#so any variation of tortie i assume is female

[mallowstep]

Genetics ask! I know that male torties/torbies are very rare and caused by a genetic mutation, but with those who do exist, are there any prerequisites with their parents? I’m assuming they’d have to carry the red gene since tortoiseshell is one red, one not-red, but I barely know anything. And based on this, is it better to just headcanon cats like Redtail as biologically female?

alright! hello, anon.

since i had to do more research than usual for this one, reminder that:

i am not an expert. i can and will be wrong. you can find my self-corrections under #corrections, but those are only things i or others have noticed, and that i've had the time to write a correction to and explain.

disclaimers out of the way, let's talk about tortie toms. (and torbie toms, and calico toms, it's all the same deal.)

if you know how ginger works, you can skip the next few paragraphs.

orange (ginger, red, etc.) is sex-linked in cats. what this means is that the gene that causes orange cats is on the x chromosome. it is also codominant, which means that having an orange x chromosome (Xo) and a non-orange x chromosome (X) is not black or orange, but both.

basically:

X or XX: black

Xo or XoXo: orange

XXo: tortoiseshell

yeah?

now, for the rest of this post, i'm going to be writing O and o instead of Xo and X because it's one less character and i don't run the risk of putting three x chromosomes together.

okay. so because torties need two x chromosomes, they're typically female. the way tortie itself works is basically, cells activate one of the genes (O or o) at random, creating patches. so you need two copies.

wikipedia says about a third of male torties have klinefelter's, which is the XXY karyotype. while this does have physical changes associated with it, the only way to confirm (humans have) klinefelter's is to test it genetically.

luckily, cats are very helpful about demonstrating it. what with them being tortie and all.

(we're also lumping in the variations of klinefelter's here. you can get XXYY, etc., and they all fit into the same broad idea.)

anyway, the extra x chromosome can come from either the mother or the father. this makes tortie toms...not quite easier, since the prereqs are the same, but y'know. if mom is Oo, dad doesn't matter. if mom is OO, dad has to be o, and if mom is oo, dad has to be O. same rules as usual.

XXY toms are going to be...not sterile, but pretty infertile. using human stats, about 50% can produce sperm, although the likelihood of them having kits is still low. humans with klinefelter's are also taller than average, so keep that in mind.

again, and this might be a correction on my part, i can't remember, but tortie toms aren't strictly going to be visibly different than other toms.

okay, so most people stop at klinefelter's, but there are two other ways to get tortie toms: mosiacism and chimerism. these are often confused/combined, but because i strive for generally being accurate, i'll go over them both.

mosaic cats carry multiple genetic lines, because of a mutation. this can either be somatic (happens in the body, is not hereditary), or germline (happens in reproductive cells of parents, is hereditary).

this is not always a gain of a line, you can lose a chromosome as well. the difference between somatic and germline and how it affects torties goes over my head, so i'm not going to speak to it, other than i'm pretty sure we're talking about somatic mosaicism. i think. again, not a biologist or geneticist, just a hobbyist with an internet connection.

right, so what happens is basically, some cells lose their extra x chromosome, giving you a cat with karyotype XXY/XY. these cats are more likely to be fertile and generally have less effects of klinefelter's. i'm not entirely sure how this affects tortie presentation, if at all, but it does happen.

i suppose you could also have some kind of mutation that gives you an extra x spontaneously, but that would be unlikely to cause torties, because it would also have to mutate into the other O allele.

again, i really want to stress that while i'm not bullshitting, i'm also not speaking definitively here.

last up is chimerism, where two embryos fuse in the womb, creating mixed genes.

i'm using a picture of a dog, here, because this is what goes through my head when i think of chimeras. you'll have to take my word for it, but while this would be a normal tortie cat, it can't really happen in dogs without some kind of mutation. and chimerism, given the extent of the patching, is pretty likely.

right! chimera torties are going to be, afaik, normal levels of fertile, although it's likely that they can pass on either black or red, not both.

