That’s a nice list and all of them are very vital.
I’m going to have to look up this hidden gene phenomenon, I’ve not heard if it.
I’m not a spider fan but I don’t disagree with people owning them, so really I can’t add any comments on them.
Also I wondered, is DNA testing a thing for snakes? Can you tell exactly what genes are present and work out it’s exact morph/heritage or does that need a huge database of sorts to start with?
Edit: are we talking hidden gene woma here?
Lmao he’s putting it on a list of myths lol not saying it’s true
Source:
Ball pythons are different from other snakes in how they pass on their genetics. To understand how, we have to think about genetics generally. Until very recently, all snakes were thought to have ZW chromosomes.
DNA. As you know, DNA dictates the appearance and physical structure of an animal. The sex chromosomes are what give male and female animals different sex organs and structures.
Humans have an XY system. Women have XX sex chromosomes, whereas men have XY chromosomes. This means that it’s the sperm rather than the egg which decides the sex of offspring.
That’s because there’s a 50% chance the man will pass on an X chromosome, or a Y chromosome. The woman will always provide an X chromosome to whatever offspring they produce.
In animals with ZW chromosomes, females are heterogametic, i.e., they are the ones with two different chromosomes (ZW). Males are homogametic (ZZ). They have two exact copies of the same chromosome.
This means that it’s the female’s egg that decides which sex the offspring will be. It was thought for half a century or more that this was the case for all snakes—but it’s not. Ball pythons, at least, are XY rather than ZW.
In humans, the X and Y chromosomes don’t tell the body much more than what sex you are. But in some animals, snakes included, their sex-determinant chromosomes can also determine their size, color, pattern and so on as well as their sex. This is crucial to how banana ball python genetics works.
This is crucial because according to a paper in Current Biology
(https://www.sciencedirect.com/science/article/pii/S096098221730711X)
, the banana ball python morph is in the snake’s X chromosome. It also matters because up until this discovery was made, banana ball python genetics didn’t make sense. Until recently, they were an anomaly among ball python morphs.
What’s confused breeders up until now has been this. The banana offspring of a male banana ball python whose father was also a banana will be 95% male. Female banana ball pythons can produce both male and female banana ball pythons.
But all of the banana offspring of a male banana ball python whose mother was a banana will be 95% female. Search for banana ball pythons for sale, and you’ll come across the terms ‘male maker’ and ‘female maker’ all the time—this is what that means.
This only works if the male has XY sex determinant genes, and the female has XX. To clarify further:
This wouldn’t have made sense if ball pythons had ZW genetics. If that were the case, then a male banana ball python would have equal parts male and female banana ball python offspring.
On rare occasions, genetics can bend these rules. Sometimes, part of one chromosome will detach and then attach itself to the other chromosome.
According to a paper published in Genetics
(https://www.semanticscholar.org/paper/Chromosome-Structure-and-Crossing-Over.-UHL/76e430cd69d4d67797ace147da2d51caa4d413d9)
, this is known as chromosomal crossover. In the case of a male who inherited their banana gene from another male, if the banana gene crosses over to the X chromosome, their daughter could inherit it. This only happens rarely.
Why Is Breeding Banana Ball Pythons Different?
It’s different because the banana morph is a part of the X chromosome, but no other ball python morph is. There’s no such thing as a ‘male maker’ enchi, or a ‘female maker’ albino.
That’s because the genetic mutations that create these morphs aren’t within the sex chromosomes. They’re therefore passed down in equal ratios, no matter what the sex of the offspring, unlike the banana morph.
And not only that, but it’s different because other snakes are still known to have ZW chromosomes. According to the journal Evolution less genetically ‘advanced’ snakes like boas and other pythons do have ZW sex chromosomes. It’s little wonder breeders were so confused.
Wow… I see that I have garnered a whole bunch of replies here. However, I have been tangled in meetings all afternoon and I am about to drop in to another couple hours worth so… I will hit on these replies when I can get a free minute but in all likelihood that will be tomorrow at some point.
In the meantime, please feel free to ask more questions 
Glad to see this got some thinking and learning and teaching going! Thanks for all the input.
