Talk:ZW sex-determination system

Notes

I am not sure about the usage of this terminology, and request the editor(s) involved to provide citations. User:DGG 04:12, 1 January 2007 (UTC)

Which terminology? --Ķĩřβȳ♥ŤįɱéØ 10:48, 1 January 2007 (UTC)

Information regarding the homology of the platypus sex chromosomes and the eutherian sex chromosomes is old and incorrect. Further studies have revealed the platypus X chromosomes have a great deal of homology with the chicken Z yet no homology with the eutherian X chromosomes. Phisch Tarko (talk) 12:34, 6 April 2008 (UTC)

an aside

If I read this right, it means that "the birds and the bees" are actually quite unsuitable subjects for a human sexuality lecture. - Keith D. Tyler ¶ 21:54, 20 June 2007 (UTC)

Vice-versa

Last paragraph currently says:

Chromosomes in the ZW region in birds are autosomal in mammals, and vice-versa.

Does vice versa mean:

(All) autosomal chromosomes in mammals are in the ZW region in birds.

Surely not. After some cogitation, I thought maybe this:

Chromosomes in the XY region in mammals are autosomal in birds.

If so, vice versa is inappropriate. In any event , could someone make this clearer? Thanks. —johndburger 15:52, 21 May 2008 (UTC)

Inaccuracy

I think the thing stating that one or the other gamete determines sex is wrong, in all systems it's the overall mechanism not either gamete that makes the determination. The distinction is in which gender gets the homogeneous gametes as I understand it. 72.228.177.92 (talk) 19:03, 30 December 2011 (UTC)

Asexual reproduction

"However, because of their WW chromosomes, any offspring they produce will be female", does this mean if she reproduces asexually her offspring will be female (which is obvious), or that even if she reproduces with a male, her offspring will be only female, and if this is the case, why? Bumblebritches57 (talk) 02:41, 22 April 2015 (UTC)

There can be no ZZ offspring if the mother always contributes a W. Sminthopsis84 (talk) 23:04, 22 April 2015 (UTC)

That makes sense, for some reason I equated ZZ as the equivalent of XX in mammals. Bumblebritches57 (talk) 23:46, 22 April 2015 (UTC)

Clarification needed

The second paragraph of the Significance section reads:

"The platypus, a monotreme mammal, has a system of 5 pairs of XY chromosomes. They form a multiple chain due to homologous regions in male meiosis and finally segregates into XXXXX-sperm and YYYYY-sperm. The bird Z-like pair shows up on opposite ends of the chain. Areas homologous to the bird Z chromosome are scattered throughout X3 and X5."

This needs some sort of clarification and/or context, especially regarding the 3rd sentence. It's unclear what exactly "bird Z-like pair" means, and the way it's phrased makes it seem like it's been talked about before when it hasn't. The paragraph then goes on to say that the platypus doesn't actually have X chromosomes, further confusing the paragraph by indicating that none of it was actually notated in any sort of correct way. 2600:1702:3C80:3050:310D:7AD3:D74C:903A (talk) 03:40, 2 June 2020 (UTC)