bluuebunny/crossref_metadata_2025 huggingface dataset:
TRANSFER OF LEAF RUST RESISTANCE FROMAEGILOPS SPELTOIDESTOTRITICUM AESTIVUM
Authors: Dvořák J.
Published: November 2014

Five accessions of Aegilops speltoides resistant to race 5 of leaf rust were crossed and backcrossed four or five times to wheat cultivars Manitou and Neepawa. The resistance transferred from each accession to the recurrent parents appeared to be controlled by one incompletely dominant gene. Since a majority of resistant lines show complete chromosome pairing when heterozygous and segregate in a monofactorial ratio of 3 resistant to 1 susceptible, the Aegilops genes must be on wheat chromosomes. The present experiment shows that if extensive homoeologous chromosome pairing occurs in the F1hybrids, introgression can occur directly from a diploid into a hexaploid. The origin of polyploids in the Triticum-Aegilops polyploid complex is briefly discussed, and it is stressed that polyploidy is closely and inversely related to introgression. Whether introgression or polyploidy is going to occur depends largely on the genomic relationships and the extent of chromosome pairing in the F1hybrid.
ESTIMATION OF TIME OF DIVERGENCE FROM PHYLOGENETIC STUDIES
Authors: Chakraborty Ranajit
Published: November 2014

Recent studies with comparative data on base sequences of homologous DNAs or amino acid sequences of homologous proteins indicate that simultaneous estimation of phylogenetic structure and time of divergence is often cumbersome and time consuming. On the other hand, when the topology of an evolutionary tree is known, it is shown in this paper that the least squares theory may be applied to obtain simple estimates of the relative time lengths for each segment of the tree under the assumption of uniform random substitutions in each segment. The method is illustrated with amino acid sequence data on various globin molecules and cytochrome c. The evolutionary significance of some of the estimates is also discussed.
HYBRIDIZATION BETWEEN THE NEARCTIC ANOPHELES PUNCTIPENNIS AND THE PALEARCTIC ANOPHELES ATROPARVUS
Authors: Kreutzer Richard D.
Published: November 2014

Interspecific crosses were made between the Palearctic species Anopheles atroparvus Van Thiel and the Nearctic species A. punctipennis Say. Except for most of the X chromosomes, an inverted region in 3R, and band intensity differences the salivary gland chromosome banding patterns are the same in both species. Despite this high level of chromosomal homology very little synapsis of identically banded regions was observed in hybrid complements. This asynapsis and the fact that no adults were produced from either the cross or the reciprocal indicate that there are significant genetic differences between the species.
THE GENETIC CONTROL OF FLAVONOID SYNTHESIS IN MAIZE
Authors: Styles E. Derek , Ceska Oldriska
Published: November 2014

Two classes of flavonoid pigments commonly found in Zea mays are anthocyanins, which can be produced in almost any tissue, and phlobaphenes, which are found predominantly in the cob and pericarp. Chromatographic analysis of genetic stocks shows that the R locus controls the production of anthocyanins and other flavonoids hydroxylated at the 3-position, together with their precursors, and the P locus controls the production of C-glycosylflavones and their precursors; the 3-deoxyanthocyanins, and the phlobaphenes. The two pathways are controlled independently, even though there are some precursors common to both pathways. A scheme for the genetic control of flavonoid synthesis in maize is presented, and possible mechanisms for the independent control of the two pathways are discussed.
INHERITANCE OF LEAF PEROXIDASES IN OATS
Authors: Yen S. T. , Sadanaga K.
Published: November 2014

Starch gel electrophoresis of leaves of diploid, tetraploid, and hexaploid wild species as well as hexaploid cultivars and mutants of oats (Avena) disclosed several faint and three stable peroxidase bands, designated F, M, and S, in the anodal gel. The F band was observed only in the hexaploids, the M band in some diploid, tetraploid, and hexaploid species, and the S band in some diploid and tetraploid species. The inheritance was studied of banding patterns F+M, F, M, and Null observed in the cultivars. The hybrids had only the combined bands of both parents, as did the mixture of leaf juices. Genetic studies in the F1and F2populations of crosses among parents differing in the four banding patterns revealed that band F was controlled by a dominant gene and band M by one or two independent genes. A segregation ratio of 11F+M:4M:1F in the F2populations of a cross between F × M parents indicated that one of the genes controlling band M is allelic to and codominant with the gene controlling band F.
GENOMIC EFFECTS ON THE DURATION OF MEIOSIS IN TRITICALE AND ITS PARENTAL SPECIES
Authors: Roupakias D. G. , Kaltsikes P. J.
Published: November 2014

The effect of the D and R genomes on the duration of meiosis and its stages was studied in the following materials: 1. AABBDD (Triticum aestivum L. em. Thell.); 2. AABB (extracted from AABBDD); 3. AABBRR and AABBDDRR (× Triticosecale Wittmack); 4. AABBD; 5. ABRR; and 6. RR (Secale cereale L.). Genomes AB, D and R were the same irrespective of the material in which they were found. At 20 °C and continuous illumination meiosis lasted 32.8 to 44.5 h in the AABBDD; 44.1 to 44.6 h in the AABB; 46.4 to 51.3 h in the AABBRR; 43.6 h in the AABBDDRR; 44.5 h in the AABBD; 51.6 to 52.7 h in the ABRR and 52.6 h in the RR genotype. Addition of the D genome to the AABB and AABBRR genotypes resulted in (1) elongation of the stage of nucleolar fusion (2) shortening of the combined duration of zygotene and pachytene and (3) reduction of the total duration of meiosis in AABBRR while it had no effect on AABB. Addition of the R genome to AABB resulted in the elongation of the total duration of meiosis and its stages while it had no significant effect when added to AABBDD. It was concluded that the variation observed in the duration of meiosis and its stages among the various cereal genotypes studied was more likely due to genes carried by the D and R genomes rather than to simple changes in ploidy level or DNA content.
NULLISOMIC AND MONOSOMIC ANALYSES OF GENES CONTROLLING LEAF PEROXIDASES IN OATS
Authors: Yen S. T. , Sadanaga K.
Published: November 2014

