bluuebunny/crossref_metadata_2025 huggingface dataset:
HOMOEOLOGY BETWEENAGROPYRON ELONGATUMCHROMOSOMES ANDTRITICUM AESTIVUMCHROMOSOMES
Authors: Dvořák J.
Published: November 2014

Genetic compensation of Agropyron chromosomes for wheat chromosomes in the male gametophyte and compensation of Agropyron chromosomes for wheat chromosomes in disomic substitutions were used to investigate relationships between the chromosomes of Agropyron elongatum (Host.) P.B. (2n = 2x = 14) and Triticum aestivum L. emend. Thell. (2n = 6x = 42). Gametophytic compensation indicated that A. elongatum chromosomes I, II, III, IV, and VII were related to wheat chromosomes of homoeologous groups 1, 7, 4, 3, and 6, respectively, and were designated 1E, 7E, 4E, 3E, and 6E. Chromosomes V and VI appeared to be related to homoeologous group 2. Other analyses showed that chromosomes V and VI originated from arm exchanges between chromosome 2E and other Agropyron chromosomes. An unaltered disome of Agropyron chromosome 2E was added to the wheat chromosome complement. In the disomic substitutions Agropyron chromosomes 1E, 6E, and 7E compensated for all three wheat homoeologues of the respective homoeologous groups. Chromosome 4E fully compensated for chromosome 4D but only partially for chromosomes 4A and 4B. Chromosomes V and VI compensated poorly or not at all for wheat chromosomes of group 2.
INHERITANCE OF AN UNUSUAL COLOR VARIANT IN THE GRASSHOPPER MELANOPLUS SANGUINIPES
Authors: Chapco W.
Published: November 2014

The inheritance of "red back" in the migratory grasshopper, Melanoplus sanguinipes (Fabricius), is investigated. The phenotype, a reddish-brown color, is restricted to adults and extends from the dorsal surface of the metazona of pronotum to the fastigium of vertex. Standard crosses with "normal" grasshoppers indicate that "red back" is inherited as an autosomal dominant trait, there being some association with reduced viability. Two-point testcrosses involving another trait, "hind tibia color", reveal the presence of linkage between the two traits. Map distance estimates are 19.4 and 8.8 units in females and males, respectively.
GENETIC AND LINKAGE ANALYSES OF MAROON EYE AND ACID PHOSPHATASE I IN CULEX TRITAENIORHYNCHUS
Authors: Dubash Cusrow J. , Sakai Richard K. , Baker Richard H.
Published: November 2014

Maroon eye (ma) and the acid phosphatase I (Acph-1) system of Culex tritaeniorhynchus Giles were subjected to genetic and linkage analyses. Both loci are linked to the linkage group 2 locus, ebony body (e), and the gene sequence is ma - e - Acph-1. Experiments also revealed that maroon eye is temperature sensitive.
MEIOTIC CHROMOSOME BEHAVIOR IN MONOPLOID SUGARBEET
Authors: Yu M. H.
Published: November 2014

The meiotic behavior of a monoploid plant of sugarbeet (Beta vulgaris L.) was studied. At meta-anaphase I univalents, bivalents and trivalents, and secondary associations of up to three chromosomes were observed, with an average of 8.65 I + 0.16 II + 0.01 III per cell or 0.18 chiasmata per cell. Chromosomes migrated to the poles at anaphase I in all possible numerical groupings. Various numbers of laggards, dividing laggards, bridges, and fragments occurred at both divisions. It appears that two or more duplications are present in the genome of this monoploid plant.
A CYTOGENETICAL ANALYSIS OF STERILE MUTANTS INCAENORHABDITIS ELEGANS
Authors: Mounier Nicole , Brun Jean
Published: November 2014

The regulation of gametogenesis in the hermaphrodite and proterandrous nematode Caenorhabditis elegans is introduced here through the analysis of nonconditional sterile mutants. To investigate the mechanisms which allow the two gametogenetic phases to succeed each other in the same ovotestis, three mutants were studied cytogenetically. Two of the mutants exhibit only the spermatocyte phase and the third shows a greatly reduced and disturbed oogenesis. These three mutations all produce large decreases in ovotestis size and gonocyte number. Each of the three is monofactorial, recessive, autosomal and independent. Homozygous mutant males are also sterile. The gametogenesis phases which could be disturbed by mutation were determined by cytological analysis of the ovotestis of 12 other sterile strains. These phases occur during mitotic divisions of the genital primordium, zygotene chromosome pairing, male meiosis and spermiogenesis, oogenesis induction and oocyte maturation. These steps of gametogenesis need a wild-type genie activity to occur normally. It appears that spermatogenesis and oogenesis are two genetically independent processes, and that oogenesis is rather autonomous and its induction would depend on a hormonal factor.
CORRELATIONS BETWEEN CHROMOSOME SEGMENTS AND FITNESS INDROSOPHILA MELANOGASTER. IV. FECUNDITY, VIABILITY AND THE THIRD CHROMOSOME
Authors: Chapco William
Published: November 2014

Unmarked segments within the third chromosomes of three different Drosophila melanogaster lines were assessed for their effects on egg production and egg viability. By making a series of crosses among original and derived recombinant lines, it was possible to estimate parameters representing additive, dominance (for egg production), and interaction effects of the segments. Each segment influences both traits, but to extents which are dependent on the genetic background provided by an adjacent segment. There is no clear pattern, however, with respect to the segments' joint effects on the two characters. Unlike in the previous study involving the X chromosome, the majority of the derived recombinant lines were superior in fitness to their original lines. The agricultural implications of this result with respect to the manipulation of chromosomal segments in order to achieve higher yields are discussed.
KARYOLOGICAL STUDIES ON AVENA HYBRIDA FROM THE WAKHAN OF NORTH EASTERN AFGHANISTAN
Authors: Huss H.
Published: November 2014

