Who of them is heterozygous - male or female?

[Julia_piton]

Hello.
I really like pythons regius.
Can you tell me: who of them is heterozygous - male or female?
Thank you.

[Stewart_Reptiles]

Hello.
I really like pythons regius.
Can you tell me: who of them is heterozygous - male or female?
Thank you.

Not sure about your question, both male and female can be Het.

[Ax01]

Hello.
I really like pythons regius.
Can you tell me: who of them is heterozygous - male or female?
Thank you.

[Julia_piton]

I probably did not quite ask the question. And I will try to narrow it down:
yx-chromosome: in the male or in the female bold python?

[Trisnake]

Female is heterozygous (zw) and male is homozygous (zz), flipped from the mammalian XY system but otherwise similar. This is how I understand it at least.

A couple months back someone posted an article over this, I think it was in relation to parthenogenesis but I don’t remember if the study group were royal pythons or Burmese (maybe both). I will try to find the article however they’re relatively closely related species and I would assume their sex chromosomes would be assorted similarly.

Someone correct me if I’m mistaken.

[fieldfare]

I was going to say that reptiles (including birds) have ZW females and ZZ males but there's actually a lot of variation that I didn't think about until I googled it. Apparently some reptiles use XY/XX, some do ZW/ZZ, and some rely on incubation temperature so there's a lot of options. To answer your question, as far as I can tell, all snakes are ZW/ZZ.

[Trisnake]

Here’s the original post, with the linked article: https://ball-pythons.net/forums/show...Boa-and-Python

After reviewing it again, I think I may have misunderstood the first time around. According to the study, pythons and boas exhibit an XY sex chromosome system and the females are actually homozygous XX and the males are heterozygous XY.

[asplundii]

According to the paper put out by Dr. Warren Booth, ball pythons (and all pythons for that matter) are X/Y sex-chromosome so the females will be XX and the males will be XY


https://docs.wixstatic.com/ugd/dfa18...9c24176674.pdf

[paulh]

... the females are actually homozygous XX and the males are heterozygous XY.

Better terminology would be homogametic and heterogametic. Female ball pythons are XX and therefore homogametic. Males are XY and therefore heterogametic.