Genetics 20 : — Nucleic Acids Res 25 : — Creation of house fly neo-Y Chromosomes We hypothesize that the recent duplication of Md-ncm that created Mdmd Sharma et al. Our results suggest that the Y and X M Chromosomes are morphological variants of neo-Y Chromosomes that arose when at least one ancestral X Chromosome recently acquired Mdmd.
After establishment and at any stage of evolution, sex chromosomes can persist at the current stage blue arrowsprogress in establishing larger areas of recombination suppression gray region, top right chromosomes and divergence red region, right side chromosomesor turnover gold arrows with either a new sex-determining gene evolving or moving the sex-determining gene to a new location in the genome.
The W, X, Y and Z of sex-chromosome dosage compensation. The location of eighteen genes in Lebistes reticulatus. Genes that are carried by either sex chromosome are said to be sex linked. The frequency of sex in fungi. Epigenetic regulation of gene expression: how the genome integrates intrinsic and environmental signals.
Transposable elements and the epigenetic regulation of the genome. Fisher RA.
Fourth, house flies that carry only a single copy of either the X or Y Chromosome i. Trends Genet 29 : — There are however numerous lines of evidence that, when taken together, reveal a remarkable level of dynamicism in some minor sex chromosomes that act to counter degeneration.
Although the Drosophila melanogaster Y chromosome is karyotypically quite large, it is completely distinct from the paired X chromosome and carries just 12 known genes Koerich et al. The male-determining activity on the Y chromosome of the housefly Musca domestica L.
Author manuscript; available in PMC Mar In addition to their role in fertility and fecundity, the sex-limited nature of these genomic regions results in unique evolutionary forces acting on Y and W chromosomes, implicating them as potentially major contributors to sexual selection and speciation.
These turnover events likely represent changes directly from existing sex chromosome systems rather than complete losses of sex chromosomes followed by gains. These cases of sex chromosome systems completely lacking minor sex chromosomes further supports the assumption that the Y and W are, in the best cases, entirely expendable, and in the worst cases, in terminal decline.
Six novel Y chromosome genes in Anopheles mosquitoes discovered by independently sequencing males and females. Sex chromosomes and the evolution of sexual dimorphism. Consistent with the results from the aabys strain, the average relative male-to-female sequencing coverage within genes in both A3 and LPR is similar across all six chromosomes Fig.
Sex determination: why so many ways of doing it?