White campion (Silene latifolia, Caryophyllaceae) is a classical model species for studies of sex determination and chromosome evolution in dioecious plants. Deletion mapping this revealed the presence two Y-linked determining genes—the stamen promoting factor (SPF) gene gynoecium suppressing (GSF), which inspired development classic ‘two genes’ dioecy evolution. We recently identified GSFY tha...

Sex chromosomes of the Japanese frog Rana rugosa are heteromorphic in the male (XX/XY) or in the female (ZZ/ZW) in two geographic forms, whereas they are still homomorphic in both sexes in two other forms (Hiroshima and Isehara types). To make clear the origin and differentiation mechanisms of the heteromorphic sex chromosomes, we isolated a sex-linked gene, ADP/ATP translocase, and constructed...

A study of chromosomal analysis for 200 breeding bulls of different breeds of cattle (Jersey, Holstein Friesian, Sahiwal and Cross-bred) and Nili-Ravi buffalo, maintained at Semen Production Unit, Qadirabad and Livestock Experiment Station, Bhunikey (Pattoki) was carried out. Micromethod was adopted for leukocyte culture and chromosomes were trapped at metaphase stage. The diploid number of chr...

What makes males males, and females females? For the majority of animals, the answer lies in the sex chromosomes, which come in two distinct types, with the combination in which they are doled out determining the gender of the offspring. Most other traits are determined by genes found on matched pairs of chromosomes (‘‘autosomes’’), one from each parent, which, through dominant and recessive re...

Species with undifferentiated sex chromosomes emerge as key organisms to understand the astonishing diversity of sex-determination systems. Whereas new genomic methods are widening opportunities to study these systems, the difficulty to separately characterize their X and Y homologous chromosomes poses limitations. Here we demonstrate that two simple F-statistics calculated from sex-linked geno...

Sex in reptiles is determined by genes on sex chromosomes or by incubation temperature. Previously these two modes were thought to be distinct, yet we show that high incubation temperatures reverse genotypic males (ZZ) to phenotypic females in a lizard with ZZ and ZW sex chromosomes. Thus, the W chromosome is not necessary for female differentiation. Sex determination is probably via a dosage-s...

In this study, a detailed chromosome analysis of the endemic Cappadocian Chub, Squalius cappadocicus in Melendiz Stream (Aksaray) was performed. The standard Giemsa staining, C-banding (CBG and CB-DAPI), Ag-NOR technique were applied. diploid number 50; its karyotype formula 14M + 16Sm 10St 10A. Heteromorphic sex chromosomes weren’t detected studied specimens. all chromosomal arms (NF) 90. C-ba...

Background When gonadal sex reversal occurs in mammalian species, the resultant XX males and XY females become infertile or subfertile, suggesting critical roles of sex chromosomes in germ cell differentiation. The objective of our study is to clarify the mechanism of infertility in the B6.YTIR (XY) sex-reversed female mouse, which can be attributed to a failure in the second meiotic division i...

A wide variety of sex determination systems exist among squamate reptiles. They can therefore serve as an important model for studies of evolutionary transitions among particular sex determination systems. However, we still have only a limited knowledge of sex determination in certain important lineages of squamates. In this respect, one of the most understudied groups is the family Helodermati...

Chromosomal patterns of experimental animals are useful tools for cytogenetics research and animal breeding. Chromosome investigations of the hairless guinea pig are rare, therefore, karyotype of hairless guinea pigs (twelve male and female) was studied using metaphase spreads of bone marrows and G banding techniques. The chromosomes diploid number was 2n= 64 and polymorphism of three type chro...