The mitotic chromosome morphology and the meiotic chromosome behavior of Avena hybrida Peterm. are described for the first time. The haploid idiogram could be separated into four groups, the chromosomes within each being morphologically similar. There are three SAT-chromosomes (arm ratio (r) = 1.74-2.92), four metacentric chromosomes (r = 1.07-1.14), seven submetacentric chromosomes (r = 1.22-1.68) and seven subtelocentric chromosomes (r = 1.75-2.42). The idiogram of A. hybrida was compared with those of A. sativa cvs. 'Condor' and 'Markton'. Three chromosomes of 'Condor' differed significantly from those of A. hybrida, whereas no differences were apparent between the karyotypes of A. hybrida and A. sativa cv. 'Markton'. At meiosts 21 bivalents were regularly formed.
ANALYSES OF MEIOTIC METAPHASE IN HAPLOIDS AND HYBRIDS OF HAPLOID × DIPLOID FLAX (LINUM USITATISSIMUM)
Authors: Murray Beatrice E.
Published: November 2014

Haploids (2n = x = 15) and the F1progeny from haploid × diploid crosses of haploid-diploid twins in the flax cultivar Rocket 4 (Linum usitatissimum L.) were analyzed cytologically. In the pollen mother cells (PMC) of haploids, there was variation in the behavior of meiotic chromosomes. There was no chromosome pairing or secondary associations. At meta-anaphase I, the chromosomes either divided and separated to the poles 1) unequally, 2) equally, 3) irregularly, or 4) separated as clusters of undivided chromosomes. All types were present at different frequencies in each haploid. Haploid × diploid crosses produced diploid (2n = 2x = 30), aneuploid (2n = 2x = 31 to 33) and triploid (2n = 3x = 45) F1progeny at a frequency of 58%, 20% and 22%, respectively. Diploids formed regular bivalents. In the PMCs of aneuploids, the extra chromosomes formed trivalents or remained unassociated as univalents. Chromosomes in the PMCs in triploids predominantly formed trivalents. The relevance of the meta-anaphase I pattern to the potential utilization of haploid flax is discussed.
CHROMOSOMAL ANALYSIS OF 159 BOVINE EMBRYOS COLLECTED 12 to 18 DAYS AFTER ESTRUS
Authors: Hare W. C. D. , Singh Elizabeth L. , Betteridge K. J. , Eaglesome M. D. , Randall G. C. B. , Mitchell D. , Bilton R. J. , Trounson A. O.
Published: November 2014

One hundred and fifty-nine embryos were analysed in conjunction with embryo transfer studies. Chromosome preparations were made from small biopsy fragments of trophoblast, from large portions of trophoblast and the inner cell mass, or from the entire embryo. Results obtained from fragments were similar to those obtained from large portions of trophoblast and inner cell mass. No structural chromosomal abnormalities were observed. Single triploid, diploid-triploid and diploid-hexaploid and 66 diploid-tetraploid embryos were found. The 41.5% incidence of diploid-tetraploid embryos was relatively high, and appeared to be associated with a donor factor. The transfer of 49 biopsied and analysed embryos to recipients resulted in 15 pregnancies, seven with diploid-tetraploid embryos having up to 25% of polyploid cells. The diploid-triploid and diploid-hexaploid embryos were among the transfers that did not result in pregnancy. The low incidence of embryos with chromosomal abnormalities, excluding the diploid-tetraploid embryos, may have been due to the embryos being analysed at 12 to 18 days of age rather than at an earlier age before death or degeneration could have occurred.
RESISTANCE TO PUCCINIA GRAMINIS AVENAE AND P. CORONATA AVENAE IN THE WILD AND CULTIVATED AVENA POPULATIONS OF IRAN, IRAQ AND TURKEY
Authors: Martens J. W. , McKenzie R. I. H. , Harder D. E.
Published: November 2014

Tests of over 1400 Avena accessions, comprising eight species, from Iran, Iraq and Turkey have shown that resistance to oat stem rust caused by Puccinia graminis Pers. f. sp. avenae Eriks and E. Henn. occurs infrequently in the Avena populations of the region and was found only in A. barbata Pott ex Link and A. sterilis L. Resistance to oat crown rust caused by P. coronata Cda f. sp. avenae Eriks, was common in A. barbata from Turkey and in A. sterilis from all three countries. The inheritance of resistance conferred by two genes from the region, Pg-15 and Pc-54 is described. Gene Pg-15, the first stem rust resistance gene found in this region, is partially dominant and independent of the Pg-2, Pg-9, Pg-12 and Pg-13 loci. It conferred resistance to races that are important in North America. Gene Pc-54 was also the first crown rust resistance gene to be identified from this region. It was usually recessive, and allelic or closely linked with gene Pc-35.
MUTATION OF A GENE FOR YELLOW PIGMENT LINKED TO Lr19 IN WHEAT
Authors: Knott D. R.
Published: November 2014

In earlier work it had been found that Agatha, a wheat-Agropyron derivative carrying gene Lr19 for leaf rust (Puccinia recondita Rob. ex Desm.) resistance, also carried an undesirable gene for yellow flour pigment. Agatha was treated with ethyl methanesulphonate in an attempt to mutate the gene for yellow pigment. The M2 plants were tested for pigment levels, plants that appeared to be low were selected and the results confirmed on their M3 progeny. Two apparent mutants with low pigment levels were obtained.
MUTAGENIC EVALUATION OF 1,1,2,3-TETRACHLORO-2- PROPENE, A CONTAMINANT IN PULP MILL EFFLUENTS, USING A BATTERY OF IN VITRO MAMMALIAN AND MICROBIAL TESTS
Authors: Ellenton Jennifer A. , Douglas George R. , Nestmann Earle R.
Published: November 2014