Monosomics derived from oat cultivars 'Cherokee' (M monosomics) and 'Kanota' (MK monosomics) were used in an attempt to locate gene Px-5a and its allele Px-Sb that control leaf peroxidase bands F (fast) and M (median), respectively, and an independent gene, Px-6a, also controlling band M. M monosomics have band M, and MK monosomics have bands F and M. Nullisomic and monosomic analyses revealed that monosomic MK7 gave a peroxidase banding pattern consistently different from other MK monosomics. Monosomic progeny of MK7 had F and M bands, but nullisomic progeny had only the F band. Monosomic F1 hybrids between MK7 and Columbia (null) and MK7 and Garton 784 had only band F. These results suggested that Px-6a, controlling leaf peroxidase band M, was located on the monosome of MK7, and Px-5a and its allele, Px-5b, must be on a different chromosome. The monosome in MK7 is a SM chromosome.
STRUCTURAL REARRANGEMENTS OF CHROMOSOMES IN THE DOMESTIC CHICKEN: EXPERIMENTAL PRODUCTION BY X-IRRADIATION OF SPERMATOZOA
Authors: Wooster W. E. , Fechheimer N. S. , Jaap R. G.
Published: November 2014

In order to produce chicks heterozygous for structural aberrations of chromosomes, 67 hens were inseminated with semen that had been exposed to 1200 R of X-rays. A sample of 204 chicks was hatched and survived. Among these, 18 (8.9%) contained rearrangements comprising 19 translocations and one pericentric inversion. All 10 males and eight females heterozygous for rearrangements were fertile and transmitted these rearrangements to approximately half their hatched progeny. Each of the major chromosomes of the chicken karyotype, except number 6, was involved in one or more of the translocations. The pericentric inversion was of a segment of chromosome number 2.
INHERITANCE AND LINKAGE RELATIONSHIP OF NOTCHED KERNEL IN RICE (ORYZA SATIVA)
Authors: Pavithran K.
Published: November 2014

Studies on the genie interrelationship of Nk (notched kernel) in indica rice reveal that Nk is closely linked with Sh and inherited independently of CAP, Pr, Ps, Psh, Pig, Plm and Pla. The gene Sh has been assigned to the XIIth linkage group along with Nk. The significance of this new linkage relationship has been discussed in relation to the frequency of occurrence of notched kernel.
SEX-LIMITED AND SEX-MODIFIED GENETIC DEFECTS IN SWINE — CRYPTORCHIDISM
Authors: Sittmann K. , Woodhouse B.
Published: November 2014

Review of published data suggests that cryptorchidism in Chester Whites and Yorkshires is caused by completely penetrant, recessive genes at two autosomal loci; in Lacombes, multifactorial modes of inheritance are more plausible. Different genetic systems control presence of the trait vs. number of sides affected; left testes are retained more often in almost all samples. Contrary to previous claims prenatal viability of homozygous males and females is normal. Genes causing cryptorchidism are unlikely to affect many other malformations in either sex, but pleiotropy is suggested to extend to economic traits such as conformation in females.
RECOMBINATION VALUES AND THEIR ERRORS
Authors: Butler L.
Published: November 2014

Two four-point testcrosses comprising 87,000 tomato plants were grown and the data collected from 28 subgroups. Each subgroup consisted of 2,000 or 5,000 plants and should give a valid estimate of the three recombination values. The 28 values for each interval give more outlyers (23% are outside the 95% limits set by the standard deviation calculated by the binomial formula [Formula: see text]) than would be expected by chance. If each subgroup was regarded as the control and the other groups tested against this, then 42% of the time the two subgroups would be significantly different. It is suggested that there are many cases in the literature where this comparison has been made and the significant difference wrongly ascribed to treatment. While the causes of these changes in recombination value are unknown and therefore uncontrollable, they must be anticipated in all such studies. Control and treatment must be replicated enough that chance extreme values will not be attributed to treatment.
MITOTIC INSTABILITIES IN TETRAPLOID, HEXAPLOID, AND OCTOPLOID BROMUS INERMIS
Authors: Tan Geok-Yong , Dunn G. M.
Published: November 2014

Mitotic irregularities were observed in the root tip cells at three ploidies, tetraploid (4x), hexaploid (6x), and octoploid (8x), of smooth bromegrass (Bromus inermis Leyss.). These included endomitosis, fragments, chromosomes excluded from the spindle, anaphase bridges, laggards and micronuclei, at different stages of mitosis. High frequencies of anaphase irregularities were detected at the 4x and 6x levels. The commercial octoploid was more stable. Intraplant variations of some morphological characters in smooth bromegrass may be attributed to chromosomal instabilities in somatic cells.
CHROMOSOMES AND DNA OF MICROTUS II. CONFIRMATION OF DELETION OF CONSTITUTIVE HETEROCHROMATIN IN M. AGRESTIS CELLS IN VITRO
Authors: Cooper J. E. K.
Published: November 2014

