Potential explanation for banana inheritance pattern

[DRW_Reptiles]

I've brought this up a few times and have posted papers done on other animals such as one on a species of Tilapia that explains this. Yet the all mighty smart genetics experts here shoot it down as garbage, as it was not myself who did the studies or wrote the papers. I have never suggested that the chromosomes were swapped, but the studies have shown the same sex linked sex ratios.
I research a lot and do know quite a bit about genetics. It doesn't take a degree to learn things. On the same note, not everyone with a degree is smart, or has common sense.

I think that you may be on to something though and what you propose is not uncommon.

Great work!

Yeah, for the sex-linked pattern to make sense, the male has to be heterogametic (ZW). Otherwise, for an incomplete dominant trait, you wouldn't expect to see all banana male offspring or all banana female offspring when the father is the one carrying banana. Even if it were some weird epigenetic thing it would be hard to understand.

I was kind of surprised when I couldn't find any papers that conclusively show that male pythons/boas are ZZ. But since the chromosomes can't be distinguished visually in a karyotype, you'd have to sequence the genome, which is expensive. It's logical to assume they are ZZ but as we have seen in other lineages, the homo/heterogametic sexes can swap during evolution. But without any hard evidence it is just a fishing expedition that costs lots of money.

I did read a paper where they sequenced the genome of a female boa (presumably because they thought they are ZW) and found the sex chromosomes to be homomorphic throughout their entire length and that recombination (crossing over) happens pretty much along the entire chromosome. They were suprised they couldn't locate a region that was different between the Z and W and could thus serve as a sex-determining region, although they addressed possible reasons for this. Of course I have my own idea of why they couldn't find it (the animal would actually need to be ZW). Too bad they didn't sequence a male

I have a PhD in genetics, and some might scoff at how I explained this (the fact that it was after 1:00 am is partially to blame), but I wanted to make it accessible. I try to never be condescending about science. At the same time I stressed that this is just an interesting thought experiment since I don't want people to go away thinking that this is the case when there isn't really any evidence for it other than the banana inheritance pattern itself. I have sat on this ever since the bizarre inheritance of banana was reported by some breeders, because I figured I was overlooking something, but I still see no reason why this can't be the case. Simply swapping the homo/heterogametic sex makes the whole inheritance pattern make sense. Hopefully as snake genomes continue to be explored with modern tools we'll know the real answer eventually.

Thanks for your interest!