones and 1 German one under the crossing scheme similar to North Carolina Design II. Total berry and total marketable yields were positively and significantly correlated with average berry weight, berries per flower stalk, yield per flower stalk, leaf area, and petiole diameter, but negatively correlated with stolon number and flower stalk number. The inverse relationships between flower stalk number with average berry weight, and with berries per flower stalk may be genetically dependent or arise from developmentally induced relationships. Plant height appeared to be a good indicator of both early and early marketable yields; petiole number was considered the best indicator of soluble solids and easy capping, while soluble solids may be of value as an indicator of both late and late marketable yields. In general, no genetic barrier was detected to combine high yield with good quality of the berry.
CYTOLOGY AND GENETICS OF A PRONOTAL-WING TRAIT IN THE GERMAN COCKROACH
Authors: Ross Mary H. , Cochran Donald G.
Published: November 2014

A new pronotal-win g mutant of the German cockroach, Blattella germanica (L.), has been described and studied. Morphologically, it is similar to previously described translocation proving traits (T(9, 10)Pw) in this species. Genetically it is inherited as an autosomal semidominant lethal with somewhat reduced viability especially through the males. Cytologically the trait is associated with a terminal deficiency of the ninth pair of meiotic chromosomes, and has been named Df(9)Pw. It is linked with the group VIII markers ru and st at average map distances of 3.4 and 1.5 units, respectively, thus allowing, for the first time, a positive linkage group-autosome correlation for the German cockroach. Comparative studies of the deficiency and translocation Pw traits have produced an approximation of translocation breakpoints and centromere location on autosomes 9 and 10, establishment of the relationship between the deficiency and the translocation, and a tentative assignment of specific traits to specific locations on chromosome 9. The genetic makeup of the prowing locus is also discussed.
VARIABILITY IN DNA CONTENT AND NUCLEAR MORPHOLOGY OF THE ALEURONE CELLS OF AVENA FATUA (WILD OATS)
Authors: Maherchandani N. J. , Naylor J. M.
Published: November 2014

Nuclei of mature aleurone cells of Avena fatua do not conform to the general rule of DNA constancy. That is, a frequency distribution of nuclear DNA values in aleurone shows a continuous range from less than 2C to greater than 6C, with no accumulation of values at 3C and 6C as expected in a mature triploid tissue.This departure from DNA constancy apparently is not due to irregularity in mitosis. It may reflect DNA turnover or DNA amplification during differentiation. The possible adaptive function of DNA amplification in aleurone is discussed.
OIL COMPOSITION OFMENTHA AQUATICA×M.SPICATAF1HYBRIDS IN RELATION TO THE ORIGIN OFX M.PIPERITA
Authors: Murray Merritt J. , Lincoln David E. , Marble Phillip M.
Published: November 2014

Fertile M. aquatica L. (2n = 96) having the genotype cc AA PP RR ff and 40–80% menthofuran hybridized with fertile M. spicata L. (2n = 48) or M. spicata L. var. crispata Schrader (2n = 48) having the genotype Cc Aa PP rr FF, a strong spearmint odor, and the ketones carvone and dihydrocarvone produced sterile F1hybrids (2n = 72) that had a ratio of 1 hybrid having the 2-oxygenated ketones carvone and dihydrocarvone to 1 hybrid having the 3-oxygenated ketones pulegone and menthone. M. aquatica hybrids with an S1strain of M. spicata having the genotype CC (AA, Aa, or aa) PP rr FF and carvone are all carvone/carveol/carveyl acetate odored, whereas hybrids with S1strains of M. spicata having the genotype cc AA PP rr FF and the ketones pulegone and menthone are all somewhat peppermint odored but highly variable in oil composition. Gas chromatographic analyses of the peppermint-type hybrids having the genotype cc (AA or Aa) PP Rr Ff show that all hybrids have the same 14 major oil constituents as the Mitcham cultivar (source of all U.S. produced peppermint oil) and one non-Mitcham strain of X M. piperita L. but in very different quantitative amounts. Individual hybrids differed greatly in the quantitative amounts of 13 of the 14 oil constituents and organoleptic tests indicate that there are probably equally great differences in the minor oil constituents. The great variability of the F1hybrids in morphological appearance is largely due to the heterozygosity of the M. spicata parent, since the self-pollinated progeny of M. aquatica are indistinguishably alike. Certain hybrids resemble the natural strains of X M. piperita, whereas others do not. We were unable to make the 66-chromosomed cytotype, but have studied three secondary cytotypes having 84, 96, and 120 chromosomes.
EPISTATIC BIAS IN ADDITIVE AND DOMINANCE VARIATION AND GENETIC ASSOCIATIONS BETWEEN TWO QUALITY TRAITS IN BREAD WHEAT
Authors: Bains K. S. , Gill K. S. , Sehgal K. L.
Published: November 2014