The distribution of constitutive heterochromatin has been examined by C-banding in two somatic cell lines, grown in vitro, from a female Microtus agrestis. One line retains one intact X chromosome together with the short arm of the other X chromosome, while the other cell line retains only the short arm of one X chromosome. Thus, each cell line has lost substantial amounts of heterochromatin from the sex chromosomes, but this material has been deleted from the cells, and not translocated to other chromosomes. Nonetheless, both cell lines continue to propagate well in vitro.
DIFFERENTIAL GIEMSA STAINING IN PLANTS. V. TWO TYPES OF CONSTITUTIVE HETEROCHROMATIN IN SPECIES OFAVENA
Authors: Yen Sheng-Tian , Filion W. Gary
Published: November 2014

Modified ASG (Acetic/Saline/Giemsa) and BSG (Barium hydroxide/Saline/Giemsa) chromosome banding techniques applied to several diploid species of oats produced two distinct types of C-banding patterns. One pattern consisted mainly of centromeric bands with occasional telomeric and/or intercalary bands while the other was comprised only of prominent telomeric and intercalary bands. These two banding patterns which probably reflect two distinct types of constitutive heterochromatin resulted from a change in the HCl hydrolysis temperature prior to the application of the ASG or BSG technique; hydrolysis at 60 °C yielded the centromeric bands and hydrolysis at room temperature produced telomeric and intercalary bands. Since all species examined reacted in a similar manner, precise Giemsa banding patterns should now be possible for all or most species of oats.
INHERITANCE AND LINKAGE OF A MAGENTA FLOWER GENE IN SOYBEANS
Authors: Buzzell R. I. , Buttery B. R. , Bernard R. L.
Published: November 2014

Magenta flower color in soybeans (Glycine max (L.) Merr.) was found to be controlled by a mutant gene, wm, in the presence of W1which is the common gene for purple flowers. These two genes are closely linked (2.2 ± 0.7% recombination) and are members of what is proposed as Linkage Group 8. The wm reduces flavonol content of flowers and of leaves, and is a deleterious mutant in terms of photosynthetic rate and bean yield.
CHINESE HAMSTER CELL LINES RESISTANT TO THE CYTOTOXIC ACTION OF FLUORIDE
Authors: Mankovitz Ralph , Kisilevsky R. , Florian Marie
Published: November 2014

The proliferation and efficiency of colony formation of a Chinese hamster ovary cell line, CHO, was found to be inhibited by concentrations of fluoride ≥ 10−3 M. From mutagenized populations of CHO cells, clones were isolated that were from 1.6 to 13 times more resistant than the wild-type to the cytotoxic action of fluoride. The resistant clones were found to be stable in the absence of selection. The fluoride sensitivity of wild-type and fluoride resistant clones was not altered by changes in the pyruvate concentration in the culture medium, indicating that the cytotoxic effect of fluoride is not due to the action of fluoride on the glycolytic pathway. On the other hand, both the incorporation of3H-leucine into acid precipitable material and the distribution of polyribosomes were sensitive only to fluoride concentrations that were cytotoxic, suggesting that the molecular basis of fluoride induced cytotoxicity in both wild-type and fluoride resistant cells is the sensitivity of protein synthesis to fluoride. At concentrations of fluoride at which the wild-type cells are inhibited but fluoride resistant cells are not, the intracellular concentration of fluoride in the fluoride resistant cells was found to be 1/5 to 1/10 that of the wild-type, suggesting that fluoride exclusion is the basis for resistance in the resistant lines.
LINKAGE STUDIES INTRIBOLIUM CASTANEUM. XI. THE MAP POSITION OFCHARCOAL, A PSEUDOALLELE OFBLACK
Authors: Brown Eric , Sokoloff Alexander
Published: November 2014

Charcoal, (Chr), an autosomal dominant with recessive lethal effects is located in linkage group III in Tribolium castaneum (Herbst). Its map position has been determined in respect to aureate (au), light ocular diaphragm (lod) and black (b). The distances between the various genes vary, depending on the sex of the cross. The Chr ++/+ lod au ♂ × +lod au/+lod au ♀ crosses give the following recombination values: au-lod = 22.19 ±.42%, Chr-lod = 20.03 ±.40% and Chr-au = 41.28 ±.49%. The reciprocal crosses give au-lod 28.08 ±.45%, Chr-lod = 17.67 ±.38% and Chr-au = 44.11 ±.50%. For the larger distances encompassed by the Chr-au region the recombination values in the two sexes were not significantly different. For the shorter distances the recombination values were significantly higher in the males than in the females in the au-lod region. They were not found to be significantly different in the Chr-lod region probably because of difficulty in identifying lod and non-lod beetles in the presence of Chr. Tests of allelism indicate that Chr and black b are pseudoalleles which recombine at a different rate in the two sexes. Chr +/+b ♂ × +b/+b ♀ gave 0.07% recombinants, while the reciprocal cross gave 0.014% recombinants, a significant difference. The data suggest that the order of the genes in this linkage group is Chr - b - lod - au.
SEGREGATION OF "RED" AND "YELLOW" NEEDLE LESION TYPES AMONG MONOAECIOSPORE LINES OF CRONARTIUM RIBICOLA
Authors: McDonald G. I.
Published: November 2014

Monoaeciospore lines of Cronartium ribicola (J. C. Fisch. ex Rabenh.) segregated for needle lesion type to produce a pattern expected from a heterothallic rust. Published evidence and the segregation patterns both support the conclusion that C. ribicola is heterothallic. Segregation for homozygous off-types required further explanation. Aeciospore and urediospore "fertilization" of sporidial infections are hypothesized. The basis for these hypothesized modes of fertilization and the effect they would have on genetic analysis of C. ribicola are discussed.
A LIGHT-MICROSCOPIC STUDY OF SOME TRANSLOCATIONS IN ASPERGILLUS NIDULANS
Authors: Boothroyd E. R.
Published: November 2014