(while i'm here, before we move on, there are a lot of types of chimeras. this type is called tetragametic chimerism, and it's rare in humans but more common in other animals. it's hard to know how common it is, because the differences are often very subtle, and hard to test. it's also not mutually exclusive with mosaics or klinefelter's, just to really muddy the waters.)

i don't have statistics for how common mosaics and chimeras are, and there's always, "a different type of mutation that doesn't fall into this category"

for mosaics and chimeras, the rules for inheritance seem to be the same as for klinefelter's. there's the added note that, because there can be multiple sires within one litter, a ginger queen could have kits with a ginger tom, and get a tortie son, as long as she also...ahem...with a black(/brown, etc.) tom. (or vice versa, with all brown and a ginger.)

okay! so that's basically how it happens.

as for the second part of this question, well. "is it better?" is a matter of opinion. i don't think anyone is wrong for having tortie toms. i don't care. (a) it is possible, and (b) we're all just having fun.

i, personally, do not think redtail is karyotype XX, because i like him being sandstorm's father with brindleface. idk. i like brindleface. yes, i know this raises huge genetic problems, and it's not very canon. i don't really care. i read that redtail fic where he thinks about sand&brindle as he's dying and it hasn't left me.

that said, i'm still a sucker for trans redtail. love it. idk, this is kind of hard to explain. like? it's not my headcanon, but i still appreciate it.

anyway! to the point: if you care about statistics and likelihoods and how many tortie toms you've had in the clan, yes, you're probably better off saving your chromosome anomalies for when they need to have kits, and using XX karyotype for the rest.

(under the cut: matthew rambles about trans cats and gender identity for a while)

i'm pretty sure cats don't have the western concept of gender. i don't think they have a human concept of gender, either, but at some point i need to be able to pin down something, and i think a third/fourth gender is closer to what they have.

i've been thinking about this a lot lately, because i decided i wasn't satisfied with my old approach to trans cats. i can do better than that. i decided cats don't have gendered pronouns, so why should the solution be, "trans cats don't really get to do anything about it"

no. i am dissatisfied with that.

at the same time, for specific reasons: i also don't think cats are trans in the western sense of the word.

because if for nothing else, remember that cat sexual dimorphism has a bigger effect on their life than in humans.

like, queens are going to be uncomfortable around male cats they don't hella trust and their kits. that doesn't go away if said male cat isn't a tom. y'know?

i'm in a constant state of tweaks with this, because i basically: form opinion, test opinion, refine opinion. my initial opinion was too harsh. and!

part of what's changed is i decided i wanted fernsong to be able to raise his kits in the nursery instead of ivypool. so i had to adjust how i think the nursery and queens work, slightly, to permit for that. now, i can turn back to gender and think about it some more.

i'm not going to coin any new terms, because i'm not in that kind of mood, but i think there is some idea of a female cat who is not a she-cat. i don't think the cats would call them a tom, but i'm not sure what they would say or how they would describe it.

i think they would just, on some level, get it.

actually okay you know what! i do need some lingo here. queens = cats who are raising kits in the nursery. she-cats = XX karyotype, considers self female (cis, if you will). toms = XY karyotype, considers self male (cis, again). and uh...we'll go with...

god i hate. i don't want anything i say in this ramble to be considered "words i am going to now use consistently" because i literally just need some way to describe this for my own sanity. with that in mind, let us use molly for XY karyotype, but not a tom, and...how about gib for XX karyotype, not a she-cat.

again, i don't want that to be considered permanent, i'm just fishing at words people use to describe cats so i can have something to work with.

right so, i don't think cats think gib and tom are equivalent, but i also don't think they (as a society) care about that.

like, okay, let's say redtail is XX, but not a she-cat. there's nothing to really be done (heck, if he wants to be a queen, that's still fine), cats don't have gendered pronouns or names, but at the same time, there's an intuitive understanding of what that means.

this kind of ties into the matriarchy, kind of? like, hm, queens are an important part of the matriarchy, but at the same time, she-cats inherit family lines. not that cats inherit much, but still.

i'm getting very abstract here. take, uh, like let's say a hypothetical trans mothwing. i think a lot of people have that headcanon?

and i think, like, mothwing would not be considered a tom. if cats had a concept of sexuality, leafpool would not be straight, because she likes mothwing, and mothwing is not a tom.

but! i would still think willowshine probably is the first line for nursery visits, at least when the kits are very young.

and i don't think anyone there would be unhappy with that deal.

right. i just kept rambling for a while, because i've been thinking about this and obviously it's semi-tied to the question.

tl/dr: cats don't care about gender, because they are cats meowing at each other in the woods. if a cat says they're not agab, everyone is just cool with that.