bluuebunny/crossref_metadata_2025 huggingface dataset:
A REVISION OF MUTATION BREEDING PROCEDURES IN ARABIDOPSIS BASED ON A FRESH ANALYSIS OF THE MUTANT SECTOR PROBLEM
Authors: Harle J. R.
Published: November 2014

The M2 progeny of a small number of mutagen-treated seeds (0.5% diethyl sulfate in water for 1 hr at 30 °C.) were examined in detail in petriplate culture to clarify the relationship of the morphogenesis of the inflorescence to the production of mutants for selection. All detected mutant individuals were cultured to maturity on minimal medium and re-examined in the M3 generation. The data showed that the incidence of mutational events was predicted by a Poisson distribution calculated on the basis of 0.78 mutations per M1 plant. Sector size was calculated on the basis of the frequency of mutant seedlings derived from the self-pollinated flowers, and was estimated as 87% of the tissue of a flower, and as 12% of the tissue of an inflorescence. This corresponded to 8.52 sectors per inflorescence, and therefore to eight or nine cells in the multicellular embryo of the treated seed. One hundred and seventeen viable mutants were detected in this work, although forty of them were sterile. Fifty-two mutations affected leaf colour, and twenty-five affected morphology. No definite evidence was produced about the incidence of lethal mutations, as inviable plants were found with similar frequency in both treated and control material. A scheme for mutagenesis research and mutation breeding in Arabidopsis was suggested, involving the culture of all M2 seedlings from the main inflorescence of each treated plant.
LEAF ESTERASE ISOZYMES INAVENAAND THEIR RELATIONSHIP TO THE GENOMES
Authors: Craig Iris L. , Murray Beatrice E. , Rajhathy Tibor
Published: November 2014

Leaf esterase patterns of natural populations of diploid, tetraploid and hexaploid Avena species were separated by disc electrophoresis. The zymotypes of the A genome diploids A. hirtula, A. strigosa and A. longiglumis differed from the C genome diploids A. pilosa and A. ventricosa. The tetraploids A. barbata, A. magna and A. murphyi had distinctive zymotypes. The A. barbata zymotype resembled the A genome diploids which supports the cytological evidence for homoeology between the genomes. Avena magna and A. murphyi were a combination of the A and C diploid patterns with A. murphyi resembling the C more than the A pattern. The zymotypes of the hexaploids A. sterilis and A. sativa revealed the expected A, C and AC genome ancestry. Band affinity ratings within and between genomic groups agreed with the cytological evidence and cross-compatible relationships, the exception being the C — AC species that have high affinity ratings but are apparently cross-incompatible.
CHROMOSOME RELATIONSHIPS OF TRIFOLIUM UNIFLORUM TO T. REPENS AND T. OCCIDENTALE
Authors: Chen Chi-Chang , Gibson Pryce B.
Published: November 2014

The relationships of Trifolium uniflorum L. (2n = 32) to T. repens L. (2n = 32) and T. occidentale Coombe (2n = 16) were studied by determining chromosome associations at metaphase I in interspecific hybrids. In a hybrid between T. uniflorum and autotetraploid T. occidentale the number of quadrivalents was 2.81. In four plants of the hybrid T. repens × T. uniflorum the number of quadrivalents ranged from 0.58 to 2.25. The presence of quadrivalents in the hybrids indicates that T. uniflorum, T. repens, and T. occidentale may share a similar genome.
GENETIC ANALYSIS OF COLEOPTILE ELONGATION IN BARLEY
Authors: Verma M. M. , Virk D. S. , Singh S. B.
Published: November 2014

The magnitude of heterosis, heterobeltiosis, relative magnitude of variances for general combining and specific combining ability, components of variation and the graphic analysis in a five-parent diallel cross in barley revealed the predominance of a non-additive nature of gene action for coleoptile elongation in barley. Further studies to reveal the non-allelic gene interaction are indicated.
ACTIVITY AND RELATIVE MOBILITY OF PEROXIDASE ISOENZYMES IN GENOTROPHS AND GENOTYPES OF FLAX (LINUM USITATISSIMUML.)
Authors: Fieldes M. A. , Tyson H.
Published: November 2014

Acrylamide gel electrophoresis was used to separate anionic peroxidase isoenzymes in genotypes and genotrophs of flax. Activities and relative mobilities were measured directly from the separations on the gels.The effects of growth of one flax genotype in soil supplemented by either nitrogen, phosphorus and potassium (NPK) or nitrogen and potassium (NK) on subsequent generations of its progeny produced by complete selfing were studied. Both activity and relative mobility of anionic peroxidase isoenzymes displayed effects of fertilizer treatments applied in previous generations. NPK increased the relative mobility of all isoenzymes, while depressing the activity of at least three of them. Successive generations of growth in NPK produced approximately linear increases in relative mobility. Such environmentally induced heritable changes were detectable five generations later.Two other flax genotypes were crossed, and relative mobility and activity of anionic peroxidase isoenzymes were examined in both parents and F2progeny. Between parents, there were differences in relative mobility for two of the four isoenzymes; their F2hybrids showed intermediate mobility for these particular isoenzymes. There were no differences between reciprocal F2hybrids for mobility or activity of any isoenzyme. The parents differed in activity in all four isoenzymes; the F2hybrids displayed dominance towards the lower activity parent for each of the isoenzymes.Total anionic isoenzyme activity was highly correlated with gross peroxidase activity measured prior to electrophoretic separation.
PHYLOGENETIC AFFINITIES IN TRITICINAE STUDIED BY THIN-LAYER CHROMATOGRAPHY
Authors: Dass H. C.
Published: November 2014