The mutagenicity of 1,1,2,3-tetrachloro-2-propene (TCP), a component of chlorinated pulp mill effluents, was investigated with a battery of in vitro mammalian and microbial assays. In fluctuation tests, TCP showed potent mutagenic activity with Salmonella typhimurium strain TA1535 but only very weak activity with Escherichia coli WP2. In Chinese hamster ovary (CHO) cells, TCP without metabolic activation induced chromosome aberrations. This activity was enhanced by the addition of Aroclor 1254-induced rat liver preparation (S9). Endoreduplication was also induced by TCP in the presence of S9. Without activation, TCP caused an increase in the number of sister chromatid exchanges (SCEs), however this increase was eliminated by S9. TCP did not cause DNA damage in CHO cells as measured by alkaline sucrose gradient sedimentation either with or without metabolic activation.
INDUCED PAIRING BETWEEN A WHEAT (TRITICUM AESTIVUM) AND AN AGROPYRON ELONGATUM CHROMOSOME
Authors: Yasumuro Y. , Morris R. , Sharma D. C. , Schmidt J. W.
Published: November 2014

A study was initiated to transfer genes for stem- and leaf-rust resistance from a chromosome (designated 6Ag) of Agropyron elongatum (Host) Beauv to a homoeologous chromosome (6D) of wheat (Triticum aestivum L. aestivum group) by inducing pairing between 6Ag and 6D in the absence of the Ph gene on wheat chromosome 5B. Plants monosomic for SB, 6D and 6Ag were crossed with Chinese Spring nullisomic-5B tetrasomic-5D or with Chinese Spring monosomic or trisomic for SB with an induced mutation, phlb, of the Ph locus. Tests of 282 offspring in the seedling stage for reaction to the stem rust pathogen, Puccinia graminis Pers. f. sp. tritici Eriks. &E. Henn. race 56 or 15B-2, were used to identify 70 plants with 6Ag, which was transmitted through 25% of the female gametes. Meiotic observations on 51 of these plants indicated that six were monosomic for 6D and 6Ag, but lacked an entire 5B or had 5B with the phlb mutation. The frequency of metaphase I cells with pairing between 6D and 6Ag averaged 4.94% in three plants that were nullisomic for 5B and 2.48% in two plants that had a single dose of 5B with the phlb mutation.
Ag-NORs VARIATION AND BANDING HOMOLOGIES IN TWO SPECIES OF BOVIDAE: BUBALUS BUBALIS AND BOS TAURUS
Authors: Berardino D. Di , Iannuzzi L. , Bettini T. M. , Matassino D.
Published: November 2014

G,Q and R-banding pattern comparisons between the Murrah type of Bubalus bubalis L. (2n = 50) and the Holstein Friesian breed of Bos taurus L. (2n = 60) chromosomes revealed that the autosomes are similar in both species; in the former, the five pairs of submetacentrics correspond to centric fusions of chromosomes 1-29, 2-22, 8-19, 5-28 and 16-25 in the latter. Silver staining on somatic cells of buffalo revealed telomeric Ag-NORs located on six pairs of autosomes, identified as 3p, 4p, 8, 21, 23 and 24. Only one pair of nucleolus organizer chromosomes is common to both species, namely the 4p of buffalo which corresponds to the 28 of cattle. The remaining NORs are located on different pairs. Out of 18 individuals, the number of Ag-NORs per cell varied between 3 and 10, with a mean value of 6.3 ± 1.7; the mean number of nucleolar associations per cell was between 0.1 and 1.8. In the total population of 317 cells the two variables followed the binomial and the Poisson distributions, respectively, and their correlation coefficient was not statistically significant (r = +0.36). In addition to the mean number of Ag-NORs, the mean number of nucleolar associations per cell should be used for a better understanding of the differences among individuals.
THE KARYOTYPE OF ECHINOCOCCUS MULTILOCULARIS (CESTODA: TAENIIDAE)
Authors: Rausch V. R. , Rausch R. L.
Published: November 2014

The chromosomes of Echinococcus multilocularis Leuckart, 1863 have been described, based on components of cells from the adult stage and the larval stage of the cestode. Chromosomal complements of 2n = 18, n = 9 were confirmed. The fundamental number of chromosomal arms was 24. Karyograms are presented, in which the 18 elements are grouped according to arm-ratios and size. An idiogram of G-bands is included.
PRELIMINARY EVIDENCE OF GENETIC CONTROL OF SEX CHROMOSOMAL SYNAPSIS IN THE MOUSE
Authors: Blecher Stan R. , Gollapudi Bala Bhaskar , Kamra Om P.
Published: November 2014

Highly inbred strains of mice have contrasting means and low ranges for the trait of gonosomal univalency at diakinesis-metaphase I. Randomly bred and mixed strains have wider ranges. The inbred strain DBA/2J has a high mean, and this character is evidently transmitted through the male parent. This material may provide a valuable model for study of genetic control of XY pairing.
REACTION OF WHEAT TO COMMON ROOT ROT: IDENTIFICATION OF A MAJOR GENE, Crr, ON CHROMOSOME 5B
Authors: Larson Ruby I. , Atkinson T. G.
Published: November 2014

Triticum aestivum L. cv. S-615 has a dominant gene for susceptibility to common root rot and cv. Apex a recessive gene for resistance on chromosome 5B. One hundred and twenty-two lines, each homozygous for a different random crossover between loci on Apex and S-615 chromosomes 5B, but near-isogenic with S-615 for the other 20 chromosomes, were tested for root rot reaction in soil naturally infested with the causal organism, Cochliobolus sativus (Ito and Kurib.) Dachs. ex Dastur, to determine whether the two genes are alleles. The ratio of resistant to susceptible lines was 1:1, and there were no intermediate or transgressive types. It was concluded, therefore, that the genes for resistance and susceptibility are alleles. The recessive gene for resistance has been given the symbol Crr for Cochliobolus root rot. Minor genes appear to exist on chromosome 5B of Apex which, when combined in some of the crossover lines with the dominant gene for susceptibility, crr, increase the percentage of seedlings killed by the disease but not the mean root rot rating of these lines
PARENTAL EFFECTS ON CHROMOSOME DOUBLING FOR THE PRODUCTION OF PRIMARY TRITICALE
Authors: Tanner D. G.
Published: November 2014

