A female’s egg carries either a Z or W chromosome, whereas a sperm always has a Z chromosome. Hence, an egg with a Z/W chromosome decides the primary sex. Grasshoppers The XX-XO system operates in some grasshopper species. Here, the males lack a Y chromosome, and the ‘O’ repre...
The gonadoblastoma on the Y-chromosome (GBY) region is associated with an increased risk of developing type II germ cell tumors/cancer. The present study reports a unique case of a phenotypically normal female (age 17 years), presenting with primary amenorrhea and later diagnosed with 46,XY...
The gonadoblastoma on the Y-chromosome (GBY) region is associated with an increased risk of developing type II germ cell tumors/cancer. The present study reports a unique case of a phenotypically normal female (age 17 years), presenting with primary amenorrhea and later diagnosed with 46,X...
Sex Chromosome Mosaicism (XO/XX/XXY/XY) in a Phenotypic Female Robert L. Kaufman, MD; David L. Rimoin, MD, PhD; Ralph B. Woolf, MD; et al Richard J. Warren, PhD; William S. Sly, MD Author Affiliations JAMA. 1971;215(12):1941-1944. doi:10.1001/jama.1971.03180250033007 Full...
In this study, we analyse several behavioural traits in the African pygmy mouse (female attractiveness, aggressiveness and anxiety in both sexes) in order to answer two questions: does sex chromosome complement affect behaviour independently from gonadal sex in a species with naturally occurring sex ...
Chromosomal aspects and inheritance of the XY female condition in Akodon azarae (Rodentia, Sigmodontinae)AkodonAkodon azaraeXY femalessex reversalX-chromosomeThe populations of several species of and F offspring of 16 crosses.It was seen that the correlation between X type and the sexual phenotype of...
It was noted only recently that the mammalian X/Y sex chromosome system originated late in our therian ancestors. The question is, what makes the X/Y sex chromosome system so special that it has replaced the original Z/W sex chromosome system? Two classes of genes are overrepresented on the...
Rapid testing versus karyotyping in Down's syndrome screening: cost-effectiveness and detection of clinically significant chromosome abnormalities In all, 80% of antenatal karyotypes are generated by Down's syndrome screening programmes (DSSP). After a positive screening, women are offered prenatal fo....
A trivalent is thus formed at male meiosis, and there is on average one less chromosome in XV individuals, whether male or female, than in XX females (Gileva, 1973, 1975; we say "on average" because the diploid number is variable due to the presence of B chromo- somes). It is not...
27. Members of the family Chelidae have generally high diploid chromosome numbers ranging from 2n = 48 to 2n = 6410,20. Stable sex ratios of hatchlings incubated across a range of constant temperatures suggest the presence of GSD in at least three chelid species (Mesoclemmys gibba,...