Thin-layer chromatography was used to assess the phylogenetic affinities in Triticinae. Leaf phenolics of Aegilops speltoides, Ae. bicornis, Ae. squarrosa, Triticum monococcum, T. dicoccoides, T. dicoccum and T. aestivum ssp. spelta were screened on cellulose coated plates. The chromatographic data were analysed statistically and a similarity index (biochemical distance) calculated. This index corresponded most closely with conventional concepts of affinities. T. dicoccoides and T. dicoccum were found to be closer to Ae. bicornis than to Ae. speltoides which suggests that Ae. bicornis is more probably the B genome donor. The contribution of the D genome by Ae. squarrosa was further confirmed. Correlation between the two tetraploids T. dicoccoides and T. dicoccum as well as with T. aestivum was high. Among the Aegilops species studied, Ae. speltoides most closely resembled T. monococcum. Low affinity in terms of the biochemical distance of T. monococcum with emmer wheats and T. aestivum throws doubt upon its direct contribution of the A genome.
END-TO-END ATTACHMENT OF HAPLOID CHROMOSOMES OF ORNITHOGALUM VIRENS
Authors: Ashley Terry , Wagenaar E. B.
Published: November 2014

The three prophase chromosomes in the haploid nucleus of Ornithogalum virens pollen are attached end-to-end in an open chain. This lends support to the suggestion that the ring configuration, in which homologous chromosomes lie opposite one another in somatic cells, is involved in recognition and pairing of homologues during meiotic prophase. It is also suggested that affinity of ends may be a general property of plant chromosomes.
EFFECTS OF GAMMA RADIATION ON THE CHROMOSOMES OF GRYLLIDAE (ORTHOPTERA)
Authors: Lim H.-C. , Kevan D. K. McE. , Vickery V. R.
Published: November 2014

Six species of Gryllidae — Gryllus assimilis, G. bimaculatus, G. pennsylvanicus, Acheta domesticus, Scapsipedus marginatus and Allonemobius allardi — were subjected to gamma radiation treatment (dosages varied from 1000 rads to 2446 rads) in order to induce chromosomal abnormalities. Gamma radiation was found to affect development, survival and reproduction. Effects of gamma rays were similar in all of the species studied, but sensitivity varied between the different species.
ASSOCIATION OF CHILDREN'S DISEASES IN FAMILIES FROM RECORD LINKAGE DATA
Authors: Simpson Nancy E. , Alleslev L. Jane
Published: November 2014

A method is described for determining which diseases cluster more frequently in families as indicated by data drawn from a large population of linked family records. First, a screening test determined which diseases were distributed differently in sibs than in the general population using a chi-squared test. Fisher's exact test was used for two subsequent analyses to handle the small expected values for affected sibs. One analysis identified index diseases which occurred more frequently than expected in the sibs of index cases and the other test identified which diseases other than those of the index case were actually associated with index diseases.The methods were tested-using data from a "Registry for Handicapped Children and Adults" and the vital registrations for the Canadian province of British Columbia, which had been linked by computer into family groups by Newcombe. The index disease occurred more frequently than expected in sibs for erythroblastosis, strabismus, immaturity, post-natal asphyxia and atelectasis and mental deficiency. Familial associations which had not been previously reported were: erythroblastosis with diseases of the digestive system, strabismus with diseases of the nervous system and sense organs, immaturity with both diseases of early infancy and stillbirths, post-natal asphyxia and atelectasis with stillbirths, congenital malformations of the digestive system with other congenital malformations and mental deficiency with diseases of the respiratory system.The shortcomings of the data are discussed, and instances in which the results are not conclusive, or are not readily interpretable, but are indicative of possible interesting problems in need of investigation, are noted.
MORPHOLOGICALLY DISTINCTIVE X CHROMOSOME IN THE FEMALE CHROMOSOME COMPLEMENT OF THE RABBIT
Authors: Martin-DeLeon Patricia A.
Published: November 2014

Further evidence is provided to support the classification of the X chromosome of the domestic rabbit as one which is medium-sized with a sub-metacentric centromere. In female metaphase plates, one X chromosome may be easily identified by its striking heteropycnosis, smoothness of outline, thinner chromatid arms in relation to others in the complement, and peripheral or near-peripheral location. Occasionally a kink is seen midway along its long arm.
INTERPRETATION OF SEX CHROMOSOMAL RNA SYNTHESIS IN THE OPOSSUM, DIDELPHIS VIRGIMANA
Authors: Schneider Lawrence K.
Published: November 2014

RNA synthetic activity is detectable in both sex chromosomes of cultured lymphocytes from male and female opossums (Didelphis virginiana). The possibility that this synthesis may represent genetic activity in the sex chromosomes is discussed. A hypothesis is presented which suggests translocation of autosomal material to sex chromosomes in the evolution of D. virginiana from D. marsupialis. This hypothesis might also explain some or all of the many other unusual cytogenetic characteristics of D. virginiana.
THE COMBINED EFFECT OF CHEMICAL MUTAGEN AND VIRUS ON DNA REPAIR, CHROMOSOME ABERRATIONS AND NEOPLASTIC TRANSFORMATION
Authors: Stich H. F. , Hammerberg O. , Casto B.
Published: November 2014

The combined effect of chemical mutagen and oncogenic virus was examined by exposing cultured cells of Syrian hamsters to 4-nitroquinolin-1-oxide (4NQO) and human (AD12) or simian (SA7) adenovirus. The level of DNA repair synthesis, frequency of chromosome aberrations, and neoplastic transformation were used as parameters. The combined application of 4NQO and virus did not alter the level of DNA repair, had a cumulative effect on the frequency of metaphases with chromosome aberrations and produced an up to 23-fold enhancement of viral induced cell transformation.
THE BLACKBERRY MUTANT OFSORDARIA FIMICOLA
Authors: Pollock Robert T. , Johnson Gregg A.
Published: November 2014

