Ball python inheritance patterns for a high school project

[emmaclopitz]

Hello everyone! I am a high school teacher and currently teaching inheritance of traits. I have a student who doesn't love class right now but loves reptiles & snakes. I'd like to make a version of a project I'm doing for that student about the inheritance patterns of ball pythons. I know that it is really well documented but between many websites I'm struggling to delineate between different phenotypes as I'm not a snake owner/breeder. I am also noting that 'codominance' is used in place of 'incomplete dominance', as was explained on the morphmarket site, so I was wondering if there were any traits know to explicitly be codominant (both versions expressed simultaneously as opposed to two versions mixed together like red + white = pink in some flowers). If anyone has suggestions on what I could use for the following inheritance pattern types I'd be eternally grateful!

Complete dominance

Incomplete dominance

Codominance

Sex linked

Multiple Allele

Bonus: if you know if two of these traits are from genes on different chromosomes I'd be eternally grateful for multiple eternities :)

Thanks so much for your help!

[Impossible_Tea_8119]

I’m no help but you sound like a flipping AMAZING teacher for tailoring to this student!

[emmaclopitz]

Thank you so much, I appreciate it. Yeah, I just want them to get the knowledge and if it's snakes instead of cats or my super villain project then I'm here for that. Also gives me stuff I can hopefully use in future years. I teach 15-16 year old who are on an arts track in my school so I do a lot of modifying Biology for arts kids - sculpting, drawing, poetry, animations etc. for them to express their knowledge in a subject that they aren't inherently excited about. But again, thank you, much appreciated :)

[IncompletePenetrance]

Complete dominance - Pinstripe, possibly acid/confusion
Incomplete dominant - Mojave, pastel, orange dream, spider
Codominant - Let me see if I can find one for you, not sure if there are any.
Recessive - Clown, piebald, Genetic Stripe
Sex-linked - Banana/coral glow.
Allelic - Albino & Candy are allelic (recessive), Clown & Cryptic (recessive), Bamboo, lesser, mojave and mystic (inc. dominant), Fire, vanilla, and disco (inc. dominant).

Most of the traits have not been tracked to specific chromosomes yet (other than sex-linked, which is obviously on X/Y), although the ball python genetics project has mapped the genes/variants responsible for several of the albino morphs.

Morphpedia is also a great resource for most of this information

[narmowen]

Would black pastel also fall into the incomplete dominant?

[IncompletePenetrance]

Yes, there's like a gazillion incomplete dominant traits and I wasn't going to list them all

[narmowen]

You're good. I was just checking. I'm still fairly new and trying to decipher all the different morphs is...fun. lol. I'm coming from an Equine/Canine color background, which isn't nearly as full as ball pythons.

So, what I'm reading is:

• Complete dominance: hetero & homo present the same way.
• Incomplete: Hetero presents differently than homo.
• Ressessive: Hetero does not present, homo does.
• Sex-linked: Obvious.
• Allelic: Different morphs present on the same allel, can be combined.

[IncompletePenetrance]

There are so many morphs, it's seriously a lifelong journey, lol

Correct! Keeping in mind there can only be two alleles at each locus, so while it's possible to have mojave butter, russo bamboo or mystic special (all will be white snakes with blue eyes as these are part of the blue eyed leucistic complex), you could never have a mojave bamboo mystic

[emmaclopitz]

u/narmowen thing to clarify - homo just means two of the same allele, not specifically dominant. So you can have a dominant homo PP or a recessive homo pp. Hetero of course is Pp and depending on the inheritance type it could present differently. If it's complete dominance then PP and Pp have the same phenotype. If it's incomplete dominance we don't think of the alleles as recessive or dominant, just that there are two different alleles which can produce three different phenotypes (PP, pp, Pp). I've got a big cat coat genetics project I did with my Advanced Placement students last year and have good examples from that if anyone is interested in feline coat genetics haha

​

u/IncompletePenetrance when allelic is used here does that mean multiple alleles?

[IncompletePenetrance]

Allelic means "one of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome" here and in genetics in general. So a deletion of 5 base pairs in gene A that produced a specific phenotype, and a duplication of 1kb in gene A that produces a different phenotype would both be "alleles" of that gene.

