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Evolution for the sex that is avian from an ancestral pair of autosomes

Mittwoch, Februar 5th, 2020

Evolution for the sex that is avian from an ancestral pair of autosomes

Communicated by Mary F. Lyon, healthcare Research Council, Oxon, uk (received for review January 30, 1998)

On the list of mechanisms whereby intercourse is set in animals, chromosomal intercourse determination is situated in a wide array of distant taxa.

The widespread not ubiquitous event, not really within lineages, of chromosomal sex dedication shows that sex chromosomes have actually developed separately many times during animal radiation, but firm proof because of this is lacking. The absolute most model that is favored this technique is gradual differentiation of ancestral pairs of autosomes. As recognized for mammals, intercourse chromosomes might have a really ancient origin, and has now even been speculated that the intercourse chromosomes of mammals and wild wild wild birds would share a chromosomal ancestry that is common. In this research we revealed that the 2 genes, ATP5A1 and CHD1, up to now assigned to your female-specific W chromosome of birds both occur in a really closely associated copy regarding the Z chromosome but they are perhaps not pseudoautosomal. This suggests a typical ancestry for the two intercourse chromosomes, in keeping with the development from a set of autosomes. Relative mapping demonstrates, nevertheless, that ATP5A1 and CHD1 aren’t sex-linked among eutherian animals; that is additionally maybe perhaps not the instance in the most common of other genes to date assigned to your avian Z chromosome. Our outcomes declare that the development of intercourse chromosomes has happened individually in animals and wild wild wild birds.

The mechanisms whereby sex is determined are clearly diverse: chromosomal sex determination (CSD; with male or female heterogamety), mono- or polyfactorial sex determination not associated with heteromorphic sex chromosomes, environmental sex determination, cytoplasmic sex determination, and arrhenotoky (haplo-diploidy; ref. 1) although the concept of sexual reproduction is found among essentially all eukaryotes. (mehr …)