Intergeneric hybridization between six hexaploid wheat (Triticum aestivum L.) cultivars and five inbred rye (Secale cereale L.) lines was used to study the influence of parental genotypes upon chromosome doubling after colchicine treatment. Significant differences were attributed to independent effects of the wheat and rye parents. Self-fertility of the derived amphidiploids was positively correlated with colchicine responsiveness.
THE ANALYSIS OF MEIOSIS IN HYBRIDS. II. TRIPLOID HYBRIDS
Authors: Alonso L. C. , Kimber G.
Published: November 2014

Methods are developed that allow a quantitative determination of relative affinity in triploid hybrids. This results in new insights into the analysis of meiosis in hybrids, genomic relationships and the assignment of genome symbols. The separate recording of open and closed chromosome figures in meiotic analyses is shown to be essential.
THE ANALYSIS OF MEIOSIS IN HYBRIDS. III. TETRAPLOID HYBRIDS
Authors: Kimber G. , Alonso L. C.
Published: November 2014

Models are developed which simulate expected chromosome pairing in tetraploid hybrids in plants. Comparison of the various models with observed meiotic data allow the investigation of species and evolutionary relationships, genomic affinity and the effects of pairing-regulator genes.
PRODUCTION OF ANTHER-DERIVED DIHAPLOID PLANTS IN AUTOTETRAPLOID MARROWSTEM KALE (BRASSICA OLERACEAVAR.ACEPHALA)
Authors: Keller W. A. , Armstrong K. C.
Published: November 2014

Microspore embryogenesis was induced in anthers of Brassica oleracea L. var. acephale D.C. cv. 'Polkow' (autotetraploid marrowstem kale) cultured under conditions similar to those previously developed for B. campestris and B. napus. Embryogenesis was stimulated by an initial high temperature culture treatment with maximal embryo yields obtained when anthers were cultured at 35 °C for one day prior to maintenance at 25 °C. Although most of the microspore-derived embryos failed to develop directly into plantlets, regeneration could be achieved from cultured hypocotyl explants. More than 60% of the regenerates had small, sterile flowers and cytological analysis of some of these plants revealed that they were dihaploids (2n = 2x = 18). Plant regeneration could be induced from dihaploid stem explants, thereby providing a potential method for propagation and maintenance of sterile material.
CHROMOSOME DIFFERENTIATION IN POLYPLOID SPECIES OFELYTRIGIA, WITH SPECIAL REFERENCE TO THE EVOLUTION OF DIPLOID-LIKE CHROMOSOME PAIRING IN POLYPLOID SPECIES
Authors: Dvořák J.
Published: November 2014

Triticum aestivum L. em Thell ditelosomics 7AL and 7DS and T. aestivum-Elytrigia elongata (Host) Holub (2n = 2x = 14) ditelosomic additions were crossed with "E. elongata 4x" (2n = 4x = 28), E. caespitosa (C. Koch) Nevski (2n = 4x = 28), and E. intermedia (Host) Nevski (2n = 6x = 42). The effect of each Elytrigia genotype on homoeologous (heterogenetic) chromosome pairing was assessed by comparing the pairing frequencies of T. aestivum cv. Chinese Spring telosomes 7AL and 7DS in the hybrids with the pairing frequency of telosome 7AL in haploid Chinese Spring. The genotype of "E. elongata 4x" had no effect on heterogenetic pairing in the hybrids. Although some genotypes of E. caespitosa and E. intermedia promoted heterogenetic pairing in the hybrids, others had no effect. Telosome VS of E. elongata interacted in a complementary fashion with the genotype of "E. elongata 4x," but not with the genotypes of Chinese Spring and E. caespitosa, and it promoted heterogenetic pairing. In hybrids in which the wheat diploidizing genes were active at the normal level, the E. elongata telosomes paired with chromosomes of "E. elongata 4x" in 5.8% to 24.6% of the cells, with chromosomes of E. caespitosa in 0.0% to 1.0% of the cells, and with chromosomes of E. intermedia in 0.0% to 2.8% of the cells. A model of chromosome differentiation is discussed and special attention is devoted to the origin of diploid-like pairing in polyploid species.
CHANGES IN LEVELS OF ALCOHOL DEHYDROGENASE DURING THE DEVELOPMENT OFDROSOPHILA MELANOGASTER
Authors: Anderson Steven M. , McDonald John F.
Published: November 2014

The results of an analysis of the biochemical basis of changes in alcohol dehydrogenase (E.C.1.1.1.1) activity over Drosophila development are presented. The data indicate that (1) the characteristic changes that occur in ADH activity over development are predominantly, if not exclusively, the result of quantitative changes in the amount of enzyme present rather than qualitative changes affecting the enzyme's specific activity and (2) the fluctuations in amount of ADH which occur during development are not the result of the only known form of post-translational modification capable of affecting the biochemical properties of the enzyme. We conclude that developmental changes in amount of ADH are most likely the result of fluctuations in the turnover of the ADH protein.
SELECTION FOR MALATHION-RESISTANCE INDROSOPHILA MELANOGASTER
Authors: Singh R. S. , Morton R. A.
Published: November 2014

Results from a long-term selection experiment for malathion-resistance in Drosophila melanogaster are described. A pooled population of 40 locally-caught, iso-female lines was exposed to increasing concentrations of malathion in the food at both a high selection intensity (MH) and a lower intensity (ML). The response was consistent with a polygenic system. Both adult and larval resistance increased in parallel. Changes in the dose-response curve of adults could be approximately described by a dose-modification factor. Larval resistance was more complex; both selected populations showed a maternal effect which could not be explained by sex-linked genes. Larval resistance in the selected populations behaved as a co-dominant trait with respect to the susceptible controls. Adult resistance was dominant in the ML and co-dominant in the MH population, suggesting that different genes conferring resistance were selected. The selection procedure also produced a developmental delay in both populations, dependent on malathion concentration, but present even in its absence.
PLEIOTROPIC, RECESSIVE-LETHAL MUTANTS ASSOCIATED WITH PURINE METABOLISM INDROSOPHILA MELANOGASTER
Authors: Nash David , Woloshyn E. P. , Mehl Y. -M. , Janca F. C.
Published: November 2014