A cytological investigation of the ascomycete, Aspergillus nidulans (Eidam) Winter, was undertaken to test the feasibility of using simple light-microscopial techniques to study chromosome aberrations for the correlation of chromosomes and linkage groups in this genetically well analysed fungus. Pachytene chromosome analysis was not possible, because the chromosomes are very small, do not spread well when squashed, and show very little structural detail. Some catenations were seen at first metaphase in translocation heterozygotes either as dense masses or, more rarely, as open rings. Lagging chromosomes were also seen at low frequency in both first and second anaphase and telophase in translocation but not in control material. The limited evidence from the study shows that meiotic chromosome behaviour in Aspergillus nidulans heterozygous for reciprocal translocations is probably similar to that in some higher organisms. However, the species is not suitable for detailed cytological analysis, at least by the techniques employed.
THE ACTION OF THE INTENSIFIER (IN) GENE IN FLAVONOID PRODUCTION IN ALEURONE TISSUE OF MAIZE
Authors: Reddy Arjula R. , Peterson Peter A.
Published: November 2014

The intensifier (in) allele in the homozygous recessive condition, in the appropriate genetic background, accentuates the formation of anthocyanin pigments in the aleurone tissue of maize. In a comparative genetic analysis with In and in combinations of five gene loci of the anthocyanin pathway, A, A2, Bz, Bz2, and Pr, in single and double recessive condition, it was possible to determine the effect of in on the expression of these genes in terms of the quality and quantity of the accumulated pigments. It was found that the recessive in greatly increases the quantity of anthocyanins, 3-deoxy anthocyanins, and leucoanthocyanidins in appropriate genotypes. On the contrary, in did not cause any qualitative differences in the pigment composition. The in showed a dosage effect in increasing the pigment levels. Also, observations were made on the interaction pattern of in with certain controlling-element alleles of the En system. A significant increase in the pigment content was observed due to the in effect without any qualitative changes. The nature of in action and its position in the anthocyanin pathway is discussed in the light of these data.
THE CELL CYCLE OF AN ESTABLISHED CELL LINE OF THE MOSQUITO AEDES AEGYPTI
Authors: Baim Amy S. , Mukherjee Asit B.
Published: November 2014

The duration of the cell cycle and its four phases was determined for a cell line of the mosquito, Aedes aegypti (L.), using high-resolution autoradiography. The total cell cycle time is 12.5 h, with G1 comprising 1.66 h, S – 4.5 h, M – 3 h, and G2 3.33 h. These results are compared with those of other mosquito species.
THE CYTOGENETIC POSITION OFAVENA DAMASCENAAMONG THE DIPLOID OATS
Authors: Cahana H. , Ladizinsky G.
Published: November 2014

The diploid oat Avena damascena was successfully crossed with the diploids A. prostrata and A. strigosa. Chromosome pairing in A. strigosa × A. damascena hybrid indicated that the two parental species differ by three translocations. This hybrid also was completely sterile. The greater affinity of A. damascena to A. prostrata than to A. strigosa could be concluded from the smaller number of multivalents and the partial fertility of the A. prostrata × A. damascena hybrid. Although the number of chromosome rearrangements between A. damascena and A. strigosa was compatible with those found between A. prostrata and these two species, a marked difference in the frequency of the various translocations was noted. Predominantly bivalent pairing characterized the A. prostrata × A. damascena amphidiploid. The lack of segregation of a marker gene in the F2indicated conspicuous preferential pairing in this amphidiploid. A comparison of the number of bivalents per cell in this and in other amphidiploids involving the strigosa-like species suggests that the A. damascena genome has a high potential for preferential pairing.
INVITATION PAPER: PROBLEMS OF ASSESSING THE GENETIC IMPACT OF MUTAGENS ON MAN
Authors: Newcombe Howard B.
Published: November 2014

Available human data, of the kinds needed to assess the genetic harm to man from possible changes in his mutation rate, currently suffer from major limitations. In particular there is uncertainty about a) the total amount of hereditary disease, b) the fraction of this that is mutation-related and therefore likely to be increased in frequency as a result of exposures to elevated levels of environmental mutagens, and c) the severities of the mutation-related conditions and the collective public health importance of any anticipated increases in their frequencies. Standards of protection against environmental mutagens cannot be set on the basis of laboratory data alone, and more effort on the part of geneticists will need to be directed towards quantitative assessment of the impact of the mutagens in terms of human disease. The needs for relevant human data, and various deficiencies in the statistical information that is currently available, are discussed.
HYBRIDIZATION BETWEEN ANNUAL AND PERENNIAL DIPLOID SPECIES OF HELIANTHUS
Authors: Whelan Ernest D. P.
Published: November 2014

Hybrid characteristics, fertility and meiosis are described for the first interspecific hybrids to be obtained from crosses of the two perennial species (2n = 34) Helianthus giganteus and H. maximiliani with the annual species H. annuus (2n = 34). A single, highly pollen-sterile hybrid, H. giganteus × H. annuus cv. Krasnodarets, had abnormal meiosis with meiocytes containing univalents and multivalents. It was completely female sterile. The three H. giganteus × wild H. annus and four H. maximiliani × wild H. annuus hybrids had less than 5% normal pollen, and meiotic behavior suggested the presence of at least three interchanges and a paracentric inversion. Small quantities of seed were obtained by backcrossing with H. annuus cv. Saturn.
CORRELATION BETWEEN DIRECT AND MATERNAL GENETIC EFFECTS ON BODY WEIGHT IN MICE
Authors: Nagai J.
Published: November 2014

