Variability of C-banding patterns in Japanese quail chromosomes

Genome ◽  
1991 ◽  
Vol 34 (6) ◽  
pp. 993-997 ◽  
Author(s):  
C. A. de la Seña ◽  
N. S. Fechheimer ◽  
K. E. Nestor

Observations were made of the C-banding patterns in several cells from 182 Japanese quail embryos to detect presence of stable variants. Each of the eight largest autosomes contains a C-band at the centromeric region. The short arm of autosome 8 is C-band positive, as is the entire W chromosome. The Z chromosome consistently contains an interstitial C-band in the long arm and a less prominent one in the short arm. Distinct variants of chromosome 4 and the Z chromosome were observed. In the Z chromosome a C-band at the terminal region of the short arm was markedly elongated in some embryos. Likewise, the short arm of chromosome 4 was much more prominent in one or both of the homologues in some embryos. Most of the microchromosomes contain a prominent C-band. The heteromorphisms are useful chromosome markers to detect the origins of heteroploidy in early embryos.Key words: C-band variants, Japanese quail, Coturnix.

1982 ◽  
Vol 24 (6) ◽  
pp. 667-673 ◽  
Author(s):  
T. A. Bongso ◽  
M. Hilmi

The chromosomes of the Murrah (River), Swamp (Malaysian kerbau), F1 hybrid (Murrah × Swamp) and first generation backcross (F1 hybrid female × Murrah male) buffaloes (Bubalus bubalis L.) were studied using Giemsa (G) and centromeric (C) banding techniques. The diploid chromosome number for the Murrah was 2n = 50, Swamp 2n = 48, F1 hybrid 2n = 49 and two backcross animals had 2n = 49 and 2n = 50, respectively. The largest two metacentric chromosomes of the Swamp resulted from a tandem fusion between the two chromosomes 4p and 9, respectively, of the Murrah karyotype. The F1 hybrid (2n = 49) and one of the backcrosses (2n = 49) had karyotypes intermediate to the Murrah and Swamp parents. The C banding patterns were useful in identifying the X and Y chromosomes of the buffalo and demonstrated that a major portion of the centromere region of chromosome 9 was not incorporated into chromosome 4 during the tandem fusion.


Genome ◽  
1990 ◽  
Vol 33 (5) ◽  
pp. 686-689 ◽  
Author(s):  
Charles M. Papa ◽  
R. Morris ◽  
J. W. Schmidt

Two winter hexaploid triticale populations derived from the same cross were selected on the basis of grain appearance and agronomic performance. The five lines from 84LT402 showed more kernel shriveling than the four lines from 84LT401. The derived lines were analyzed for aneuploid frequencies, rye chromosome banding patterns, and meiotic stability to detect associations with kernel development. The aneuploid frequencies were 16% in 84LT401 and 18% in 84LT402. C-banding showed that both selection groups had all the rye chromosomes except 2R. The two groups had similar telomeric patterns but differed in the long-arm interstitial patterns of 4R and 5R. Compared with lines from 84LT402, those from 84LT401 had significantly fewer univalents and rod bivalents, and more paired arms at metaphase I; fewer laggards and bridges at anaphase I; and a higher frequency of normal tetrads. There were no significant differences among lines within each group for any meiotic character. Since there were no differences within or between groups in telomeric banding patterns, the differences in kernel shriveling and meiotic stability might be due to genotypic factors and (or) differences in the interstitial patterns of 4R and 5R. By selecting plump grains, lines with improved kernel characteristics along with improved meiotic stability are obtainable.Key words: triticale, meiotic stability, C-banding, Secale cereale, heterochromatin.