The blackberry mutant of Sordaria fimicola is characterized by sparse mycelium, bands of darkly pigmented hyphae radiating from the colony edge toward the center, premature protoperithecium development, the collection of a mass of ascospores in a droplet of water at the tip of the perithecium, and the inhibition of perithecium development in a wild-type colony at the line of intersection with a mutant colony. The gene is 10.5 map units from the tan ascospore color mutant. The blackberry inhibitor is a low-molecular weight compound which blocks the development of wild-type perithecia less than 36 hr old. Inhibitor secretion by blackberry decreases rapidly 24 hr after perithecium development begins.
CONSTITUTIVE HETEROCHROMATIN IN MOUSE CHROMOSOMES TREATED WITH TRYPSIN
Authors: Ray M. , Hamerton J. L.
Published: November 2014

Chromosome preparations from three sublines of mouse L-cells (A9, B82 L60) were made by conventional air-drying methods and the slides treated both by trypsin digestion and the C-banding methods, in order to investigate and compare the distribution of constitutive heterochromatin in these cells. Comparisons were also made with human and Chinese hamster cells. The mouse heterochromatic sites observed, including the interstitial sites found on the marker chromosomes, were similar for each line irrespective of the method used. The interstitial heterochromatic sites in the marker chromosomes 1 and 3 correspond to the locations of the secondary constrictions. The trypsin digestion method reveals the sites of constitutive heterochromatin in mouse chromosomes, but not in human or Chinese hamster chromosomes. All mouse chromosomes could be distinguished from those of Chinese hamster in the hybrid cells between mouse and Chinese hamster cell lines. The method is simple to use and therefore will facilitate the identification of mouse chromosomes within and between the cell populations of different origins and within cell hybrids.
TEMPERATURE EFFECTS ON COMPLEMENTATION PATTERNS AT THEAD-3BLOCUS OFNEUROSPORA CRASSA
Authors: Griffiths A. J. F. , Hale J.
Published: November 2014

Three out of ten randomly selected base-pair substitution mutations of the ad-3B gene show altered complementation patterns at 37 °C. One other ad-3B mutant is auxotrophic only at 25 °C, partially reverting to wild type at 37 °C. It is thus formally cold-sensitive. One other mutant is leaky at 25 °C, but fully auxotrophic at 37 °C. All these effects are attributable to the temperature-sensitivity of protein conformation.
CHROMOSOMAL POLYMORPHISM AND INTER-RELATIONSHIPS IN PISSODES WEEVILS: ADDITIONAL CYTOGENETIC EVIDENCE OF SYNONYMY
Authors: Smith S. G.
Published: November 2014

Chromosome comparison and crossability tests compel relegating 6 of 10 Hopkins' Pissodes taxa to synonymy, namely, utahensis with similis Hopk., nigrae and alascensis with rotundatus Lec., fraseri and piperi with dubius Rand., and curriei with affinis Rand. Two, dubius and rotundatus, and possibly a third, affinis, of the four valid species revealed meiotic markers of semi-incompatibility not previously encountered; presumably, as in the strobi complex, the fourth, similis, is merely devoid of the necessary chromosomal diagnostic.
INHERITANCE OF OIL AND PROTEIN CONTENT IN A DIALLEL CROSS OF SESAME (SESAMUM INDICUML.)
Authors: Murty D. S. , Hashim M.
Published: November 2014

Ten self-pollinated lines of Sesamum indicum L. of diverse ecogeographic origin were crossed in all possible combinations to make a complete diallel cross and analysed to determine gene action controlling oil and protein content. The overall parental and hybrid means for oil did not differ significantly whereas for protein content the overall hybrid mean was significantly less than that of the parents. Significant maternal effects were also detected for protein content. Both oil and protein content were found to be governed by additive as well as dominance gene action, the latter playing a major part. Non-allelic interactions of a complementary nature were detected for both the characters in the Wr/Vrgraphs. Dominance was mostly for higher oil content and lesser protein content. Ratios of average dominance in the range of overdominance were obtained for both the characters. Heritabilities of 23 and 30% were obtained for oil and protein content respectively.
VARIATIONS IN GENETIC ARCHITECTURE AT DIFFERENT DOSES OF γ-RADIATION AS MEASURED BY LONGEVITY INDROSOPHILA MELANOGASTER
Authors: Westerman Jane M. , Parsons P. A.
Published: November 2014

Longevity (as a measure of resistance to irradiation) has been examined after different doses of60Co γ-rays, in four inbred lines and their hybrids in D. melanogaster. The control data showed some additive and non-additive effects. At 40, 60, 80, 100 and 120 krads, non-additive effects were highly significant, but additive effects were significant only at 100 and 120 krads, in particular the latter. Thus the genetic architecture varies with dose. Detailed genetic studies probably are simplest to carry out at high doses, because of the importance of additive effects.
REPRODUCTIVE ERRORS IN ANEUPLOIDS: GENERATION OF VARIANT EXTRA-CHROMOSOMAL TYPES BY TOMATO PRIMARY TRISOMICS
Authors: Rick Charles M. , Gill Bikram S.
Published: November 2014

Primary trisomics of the tomato spawn an array of other primary trisomics as well as such modified types as secondary, tertiary, and telo-trisomics and primary tetrasomics. Five useful, previously undescribed trisomic types were thereby obtained. Although the frequency of deviant types is very low, they can be readily screened from the total population by their markedly differing phenotypes. It is therefore feasible to obtain specific desired types of aneuploids by systematically seeking them in progenies of the corresponding primary trisomic. The data suggest, although they are not sufficiently extensive to prove, that the deviating aneuploids tend to have shorter chromosomes of the tomato complement as their extra elements and tend to be more frequent in the progeny of trisomics for the shorter chromosomes. Cytological studies of triplo-5, the most prolific source of deviants, revealed a substantial frequency of laggards and chromosomes otherwise behaving abnormally at anaphase of both meiotic divisions, thus suggesting mechanisms to account for the origin of the deviant aneuploids.
SPORADIC (GqGq) TRANSLOCATIONS IN DOWN'S SYNDROME
Authors: Ying K. L.
Published: November 2014