A new method to estimate the correlation between additive direct genetic effects (Ao) and additive maternal genetic effects (Am) on body weight was devised to apply to crossfostering data in mice. The correlation between Ao on body weight at 42 days (adult age) and Am on body weight at 12 days (preweaning age) was estimated as 0.561. The nature of this correlation was defined genetically.
CONSERVATION OF NUCLEOLUS ORGANIZER REGIONS DURING EVOLUTION IN SHEEP, GOAT, CATTLE AND AOUDAD
Authors: Henderson L. M. , Bruère A. N.
Published: November 2014

There are ten nucleolus organizer regions (NORs) in domestic sheep (Ovis aries L.), cattle (Bos taurus L.), goat (Capra hircus L.) and aoudad (Ammotragus lervia Blyth) and these are located terminally on chromosomes with homologous G-banding patterns. The similarity in number of nucleolus organizer regions in these species may indicate that their ribosomal DNA regions are infrequently involved in exchange events which could lead to different numbers of active nucleolus organizer regions. Other possible explanations of the conservation of number of nucleolus organizer regions in these species are discussed. The homology of NOR location in these species supports the idea that the Bovidae karyotype tends to be fairly stable apart from changes due to centric fusion events.
DIRECT GENETIC AND POSTNATAL MATERNAL GENETIC EFFECTS ON BODY COMPOSITION IN MICE SELECTED FOR BODY WEIGHT
Authors: Hayes J. F. , Eisen E. J.
Published: November 2014

Line crossfostering techniques were used to study differences among selected and control lines of mice in direct genetic and postnatal maternal genetic influences on preweaning (day 12) body weight and composition. The lines were selected for high (H6) and low (L6) 6-week body weight and the control line (C2) was maintained by random selection. There were positive correlated responses to selection in both direct genetic and postnatal maternal genetic effects on body weight and weights of all body components (P < 0.01) except for water and ash weight in H6. The correlated responses in postnatal maternal genetic effects were of the same order of magnitude as those in direct genetic effects. Correlated responses were greater in L6 than in H6. Correlated responses in direct genetic effects were positive (P < 0.01) for water percent in H6 and ether extract percent in L6, and negative (P < 0.01) for water percent and lean percent in L6. Correlated responses in postnatal maternal genetic effects were positive for ether extract percent and negative for water percent (P < 0.01). Correlated responses were far greater in L6 than in H6 and were greater for postnatal maternal genetic effects than for direct genetic effects. Analyses of covariance results indicated line differences in the relative growth rates of the body components.
GENOTYPE × ENVIRONMENT INTERACTIONS IN SMOOTH BROMEGRASS. I. YIELD
Authors: Tan Wai-Koon , Tan Geok-Yong , Walton P. D.
Published: November 2014

Twenty-one progenies and the parents of a 7 × 7 half diallel cross of smooth bromegrass (Bromus inermis Leyss.) were evaluated at four locations in Alberta in each of two years, for genetic variation and genetic by environment interactions in the expression of their yield potentials. Years, locations and their interactions were highly significant in the combined analysis of variance. Combining ability analysis revealed that general combining ability (GCA) and specific combining ability (SCA) were both important in the expression of yield, including spring, fall and annual yield, whereas GCA was more important than SCA for yield per area. Although the genotype × environment interactions were all highly significant, variation accounted for by combining ability effects was generally higher than the interaction effects of GCA and SCA respectively, with environments. High average GCA effects for spring, fall and annual yield were demonstrated for the clones UA5, UA9 and B42. These together with the high average SCA effects suggested that the three clones could be included in a synthetic to develop high yielding cultivars. The results suggested that recurrent selections involving multi-location and multi-year testing seems necessary in breeding for high yielding bromegrass cultivars in Alberta.
ELECTROPHORETIC VARIATION AND DIFFERENTIATION IN FOUR STRAINS OF DOMESTICATED RAINBOW TROUT (SALMO GAIRDNERI)
Authors: Busack Craig A. , Halliburton Richard , Gall G. A. E.
Published: November 2014

A total of 1462 rainbow trout (Salmo gairdneri Richardson) representing four California domestic strains, were examined electrophoretically at 24 gene loci to investigate the amount of genetic variability within strains and genetic differentiation between strains, relative to wild populations. Estimated heterozygosities of 0.071 to 0.134 were similar to those reported for wild populations and thus indicated that the domestic strains were at least as variable as wild populations. Genetic distances between strains ranged from 0.011 to 0.067, values typical of the level of differentiation observed between local conspecific populations in a variety of organisms. It was suggested that this high level of heterozygosity is due to mixing of populations in the strains' histories and perhaps also to balancing selection.
REDUCTION OF SENSITIVITY TO ULTRAVIOLET LIGHT IN EXCISION-DEFICIENT Escherichia coli STRAIN WP2 uvrA
Authors: Nestmann Earle R.
Published: November 2014

Mutants with increased resistance to UV light were isolated from Escherichia coli WP2 uvrA. Most of these isolates were designated as true or partial revertants of the uvrA− mutation. However, one class of mutants showed only a moderate increase in resistance to UV. The gene responsible for this phenotypic change is closely linked to the lac locus and has been designated the suuA gene (suppressor of uvrA).
SPERM SIZE ABNORMALITIES IN HOMOZYGOUS AND HETEROZYGOUS In(5)9Rk MICE
Authors: Hugenholtz A. P. , Bruce W. R.
Published: November 2014