Three kinds of complementing mutants of Drosophila melanogaster assigned to the gua 1, pur 1 and ras loci fail to complement with a single class of recessive lethals, previously designated raspberry lethals (ras-1). These lethals are apparently point mutations. The gua 1, pur 1 and ras loci are closely linked. Their phenotypes implicate defects in three components of purine metabolism. It is suggested that the complementation pattern is best explained if the three loci are functionally related at the genetic as well as at the metabolic level.
INHERITANCE OF A ROLLED-LEAF TRAIT INBROMUS INERMIS
Authors: Lea Ho Zoo , Dunn G. M.
Published: November 2014

The inheritance of a rolled-leaf trait was investigated in smooth bromegrass (Bromus inermis Leyss). The trait is expressed early in seedling growth. The leaf blades roll inward from the leaf margins toward the midvein to a varying extent. Most of the rolled and F1plants contained an octoploid number of 56 chromosomes. Genetic data were obtained from the S1, S2, BC1, BC1selfed, F2and F3generations. Observed segregation ratios could best be explained by a single factor tetrasomic gene with (a) differential transmission rates of the homozygous rolled gametes through seed and pollen parents, and (b) incomplete dominance requiring at least two doses of the normal allele to suppress expression of the rolled-leaf trait. The incompletely dominant normal allele of the rolled-leaf gene was represented by the symbol R, and the rolled-leaf allele by the symbol r. Therefore, a phenotypically normal plant would be RRRR, RRRr or RRrr, and a rolled-leaf plant would be Rrrr or rrrr. Possible explanations were presented for the rare segregant and for reciprocal differences in segregation ratios.
KARYOTYPE OF HYMENOLEPIS CITELLI (CESTODA: CYCLOPHYLLIDEA)
Authors: Ward E. J. , Evans W. S. , Novak Marie
Published: November 2014

The karyotype of Hymenolepis citelli (McLeod, 1933) has been studied using early cleavage embryos isolated from 9-day-old worms that had been pretreated for 4 h at 37.5 °C in culture medium containing 0.03% colcemid. A diploid number of 12 was observed.
CONSERVATIVE CHROMOSOMAL CHANGE IN THE BAT FAMILY MORMOOPIDAE
Authors: Sites Jr. Jack W. , Bickham John W. , Haiduk Mike W.
Published: November 2014

G-band patterns are described for the karyotypes of both genera and all subgenera of mormoopid bats. A nomenclatural system is proposed for the mormoopid genome in which each autosomal arm is numbered and all bands on each arm are numbered from the centromere to the telomere. G-band patterns indicate that the karyotypes have remained stable throughout the evolution of the family; both species of Mormoops appear to differ from Pteronotus only by the presence in the former of a prominent G-positive region proximal to the centromere of arm 2. Mormoops blainvilli also possessed a prominent G-positive band in the distal end of arm 9 that stained lightly in all other species. C-band patterns of Mormoops megalophylla showed that most heterochromatic regions were centromeric, and silver-nitrate staining in this species and two species of Pteronotus showed that all possessed three pairs of nucleolar organizer regions on the centromeric ends of acrocentric chromosomes. G-band patterns suggest that the karyotype of all Pteronotus is primitive for the family.
TRANSFER OF CORNERSTONE MALE-STERILITY MUTANT TO TETRAPLOID WHEAT AND HEXAPLOID AND OCTOPLOID TRITICALES
Authors: Hossain M. A. , Driscoll C. J.
Published: November 2014

A γ-ray induced male-sterility mutant on chromosome 4A of Triticum aestivum L. (Cornerstone mutant ms1c) was transferred to T. durum Desf. by backcrossing. Selfed heterozygotes of T. durum produced fewer male-sterile plants than those of T. aestivum. Male-sterile plants of T. durum and T. aestivum were crossed with diploid rye (Secale cereale L.) and fertile hexaploid and octoploid triticales were obtained following colchicine treatment of the F1's. Thus, rye is able to restore fertility at both of these ploidy levels.
A CYTOLOGICAL STUDY OF THREE SPECIES AND A HYBRID TAXON OF LYCOPODIUM (SECTION COMPLANATA) IN ONTARIO
Authors: Hersey R. E. , Britton D. M.
Published: November 2014

A cytological study was carried out on three species and a hybrid taxon of Section Complanata Vict, of the genus Lycopodium L. in Ontario, Canada. The taxa studied were L. complanatum L., L. flabelliforme (Fern.) Blanchard, L. tristachyum Pursh and L. × habereri House. These taxa were examined cytologically in order to determine chromosome number and to study and compare meiosis in hybrids with meiosis in nonhybrid specimens. The chromosome number for all taxa was found to be n = 23, a number in agreement with the more recent chromosome number reports for these particular lycopods. Meiosis in L. × habereri, was found to be identical to meiosis in L. complanatum, L. flabelliforme and L. tristachyum, i.e. no irregularities were observed in the meiosis of the hybrid. Similar results were also obtained for specimens expressing morphological intermediacy between the taxa, L. complanatum and L. tristachyum and therefore possible hybrids of these two taxa. This result was completely unexpected in light of genome analysis in other pteridophytes. Due to the occurrence of regular meiosis in hybrids, cytological evidence cannot be used as a means of verifying hybridization, at least within Section Complanata of the genus Lycopodium.
THE EFFECTS OF MOLYBATE, TUNGSTATE ANDlxdON ALDEHYDE OXIDASE AND XANTHINE DEHYDROGENASE INDROSOPHILA MELANOGASTER
Authors: Bentley M. M. , Williamson J. H. , Oliver M. J.
Published: November 2014

The effects of dietary sodium molybdate and sodium tungstate on eye color and aldehyde oxidase and xanthine dehydrogenase activities have been determined in Drosophila melanogaster. Dietary sodium tungstate administration has been used as a screening procedure to identify two new lxd alleles. Tungstate administration results in increased frequencies of "brown-eyed" flies in lxd stocks and a coordinate decrease in AO and XDH activities in all genotypes tested. The two new lxd alleles affect AO and XDH in a qualitatively but not quantitatively similar fashion to the original lxd allele. AO and XDH activity and AO-CRM levels appear much more sensitive to mutational perturbations of this gene-enzyme system than do XDH-CRM levels in the genotypes tested.
CYTOLOGICAL STUDIES IN KRIGIA (ASTERACEAE)
Authors: Chinnappa C. C.
Published: November 2014