Ten cases of Down's syndrome with sporadic (GqGq) translocations have been encountered in the author's laboratory over the past 8 years. The application of quinacrine banding technique on nine available cases revealed that in each instance two 21 chromosomes were involved in the translocation.
KARYOLOGY OF NORTH AMERICAN NATRICINE SNAKES (FAMILY COLUBRIDAE) OF THE GENERA NATRIX AND REGINA
Authors: Kilpatrick C. William , Zimmerman Earl G.
Published: November 2014

Four species of the water snake genus Natrix have a distinctly different pattern of chromosomal morphology than found in two species of the related genus Regina. Natrix all have a karyotype with seven pairs of large or medium-sized submetacentric autosomes, three pairs of medium-sized subtelocentric autosomes, and seven pairs of small metacentric autosomes. All have a 2n of 36 with a submetacentric Z and submetacentric or subtelocentric W. The autosomal complement of Regina consists of seven pairs of large to medium-sized submetacentrics, five pairs of medium-sized submetacentrics, and five pairs of small metacentrics. The Z and W are both submetacentric chromosomes. The sex chromosomes are easily distinguished in both genera. The relationships of Natrix and Regina and Old World Natrix are discussed, as well as chromosomal variation in closely related species in the family Colubridae.
PERICENTROMERIC CHROMOSOME BANDING IN HIGHER PLANTS
Authors: Stack S. M. , Clarke C. R.
Published: November 2014

By using a modified Giemsa staining technique, which is thought to indicate the presence of repetitive DNA, pericentric heterochromatin was stained in the chromosomes of two plant species, Plantago ovata and Allium cepa. Apparently in plants, just as in animals, there is a tendency for constitutive heterochromatin and repetitive DNA to associate with chromosome centromeres.
CYTOPLASMICALLY INHERITED ETHIDIUM BROMIDE RESISTANCE IN SUPPRESSIVE PETITES OF SACCHAROMYCES CEREVISIAE
Authors: Bech-Hansen N. T. , Rank G. H.
Published: November 2014

Neutral petites were induced in three different [rho+] strains by treating with ethidium bromide. However, EB treatment of spontaneously generated suppressive petites, which were derived from the same [rho+] strains, produced no neutral petites and moreover had little or no effect on the suppressiveness of the petities. Genetic analysis showed that the ethidium bromide resistance of the suppressive petites was a manifestation of cytoplasmically inherited, respiratory deficiency.
INHERITANCE OF STEM RUST RESISTANCE TRANSFERRED FROM DIPLOID WHEAT (TRITICUM MONOCOCCUM) TO TETRAPLOID AND HEXAPLOID WHEAT AND CHROMOSOME LOCATION OF THE GENE INVOLVED
Authors: Kerber E. R. , Dyck P. L.
Published: November 2014

Resistance to stem rust (Puccinia graminis Pers. f. sp. tritici Eriks. and and E. Henn.) was transferred from diploid wheat, Triticum monococcum L. cv. RL 5244, to Stewart tetraploid and Marquis hexaploid cultivars by interspecific hybridization. Genetic studies at the diploid, tetraploid and hexaploid levels indicated that a dominant gene gave resistance to the seven races of rust tested. Differential transmission of this gene was noted in some of the intradiploid and intrahexaploid crosses. The degree of resistance, as indicated by infection type, decreased with increasing levels of ploidy. This newly identified gene, designated Sr22, is located on chromosome 7A and is different from resistance genes Sr8, Sr13 and Sr15, which are also on chromosomes of the A genome.
CHROMOSOME PAIRING IN HEXAPLOID HYBRIDS FROM BROMUS ERECTUS (2n = 28) × B. INERMIS (2n = 56)
Authors: Armstrong K. C.
Published: November 2014

Meiotic chromosome pairing was studied at metaphase I of B. erectus (2n = 28), B. inermis (2n = 56) and interspecific hybrids from B. erectus × B. inermis (2n = 42). The B. erectus material averaged 2.08 IV + 0.11 III + 9.51 II + 0.35 I and B. inermis 0.05 VIII + 0.06 VI + 0.02 V + 2.25 IV + 0.11 III + 22.95 II + 0.25 I. The hybrid plants (2n = 42) averaged 0.18 VI + 1.90 IV + 0.19 III + 16.10 II + 0.39 I and one hybrid with 2n = 41 averaged 0.08 VI + 0.02 V + 0.95 IV + 0.50 III + 17.42 II + 0.72 I. Karyotype evidence supported the conclusion that B. erectus was an autotetraploid. The karyotype contains four large satellites and four subterminal chromosomes but the other four groups of four are median, with one group possibly a submedian. Since chromosome pairing in the hybrids was complete and the quadrivalent frequency in the parents and hybrids was similar, it was concluded that the genomic formula of B. erectus, B. inermis, and the hybrid was AAAA, AAAABBBB, and AAAABB, respectively.
MATERNAL AGE EFFECT ASSOCIATED WITH YELLOW PIGMENT IN MALPIGHIAN TUBES OFDROSOPHILA MELANOGASTER
Authors: Nickla Harry
Published: November 2014

Using chromatographic and fluorometric methods a maternal age effect was demonstrated which involves yellow pigment accumulation in the Malpighian tubes of light (lt) flies. As age of females (lt+/lt and lt/lt) increases, yellow pigment accumulation in lt/lt offspring increases. The influence of maternal age is most dramatic in young females aged 1 to 5 days prior to mating. In addition, fertility decreases as maternal age increases. A medium effect was noted whereby females reared on fresh medium produce lt/lt offspring with slightly more yellow pigment in their Malpighian tubes than offspring of females reared on "worked" medium. The opposite effect was observed for fertility. Results are discussed in terms of accumulation of pteridines (and closely related compounds) as females age and changes in RNA and DNA content in the eggs of aging females.
FACTORIAL GENETIC ANALYSIS OF A TWO-LOCUS SYSTEM IN BARLEY
Authors: Jana S.
Published: November 2014