Grain protein and Pelshenke value in 8 × 8 diallel crosses and after eliminating the interacting arrays were genetically analysed. All the dominance variation for grain protein was due to epistatic interactions. The dominance component for Pelshenke value was considerably inflated by epistasis. For both characters, the dominance component was affected more by the epistatic bias than the additive component of genetic variance, resulting in considerably low narrow-sense heritability estimates. Covariance between grain protein and Pelshenke value was primarily due to additive gene effects and was attributed to pleiotropic relationships in the absence of genetic linkage. An ambidirectional trend of dominance with an asymmetric distribution of dominant and recessive alleles among the cultivars was observed for grain protein, whereas preponderance of the dominant decreasing genes with more isodirectional gene distribution was operative for Pelshenke value. Correlated responses of these quality traits to selection due to high additive genetic correlation and degree of co-inheritance in relation to their gene action is stressed.
SELECTION PRESSURE IN CELL POPULATIONS OF VICIA HAJASTANA CULTURED IN VITRO
Authors: Singh B. D. , Harvey B. L. , Kao K. N. , Miller R. A.
Published: November 2014

Tissue cultures from mature seeds of Vicia hajastana Grossh (2n = 10) were maintained in liquid B5 medium with 4.5 × 10−6 M 2,4-D. Initially the cultures had a very low frequency of diploid cells, which increased to 91.7% after 295 days in culture, indicating a strong selection for diploid cells. Chromosomes with changed morphology were observed and anaphase analysis showed various abnormalities. The frequency distribution of different chromosomes of the genome in aneuploid cells was nonrandom.
IN VITRO LEUCOCYTE CULTURES OF SYRIAN AND CHINESE HAMSTERS
Authors: Szajkowski S. , Ray M. , Moore K. L.
Published: November 2014

An investigation of a variety of different separation procedures and culture conditions was made in order to evaluate the methods for culturing leucocytes in vitro of Syrian and Chinese hamsters. Dextran (6%), human AB serum and fetal calf serum (FCS) were used as separating agents. In the Chinese hamster the best results were obtained with AB serum whereas in the Syrian hamster adequate separation was obtained with all three agents. Supplementation of the culture medium with FCS provided the most favourable conditions for cell survival in culture. Maximal numbers of mitoses were obtained after 4 days of culture at 37 °C with the Syrian hamster (0.5%) and after 5 days with Chinese hamster (0.2%). Leucocytes of Syrian and Chinese hamsters were also cultured following immunization with each of the ABO sera as well as with FCS. Both macro- and micromethods were partially successful. Using the macromethod, no mitoses were observed in the Chinese hamster, but a few in Syrian hamsters immunized with B serum. With the micromethod, mitotic figures were observed in Syrian hamsters immunized with B serum, O serum and FCS, and Chinese hamsters with O serum and FCS. Leucocytes of the Chinese hamster proved difficult to culture successfully by any of the methods used, whereas, with the Syrian hamster, immunization with FCS and culture using micromethod gave the best results.
EFFECT OF HUMAN FOLLICULAR AND TUBAL FLUIDS ON HUMAN, MOUSE AND RAT SPERMATOZOA IN VITRO
Authors: Mukherjee Anil B. , Lippes Jack
Published: November 2014