The genus Krigia Schreb. consists of nine species representing diploid and polyploid taxa. Karyotype morphology and meiotic pairing of chromosomes for five species are described. Krigia cespitosa (2n = 8) and K. biflora (2n = 10) are diploids. Krigia montana with 2n = 20 is a tetraploid. Diploid and tetraploid forms of K. virginica with 2n = 10 and 20 were also studied. Krigia dandelion 2n = 60 is a high polyploid species.
INHERITANCE OF ALLOZYMES IN ATLANTIC HERRING (CLUPEA HARENGUS HARENGUS)
Authors: Kornfield Irv , Gagnon P. S. , Sidell Bruce D.
Published: November 2014

Progeny from single pair crosses of Atlantic herring were examined to determine the heritability of genetic variation at seven polymorphic allozyme loci. Mendelian inheritance of codominant autosomal alleles was established for IDH-2, LDH-1, LDH-2, ME-2, PGM-1, and PGI-2. This demonstration of Mendelian inheritance is essential for accurate interpretation of allozymic variation among natural populations of this pelagic species.
THE DEVELOPMENTAL ANALYSIS OF ALDEHYDE OXIDASE ACTIVITY INCINALLELIC HETEROZYGOTES OFDROSOPHILA MELANOGASTER
Authors: Bentley M. M. , Williamson J. H.
Published: November 2014

Aldehyde oxidase (AO) activity has been determined at 11 stages during the development of selected cin allelic homo-, hemi- and heterozygotes in Drosophila melanogaster. The AO activity levels found during development were completely consistent with the levels previously reported for adults, less than 24 h of age (Bentley and Williamson, 1979b). All of the cin homo- and hemizygotes tested exhibited no significant levels of AO activity at any of the 11 stages during development. All cin allelic heterozygotes, which were defined as complementing in adults, less than 24 h of age, displayed similar levels of complementation at all stages tested. Conversely, all cin allelic heterozygotes which were defined as noncomplementing in adults, less than 24 h of age, were found to lack measurable AO activity at all developmental stages tested.
THE EXPRESSION OF COLD HARDINESS IN TRITICUM SPECIES AMPHIPLOIDS
Authors: Limin A. E. , Fowler D. B.
Published: November 2014

A total of 18 amphiploids wre produced from interspecific crosses involving T. durum Desf., T. dicoccum Shrank., T. araraticum Jakubz., T. ventricosum Ces., T. aestivum L. em. Thell. and T. tauschii (Coss.) Schmal. The amphiploids and their parents were evaluated for cold hardiness to determine its expression in the synthetic hexaploid reconstituting the ABD genome of common wheat and in other genomic combinations. Cold hardiness of the parents was not additive in the artificially produced amphiploid; rather, the expression of cold hardiness was dependent upon the specific combining ability of the parents. None of the amphiploids exceeded the most hardy T. durum parents in cold hardiness. The poor general combining ability of the synthetic amphiploids suggests that the addition of the D genome of T. tauschii to the AB genome of tetraploid wheat would not have given the original hexaploid wheats a significant initial cold hardiness advantage. From the results of this study it appears more probable that the high level of cold hardiness present in the hexaploid wheats evolved through genetic mutation and/or recombination followed by selection at the hexaploid level.
GENETIC REGULATION OF HETEROGENETIC CHROMOSOME PAIRING IN POLYPLOID SPECIES OF THE GENUSTRITICUM sensu lato
Authors: McGuire Patrick E. , Dvořák Jan
Published: November 2014

Polyploid species of Triticum sensu lato were crossed with Triticum aestivum L. em. Thell. cv. Chinese Spring monotelodisomics or ditelosomics that were monosomic for chromosome 5B. Progeny from these crosses were either euploid, nullisomic for 5B, monotelosomic for a given Chinese Spring chromosome, or nullisomic for 5B and monotelosomic simultaneously. The Chinese Spring telosome in the hybrids permitted the evaluation of autosyndesis of chromosomes of the tested species. In addition, several Chinese Spring eu- and aneuhaploids were produced. Genotypes of T. cylindricum Ces., T. juvenale Thell., T. triunciale (L.) Raspail, T. ovatum (L.) Raspail, T. columnare (Zhuk.) Morris et Sears, T. triaristatum (Willd.) Godr. et Gren., and T. rectum (Zhuk.) comb. nov. were all shown to have suppressive effects on heterogenetic pairing in hybrids lacking 5B or 3AS, whereas T. kotschyi (Boiss.) Bowden had no effect. It was concluded that diploid-like meiosis in these species is due to genetic regulation. A number of these genotypes promoted heterogenetic pairing in the presence of 5B. A model is presented to explain this dichotomous behavior of the tested genotypes. Monotelosomic-3AL haploids had a greater amount of pairing than did euhaploid Chinese Spring, which substantiated the presence of a pairing suppressor(s) on the 3AS arm. Evidence is presented that shows that T. juvenale does not have a genome homologous with the D genome of T. aestivum.
THE EFFECT OF TELOMERIC HETEROCHROMATIN FROM SECALE CEREALE ON TRITICALE (× TRITICOSECALE). I. THE INFLUENCE OF THE LOSS OF SEVERAL BLOCKS OF TELOMERIC HETEROCHROMATIN ON EARLY ENDOSPERM DEVELOPMENT AND KERNEL CHARACTERISTICS AT MATURITY
Authors: Gustafson J. P. , Bennett M. D.
Published: November 2014