Sperm abnormalities were scored in In(5)9Rk homozygotes, heterozygotes and in the inbred strains, C57BL/6J, C3H/HeJ, DBA/2J and JUFaCt, used to produce the heterozygotes. The sperm abnormalities of the inversion heterozygotes were remarkable, about 40% were either double-headed or abnormally large in size. The double-headed sperm had head dimensions similar to those of normal-sized sperm, but the large sperm heads were 1.2 times longer and 1.3 times wider and presumably had twice the usual nuclear volume. This observation suggests that the anaphase bridge formed in inversion heterozygotes resulting from the paracentric inversion may constitute an impediment to cytokinesis and may lead to two genomes being packaged into a single sperm. If this is a general phenomenon, sperm morphology may provide a useful screen for paracentric inversions.
COMPARISON OF FOUR METHODS OF SELECTION FOR RESISTANCE TO LEPTOSPHAERULINA BRIOSIANA IN ALFALFA
Authors: Hill Jr. R. R. , Leath K. T.
Published: November 2014

Three cycles of selection for resistance to Leptosphaerulina briosiana (Poll.) Graham &Luttrell were conducted in two alfalfa (Medicago sativa, L.) germplasm pools, MSA and MSB. Each germplasm pool was used to compare four methods of selection: phenotypic recurrent, half-sib family, full-sib family, and alternating generations of selfed family and half-sib family. Response to selection for resistance to L. briosiana was greater in MSA than in MSB. Differences between selection methods were not significant. Selection for resistance to L. briosiana generally increased resistance to Stemphylium botryosum Wallr., but the magnitude of the correlated response varied with germplasm pool and selection method. The initial selfed families in both germplasm pools were significantly less resistant to Colletotrichum trifolii Bain than the other family types. Resistance to C. trifolii increased with selfed family selection for resistance to L. briosiana in MSA but not in MSB.
TRYPTOPHAN-REQUIRING PARENTAL STRAINS YIELDSALMONELLA TYPHIMURIUM×ESCHERICHIA COLIHYBRID RECOMBINANTS WITH FUNCTIONAL TRYPTOPHAN OPERONS
Authors: Stetter Dennis W. , Middleton Richard B.
Published: November 2014

Crosses between an Escherichia coli Hfr trp strain and three Salmonella typhimurium F−trp strains produced some trp+hybrids in which the tryptophan operon is composed of genes from both parental species.
THE SAMPLING VARIANCE OF HERITABILITY OF AN INDEX
Authors: Lin C.Y.
Published: November 2014

A method was presented for the sampling variance of heritability of an index estimated by regression method. When the number of traits in the index is reduced to one trait, the formula derived is equivalent to Osborne and Paterson's estimation for the sampling variance of heritability for a single trait. A numerical example was given to illustrate the computation.
EXPERIMENTAL INVESTIGATION OF ERRORS OF HERITABILITY ESTIMATES IN INDEX SELECTION
Authors: Lin C. Y. , Pevzner I. , Friars G. W.
Published: November 2014

Three generations of index selection for the combined genetic gain in 13-day larval and 21-day pupal weight were carried out in each of three replicates in Tribolium castaneum. Five indexes were constructed using differing levels of heritability for larval weight (0.9, 0.7, 0.5, 0.3 and 0.1). The effect of parameter estimation errors, involving larval weight, on the efficiency of index selection was thus evaluated experimentally. The results from this experiment confirmed the theoretical expectations that errors of parameter estimation would affect the efficiency of index selection. The present study further showed that the overestimation of the parameters would affect the selection efficiency more than the underestimation. The combined gain was found to be realized mainly through genetic change in pupal weight, a trait with lower heritability.
ELECTROPHORETIC PATTERNS OF OAT PROLAMINES AND SPECIES RELATIONSHIPS IN AVENA
Authors: Kim S. I. , Mossé J.
Published: November 2014

Starch gel electrophoretic studies on seed prolamines of 17 different di-, tetra-, and hexaploid Avena species were undertaken to determine species relationships and the evolutionary process of the polyploids. Significant intraspecific variation was observed. Electrophoregrams of each species were obtained by superposing all the bands found in the same species and in total, 17 bands were observed. Clear differences were found between species in their patterns, which allowed determination of the bands specific to three genomes (A, C and D). Like the diploids, the tetraploids can be divided into two groups on the basis of electrophoretic patterns: A. barbata and A. magna-A. murphyi. It is evident that A. magna-murphyi group is derived from both the A and C genome species of diploids while A. barbata is derived from the A genome species only. The similarity between A. magna and A. murphyi was also confirmed. The hexaploids were derived from A. magna-murphyi group and a D genome ancestor although the last one is not discovered yet.
FAMILIAL MUTAGEN SENSITIVITIES: ARE THESE THE HALLMARKS OF MEIOTIC OR MUTATOR MUTANTS IN HUMANS
Authors: Hoar David I.
Published: November 2014

Mutagen hypersensitivity (MHS) has been found to be associated with abnormalities in DNA metabolic processes in many prokaryotic and eukaryotic organisms. The study of fibroblasts derived from humans with genetic diseases believed to have altered DNA metabolism, has also revealed patterns of MHS. In this paper results are presented that suggest MHS patterns unrelated to obvious disease can be inherited in a dominant fashion. As these individuals exhibiting MHS patterns have been observed in families with poor reproductive history, new syndromes, or ontogenetic problems (including malignancies) there may be a causal relationship between these events and the MHS. These events which may have a genetic basis appear as maternal or paternal effect mutants as the consequences are observed in reduced reproductive fitness or abnormal progeny. Since these effects are similar to the events precipitated by the meiotic or mutator mutants in Drosophila, it is specualted that the MHS patterns may be the hallmarks of such mutants in man.
ROUGH-TEXTURED: A FEATHER STRUCTURE MUTANT OF JAPANESE QUAIL
Authors: Roberts C. W. , Fulton J. E.
Published: November 2014

