Morphs on different genders of BP's

[PitOnTheProwl]

Excuse the ignorance, but is it safe for a male bp to be paired up to 16 times? Is that going to cause him any issues down the line?

Depends on the person. Some dont care about anything but the money.

[BPGator]

Honestly, I don't think the exact mechanism of inheritance has been determined. Basically there's something a bit odd going on with the inheritance which doesn't make it act like a typical sex linked gene but it is somehow related to sex. Generally males who had a male banana parent will only have male babies come out as banana. A male with a female banana parent will generally have only female babies come out as banana. A female banana will have both male and female bananas.

I thought there was a study that showed BP sex inheritance is similar to humans where males are XY are females are XX. Male parents give an X or Y chromosome and the female parent gives an X chromosome. Based on this and that the Banana mutation is attached to the sex chromosome it showed why the banana gene produces only certain offspring:

A Male Banana has X and Y chromosomes. If the male parent was Banana, then its Y chromosome carries the banana mutation. It will only pass on the banana mutation when it passes its Y chromosome and produces male offspring. If the female parent was Banana, then its X chromosome carries the banana mutation and it will only pass on the banana mutation when it passes its X chromosome and produces female offspring.

A female Banana has two X chromosomes. One of those X chromosomes would carry the banana mutation. But it can only pass an X chromosome to offspring and the gender is determined by the non-banana males X or Y chromosome. This results in the female banana being capable of producing both male and female Banana offspring.

If this is the case, why do you say "generally". Does it not always work out this way?

[cchardwick]

I was thinking about mentioning the male / female ratios with Banana / Coral Glow but that was a little more involved than the original question. You should in theory get the same number of morph combos when breeding a two gene male and two gene female no matter which one is male or female (not considering the sex ratios of the babies coming from Bananas, all other morphs would come out the same). The sex ratios of Bananas is a whole different level of complexity. I have a male coral glow, not sure if it's a male maker or female maker. I should find out this year as I'm pairing him up to two females, should be interesting!

Normally the max for breeding a male is five females, but I have seen videos of breeders that showed their breeding charts. I stopped the video and counted the females from their one male, he had 16 females! Not sure how successful that would be. Normally you want to have at least one lock per month per snake. So if you gave that male one female per day with weekends off, assuming the occasional lock would set you back, it would be pairing every female just once per month. That would have to be a lock every single time for all snakes every month for a good success rate, pretty much impossible. I doubt that more than half of them would take, probably most would have a few good eggs and slug out the rest. I think the best success rate would be 2-3 females per male.

[Kcl]

I thought there was a study that showed BP sex inheritance is similar to humans where males are XY are females are XX. Male parents give an X or Y chromosome and the female parent gives an X chromosome. Based on this and that the Banana mutation is attached to the sex chromosome it showed why the banana gene produces only certain offspring:

A Male Banana has X and Y chromosomes. If the male parent was Banana, then its Y chromosome carries the banana mutation. It will only pass on the banana mutation when it passes its Y chromosome and produces male offspring. If the female parent was Banana, then its X chromosome carries the banana mutation and it will only pass on the banana mutation when it passes its X chromosome and produces female offspring.

A female Banana has two X chromosomes. One of those X chromosomes would carry the banana mutation. But it can only pass an X chromosome to offspring and the gender is determined by the non-banana males X or Y chromosome. This results in the female banana being capable of producing both male and female Banana offspring.

If this is the case, why do you say "generally". Does it not always work out this way?

I had to look into this because I'm no expert on ball python genetics. Step 1 is determining what sex chromosome system they follow. The problem is that many snakes have been determined to be ZW where the female is the heterogametic one (having two different chromosomes). However, this doesn't match up with the inheritance pattern for coral glow.

While I haven't quite finished reading this paper (working on it), it looks like the coral glow gene was part of the basis of this 2016 paper that showed that pythons feature the XY inheritance system. If they're using the XY inheritance system, coral glow may well be just sex-linked, with the rare exceptions for male or female maker bananas throwing the opposite sex bananas being a case of cross-over.

https://www.researchgate.net/publica...cationCoverPdf

It was previously assumed that all snakes were ZW. Working off that assumption, coral glow/banana's inheritance pattern doesn't fit any normal sex-linked inheritance.