The relationships between telomeric heterochromatin on rye (Secale cereale L.) chromosomes, the occurrence of aberrant endosperm nuclei early during endosperm development, and kernel characteristics as seen at maturity were investigated in hexaploid spring triticale (× Triticosecale Wittmack). A positive relationship was established between the presence of telomeric heterochromatin on the short arms of rye chromosomes 4R/7R and 6R, and the production of aberrant endosperm nuclei. The removal of telomeric heterochromatin blocks from either 4R/7R or 6R significantly reduced the occurrence of nuclear instability in endosperm, and the effect of losing more than one block of telomeric heterochromatin was additive. A strong relationship was also noted between the absence of telomeric heterochromatin blocks on the short arms of rye chromosomes 4R/7R and 6R, and both higher thousand kernel weight and test weight at maturity. This relationship was also additive depending on whether one or two blocks of telomeric heterochromatin were missing. The absence of telomeric heterochromatin blocks on 4R/7R and 6R was significantly related with increased yield. The results show that amount of telomeric heterochromatin on some rye chromosomes is closely related to the occurrence of aberrant endosperm nuclei early during endosperm development and kernel characteristics at maturity.
LINKAGE RELATIONSHIPS AMONG 19 POLYMORPHIC ALLOZYME LOCI IN COASTAL DOUGLAS-FIR (PSEUDOTSUGA MENZIESII var. MENZIESII)
Authors: El-Kassaby Y. A. , Sziklai O. , Yeh F. C.
Published: November 2014

Linkage relationships among 19 different polymorphic loci in coastal Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco) were studied. A total of 115 of 171 possible two-locus combinations were tested. Out of the 115 combinations, a total of 106 conform to the hypothesis of independence between loci indicating that no linkage exists between these pairs. Of the remaining nine pairs, two were tightly linked with recombination frequencies of 0.02 (Aat2:Pgi2) and 0.22 (Aat3:Sod). The remaining were loosely linked, with recombination frequencies varying between 0.33 and 0.42. Two of these nine linked pairs have been detected in other conifer species. It was not possible to study three-point linkages due to the lack of appropriate combinations. To our knowledge, these results provide the first demonstration of genetic linkage in Douglas-fir.
α-AMANITIN RESISTANCE IN THREE WILD STRAINS OF DROSOPHILA MELANOGASTER
Authors: Phillips J. P. , Willms J. , Pitt A.
Published: November 2014

Three wild strains of D. melanogaster have been identified which are resistant to normally lethal levels of the fungal toxin, α-amanitin. Dietary LD50s for Oregon-R, the reference strain, and Ama-KTT, Ama-MI and Ama-KLM, the resistant strains, are 1.2, 35, 30 and 10 μg α-amanitin/vial, respectively. Resistance in all three strains is a digenic trait, being determined by two independently acting dominant genes, Ama-1, Ama-2, either of which is sufficient to confer resistance and which are located at approximately 18.8 and 100.7, respectively, on chromosome 3. Resistance to α-amanitin in all three strains is apparently not mediated by modification of RNA polymerase form II nor by failure of toxin transport or by toxin inactivation.
CINNAMON: A MUTANT OF JAPANESE QUAIL
Authors: Fulton J. E. , Roberts C. W. , Cheng K. M.
Published: November 2014

From a population of Japanese quail homozygous for brown plumage, three chicks hatched with light orange-brown down and red eyes. Genetic tests showed that this color dilution was inherited as a simple autosomal recessive trait. This new plumage mutation was called cinnamon (cin).
NULL MUTANTS OF THEAANDaMATING TYPE ALLELES OFNEUROSPORA CRASSA
Authors: Griffiths A. J. F.
Published: November 2014

Thirty-five null mutants have now been obtained of the A mating type allele, which have simultaneously lost both known functions-heterokaryon incompatibility and sexual compatibility with strains of the opposite mating type, a. The mutants, designated Am, were obtained by selecting for heterokaryon compatibility following UV-irradiation of the normal A. Twenty-five of the mutations were viable as homokaryons. Both functions reverted together when two of these were irradiated. In most respects, Ammutations resemble the previously reported ammutations in their behavior. The Ammutations differ, however, in failing to produce illegitimate empty perithecia in crosses with testers of the same mating type from which they originated. — The previously obtained ammutants were characterized further. It was confirmed that these ammutants show abortive mating reactions, legitimate and illegitimate, with several tester strains, thus showing that such reactions are fundamental properties of the mutants themselves. In support of this, it was shown that the A-like behavior of amstrains in the illegitimate reaction is not due to acquisition of determining elements through cytoplasmic contact with A in heterokaryons. It is possible that the sterile ammutants can be carried through a cross by a fertile heterokaryotic partner, but an extended study of meiotic products presumed to stem from this process confirmed that if such a process occurs it can involve no recombination on linkage group I. The single fertile ammutant was shown to have normal recombination on L.G.I. Escape from (A + a) incompatibility was shown to be possible in the identical heterokaryon used for aminduction. Escape cannot be ruled out as a source of nonrecoverable ammutations.
ON THE Y CHROMOSOME OF THE MURRAH BUFFALO (BUBALUS BUBALIS)
Authors: Yadav B. R. , Balakrishnan C. R.
Published: November 2014

Unequivocal identification of the Y chromosome of the Indian river buffalo (Bubalus bubalis) was not possible by conventional techniques as it could not be distinguished from the small acrocentric autosomes. Based on C-band characteristics and relative length measurements, it is proposed that the Y chromosome is not the smallest acrocentric but is intermediary in length between the 19th and 20th pairs. Supporting evidence to this hypothesis accrues from G-banding.
CHROMOSOMES OF CHINESE SPRING WHEAT CARRYING GENES FOR CROSSABILITY WITH BETZES BARLEY
Authors: Fedak George , Jui Perry Y.
Published: November 2014

Chromosome substitution lines of the variety Hope in Chinese Spring (Triticum aestivum L.) were crossed onto Betzes barley (Hordeum vulgare L. emend. Lam.). Three substitution lines of Hope involving chromosomes 5A, 5B, 5D gave no seed-set indicating that their counterparts in Chinese Spring were responsible for crossability with barley and that they function in complementary fashion. Other chromosomes of Hope had minor effects on crossability with barley.
SEX LINKAGE OF THE GLUCOSE 6-PHOSPHATE DEHYDROGENASE LOCUS IN THE FLOUR BEETLE TRIBOLIUM CASTANEUM
Authors: Dawson Peter S. , Hollingsworth Nancy M.
Published: November 2014