Human follicular and tubal fluids, as well as mixtures of the two, were tested on the acrosome staining reaction of human, rat and mouse spermatozoa. In all three species, heat-inactivated follicular fluid (56 °C for 30 min) enhanced sperm motility, whereas non-inactivated fluid immobilized the sperm. Spermatozoa obtained from the epididymis of rats and mice, and that derived from human ejaculates had striking acrosome staining reaction (acrosome-blue; nucleus-red), whereas, after treatment with human follicular or tubal fluids, the acrosome staining reaction was lost. In the mouse, a correlation was found between the loss of acrosome staining reaction and the rate of in vitro fertilization and subsequent development of blastocysts. These data suggest that (a) factor(s) for sperm capacitation are present in human follicular and tubal fluids, (b) heat inactivation eliminates toxicity of follicular fluid and (c) the capacitation factor does not appear to be species specific.
A GENETIC STUDY OF BIOMASS IN TRIBOLIUM. I. PATH COEFFICIENT ANALYSIS OF BASE POPULATIONS
Authors: Krause Eliot , Bell A. E.
Published: November 2014

Biomass, an aggregate trait combining the metric trait 13-day larval weight with the reproductive fitness trait number of larvae per mating, was investigated in two unrelated base populations of Tribolium castaneum, black and pearl.The black population was characterized by smaller 13-day larvae, more larvae per mating due to a higher rate of fecundity, and a smaller biomass than was observed for the pearl population. Both genetic and phenotypic variances were higher in black than in pearl. Heritability estimates for larval weight approached 0.20 in both populations while those for the fitness traits were smaller and seldom exceeded 10%. Non-additive genetic effects as well as maternal influences were observed in both populations. Positive estimates for the genetic correlations between larval weight and number of larvae per mating were observed for both populations (0.47 for black and 0.17 for pearl).Path coefficient analyses revealed that larval number in both populations had greater genetic and phenotypic influences on biomass than did larval weight. In turn, egg number had a greater influence on number of larvae than did larval viability.
GIEMSA STAINING OF HETEROCHROMATIC AREAS OF HUMAN CHROMOSOMES FOR IDENTIFICATION
Authors: Frey Jeffery P. , Neu Richard L. , Powers Harold O. , Gardner Lytt I.
Published: November 2014

A simple technique is described for differential staining of human chromosomes with Giemsa. The procedure involves DNA denaturation with a methanol-acetic acid fixative, and subsequent annealing using a saline solution. This technique has a number of advantages over quinacrine fluorescence, and gives a more distinct banding pattern. It is a rapid, inexpensive procedure and can be done with existing equipment and material in most cytogenetic laboratories.
A SELECTIVE METHOD FOR THE ENRICHMENT OF CYTOPLASMIC MARKERS IN SACCHAROMYCES CEREVISIAE
Authors: Rank G. H. , Martin R.
Published: November 2014

Sensitive diploids of Saccharomyces cerevisiae were used to select for resistance to oligomycin and erythromycin when glycerol was used as the energy source. Genetic analyses revealed that 10 erythromycin and 4 oligomycin mutants were cytoplasmically inherited.
COMPARATIVE CYTOLOGICAL EFFECTS OF THE PESTICIDES MENAZON, METROBROMURON AND TETRACHLOROISOPHTHALONITRILE INHORDEUMANDTRADESCANTIA
Authors: Tomkins D. J. , Grant W. F.
Published: November 2014