In a hatch from an experimental population of Japanese quail Coturnix coturnix japonica 13 chicks were noted to have down, whose handling texture was extremely rough. As adults the rough-textured feather phenotype was also apparent. Genetic analysis indicated this feather structure mutant is autosomal, recessive, and inherited in a simple Mendelian fashion. The symbol rt was assigned to the rough-textured gene. A maternal effect, reducing embryo viability, was noted in progeny from rt/rt female parents. A comparison between the morphologies of the rough-textured trait in the Japanese quail and the fray feathered trait as reported in the chicken suggests the two traits do not exhibit gene homology.
CLINAL VARIATION AT AN ESTERASE LOCUS IN LITTORINA SAXATILIS AND L. OBTUSATA
Authors: Newkirk Gary F. , Doyle Roger W.
Published: November 2014

Samples of Littorina saxatilis (Olivi) and L. obtusata (L.) were taken from populations in an estuary where selection for certain shell morphologies had previously been established. These samples were examined for allelic variation at a polymorphic esterase locus. The allelic variation in L. saxatilis was correlated with the distance from the mouth of the estuary. In addition two pairs of alleles in L. saxatilis each showed a significant correlation of frequency. The same pattern of variation in L. saxatilis was observed in another estuary. The allelic variation in L. obtusata was similar to that of L. saxatilis, but the correlation of allele frequency was not significant. It is tentatively concluded that the variation at the esterase locus of these two species is maintained by selection.
CHROMOSOMAL POLYMORPHISM IN CARDINALS CARDINALIS CARDINALIS
Authors: Bass Rebecca A.
Published: November 2014

Karyotypic analyses of Cardinalis cardinalis (Linnaeus) (Passeriformes: Fringillidae) reveal a diploid number of approximately 84. Three different karyotypes were observed resulting from polymorphism of one macrochromosome pair. It is suggested that the observed polymorphism resulted from a single pericentric inversion. Similarities between karyotypes of this species and those of Zonotrichia albicollis and Junco hyemalis are discussed.
MEIOTIC REGULATION IN TRITICALE: INTERACTION OF THE RYE GENOTYPE AND SPECIFIC WHEAT CHROMOSOMES ON MEIOTIC PAIRING IN THE HYBRID
Authors: Lelley T. , Larter E. N.
Published: November 2014

The influence of parental genotype on the chromosomal pairing relationships within the wheat and rye genomes of triticale (× Triticosecale Wittmack) was investigated. Nullisomic 3A/tetrasomic 3B and nullisomic 5B/tetrasomic 5D plants of the cultivar Chinese Sping wheat were pollinated with inbred strains of rye (Secale cereale L.), the latter being selected on the basis of their average chiasma frequency. The level of chiasma number in the F1 hybrids was found to be influenced by the genotype of both the wheat and rye parents. Homeologous pairing was increased in the wheat × rye hybrids produced from inbred rye parents that exhibited high chiasma frequencies. However, this relationship was modified depending upon the genotype of the wheat parent. Increased dosage of chromosome 3B of wheat was found to increase chiasma frequency. These findings suggest that the genetic constitution of a rye parent and its specific combining ability with a certain wheat genotype markedly affects meiotic behavior of triticale.
IDENTIFICATION OF A FACTOR IN MAIZE THAT INCREASES EMBRYO FATTY ACID UNSATURATION BY TRISOMIC AND B-A TRANSLOCATIONAL ANALYSES
Authors: Shadley Jeffery D. , Weber David F.
Published: November 2014

Trisomics and B-A translocations were utilized in Zea mays L. (maize) to detect a genetic factor(s) in the long arm of chromosome 5 expressing dosage effects which increases the fatty acid unsaturation level in embryos. In all lines analyzed, trisomic-5 embryos had significantly less oleic acid and significantly more linoleic acid than diploid sibling embryos. Oleic and linoleic acid levels were unaltered by trisomy of chromosomes 3, 4, or 6; thus, trisomy per se does not cause these changes. B-A translocations involving the long arm and the short arm of chromosome 5 were used to further locate this factor(s). Altering the number of copies of the short arm of chromosome 5 had no detectable effect on the fatty acids measured; however, altering the number of copies of the long arm of chromosome 5 produced the same alterations as trisomy of chromosome 5. Thus, this factor(s) is in the long arm of chromosome 5.
THE EFFECT OF HYDROXYUREA ON MEIOSIS AND GENETIC RECOMBINATION IN THE FUNGUSCOPRINUS LAGOPUS
Authors: Raudaskoski Marjatta , Lu B. C.
Published: November 2014

Treatment with hydroxyurea (HU) inhibits fruitbody development in Coprinus lagopus (sensu Lewis). The two most sensitive meiotic stages are mid-late premeiotic S phase and the pachytene-diplotene period. A 2 or 4 h treatment at mid-late premeiotic S phase arrests fruitbody development. If the same treatment is given at pachytene and diplotene, the fruitbody completes meiosis but the spores produced are inviable. The spores from fruit-bodies treated at pachytene appear to be normal whereas those treated at diplotene are empty because the four nuclei remain in the basidium. A 2 or 4 h treatment with HU during karyogamy causes a decrease in spore viability and a dramatic increase in recombination frequency. The same treatment at metaphase II or later stages causes little damage to fruitbody development or spore viability. The effects of HU on the meiotic cell cycle suggest that the drug exerts its effect by inhibiting the synthesis of deoxynucleotides.
BANDING PATTERNS IN MAIZE MITOTIC CHROMOSOMES
Authors: Ward E. J.
Published: November 2014

