The Chromosomes of Six Species of the Drosophila lativittata Complex

1984 ◽  
Vol 32 (1) ◽  
pp. 43 ◽  
Author(s):  
IR Bock
Keyword(s):  
Y Chromosome ◽  
X Chromosome ◽  
Sexual Isolation ◽  
Species Group ◽  
Interspecific Crosses ◽  
Banding Patterns ◽  
Australian Species

Metaphase and polytene karyotypes were investigated in six Australian species of the Drosophila (Scaptodrosophila) coracina species-group: lativittata, enigma, specensis, howensis, nitidithorax and novamaculosa. The male metaphase karyotype of each species consists of three pairs of telocentric; one pair of metacentric and one pair of small heterochromatic chromosomes, plus a large acrocentric X-chromosome and a smaller acrocentric Y-chromosome. The polytene karyotype of each species consists of six arms and a small chromocentre. No inversion polymorphisms were found in the two species (lativittata and enigma) investigated for this phenomenon. Interspecific crosses obtained between enigma and howensis and between lativittata and nitidithorax revealed that the former species (between which sexual isolation is incomplete) are entirely homosequential, and differences in polytene banding patterns between the latter species are very slight. Photographic comparisons otherwise revealed that the banding sequences of all six species are substantially identical.

Mapping the mouse X chromosome: possible symmetry in the location of a family of sequences on the mouse X and Y chromosomes

Development ◽  
1987 ◽  
Vol 101 (Supplement) ◽  
pp. 107-116
Author(s):  
Philip Avner ◽  
Colin Bishop ◽  
Laurence Amar ◽  
Jacques Cambrou ◽  
Didier Hatat ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Y Chromosome ◽  
X Chromosome ◽  
Somatic Cell Hybrid ◽  
The Other ◽  
Interspecific Crosses ◽  
Somatic Cell Hybrid Panel ◽  
Mus Spretus ◽  
Y Chromosomes

Major advances in our knowledge of the genetic organization of the mouse X chromosome have been obtained by the use of interspecific crosses involving Mus spretus-derived strains. This system has been used to study sequences detected by three probes 80Y/B, 302Y/B and 371Y/B isolated from a mouse Y-chromosome library which have been shown to recognize both male–female common and male–female differential sequences. These patterns are due to the presence of a family of cross-reacting sequences on the mouse X and Y chromosomes. Detailed genetic analysis of the localization of the X-chromosomespecific sequences using both a somatic cell hybrid panel and an interspecific mouse cross has revealed the presence of at least three discrete clusters of loci (X–Y)A, (X–Y)B and (X–Y)C. Two of these clusters, (X–Y)B and (X–Y)C, lie distally on the mouse X chromosome, the other cluster (X–Y)A being situated close to the centromere. In situ hybridization shows a striking symmetry in the localization of the major sequences on both the X and Y chromosomes detected by these probes, hybridization being preferentially localized to a subcentromeric and subtelomeric region on each chromosome. This striking localization symmetry between the X and Y chromosome sequences is discussed in terms of the extensive pairing of the X–Y chromosomes noted during meiosis.

BANDING PATTERNS IN MITOTIC CHROMOSOMES OF THE RABBIT (ORYCTOLAGUS CUNICULUS)

1977 ◽  
Vol 19 (4) ◽  
pp. 625-632 ◽  
Author(s):  
F. P. H. Chan ◽  
F. R. Sergovich ◽  
E. L. Shaver
Keyword(s):  
Detailed Analysis ◽  
Y Chromosome ◽  
X Chromosome ◽  
Sex Chromosomes ◽  
Banding Pattern ◽  
Oryctolagus Cuniculus ◽  
Acrocentric Chromosome ◽  
Mitotic Chromosomes ◽  
Banding Patterns ◽  
Medium Length

A detailed analysis of rabbit mitotic chromosomes stained with quinacrine and Trypsin-Giemsa methods to elucidate the Q and G bands is presented. Each of the 21 pairs of autosomes can be identified unequivocally. The sex chromosomes can also be distinguished from the autosomes. The X chromosome is a medium length submetacentric with its own distinctive banding pattern. The Y chromosome is the smallest acrocentric chromosome and fluoresces with a medium intensity.