I disagree completely. Continuing to use the wrong term when you know it is wrong just because it is easy is not an excuse. Further, I would argue that a sizable section of the hobby do not even know it is wrong. When something is wrong, you work to correct it. We should be educating people, not perpetuating wrong information
I never said to call it “het Pastel”. As hobby terms, Pastel and SuperPastel are fine. But genetics is a defined science and as long as we all want to claim to understand the genetics of our animals then we should be using the terms correctly
Not. Most definitely NOT. Frequently people will try and argue that adding more morphs will fix the problem with a certain morph. This is like saying that if your car has a faulty carburetor you can fix it by smashing the tail lights.
Eaglereptiles pretty much covered it but in a bit more simple terms; The mutation for Banana/CG sits on the sex chromosomes. This, generally, means that the mutation is inherited in a fairly specific manner. In the specific case of balls, there is a slight deviation however that confuses people.
A little bit of science jargon here. In lower-level snakes, evolutionarily speaking, the sex-chromosomes follow the X/Y system and the sex-chromosomes themselves are highly isomorphic, e.g., same size and shape, (higher-level snakes use the Z/W system and the sex chromosomes are heteromorphic). Because the sex chromosomes are structurally very similar you can have material exchange between them and sometimes that material exchange involves the mutant gene. Clear as mud so far LOL?
So… The Banana/CG gene in your male sits on the Y chromosome. This means that only the offspring he produces that carry the Y chromosome (i.e., males) will inherit the mutation. But… Remember my mention of material exchange between chromosomes? That happens at about a 10% rate for the area that carries the Banana/CG gene. When that happens the mutation would switch from the Y chromosome to the X chromosome and so you would get a female carrying the mutation. So there is a possibility your male could produce a female, just at very low odds.
Make sense?
Yes, it is totally incorrect. Co-dominant and incomplete-dominant are two entirely different things. Claiming Co-dom really means inc-dom is like claiming the word “dog” really means “cat”
Yes, DNA testing is a thing for snakes but no, not at the level you are talking about.
Ben Morrill/Reptile Genetic Services offers sexing services from sheds for some species, primarily colubrids.
In theory, it is possible to build up a database like you describe however would be extremely cost-prohibitive. Sequencing in and of itself is pretty cheap these days but fully annotating a genome is no small task and then you have to comparatively analyze the genomes of every known mutation back against the wild-type genome, identify the mutation, which may be as minor as a single “letter” change out of around 1,500,000 “letters”. That takes a pretty significant amount of sequencing and a huge amount of computing power. Soft numbers… You might be able to pull it off for $500,000.
Not explicitly but that is the definite origin of the issue. Back in the dark ages, NERD had two similar looking animals that they called Woma. When they bred one to a Lesser it made your run of the mill Lesser Woma. When they bred the other to a Lesser it made a SoulSucker. And so they put forth the claim that there was some gene “hidden” in the second animal that caused the SoulSucker phenotype. The reality is that Woma and HGW are two completely different morphs. But that myth of a “hidden” gene persists… I can think of at least a half dozen other times it has been used to explain something rather than the more scientifically sound arguments people have put forth
@t_h_wyman I get what you’re saying… but I don’t think there’s anything damaging about calling an incomplete dom a co dom. Kinda seems “get off my lawnish.”
I don’t correct someone every time they say “The definition of insanity is doing the same thing over and over and expecting different results”…even though that is incorrect.
And I don’t interrupt every time someone misuses the term “literally,” when they mean figuratively. Lol. Some things it’s ok to just let go.
I’m happy to get educated myself…but I’d choose my audience with whom I chose to get more technical. Many people aren’t going to be interested in knowing.
I thought that might be the case.
Hopefully something special can be found within snakes that will interest scientists a bit more and maybe have such a database in the future, but searching for that 1 in 1.5mil in every morph would take a whole team many years. Then again is there a “standard” wild type out there that doesn’t have some sort of genetic mutation? What snake would be our “blank” slate?
After replying I went and did some research and that’s the only conclusion I could come to myself. If these two animals are branching off completely different ways then they are not related. They obviously have a different ancestors.
What I should put was , For some reason the wrong terms are used to describe genetic heritage in the ball python context. What you know as co-dominant in ball pythons is in all actuality incomplete dominance. Vin Russo covers this topic in his book, The Complete Boa Constrictor.