A locus involved in determination of glucose 6-phosphate dehydrogenase (G6PDH) phenotypes in Tribolium castaneum Herbst has been mapped on the X chromosome. Data from a three-point linkage experiment yielded estimated map distances of 10.2 ± 1.4 for red-pygmy and 19.2 ± 1.8 for pygmy-G6PDH, placing G6PDH between the pokey and blob loci. Tribolium castaneum joins mammals and possibly Drosophila as animals with sex-linked G6PDH. It seems difficult to attribute this to chance.
CHROMOSOME PAIRING AND ASSOCIATIONS AT MEIOSIS IN HAPLOID SOYBEAN (GLYCINE MAX)
Authors: Crane C. F. , Beversdorf W. D. , Bingham E. T.
Published: November 2014

Nine haploid plants (2n = 20) of soybean (Glycine max [L.] Merr.) (2n = 40) were examined for meiotic chromosome pairing. At pachytene, from 0 to 6 regions of apparent chromosome pairing were observed per cell. From 0 to 4 bivalents per cell were observed at diakinesis and 0 to 5 at MI-AI. Secondary associations were commonly observed at MI-AI, although these may have been artifacts of chromosomal stickiness. The degree of pairing suggests considerable duplication of the soybean genome, indicative of polyploidy. The haploids were obtained from genetic male-sterile (ms1/ms1) seed parents. All the haploids produced coenocytic microspores, a characteristic also common in the ms1/ms1, diploid genotype, which indicated that the haploids were hemizygous for ms1 and were of parthenogenetic origin.
MenNC1: A PUTATIVE REGULATORY MUTANT OF NADP-MALIC ENZYME INDROSOPHILAMELANOGASTER
Authors: Williamson John H.
Published: November 2014

MenNC1was isolated from a wild-type population as a putative NADP-Malic enzyme null-activity mutant. Detailed analysis of this mutant revealed that MenNC1homozygotes exhibit 3 to 5% of normal levels of NADP-ME activity throughout development. NADP-ME purified from MenNC1homozygotes is not different from NADP-ME purified from a standard wild-type strain when electrophoretic mobility, molecular weight, substrate kinetics and temperature optima are compared. Quantitative rocket immunoelectrophoresis has demonstrated reduction of NADP-ME-specific protein in MenNC1homozygotes proportionate to activity levels. It is suggested that MenNC1may represent a regulatory locus controlling levels of NADP-ME in Drosophila.
PROTEIN PROFILES OF FLAX GENOTROPHS
Authors: Fieldes Mary Ann , Tyson Hugh , Marriott David
Published: November 2014

Protein profiles of partially purified protein extracts from main stem tissue of Durrant's L and S flax (Linum usitatissimum L.) genotrophs were examined with one and two dimensional electrophoresis on acrylamide gels. The purification retained mainly glycoproteins. Among this reduced spectrum of plant proteins, some of the proteins separated had relative mobility (Rm) shifts between L and S. For two proteins, the Rm shifts were demonstrated in two-dimensional separations using mixtures of the L and S extracts. The Rm shifts were all in the same direction, the S protein ran slightly slower than the corresponding L protein, in both dimensions. This shift direction agreed with previous studies on Rm shifts with peroxidase and esterase isozymes and with similar shifts in acid phosphatase isozymes.
ENZYME HETEROZYGOSITY ASSOCIATED WITH GROWTH AT DIFFERENT DEVELOPMENTAL STAGES IN OYSTERS
Authors: Singh Shiva M.
Published: November 2014

Following our earlier reports on one-year-old oyster populations of Prince Edward Island (Singh and Zouros, 1978, 1981; Zouros et al., 1980), cohorts of three-year classes were studied from Cape Breton, Nova Scotia. Random samples of about 200 individuals from each year class were analyzed for four polymorphic enzymes. A number of generalizations emerged. There was a general deficiency of heterozygotes in the three age groups and this deficiency decreased with age (reflecting reduction in heterozygote deficiency). This suggests genotype-specific mortality during ontogeny. The deficiency of heterozygotes was more pronounced in slower growing, lighter individuals than in faster growing, heavier individuals. The number of heterozygous loci per individual was positively correlated with mean growth rate. The variance in weight was lower in heterozygotes; it decreased with increase in number of heterozygous loci in a given age group. Overdominance in growth rate appears to be the most plausible explanation for these observations.
PARENT-OFFSPRING REGRESSION IN REED CANARYGRASS: METHODS FOR PARENT AND OFFSPRING EVALUATION AND THEIR EFFECT ON HERITABILITY ESTIMATES
Authors: Casler M. D.
Published: November 2014

Parent-offspring regression is a common technique for estimating narrow sense heritability of quantitative characters in crop species. However, regression of progeny means on parent values evaluated in the same or similar environments may lead to biased heritability estimates. This bias arises from genotype × environment and error covariances between parents and progenies. This research dealt with the effects of these covariances on parent-offspring regression heritability estimates for several characters of reed canarygrass (Phalaris arundinacea L.). Biases to expected values of heritability due to these covariances were usually in the positive direction, supporting previous research. In this study, the genotype × location interaction covariance usually had the greatest bias effect, indicating that parents and progenies should be evaluated at least at separate locations to improve parent-offspring heritability estimates.
TIGHT LINKAGE OF TWO SEEDLING MUTANTS IN EARLY-FLOWERING TURNIP RAPE (BRASSICA CAMPESTRIS)
Authors: Hawk J. A.
Published: November 2014

A tight linkage was discovered between two seedling mutants in early-flowering forms of turnip rape Brassica campestris L. A green hypocotyl mutant, allelic to the previously reported a-2 gene, was found to be linked to a mutant characterized by wrinkled leaves and jagged petal margins, jp. The jp gene is an addition to linkage group I. The utilization of these two mutants for instructional purposes is discussed.