2020 ◽  
Author(s):  
Zahida Sultanova ◽  
Philip A. Downing ◽  
Pau Carazo

ABSTRACTSex-specific lifespans are ubiquitous across the tree of life and exhibit broad taxonomic patterns that remain a puzzle, such as males living longer than females in birds and vice versa in mammals. The prevailing “unguarded-X” hypothesis (UXh) explains this by differential expression of recessive mutations in the X/Z chromosome of the heterogametic sex (e.g., females in birds and males in mammals), but has only received indirect support to date. An alternative hypothesis is that the accumulation of deleterious mutations and repetitive elements on the Y/W chromosome might lower the survival of the heterogametic sex (“toxic Y” hypothesis). Here, we report lower survival of the heterogametic relative to the homogametic sex across 138 species of birds, mammals, reptiles and amphibians, as expected if sex chromosomes shape sex-specific lifespans. We then analysed bird and mammal karyotypes and found that the relative sizes of the X and Z chromosomes are not associated with sex-specific lifespans, contrary to UXh predictions. In contrast, we found that Y size correlates negatively with male survival in mammals, where toxic Y effects are expected to be particularly strong. This suggests that small Y chromosomes benefit male lifespans. Our results confirm the role of sex chromosomes in explaining sex differences in lifespan, but indicate that, at least in mammals, this is better explained by “toxic Y” rather than UXh effects.


Genome ◽  
1995 ◽  
Vol 38 (6) ◽  
pp. 1271-1278 ◽  
Author(s):  
Jun-Zhi Wei ◽  
W. F. Campbell ◽  
G. J. Scoles ◽  
A. E. Slinkard ◽  
R. Ruey-Chyi Wang

Russian wildrye, Psathyrostachys juncea (Fisch.) Nevski (2n = 2x = 14; NsNs), is an important forage grass and a potential source of germplasm for cereal crop improvement. Because of genetic heterogeneity as a result of its self-incompatibility, it is difficult to identify trisomics of this diploid species based on morphological characters alone. Putative trisomies (2n = 2x + 1 = 15), derived from open pollination of a triploid plant by pollen grains of diploid plants, were characterized by Giemsa C-banding. Based on both karyotypic criteria and C-banding patterns, four of the seven possible primary trisomics, a double-deletion trisomic, and two tertiary trisomics were identified.Key words: Russian wildrye, Psathyrostachys juncea, trisomic, C-banding, karyotype.


Genome ◽  
1989 ◽  
Vol 32 (4) ◽  
pp. 629-639 ◽  
Author(s):  
Ib Linde-Laursen ◽  
Roland von Bothmer ◽  
Niels Jacobsen

Giemsa C-banding patterns of the predominantly self-pollinating, annual species Hordeum marinum (2x, 4x) and H. murinum (2x, 4x, 6x) showed mostly very small to small bands at centromeric and telomeric positions, at one or both sides of the nucleolar constrictions, and at intercalary positions with no preferential disposition. A similar distribution of bands has been observed in other Hordeum species, suggesting that the pattern is the basic one in the genus Hordeum. Hordeum murinum, especially the hexaploid cytotype, was distinguished from H. marinum by having more numerous and more conspicuous bands, resulting in a significantly higher percentage of constitutive heterochromatin (9–17 vs. 4–8%). The differences in C-banding patterns supported by differences in chromosome morphology confirm that H. marinum and H. murinum are not closely related. Banding-pattern polymorphism was prevalent among populations but unobserved within populations. In spite of this polymorphism, banding patterns in combination with chromosome morphology identified homologous chromosomes of different populations of a taxon and indicated that the chromosome complements of the polyploids of both species comprised the genome of the related diploid as well as one or two "unidentified" genomes. This agrees with an alloploid origin of polyploids. The C-banding patterns of H. marinum ssp. marinum and H. marinum ssp. gussoneanum (2x) showed some divergence in spite of the close relationship. The C-banded karyotypes of H. murinum ssp. murinum and H. murinum ssp. leporinum (4x) were very similar, supporting conspecificity. Chromosome lengths and longest/shortest chromosome ratios were fairly similar to those previously published, supporting the conclusion that linear relationships of chromosomes are normally stable within genomes. The taxonomy of the two species is discussed.Key words: C-banding, karyotypes, Hordeum.


2019 ◽  
Vol 12 (2) ◽  
pp. 45-48
Author(s):  
Shao-jie Liang ◽  
Ming-xia Chen ◽  
Chun-qi Gao ◽  
Hui-chao Yan ◽  
Guo-long Zhang ◽  
...  