Backcross-derived homozygous lines of Atlas barley, isogenic except for two unlinked loci, A/a and B/b, each with two alleles, were crossed to produce five heterozygous genotypes. The nine possible genotypes were then used for detailed quantitative genetic studies at various stages in the life cycle of the plant. Components of genotypic variation attributable to additive, dominance and epistatic effects of genes were estimated by the use of the factorial genetic method. The relative magnitudes of these components for a single character were found to change considerably with the age of the plant and they also changed from character to character at the same age. Additive genetic effect, particularly of the A/a locus was the largest component of genotypic variation in the first 6 weeks of growth of the seedling. Epistasis was important at the very early stage of growth, but decreased strikingly in size at a time immediately following jointing. In general, the A/a locus was found to be genetically more active than the B/b locus for a number of metrical characters. Dominance effect of the A/a locus was responsible for about 50% of the total gene controlled variability for grain yield.
STUDIES ON THESALLOCUS INDROSOPHILA PSEUDOOBSCURA. III. THE MOLECULAR PATTERN OF DNA IN ACTIVE AND INACTIVE CHROMOSOME REGIONS
Authors: Gersh Eileen Sutton
Published: November 2014

The banding pattern at the tip of salivary gland chromosome 3 in Drosophila pseudoobscura is determined by a nearby locus, sal (salivary). A number of cytological changes in the neighborhood of the sal locus have been obtained. Their effects on the appearance of bands are interpreted in terms of the fine structure of the chromosome and the arrangement of the DNA double helix. Bands as viewed in the light microscope may become dispersed, as in puffs, or compacted, as in position effects involving their transposition to heterochromatic regions. Changes of bands are interpreted in terms of dispersion or compaction of DNA.Secondary puffing is induced in a paired sal chromosome which does not puff when unpaired, by a sal+homologue which puffs when unpaired. This is explained as being due to osmotic effects caused by added protein and gene products (RNAs) diffusing from the sal+to the sal chromosome, when they are paired, through submicroscopic interconnecting spaces within the chromosomes.
CYTOGENETIC, ECOLOGIC AND MORPHOLOGIC STUDIES IN BRAZILIAN FORMS OF PASPALUM NOTATUM
Authors: Fernandes M. Irene B. De Moraes , Barreto I. L. , Salzano F. M.
Published: November 2014

The somatic number, meiotic behavior, morphology and ecology of five forms of Paspalum notatum are reported. All of them showed a chromosome number of 2n = 40. There is a fair degree of variation in the frequencies of meiotic chromosome configurations in different strains of a given form, but for four of the five we could characterize them as showing about 2-3 IV and 14-16 II. The type Capivari presents distinct differences in relation to all others, with about 1 IV and 18 II. The prevalence of I and III is very low (about 0.1) in all forms investigated. The morphological and ecological data, in a general way, confirm the difference between Capivari and the other taxons.
A SUMMARY OF LINKAGE RELATIONSHIPS AND A REVISED LINKAGE MAP OF THE CHICKEN
Authors: Etches R. J. , Hawes R. O.
Published: November 2014

The literature pertaining to linkage relationships in the chicken has been reviewed. A new linkage map is proposed consisting of 13 linkage groups. In cases where nomenclature has been duplicated, new symbols are proposed. A tabular summary of linkage tests which have shown independent segregation is included.
THE DESIGN AND ANALYSIS OF GENETIC EXPERIMENTS TO MODIFY GENOTYPE-ENVIRONMENT INTERACTION. I. SINGLE PAIR MATINGS AND SELECTION USING ONE SIMPLE QUANTITATIVE ATTRIBUTE MEASURED IN TWO ENVIRONMENTS
Authors: Scheinberg Eliyahu
Published: November 2014

Most breeding programs are aimed at producing quantitative changes in the genetic structure of the population in question. Available theory and designed experiments have failed to show how to modify the expression of genotype-environment interaction and assume that it is negligible or is not present.This paper considers the design of an experiment to test the feasibility of modifying this interaction and gives the necessary formulae to evaluate the results. It suggests that a number of genetic groups, say each with 2n full-sibs, should be equally divided into two random sub-groups and placed in different environments, e.g., two nutritional or climatic levels. One environment is where the parents and the first group of n randomly chosen offspring are reared continuously and the other environment is the one in which the second group of offspring is reared from birth. A criterion is then established for a selection program based on the performance differential of the same simple quantitative attribute measured in full-sibs reared in the two environments. This scheme can be employed for selecting for this criterion in three directions. Extensions of these theoretical considerations for the cases of more than one simple quantitative attribute, part-whole correlated attributes, indirect selection and more complicated designs will follow.
INCREASED CHIASMA FREQUENCY IN DESYNAPTTC BARLEY IN RESPONSE TO PHOSPHATE TREATMENTS
Authors: Fedak George
Published: November 2014

The treatment of desynaptic genotypes in barley with a high rate of mineral phosphate resulted in a significant increase in the frequency of bivalents per cell as a result of an increase in the chiasma frequency.
INATE AND PHOTO-CONTROLLED MITOTIC RHYTHMS IN ONION ROOT-TIP CELLS
Authors: Bishop Richard C. , Klein Richard M.
Published: November 2014

A four-peaked diurnal rhythm in mitotic activity of dark-grown onion root-tip cells is initiated upon seed imbibition, damps rapidly and is lost within 5 days. It is abolished by continuous white fluorescent light, by continuous blue, green or red radiation, by low temperatures, high osmotica or anoxia. Photoperiodic light controls the well-known two-peaked persistent rhythm. The nature of the zeitgeber for either the inate or the photoperiodically-controlled rhythms is unknown.
INHERITANCE OF A SPONTANEOUS VIRESCENT MUTANT IN COMMON WHEAT (TRITICUM AESTIVUM L.)
Authors: Gilmore E. C. , Tuleen N. A.
Published: November 2014