The biological effects of an s-triazine insecticide: menazon (MEN), a substituted urea herbicide: metobromuron (PAT) and an aromatic hydrocarbon fungicide: tetrachloroisophthalonitrile (DAC) were compared with those of ethylmethanesulfonate (EMS) and X-irradiation. Seeds of barley (Hordeum vulgare L.) were soaked in solutions of the chemicals before determining percentage germination, seedling height and frequency of chromosomal aberrations. In addition, somatic mutations in inflorescences of Tradescantia clone 02 treated with solutions of the chemicals were counted. X-rays induced a high frequency of chromosome breaks but had no effect on any other character. In contrast, EMS had a pronounced effect on all the characters studied. Only one pesticide, PAT, had significant effects. The herbicide reduced germination percentage, seedling height and the mitotic index in barley. It is concluded that EMS and X-rays have a cytogenetic action in the treated cells, whereas PAT induced a severe physiological effect.
INHERITANCE OF SPORE COLOUR IN PUCCINIA HELIANTHI
Authors: Hennessy C. M. R. , Sackston W. E.
Published: November 2014

A mutation for loss of wall pigment in urediospores and teliospores of Puccinia helianthi Schw. is described. The mechanism of inheritance of spore colour could not be established precisely. Wall pigment appeared to be determined by one or a small number of genes, whereas pigment of the cytoplasm was unstable and influenced by environmental factors. Evidence for multiple fertilizations in single aecial cups supported earlier reports that the aeciospore should be considered the unit of fertilization in the rusts. Somatic segregation for colour was observed in F1 cultures.
CHROMOSOME MORPHOLOGY OF POA TRIVIALIS L.
Authors: Ahmed M. K. , Jelenkovic G. , Dickson W. R. , Funk C. R.
Published: November 2014

The chromosome complement in six turf-type genotypes of Poa trivialis was studied. The chromosome number was 2n = 2x = 14. On the basis of chromosome length, ratio between arm lengths, centromeric indices, and presence of constrictions all seven pairs were identified and characterized.
THE PAIRING OF AN ALIEN CHROMOSOME WITH HOMOEOLOGOUS CHROMOSOMES OF WHEAT
Authors: Athwal Raghbir S. , Kimber Gordon
Published: November 2014

The homoeology of chromosome A of Triticum umbellulatum has been determined by studying its pairing relationships with wheat telocentrics in hybrids having the chromosome constitution of 20 wheat chromosomes + one wheat telocentric chromosome + seven Triticum speltoides chromosomes + chromosome A. It has been found to be homoeologous to the group-6 chromosomes of wheat.
QUANTITATIVE VARIATION IN DNA AS RELATED TO PLOIDY LEVEL AND SPECIES IN SOME WILD ROSES
Authors: El-Lakany M. H.
Published: November 2014

Relative DNA content and chromosome number and behaviour were studied in Manitoba wild roses. The hexaploid, Rosa acicularis, contained the largest amount of DNA, about three times that of the diploid, R. woodsii. Another diploid species, R. blanda, contained less DNA than R. woodsii. One specimen, identified as R. blanda with some introgression from R. woodsii, had the same amount of DNA as the latter species. R. × dulcissima, a hybrid between R. blanda and R. woodsii, had DNA contents similar to R. woodsii. The origin of a tetraploid, with DNA contents intermediate between diploid and hexaploid species, and 14 bivalents in diakinesis, was suggested to be hybridization between R. acicularis and a diploid rose. Chromosome behaviour in meiosis and DNA content were used in a discussion of interspecific relationships.
GENETIC VARIABILITY INAEGILOPS SPELTOIDESAFFECTING HOMOEOLOGOUS PAIRING IN WHEAT
Authors: Dvořák J.
Published: November 2014

Three Chinese Spring ditelocentric lines and four Agropyron telocentric addition lines were crossed with a single population of Aegilops speltoides. Chromosome pairing was studied in the hybrid plants. The mean chiasma frequencies per cell in different hybrid plants indicate the existence of three different genotypes in the population of Ae. speltoides each differing significantly in ability to suppress the diploidizing mechanism in polyploid wheat. Plants at the three levels of pairing showed means of 6.4, 10.4 and 15.0 chiasmata per cell, respectively.Agropyron telocentric chromosomes did not pair with their wheat homoeolgues at the lowest pairing level. At intermediate and high pairing levels they did pair with wheat chromosomes. The increase in pairing of Agropyron telocentrics paralleled the increase in chiasma frequency per cell.The action of genes controlling homoeologous synapsis is discussed and it is suggested that pairing affinity between chromosomes may result from the interaction between two factors: homology in nucleotide sequences at specific sites in chromosomes, and degree of activation of these sequences.
EXPRESSION OF THE MATERNAL EFFECT INVOLVING THELIGHTLOCUS INDROSOPHILA MELANOGASTER
Authors: Nickla Harry
Published: November 2014

