#genetics talk

Is there such thing as a tortoiseshell cat with high white spotting, or is that just a calico? :3

they’re the same thing ! calico is a term used in north america for (depending on who you ask) a tortoiseshell with white or a tortoiseshell with mid-high white. in other areas, a “calico” would be called tortoiseshell and white :) fun fact: white affects a cat’s tricolor coloration so that the more white a tortie has, the more solid their spots are. here’s what i mean (phrankie cameo):

so i'm going to be honest, i'm not generally annoyed with Bad Genetics in warriors, because i understand the need for good character design, crossed with complicated cat genetics.

frostfur's family bothers me, because like. it's so. it's so wrong. every single cat. it goes so far down. and so on.

but in general, there's not a ton that actively bothers me.

that said! i do get the most annoyed when they mess up ginger inheritance. not so much tortie toms, but queens having fully ginger kits when they're black or vice versa (sparkpelt's litter, leafpool, foxleap depending on how you interpret it, etc).

uh! blossomfall and kestrelflight's spots are kind of annoying, but i've just accepted it's a new mutation in the warriors clans. very cool.

pebbleshine! she's so cute but her weird speckled thing. it's not even like, cute? like? idk. i usually default to moonkitti designs when i picture cats because i'm not really good at picturing them and i don't read the allegiances (i didn't read them when windclan's only entry was tallstar, the erins think i'm reading them now?)

and moonkitti! that pebbleshine is so cute. but she's not what she's described in the books? idk. her description is weird too just. pebbleshine.

like i wish we had more patched cats. stop w/ the weird spots thing give me more brighthearts. thunderclan has so many white cats how does it have so little patches?

sigh.

uh. and ig the only other thing is. someone was asking about leopardstar and i went off on them a lil (v sorry), and this isn't a book thing, it's a fandom thing, but like?

in general, giving a really specific cat breed for a clan cat doesn't make sense. especially bengals, this one bothers me the most, because it requires wild blood.

idk. it just. it gets under my skin. i think it's because like? i have a lot of strong feelings about the ethics of feral cats, wild outcrossings, and cat breeds, and they all kind of muddle together here.

but i digress, there's not a ton that really actively bothers me. i just kind of piece together imagry in my head from what i remember. ashfoot is a grey tabby because that's how i first pictured her.

heck! even leafpool and squilf don't actually make me angry. like, it bothers me, but you know what? maybe leafpool is secretly sandstorm and dustpelt's child. maybe they had a one night stand. i neither know nor care.

plus it means in redacted sad medicine cat au i get to leverage leafpool's appearance to my favour

it’s funny because I didn’t care about that with Yarcha and his family tree. Yarcha isn’t technically correct. maybe he himself is but not in relation to his family! 

Yarcha is genetically a black cat. Him becoming orange is caused by a phenomenon called ‘rufousing’, which means the background colour of a tabby cat (brown in case of a genetically black cat) turns reddish! This is mostly the case with Abyssinian and Somali cats (which Yarcha was based on!) If he didn’t have this strong rufousing he would look the same as his son Ma’ree, who has mostly brown fur.

This causes a problem with his daughter Rilyn though. She is a tortoiseshell, which means one of her parents must have red too (since red is one of the most dominant colours). This would mean that Yarcha would have to be a tortoiseshell too! 

i can't believe i haven't explained this !! >_<

rufousing is a polygene (multiple genes that contribute to an effect) that affects the "warmness" of a tabby cat's coat! (we don't know exactly what genes cause it yet.) basic examples, left is a black mackerel tabby with low(er) rufousing and right is a black mackerel tabby with high(er) rufousing

this is what black tabby fur looks like (source is sparrow's garden):

ignore the red fur on the right for now i can't crop it out.

agouti (aka tabby) fur has bands of eumelanin (black) and phaeomelanin (red) that makes the fur between a black tabby's stripes appear lighter and more brownish. the amount of "yellowing" this fur has is decided by rufousing!

often, rufousing is most visible in a cat's cheeks, chest, stomach, and legs. it's also especially visible in areas where more of the shaft of the fur is visible, like where this cat's fur is folding up where they're crouched:

ok obvious question: how are these not tortoiseshell tabbies?

a: although rufousing is decided by the presentation of phaeomelanin, which makes red cats red, these cats with high rufousing are still black-based! all black-based tabbies have phaeomelanin in their fur, rufousing just decides the visibility of it. notice how the stripes on tabbies with higher rufousing still remain black - if these were tortoiseshell tabbies, their stripes would also be red.

i'm sure i've explained this at some point but i can't find it everyone says thank you tumblr search function

simply, a chimera is when two zygotes fuse in utero and become one cat (this can occur in all sorts of animals and plants and other kinds of organisms as well but we're talking about cats here)

it does NOT mean all chimeras have some kind of genetically impossible patterns or are inherently visually striking. there are definitely many kinds of chimeras out there that simply go unnoticed because they are two solid black cats or a red and a white cat fused, for example. chimeras can also have patches with xx and xy chromosomes if a female and male cat fused

here's a graphic from the messybeast about it

however, chimeras can of course display coat patterns that are generally otherwise genetically impossible, for example (chimeras from the messybeast):

dense and dilute colors (red and dilute black (blue)):

point and non-point, xx and xy (red (flame) point male and non-point tortoiseshell female):

(probable chimera) shorthair and longhair:

(probable chimera) solid and tabby (dilute black (blue) and red tabby):

genetically, they're really cool. i would love to see more actual research into them!

why i get so fired up about it is the misinformation that flies around online about chimeras. if you look at that graphic from the messybeast up top, you'll see a note that a split-face appearance in tortoiseshell is not an indication of chimerism.

anyways, let's google chimeras for a second

ok.

i'm in the trenches with seeing all these "we said so" chimeras because i'm constantly tagged in them. please note! i'm not mad that people tag me in them and don't know! it's not common knowledge especially with all the people trying to catch some internet fame with their super real for sure chimeras

saw this wonderful cookies n cream cat on instagram

the messybeast has addressed this better than i could! (scroll down a about halfway on the linked page) basically: we're not 100% sure

i’d say he’s what’s called pseudomelanistic! (we don’t know exactly what genes cause this yet) this happens when an excess of melanin is produced, making dark markings much more prominent. this is also called abundism !

dx: a black classic tabby with pseudomelanism/abundism

Potentially a really dumb question, but I'm curious - is it possible for a cat to be an ACTUAL chimera without anyone ever knowing? (For example, a chimera who just.. looks like a solid blue cat)

Thanks,

Notactuallysigningoff 🌻

yes absolutely ! the only thing required for a chimera is that it’s two fertilized eggs that fused. i even think that this situation wouldn’t be that uncommon (proportionately to other chimeras - chimerism is still an insanely rare condition) considering how often litters of kittens have similar looking siblings. also bringing in the ways cats can be multicolored - eg basically any base color and white, black/chocolate/cinnamon and red (and their dilutes) - this definitely happens. in fact, one of the cherished local celebrities here at whatcoloristhatcat,

DAWNTREADER TEXAS CALBOY!!!!!