A spontaneous virescent mutant was found segregating in progeny of an F2 plant from the cross of two hard red spring wheats, II-54-30/Pitic 62. The mutant was completely recessive in the F1. F2 and backcross segregations support the hypothesis of a single locus conditioning phenotype. The homozygous mutant is normal green at 30 C and practically devoid of chlorophyll at 18 C. Very little additional chlorophyll is developed in virescent tissue when later subjected to higher temperatures. The mutant appears similar to Neatby's virescent but likely is different because seedlings of Neatby's had little chlorophyll at 30 C while this mutant was normal green.
LOCALISATION DE MUTANTS mal DANS LA REGION malB DU CHROMOSOME DE ESCHERICHIA COLI
Authors: Chung Y. S. , Hamelin C. , Donch J. , Greenberg J.
Published: November 2014

Analysis of the cotransductional frequencies of malB alleles, resistant or sensitive to lambda (λ), with outside markers metA exrA uvrA, and the probability of recombinations between these alleles indicate that the order of markers in this region of the Escherichia coli chromosome is arg metA malB λs (PAM 201) malB λs (MPEI) malB λr (P10) malB λr (B) exrA uvrA. Evaluation of the maltose permease activity shows that there is no correlation between loss of permease activity and resistance to λ at the malB locus.
LATERAL SUBUNITS IN C-BANDS OF UNREPLICATED CHROMOSOMES OF DISSOSTEIRA CAROLINA (L.) (ORTHOPTERA:ACRIDIDAE)
Authors: Bregman A. A.
Published: November 2014

The C-banding pattern is described for the chromosomes of the grasshopper Dissosteira Carolina (2n♂ = 24, ♀ = 23; XX-XO). Each of the 24 acrocentric chromosomes has a prominent C-band at the centromeric region and most chromosomes have a less prominent C-band at the distal telomeric region. Usually, one or more pairs of chromosomes has a C-band in the short arm. The C-band at the centromeric region appears to be composed of two lateral subunits in unreplicated meiotic chromosomes at anaphase II and telophase II in a number of secondary spermatocytes and in unreplicated mitotic chromosomes at anaphase in several spermatogonia. The C-band at the distal telomeric region appears similarly divided in unreplicated chromatids at anaphase I and metaphase II in several spermatocytes. The lateral subunits may be an artifact or may reflect the presence of a dual structure at C-banded regions.
THE BIARMED CHROMOSOMES OF MOUSE CELL LINE LMTK–
Authors: Rushton Alan R.
Published: November 2014

Staining for fluorescent bands and centromeric heterochromatin showed that normal mouse chromosomes could be identified as specific arms in most of the biarmed chromosomes of the mouse cell line LMTK–. Seven marker chromosomes were also characterized. The karyotype was heterogeneous with an average of 9.4 biarmed chromosomes per cell. Five specific biarmed chromosomes were present in at least 90% of the cells examined. The results indicate the presence of both relatively stable and highly variable components in the in vitro karyotype. Evidence is presented which indicates that the biarmed chromosomes have been formed by reciprocal translocation, centric fusion with retention of both centromeres, and centromeric misdivision with isochromosome formation.
MEIOTIC STUDY ON SUPERNUMERARY MICROCHROMOSOMES OF RED FOX (VULPES VULPES)
Authors: Ward E. J. , Lin C. C. , Johnston D. H.
Published: November 2014

Numerical variation of microchromosomes between animals has been confirmed for somatic cells and shown in meiotic material. Nucleolar organizers on the supernumeraries were demonstrated by attachment of nucleoli at the heterochromatin of accessory bivalents. Two types of supernumeraries may segregate in the fox, one of which probably has two structural forms. Precocious separation of accessories was noted at diakinesis.
GENIC ANALYSIS FOR PEROXIDASE ISOZYMES AND THEIR ORGAN SPECIFICITY INORYZA PERENNISANDO.SATIVA
Authors: Pai Chiang , Endo Toru , Oka Hiko-Ichi
Published: November 2014

Peroxidase zymograms of the leaf blade, leaf sheath and lemma-palea were observed in progeny of crosses between strains of Oryza perennis Moench and O. sativa L. Bands OC, 2A, and 4A were found to be specified by codominant alleles, Px1OC, Px12A, and Px14A, respectively. These alleles produced hybrid bands 1A and 3 A in their heterozygotes. Regarding band 4C specified by Px24C, (independent of Px1), it was found that a perennis strain (W120-4, derived from an Indian natural population) had the band in the leaf sheath only, while another (W120-5, from the same population) showed it in the leaf blade only. Observations of their selfed progenies and hybrids suggested that there were two independent dominant genes repressing band 4C, one (RLB4C) acting in leaf blade and the other (RLS4C) acting in leaf sheath. On this basis, the organ-specific intensity variations of the 4C band observed in four different crosses could also be explained. These genes were considered to be "regulatory genes" repressing the activity of Px24C.
THE CHROMOSOME NUMBER OF THE YEASTHANSENULA WINGEIOBSERVED IN MITOSIS AND MEIOSIS
Authors: Crandall Marjorie , Robinow C. F.
Published: November 2014

Four chromosomes were observed at mitosis in haploid as well as diploid strains and four bivalents were observed at meiosis in the diploid. Therefore it is assumed that a) the haploid number of chromosomes in H. wingei is four and b) somatic pairing occurs in the diploid.
A GENETIC STUDY OF EGG LAYING OF TRIBOLIUM IN OPTIMAL AND STRESS ENVIRONMENTS
Authors: Orozco Fernando , Bell A. E.
Published: November 2014

