Platty Daddy Solution

[RandyRemington]

Snakes have the same gender chromosomes as birds, designates Z and W. They are opposite from mammals in that it's the female that has the mismatched pair and determines the gender of the offspring:

ZW = Female
ZZ = Male

I'm not aware of any identified sex linked mutations in ball pythons yet but of course we have them in chickens so maybe will find one in ball pythons eventually. I was wondering about the banana mutation as for years there where only females reported but I understand a male was eventually hatched and the mutation does look a lot like the white smoke from another breeder who I think founded with a male.

RDR's platy producing breeding results are consistent with the hidden/special/dilute mutation that when added to lesser makes a platy just being another mutation of that same gene. The twist is that this mutation doesn't seem to have a visible effect when paired with the normal version of the gene or even when homozygous. It's only effect seems to be to dilute lesser or butter into a platy when paired together or when paired with phantom to make the phantom 44. Presumably it might well dilute mojave also but there are so few people with this gene I don't know if that has been tried yet.

Here is a list of the RDR breeding record clutch numbers with Platy production if you want to test your sex linked theory against them:

2003: 44, 51
2004: 8
2005: 5, 42, 71
2007: 7, 12, 22, 29

[soy.lor.n]

Snakes have the same gender chromosomes as birds, designates Z and W. They are opposite from mammals in that it's the female that has the mismatched pair and determines the gender of the offspring:

ZW = Female
ZZ = Male

In that case, are sex linked traits more common in females than males, or is it a completely different deal (in birds, at least)?

[RandyRemington]

The only sex linked gene I've worked with is yellow in Syrian hamsters to make calicos. It's on the X chromosome and I think works the same as cats in that only females can be calico because only they can have two copies of the yellow gene to be mismatched (one with the mutation and one without). For some reason the two yellow genes are rationalized such that parts of the body are controlled by each so a mismatched pair results in some parts of the body yellow and some not. A male is either yellow or not but a female can be part yellow and part not yellow. Combine that with a white band mutation and a black mutation to show through where not covered by yellow and you have a calico.

Having not worked with sex linked bird genes I searched and found the following page:

http://marsa_sellers.tripod.com/gene.../page1.html#t4

It looks to me like the chicken sex linked mutations they are talking about are on the Z gender chromosome so females only have one chance to get it and only pass it to their sons while a male can have either one or two copies of the mutation and pass to either gender of the offspring.

So, if we where to find a Z chromosome mutation in ball pythons it would be possible for it to be co-dominant in males producing two mutant types of males (with either one or two copies of the mutation) like in the hamsters and cats where females can have a mismatched pair of yellow genes needed to produce calicos. However, in females there would only be the possibility of at most one mutant copy (since they only have one Z) so they would either have it or not. It’s hard to say if the females with the one Z mutant copy would look the same as the males with two but that's maybe more likely than looking like the males with one. And with a dominant or co-dominant sex linked ball python mutation in a female you might be able to use it to visually see the gender of her offspring at hatching with only the males getting it like in the sex indicating chicken pairings on that website.

Although I didn't see any examples of W mutations seen only in females on that link I've heard of Y mutations in humans passed only in males. So maybe there could also be a ball python W mutation that is never seen in males. But from the chicken examples a Z mutation seen in both might be more likely and have interesting and some times offspring gender indicating results.