Cytogenetics of Some New Guinean Dasyurids and Genome Evolution in the Dasyuridae (Marsupialia)

1989 ◽  
Vol 37 (5) ◽  
pp. 521 ◽  
Author(s):  
M Westerman ◽  
PA Woolley
Keyword(s):  
Genome Evolution ◽  
Y Chromosome ◽  
X Chromosome ◽  
Nuclear Dna ◽  
New Guinea ◽  
Size And Shape ◽  
Australian Species ◽  
Extant Species ◽  
Dna Values

Karyotypes have been obtained for ten species of New Guinean dasyurid marsupials. All species have 2n = 14 chromosomes which, except for variation in size and shape of the X chromosome, are similar in morphology, not only between species but also to Australian species. The Y chromosome of all species is punctiform. C- and G-banding procedures have been applied to eight of the species and show (1) there are no major differences between species in amounts of C-band heterochromatin, and (2) the G-band patterns of the autosomes were virtually identical. These findings suggest that there have been no major karyotypic changes accompanying speciation of dasyurids in New Guinea. Since the G-banded karyotypes are also virtually identical to those reported for Australian dasyurids it would appear that this 2n = 14 karyotype probably represents the ancestral dasyurid form which can be derived as a result of a few inversions from an ancestral marsupial karyotype. These changes must have occurred very early in the dasyurid radiation as the) are found in all extant species and genera examined. However, virtually identical G-banded karyotypes may mask major differences in nuclear DNA values.

THE GIEMSA BANDING PATTERN OF THE AUSTRALIAN SWAMP BUFFALO (BUBALUS BUBALIS): CHROMOSOME HOMOLOGY WITH OTHER BOVIDAE

1976 ◽  
Vol 18 (2) ◽  
pp. 303-310 ◽  
Author(s):  
G. L. Toll ◽  
C. R. E. Halnan
Keyword(s):  
Y Chromosome ◽  
X Chromosome ◽  
Banding Pattern ◽  
Bubalus Bubalis ◽  
The Other ◽  
Giemsa Banding ◽  
Apparent Absence ◽  
Banding Patterns ◽  
Chromosome Homology ◽  
Swamp Buffalo

A Giemsa banding method was used to obtain preparations from which a G-band idiogram for the chromosomes of the Australian Swamp Buffalo (Bubalus bubalis) was constructed. Comparison with the G-banding patterns for goat, sheep, and ox chromosomes showed a remarkably close similarity between individual pairs, banding pattern homologies for the buffalo metacentric autosomes being identifiable among the acrocentric autosomes of the other species. However, the goat and sheep lacked a comparable autosome to the buffalo 10, the buffalo lacked an autosome comparable to the ox 12, the acrocentric X chromosome of the buffalo banded most closely to the goat X and was least like the ox. The buffalo Y chromosome was unlike its counterpart in the other species. The results are in keeping with the previously expressed view of evolution within the Bovidae by a Robertsonian mechanism modified by the apparent absence of one pair of autosomes from the buffalo and of a different pair from sheep and goats.

Evolution of a Y Chromosome from an X Chromosome

2019 ◽  
Author(s):  
Roberta Bergero ◽  
Jim Gardner ◽  
Deborah Charlesworth
Keyword(s):  
Y Chromosome ◽  
X Chromosome

scholarly journals Epistatic Control of Non-Mendelian Inheritance in Mouse Interspecific Crosses

Genetics ◽  
1996 ◽  
Vol 143 (4) ◽  
pp. 1739-1752 ◽  
Author(s):  
Xavier Montagutelli ◽  
Rowena Turner ◽  
Joseph H Nadeau
Keyword(s):  
X Chromosome ◽  
Genetic Basis ◽  
Mendelian Inheritance ◽  
The Other ◽  
Interspecific Crosses ◽  
Chromosome 2 ◽  
Mus Spretus ◽  
F1 Hybrid ◽  
Strong Deviation ◽  
Marker Loci