As a potential biological model of non-additive gene effects, the polygenic trait egg lay was studied in the unselected heterogenous Consejo Base Population of Tribolium castaneum in three environments: optimum (33 °C), mild stress (38 °C), and severe stress (28 °C). The measured variable was number of eggs laid by virgin females during the peak period of 7-11 days after adult emergence.Egg lay was highest in 33° (18.5 ± 0.1), followed in order by 38° (14.8 ± 0.1) and 28° (12.9 ± 0.1). Similar phenotypic variances in the optimum and mild stress environments were twice those observed in severe stress. Estimates for additive gene effects were larger than those for non-additive effects, but their relative amounts varied with environments. Heritability of egg lay was highest in the optimum environment (0.36 ± 0.03), followed by mild stress (0.30 ± 0.03) and severe stress (0.25 ± 0.03). The reverse was true for estimates of non-additive gene effects where 28° > 38° > 33° with values of 0.15, 0.09 and 0.04, respectively. All genetic correlations for egg lay in different environments were positive and large (0.69 ± 0.04 to 0.86 ± 0.02).The results suggest that egg lay in Tribolium, when observed in both optimum and stress environments, could provide an appropriate biological model for evaluating mating or selection schemes whose theoretical efficiencies vary with the relative importance of non-additive gene effects.
INTRASPECIFIC VARIATION OF NUCLEAR DNA CONTENT IN PINUS RESINOSA AIT.
Authors: Dhir Narinder K. , Miksche Jerome P.
Published: November 2014

Pinus resinosa displays a rather uniform phenotype over a relatively small geographic distribution with a 9-degree latitudinal spread. DNA quantity per cell from 20 seed sources collected throughout the growing range varied significantly by a factor of 2.2 from the lowest to the highest amount. A south-to-north increasing DNA gradient was not observed as reported previously for other members of the Pinaceae.
THE EFFECTS OF CYSTEAMINE AND AET Cl HCl ON THE INDUCTION OF MEIOTIC CHROMOSOME REARRANGEMENTS IN IRRADIATED MALE MICE
Authors: Savkovic N. , Pecevski J.
Published: November 2014

Two established chemical protective agents, β-mercaptoethylamine (cysteamine) and β-aminoethylisothiuronium (AET) Cl HCl were tested for their ability to induce chromosome translocations in totally irradiated mice with 600 R. The purpose of this investigation was to determine whether cysteamine and AET Cl HCl themselves induce reciprocal translocations and whether these chemical agents have an equally protective effect against X-ray-induced chromosomal translocations in the first meiotic metaphase. The incidence of translocations after whole-body irradiation with a 600 R was 9.07% in animals protected with cysteamine and irradiated; 3.68%; and in those protected with AET Cl HCl and irradiated with the same dose, 5.45%. Not a single chromosome rearrangement was recorded among the animals treated with cysteamine and AET without irradiation.
FURTHER STUDIES ON DIPLOPODIA. VI. SEGREGATION OF DIPLOPOD EMBRYOS FROM CHICKENS HETEROZYGOUS FOR BOTHdp-1ANDdp-3GENES
Authors: Taylor Lewis W.
Published: November 2014

Males heterozygous for both dp-1 and dp-3 genes in chickens fail to produce diplopod embryos in the expected proportion for a dihybrid ratio when mated to females heterozygous for both genes. When backcrossed to the parental diplopodia-1 and diplopodia-3 lines and when mated with singly heterozygous females derived from the original crosses, the doubly heterozygous males also fail to produce the expected numbers of dp-1 diplopods, but give normal ratios of dp-3 embryos. Females heterozygous for both genes transmit them to progeny in normal ratios.Calculations of effective male gamete segregations from backcross data, when applied to dihybrid segregations in inter se double heterozygote matings, approximate the actual proportion of diplopods obtained if deficiencies in male dp-1 gametes and a 9:6 embryonic survival ratio are assumed. Although the double recessive embryos are predominantly indicated by this test to die prior to identification as diplopods, fit of calculated to actual data suggests that some may survive to later developmental stages.Inheritance of diplopodia-1 exhibits a distortion in transmission of alleles having many features similar to genes at the T and Low loci in the male heterozygous house mouse. The aberrant segregation of the dp-1 gene in heterozygous male chickens represents a second case of this nature found in vertebrate animals.
HYBRID CHLOROSIS IN INTERSPECIFIC CROSSES OF OENOTHERA: POLYGENIC INHERITANCE OF THE NUCLEAR COMPONENT
Authors: Meer J. P. van der
Published: November 2014

Interspecific hybrids between Oenothera hookeri or O. elata and O. argillicola are severely chlorotic and die as seedlings because the chloroplasts of either species are unable to function in the presence of the chromosome complex inherited from the other (Stubbe, 1959; Stinson, 1960). In the present investigation the chromosome complex of O. argillicola was genetically partitioned into a number of small sets of chromosomes by means of backcrosses, and the chlorosis-inducing potential of these sets on chloroplasts of O. hookeri and O. elata was determined. The chlorosis-inducing potential of sets of O. hookeri and O. elata chromosomes on the chloroplasts of O. argillicola was determined in a parallel series of crosses.In both series the results indicated that the nuclear component of hybrid chlororis was polygenic. No individual foreign chromosome produced an observable degree of chlorosis while various combinations produced various degrees of chlorosis. In general, the level of the chlorosis paralleled the number of foreign chromosomes in the hybrid, the F-1 hybrid in each case being the most severely affected.
A KARYOTYPIC STUDY OF THREE SPECIES OF RAJIFORMES (CHONDRICHTHYES, PISCES)
Authors: Donahue C.S.C. William H.
Published: November 2014

A karyotypic study has been made of three species of Chondrichthyes of the order Rajiformes: the lesser electric ray (Narcine brasiliensis) of the Torpedinidae, and two stingrays, the Atlantic stingray (Dasyatis sabina) and the bluntnose stingray (Dasyatis sayi) of the Dasyatidae. The karyotypes were derived by a squash technique from gill epithelial cells after specimen injection with colchicine. The lesser electric ray has a diploid number of 28 (18 m, 4 sm, and 6 st), the smallest diploid count yet discovered in the Chondrichthyes. Both stingrays have a diploid count of 68. The Atlantic stingray has 28 m-sm and 40 st-t,; the bluntnose stingray has 34 m-sm and 34 st-t. The suggestion is made that these species may show a relationship to skates previously described in that they possess a similar number of chromosome arms. A preliminary note is made on the chromosome number of the Atlantic guitarfish.
MONOSOMIC ANALYSIS OF MUTANTS OF COTTON,GOSSYPIUM HIRSVTUML.
Authors: Kohel R. J. , Douglas C. R.
Published: November 2014