Sex identification plays an important role in avian production. Hitherto, it is difficult to distinguish the sexes of monomorphic birds based on their external features. The chromo-helicase-DNA-binding genes contain CHD-W gene and CHD-Z gene, which are located on the W chromosome and Z chromosome, respectively. Since CHD-W gene is unique to females, the polymerase chain reaction can be used for sex identification. However, extracting DNA procedures for verifying the sex is tedious and expensive. To address these disadvantages, the objective of this study was to develop a simple DNA extraction assay to efficiently process blood, liver, and feather samples. The results showed that 2% dimethylsulfoxide was suitable for processing blood, and phosphate-buffered saline was suitable for processing liver and feather samples. The specific primers were designed, and the length of the targets is 474 bp on Z chromosome and 319 bp on W chromosome. The pigeons were identified as females based on the presence of two bands on the gel, and as males based on the presence of one band. Taken together, our results suggested that feather samples were more appropriate than blood or liver for sex identification of pigeons. Compared to the traditional DNA extraction, this method shortened the assay time and reduced the cost.


Caryologia ◽  
2014 ◽  
Vol 67 (4) ◽  
pp. 314-320
Author(s):  
Diego Mattos Penedo ◽  
Jorge Luís Azevedo de Armada ◽  
José Francisco Santos da Silva ◽  
Daniel Marchesi Neves ◽  
Alcides Pissinatti ◽  
...  

2004 ◽  
Vol 20 (1) ◽  
pp. 12-14 ◽  
Author(s):  
Kristen P. Parks ◽  
Heather Seidle ◽  
Nathan Wright ◽  
Jeffrey B. Sperry ◽  
Pawel Bieganowski ◽  
...  

Hint is a universally conserved, dimeric AMP-lysine hydrolase encoded on the avian Z chromosome. Tandemly repeated on the female-specific W chromosome, Asw encodes a potentially sex-determining, dominant-negative Hint dimerization partner whose substrate-interacting residues were specifically altered in evolution. To test the hypothesis that Gln127 of Asw is responsible for depression and/or alteration of Hint enzyme activity, a corresponding mutant was created in the chicken Hint homodimer, and a novel substrate was developed that links reversal of AMP-lysine modification to aminomethylcoumarin release. Strikingly, the Hint-W123Q substitution reduced kcat/ Km for AMP-lysine hydrolysis 17-fold, while it increased specificity for AMP- para-nitroaniline hydrolysis by 160-fold. The resulting 2,700-fold switch in enzyme specificity suggests that Gln127 could be the dominant component of Asw dominant negativity in avian feminization.


2019 ◽  
Vol 158 (2) ◽  
pp. 98-105 ◽  
Author(s):  
Suziane A. Barcellos ◽  
Rafael Kretschmer ◽  
Marcelo S. de Souza ◽  
Alice L. Costa ◽  
Tiago M. Degrandi ◽  
...  

As in many other bird groups, data on karyotype organization and distribution of repetitive sequences are also lacking in species belonging to the family Hirundinidae. Thus, in the present study, we analyzed the karyotypes of 3 swallow species (Progne tapera, Progne chalybea, and Pygochelidon cyanoleuca) by Giemsa and AgNOR staining, C-banding, and FISH with 11 microsatellite sequences. The diploid chromosome number was 2n = 76 in all 3 species, and NORs were observed in 2 chromosome pairs each. The microsatellite distribution pattern was similar in both Progne species, whereas P. cyanoleuca presented a distinct organization. These repetitive DNA sequences were found in the centromeric, pericentromeric, and telomeric regions of the macrochromosomes, as well as in 2 interstitial blocks in the W chromosome. Most microchromosomes had mainly telomeric signals. The Z chromosome displayed 1 hybridization signal in P. tapera but none in the other species. In contrast, the W chromosome showed an accumulation of different microsatellite sequences. The swallow W chromosome is larger than that of most Passeriformes. The observed enlargement in chromosome size might be explained by these high amounts of repetitive sequences. In sum, our data highlight the significant role that microsatellite sequences may play in sex chromosome differentiation.


Genetica ◽  
1983 ◽  
Vol 61 (1) ◽  
pp. 65-74 ◽  
Author(s):  
J. L. Santos ◽  
P. Arana ◽  
R. Gir�ldez
Keyword(s):  

Sign in / Sign up

Export Citation Format

Share Document