The maternal effect associated with the light locus in Drosophila melanogaster was examined using chromatography and fluorometry. Homozygous light progeny from lt/lt females have less yellow pigment (composed primarily of riboflavin) in their Malpighian tubes than do offspring (lt/lt) of heterozygous females. This difference in pigment quantity is detectable during larval, pupal, and adult life. In contrast, no maternal effect could be detected for isoxanthopterin content in third-instar larvae and adults suggesting that the larval genome controls synthesis of this substance.
MEIOSIS IN THE GRASSHOPPER. II. THE PRELEPTOTENE SPIRAL STAGE DURING OOGENESIS AND SPERMATOGENESIS IN MELANOPLUS FEMUR-RUBRUM
Authors: Church Kathleen
Published: November 2014

Chromosome behaviour occurring from premeiotic DNA synthesis to leptotene of meiosis is described for both males (spermatogenesis) and females (oogenesis) in the grasshopper Melanoplus femur-rubrum. These events include a period of chromosome spiralization and contraction following premeiotic DNA synthesis and prior to leptotene. The diploid complement of chromosomes becomes visible in both sexes. No pairing between homologous chromosomes or chiasmata are observed in either sex. The results suggest that synapsis and crossing over must occur following preleptotene spiralization during spermatogenesis and oogenesis in this grasshopper.
FURTHER STUDIES ON DIPLOPODIA. V. DIPLOPODIA-3
Authors: Taylor Lewis W.
Published: November 2014

Chronologically the third member of the diplopod series of mutants was found in an inbred line of White Leghorn chickens selected for a high incidence of crooked toes. Diplopodia-3 resembled the other diplopod mutants in possessing supernumerary digits on legs and wings, a shortened upper beak and micromelia. Death occurred prior to hatching. Morphological expression of characters was less severe than with sex-linked diplopodia-4 and autosomal diplopodia-2, and approached that of autosomal diplopodia-1 except for weaker expressions on the wings. The mutant autosomal gene dp-3 was not allelic with dp-1. Relation to dp-2 could not be determined since stock carrying this mutation was no longer extant.
THYROID ACTIVITY IN LINES OF MICE SELECTED FOR LARGE AND SMALL BODY WEIGHT
Authors: Synenki R. M. , Eisen E. J. , Matrone G. , Robison O. W.
Published: November 2014

Thyroid activity was measured at 21, 31 and 42 days of age in lines of mice selected for large (H6) and small (L6) 6-week body weight and an unselected control (C2). Mean %181I uptake/(body weight).75was greatest at 21 days (weaning) and decreased exponentially thereafter with females generally having higher values than males. The L6line had a significantly (P < 0.01) higher %131I uptake/(body weight).75than H6at 31 and 42 days. For %131I uptake, disregarding body size, the H6line was significantly (P < 0.01) higher than C2, but the L6and C2, lines did not differ. Mean %131I turnover/day/(body weight).75showed results similar to %131I uptake per unit metabolic body size. However, when body size was not considered, %131I turnover in the L6line was slightly higher than H6at 31 and 42 days of age. Rate of maturation, as measured by age at opening of eyes and vagina and appearance of external ears, coat hair and nipples, was significantly (P < 0.01) more rapid in the H6line compared to L6. Within lines the correlation between growth rate and maturation rate was positive. These data suggest that there is a small positive genetic correlation between body weight at six weeks of age and thyroid activity in mice.