Monosomic analysis of 10 mutant loci in cotton, Gossypium hirsutum L., did not detect any new gene-chromosome associations. Twenty-five monosomic-mutant combinations, involving monosomics for chromosomes A1, A2, A4, A6, D17, and D18, were tested. The mutant loci tested were virescent-4, pale green, round leaf, glandless 2,3, Ligon lintless, dwarf red, withering bract, a new virescent mutant, and two new brown lint mutants.
ADDENDUM AND CORRECTION TO AN INVESTIGATION OF GENOTYPE × ENVIRONMENT INTERACTION IN RELATION TO A SELECTION EXPERIMENT IN TRIBOLIUM CASTANEUM
Authors: Malik S. , Friars G. W. , Raktoe B. L.
Published: November 2014

The analysis of the data of experiment 2 in the original paper (Canadian Journal of Genetics and Cytology, XIII, 1971, 144-154) was not exact, in that the indicator covariate was not introduced for each missing value. An analysis based on cell means has not changed any of the biological conclusions in the original paper.
THE CHROMOSOMAL COMPLEMENT OF THE YELLOW-CHEEKED VOLE:Microtus xanthognathus(Leach)
Authors: Rausch V. R. , Rausch R. L.
Published: November 2014

The karyotype of Microtus xanthognathus (Leach) is described, based on material from one female and one male vole. The diploid chromosomal number was found to be 54, and the fundamental number 62. The metacentric X-chromosome was of medium size and averaged 6.6% of the haploid complement. The designated Y-chromosome was near acrocentric. The specific distinction of M. xanthognathus and Microtus chrotorrhinus (Miller) was confirmed by the recognition of major differences in karyotype and differences in fundamental number. The distributional history of M. xanthognathus is briefly discussed.
CONSTITUTIVE HETEROCHROMATIN OF INDIAN MUNTJAC CHROMOSOMES REVEALED BY DNASE TREATMENT AND A C-BANDING TECHNIQUE
Authors: Kato H. , Tsuchiya K. , Yosida T. H.
Published: November 2014

A karyotype of a female Indian muntjac, Muntiacus muntjak vaginalis, was described. The karyotype was unique in that No. 1 and No. 3 homologous pairs were heteromorphic with respect to the size of their secondary constrictions. In these pairs, one of the homologs always had a longer secondary constriction than that on the corresponding homolog. Heterochromatin in the secondary constriction region was visualized with difficulty by a C-banding technique, but was demonstrated clearly by a DNase treatment followed by Giemsa staining, which also revealed the size difference of the secondary constriction. Centromeric constitutive heterochromatin of No. 1 chromosome was also found to differ in size between the homologs. On the basis of the heteromorphic character of No. 3 chromosome, or an X-autosome complex, it was possible to confirm autoradiographically that X-inactivation had occurred at random.
MONOSOMIC ANALYSIS OF GENES CONDITIONING STEM RUST RESISTANCE IN TWO COMMON WHEAT CULTIVARS
Authors: Sanghi A. K. , Baker E. P.
Published: November 2014

The single genes in the cultivars Morocco and Yalta conditioning resistance to stem rust culture 103-H-2, a somatic hybrid between wheat stem rust (Puccinia graminis tritici) and rye stem rust (P. graminis secalis) which possesses unusual genes for avirulence on wheat, were each located by monosomic analysis on chromosome 3B. They were estimated to be approximately 9 map units apart.
INFLUENCE OF SOURCE OF WHEAT CYTOPLASM ON THE SYNTHESIS AND PLANT CHARACTERISTICS OF HEXAPLOID TRITICALE
Authors: Hsam S. L. K. , Larter E. N.
Published: November 2014

Reciprocal F1 triticale hybrids (× Triticosecale Wittmack) produced from crosses between primary 6x amphiploids (C1) were synthesized that differed only in their source of cytoplasm. One member of each reciprocal pair possessed hexaploid (6x) wheat cytoplasm (Triticum aestivum L. em Thell), the other, tetraploid (4x) wheat cytoplasm (T. turgidum L.). Comparisons of agronomic and reproductive behavior were made between members of reciprocal F1 pairs. Initial embryo development, embryo survival in vitro, and survival of F1 wheat-rye hybrids were 10, 105, and 127% higher respectively when the female parent possessed 6x as compared with 4x wheat cytoplasm. Similarly, F1 amphiploids with 6x cytoplasm were 3.0% taller and developed 25.0% more fertile tillers than their genetically identical counterparts with 4x cytoplasm. Spike morphology and floret number were not found to be influenced by source of cytoplasm. As current triticale procedures require the synthesis of new wheat-rye amphiploids for the introduction of genetic variability, it is suggested that the utilization of 6x wheat cytoplasm would enhance such a program as well as improve the agronomic performance of triticales so synthesized.
INHERITANCE OF A VARIEGATED FOLIAGE CHARACTER IN RUSSIAN WILD RYEGRASS, ELYMUS JUNCEUS FISCH.
Authors: Lawrence T.
Published: November 2014

Segregation in population derived by crossing heterozygous progeny of Sc.260181, a variegated plant of Russian wild ryegrass, and Sc.25311, a normal plant, showed a 12 normal green:3 variegated:1 albino ratio indicating inheritance according to the dominant epistasis pattern for two factors.
ANALYSIS OF THE DIPLOID GERMLINE OF PLANTS BY MUTATIONAL TECHNIQUES
Authors: Rédei G. P.
Published: November 2014

Methods and pitfalls of analysis of the diploid germline are outlined. Attention is called to the fact that mutation recovery after seed-treatment is most effective when the maximal number of M1families are screened in minimal size M2.