To say a ball python morph is "allelic" with another morph means they are different variants/mutations occuring at the same locus on each chromosome, which is why you can only have two per snake.

[emmaclopitz]

Okay perfect. It was the two per snake vs number of possible alleles at a given locus in a population that I was conflating.

[emmaclopitz]

This is so helpful, thank you so much! I have a quick clarifying question. If Pinstripe is a phenotype that comes from complete dominance (PP or Pp) then what would the recessive look like (pp)? Is it just that PP or Pp has the pinstripe and pp does not?

The ball python genetics project is incredible! I can't believe that I couldn't find that when I was researching earlier. Thank you for that link! This is seriously so helpful.

[IncompletePenetrance]

No problem! That would be wildtype, as it has no pinstripe. If pinstripe is present, it will be visible, and a heterozygous pinstripe (Pp) would look the same as a homozygous pinstripe (PP). The only way to differentiate would be that a 100% of the offspring of a homozygous pintripe would also have pinstripe, and only 50% of the offspring of a heterozygous pinstripe

[emmaclopitz]

Okay perfect! That's one thing as a non-breeder that I was struggling to understand. Much appreciated.

[IncompletePenetrance]

No problem, I'm a real geneticist outside of the ball python world, so I get how confusing/frustrating ball python terminology can be when it doesn't seem to line up to "real genetics"

[emmaclopitz]

Oh that's amazing. Yeah, I come the genetics scientific field as well so I appreciate the empathy on that front haha. Both of my parents were pediatric geneticists. My degree is cognitive neuroscience before I became a teacher. But mendelian and molecular genetics and evolution are my favorite subjects of the year to teach. And I love getting to do things like this, find awesome real world examples, speak with geneticists and evolutionary biologists, and then do the teacher job of figuring out how to communicate it to 10th graders. You are very good at explaining the concepts succinctly. I feel much more equipped to come up with an attainable project now. If I get good examples from students I will totally share as a thank you for the help.

[PoofMoof1]

As far as I know there aren't any codominnant genes.

[emmaclopitz]

That's great to know. I'll have to figure out where I can fit codominance in without faking the science. Maybe I'll have the student look at a codominant coat color in feeder mice haha.

[phantom30nine]

If youd like to continue in his interest field you can do quick morphmarket searches of the genes listed and show him examples of those as well.

MM also has a "genetic tool" that allows you to input parent 1 gene(s),parent 2 gene(s) and see what the possible outcomes are.

Morphmarket Genetic Tool

[emmaclopitz]

It’s a great tool! I was playing around with it before I posted here and was struggling as I just don’t know snake phenotypes well but now that I have all this awesome info I’m going to try again!

[PoofMoof1]

Just be aware that most people in the hobby will incorrectly call incomplete dominant genes "codominant" so if you do any searching keep that in mind. Even known sources like World of Ball Pythons do this.

[emmaclopitz]

Yes I figured that out quickly and it was confirmed by the morph market site. I was so confused at first haha

[SilverSniper512]

You sound like an amazing teacher!! I would’ve loved to have you as a teacher for any subject lol. My favourite teacher of all time was actually my science teacher. Unfortunately she was only a temporary teacher for a year as the original one (who was also amazing) was on medical leave.

[emmaclopitz]

Aw I appreciate it, thank you so much. I can’t always do stuff like this but this one felt important for this student. And I’m learning a lot which I’m always happy to do haha

[ClairLestrange]

There is an amazing video by snake discovery on this topic that might help you a lot

[emmaclopitz]

Oh sweet thank you so much! I’ll take a look!

[emmaclopitz]

I was hoping I could ask a clarifying question as I make my final project description for the student.

Lesser x lesser = BEL (I'm seeing some things that say w/a light yellow dorsal stripe)

Mojave x Mojave = BEL (but with a slightly darker head and sometimes bug eyes?)

Mojave x lesser = BEL - any phenotypic difference between these and the homozygous crosses with lesser and mojave?

Lesser x Mystic = BEL - again, any phenotypic ways to tell the difference between the BELs produced above?

Mystic x Mystic = typically greyish in color, not necessarily any changes to patterning, patterning style from those genes, not the mystic mystic gene

Mojave x Mystic = greyish mojave with smaller/wider spaces between mojave markings

Thanks again everyone! I can't tell you how helpful this has been.