Well, here you and I differ. As a geneticist I do think there is something damaging about using the wrong term to describe something when we are actually talking about genetics.
.
I feel that I am choosing my audience quite well. If the “old-guard” called it the wrong thing and now know that then it is up to them to properly educate the new people, not continue to peddle wrong information. Forums like these (and bp .net and the former BLBC) are often frequented by newer keepers as places to learn. That is why I have, and will continue, to bang this drum. Through the efforts of people like myself and Warren Booth and Nick Mutton people actually do learn and start using the correct terms
.
If I were designing the experiment I would probably pick up a dozen or so WC bush babies and use sequencing data from them to make a consensus genome.
.
The reason is because one very big name breeder started misusing the term and everyone just accepted it as fact because he was a big name breeder. And it is not just ball pythons that it is used for, it has permeated the hobby; hognose, retics, Burms, boa, corn snakes, carpets, leopard geckos, monitors… The only species where people do not use it are the ones where no one is breeding for morphs
.
I have not read Vin’s book but I am heartened to hear he is voicing the change. And, while I have never spoken directly to Vin, my guess is that his switching to the correct usage might trace back to myself and others working to effect the change
Well I guess someone has to do it. Godspeed
Do you see this being something that is ever going to be attempted?
And do you know of any such DNA testing on any animal on such a level, except humans?
This had led me to another couple of questions that I’m about to go and search up on but if you have any input I’m really happy to hear it.
Is genetic modification a possibility with them?
If so, to what extent?
Could we take it too far with morphs to the point it’s just no longer a royal python and needs its own species name? Where no matter what it is bred with, it will not produce a normal wild type looking royal python. Or will there always be that “I’m a python” genome being passed on?
Thank you for taking your time to answer my many many questions 
I was raised to never say never, but pythons are not exactly an animal that garners a huge amount of scientific interest so it is not likely. Maybe in some not-to-distant future, when genomic sequencing and analysis becomes as cheap/easy/mundane as computers are now, hobbyists can take on the task.
.
The pedant in me would answer that the acts of selective breeding that we engage in would constitute as “genetic modification”. But I am guessing you are asking more along the lines of exogenous gene transfer and CRISPR and the like? I do not know that anyone has ever tried with snakes but there is no reason that the established methods of genetic engineering should not work, genetics is genetics is genetics. They have successfully used CRISPR to mutate anoles.
.
Over geologic time frames, sure we could drift them away from being canonical P. regius the same way we drifted dogs away from wolves. However, consider how long humans have been domesticating dogs and they (mostly) still easily back-breed to wolves. So, to all intents and purposes, they will always be P. regius no matter how morphed out we make them.
.
Any time 
That is exactly what I meant, sorry I could have worded it better. Its actually a CRISPR video by Kurzgesagt that got me thinking this in the first place. I just wasn’t sure if there would be a difference in usage of it in reptiles, but your right… Genetics is genetics.
I couldn’t have asked for a better example.
No need to apologize . I figured that was probably the case
.
Not familiar with the video but I would say the only fundamental difference is in methodology of execution due to the peculiarities of reptilian reproduction. Here is the anole CRISPR paper if you are interested:
It seems they are a lot further along that I would have believed and it seems that it may be a possibility in the distant future.
Massive thank you for sharing that with me, I’m surprised at how well I understood it.
Here’s the Kurzgesagt video if you fancy it.
I have a question on the banana/coral glow sex link information provided by eagle reptiles. Which by the way reply clears up a lot. My question is for the non-bananas in the clutch, are their sexes determined as well by the banana/cg carriers sex? Or would I get a natural male to female ratio from the non-banana/cg snakes. Thanks
My understanding is that it does…
If you have a Male Maker all bananas and combos will be males while the rest of the clutch (non banana offspring) will be females
If you have a Female Maker all bananas and combos will be females while the rest of the clutch (non banana offsprings) will be males.
@t_h_wyman and @stewart_reptiles can likely correct me if I am wrong.
Yes, but that applies to male bananas in a cross only. To add on if you cross a female banana then you should end up with both male and female bananas and non-bananas equally
My brain couldn’t comprehend this for MONTHS when I first got into the hobby I had to have someone explain it like 4 times. It was like the Friends meme with Joey and Phoebe lol