A procedure for chromosome banding in triticale has been shown to be equally effective on maize, Zea mays L., root tip chromosomes. Stocks of known knob constitution were used to demonstrate that differentially stained regions of C-banded mitotic chromosomes corresponded with knobs. The large knob and prominent chromomeres of abnormal chromosome 10 were also differentiated, as was the centric heterochromatin of B chromosomes. However, the large distal heterochromatic portion of the B was not differentiated by the procedure.
QUANTITATIVE STUDIES OF CYTOLOGICAL DAMAGE IN MOUSE TESTIS PRODUCED BY EXPOSURE TO HEAT
Authors: Cairnie A. B. , Leach K. E.
Published: November 2014

Damage in gonadal cells produced by exposure of the hindquarters of conscious male mice to water at temperatures up to 43 °C was studied by measuring the percentage of testicular cells which do not exclude trypan blue 4 h after exposure, sperm count up to ten wk later, and the percentage of morphologically abnormal sperm up to ten wk later. It was found that the percentage of cells stained with trypan blue was significantly increased by exposure for 0.5 h at 41 °C or 2 h at 37 °C. Sperm count and the percentage of abnormal sperm were affected by 0.5 h at 43 °C or 2 h at 40 °C, but not by lower temperatures. Since there is a high incidence of abnormal sperm after some heat treatments, the use of this assay for mutagen screening should be approached with caution.
DOUBLED HAPLOIDS FOR ESTIMATING ADDITIVE EPISTATIC GENETIC VARIANCES IN SELF-POLLINATING CROPS
Authors: Choo T. M.
Published: November 2014

In this study it was shown that besides additive and additive × additive genetic variances, additive × additive × additive genetic variance can also be estimated from a diallel experiment in which each cross is represented by a number of doubled haploid lines.
TRANSFER OF CYTOPLASMICALLY-INHERITED TRIAZINE RESISTANCE FROM BIRD'S RAPE TO CULTIVATED OILSEED RAPE (BRASSICA CAMPESTRIS AND B. NAPUS)
Authors: Beversdorf W. D. , Weiss-Lerman J. , Erickson L. R. , Machado V. Souza
Published: November 2014

Atrazine resistant biotypes of bird's rape Brassica campestris L. provided a potential source of cytoplasmically-inherited triazine resistance for cultivated oilseed rape. A back-crossing program was initiated to incorporate the cytoplasm of the triazine resistant bird's rape (2n = 20) into B. napus L. cv. 'Tower' (2n = 38) and B. campestris L. cvs. 'Torch' and 'Candle' (2n = 20). Three 38-chromosome progeny were identified among backcross1 (BC1) progeny of bird's rape × Tower (recurrent pollen parent). All BC1 progeny of all crosses between bird's rape (female) and cultivated oilseed rape (recurrent pollen parents) were resistant to post-emergence application of several triazines, including atrazine, cyanazine and metribuzin. In similar crosses using cultivars as the recurrent female parents, BC1 progeny were susceptible to triazines, which indicated the resistance was cytoplasmically inherited. Selection among BC2 progeny of all crosses for low erucic acid content in seed was effective. In field trials BC3's carrying cytoplasm from bird's rape were not injured by post-emergence applications of triazine herbicides which killed their recurrent cultivar pollen parents. No obvious deleterious effect of the bird's rape cytoplasm has been noted.
REPRODUCTIVE FITNESS AND ADAPTABILITY TO HETEROGENEOUS ENVIRONMENTS OFTRIBOLIUMPOPULATIONS SELECTED UNDER OPTIMUM OR STRESS NUTRITION
Authors: Yamada Yukio , Bell A. E.
Published: November 2014

The relative fitness of 16 populations of Tribolium castaneum, previously selected for large and small larval size, was examined under "GOOD" and "POOR" nutritional environments in terms of progeny numbers surviving a competition trial against a commmon tester. In addition, the effects of nutritional and humidity shifts on the stability of the selected trait in the large populations were compared to unselected base populations. Fitness in large populations remained at the original level, though the selected trait showed a large deviation from the original optimum. On the other hand, fitness in the populations selected for small larval size showed a significant reduction in fitness, and the developmental time of these small populations was greatly delayed as a correlated response. Highly significant differences were found in general adaptability as measured by growth in alternating nutritional environments. The population selected in POOR had highest adaptability, and that selected in GOOD had the lowest. Highly significant population-environment interactions were observed for adaptability to humidity shifts. The population with the highest resistance to the humidity shifts was the one with the lowest adaptation to the nutritional shifts. It was concluded that the genetic mechanisms of adaptation to these environmental stresses were specific rather than general. The concept of genetic correlation was proposed for quantifying the degree of genetic adaptation to heterogeneous environments.
ENHANCEMENT OF GENETIC EXCHANGE IN MAIZE: INTRAGENIC RECOMBINATION
Authors: Sukhapinda Kitisri , Peterson Peter A.
Published: November 2014

Two complexing agents, ethylene diaminetetraacetic acid (EDTA) and 4,7,13,16,21,24-hexaoxy-1, 10-diazabicyclo(8.8.8) hexacosane (Kryptofix™ 222), were applied to corn (Zea mays L.) plants at the time of premeiosis. Using pollen grain analysis, changes in the amounts of genetic exchange within the wx locus could be observed. The mode of action of these complexing agents is only hypothetical; the chemicals may form complexes with cations directly or indirectly associated with the DNA molecules and lead to increases in chromosome breakage and crossing-over. These two chemicals increased wx intragenic exchange significantly. The rate of the wx-intragenic recombination depends, not only on the genetic intragenic distance between wx heteroalleles, but also on the distance between the wx locus and the centromere. Repositioning of the wx locus in relation to the distance to the centromere by using translocated chromosomes showed that the centromere and the breakpoint had an inhibitory effect on the wx-intragenic recombination.