Abstract Strong deviation of allele frequencies from Mendelian inheritance favoring Mus spretus-derived alleles has been described previously for X-linked loci in four mouse interspecific crosses. We reanalyzed data for three of these crosses focusing on the location of the gene(s) controlling deviation on the X chromosome and the genetic basis for incomplete deviation. At least two loci control deviation on the X chromosome, one near Xist (the candidate gene controlling X inactivation) and the other more centromerically located. In all three crosses, strong epistasis was found between loci near Xist and marker loci on the central portion of chromosome 2. The mechanism for this deviation from Mendelian expectations is not yet known but it is probably based on lethality of embryos carrying particular combinations of alleles rather than true segregation distortion during oogenesis in F1 hybrid females.

scholarly journals Genetics of sexual isolation in male hybrids of Drosophila simulans and D. mauritiana

1996 ◽  
Vol 68 (3) ◽  
pp. 211-220 ◽  
Author(s):  
Jerry A. Coyne
Keyword(s):  
Genetic Analysis ◽  
Y Chromosome ◽  
Sibling Species ◽  
Previous Analysis ◽  
Sexual Isolation ◽  
Drosophila Simulans

SummarySexual isolation between the sibling species D. simulans and D. mauritiana is due largely to the rejection of D. simulans males by D. mauritiana females. Genetic analysis shows that genes on the X and third chromosomes contribute to the differences between males causing sexual isolation, while the Y chromosome, second chromosome and cytoplasm have no effect. These chromosome effects differ from those observed in a previous analysis of sexual isolation in hybrid females, implying that different genes cause sexual isolation in the two sexes.

scholarly journals Recombination between the mouse Y chromosome short arm and an additional Y short arm-derived chromosomal segment attached distal to the X chromosome PAR

Chromosoma ◽  
2015 ◽  
Vol 125 (2) ◽  
pp. 177-188
Author(s):  
Fanny Decarpentrie ◽  
Obah A. Ojarikre ◽  
Michael J. Mitchell ◽  
Paul S. Burgoyne
Keyword(s):  
Y Chromosome ◽  
X Chromosome ◽  
Chromosomal Segment

Roles of Anti-Müllerian hormone (Amh) and its duplicates in sex determination and germ cell proliferation of Nile tilapia

Genetics ◽  
2021 ◽  
Author(s):  
Xingyong Liu ◽  
Shengfei Dai ◽  
Jiahong Wu ◽  
Xueyan Wei ◽  
Xin Zhou ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Sex Determination ◽  
Germ Cell ◽  
Y Chromosome ◽  
X Chromosome ◽  
Nile Tilapia ◽  
Critical Period ◽  
Sex Reversal ◽  
Homozygous Mutation ◽  
Germ Cell Proliferation

Abstract Duplicates of amh are crucial for fish sex determination and differentiation. In Nile tilapia, unlike in other teleosts, amh is located on X chromosome. The Y chromosome amh (amh△-y) is mutated with 5 bp insertion and 233 bp deletion in the coding sequence, and tandem duplicate of amh on Y chromosome (amhy) has been identified as the sex determiner. However, the expression of amh, amh△-y and amhy, their roles in germ cell proliferation and the molecular mechanism of how amhy determines sex is still unclear. In this study, expression and functions of each duplicate were analyzed. Sex reversal occurred only when amhy was mutated as revealed by single, double and triple mutation of the three duplicates in XY fish. Homozygous mutation of amhy in YY fish also resulted in sex reversal. Earlier and higher expression of amhy/Amhy was observed in XY gonads compared with amh/Amh during sex determination. Amhy could inhibit the transcription of cyp19a1a through Amhr2/Smads signaling. Loss of cyp19a1a rescued the sex reversal phenotype in XY fish with amhy mutation. Interestingly, mutation of both amh and amhy in XY fish or homozygous mutation of amhy in YY fish resulted in infertile females with significantly increased germ cell proliferation. Taken together, these results indicated that up-regulation of amhy during the critical period of sex determination makes it the sex-determining gene, and it functions through repressing cyp19a1a expression via Amhr2/Smads signaling pathway. Amh retained its function in controlling germ cell proliferation as reported in other teleosts, while amh△-y was nonfunctionalized.

Sign in / Sign up

Export Citation Format

Share Document