But if it's XY, then yes, it could be the following:

Banana female x normal male: X(b)X(n) x X(n)Y - makes X(b)X(n), X(b)Y, X(n)X(n), X(n)Y.
Normal female x banana male (from banana female) - X(n)X(n) x X(b)Y - makes X(n)X(b), X(n)Y.
Banana male (from banana male) x Normal female - X(n)Y(b) x X(n)X(n) - makes X(n)Y(b), X(n)X(n).

Although in that case I'd speculate that the gene started on the Y chromosome and ended up crossing over to the X and is in a location where crossover is relatively frequent, also explaining the exceptions. But that's entirely speculation.

EDIT: Also a thing to note is that usually a sex-linked gene doesn't show up on BOTH the X and the Y chromosome or else it wouldn't really be demonstrating the sex-linked trait in the first place. The classic examples like color-blindness are found solely on the X chromosome.

[dylan815]

I had to look into this because I'm no expert on ball python genetics. Step 1 is determining what sex chromosome system they follow. The problem is that many snakes have been determined to be ZW where the female is the heterogametic one (having two different chromosomes). However, this doesn't match up with the inheritance pattern for coral glow.

While I haven't quite finished reading this paper (working on it), it looks like the coral glow gene was part of the basis of this 2016 paper that showed that pythons feature the XY inheritance system. If they're using the XY inheritance system, coral glow may well be just sex-linked, with the rare exceptions for male or female maker bananas throwing the opposite sex bananas being a case of cross-over.

https://www.researchgate.net/publica...cationCoverPdf

It was previously assumed that all snakes were ZW. Working off that assumption, coral glow/banana's inheritance pattern doesn't fit any normal sex-linked inheritance.

But if it's XY, then yes, it could be the following:

Banana female x normal male: X(b)X(n) x X(n)Y - makes X(b)X(n), X(b)Y, X(n)X(n), X(n)Y.
Normal female x banana male (from banana female) - X(n)X(n) x X(b)Y - makes X(n)X(b), X(n)Y.
Banana male (from banana male) x Normal female - X(n)Y(b) x X(n)X(n) - makes X(n)Y(b), X(n)X(n).

Although in that case I'd speculate that the gene started on the Y chromosome and ended up crossing over to the X and is in a location where crossover is relatively frequent, also explaining the exceptions. But that's entirely speculation.

EDIT: Also a thing to note is that usually a sex-linked gene doesn't show up on BOTH the X and the Y chromosome or else it wouldn't really be demonstrating the sex-linked trait in the first place. The classic examples like color-blindness are found solely on the X chromosome.

Damn.....


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[Kcl]

Actually, I'm wondering - has anyone bred a female banana and a "male-maker" banana and then bred the male offspring and found any that then make all bananas when bred with a normal (for banana at least) - both male and female? If the inheritance does work like I'm guessing, some of them would.

[dr del]

iirc female bananas throw regular sex mixes so ~90% of the super bananas would be male. the female banana offspring would throw a regular mix and the male bananas would be female makers ~90% of the time.

I may, of course, be talking through my hat.

[Kcl]

iirc female bananas throw regular sex mixes so ~90% of the super bananas would be male. the female banana offspring would throw a regular mix and the male bananas would be female makers ~90% of the time.

I may, of course, be talking through my hat.

Thanks! That lines up with my guess.

The thread linked below indicates that super bananas do end up with a regular sex ratio and some "female makers" and some "male makers".

https://ball-pythons.net/forums/show...-Super-bananas

In that case, it definitely sounds to me like the "male makers" have the banana gene on the Y chromosome and the females and "female makers" have it on the X chromosome. Also does sound like it's in a homologous spot where recombination is relatively frequent (10% or less of the opposite gender bananas) - ball pythons may have Y chromosomes that are much closer in size to the X chromosome than humans' are, there is some evidence for this in Boidae, which would make recombination easier. Not particularly useful information to me, since I'm not a breeder and more inclined towards ecology than genetics, but very interesting all the same. Much appreciated!

[dylan815]

you guys are crazy. Thanks for all the info!