by mars » Sat Mar 09, 2019 1:16 pm
below is a complete guide to modern thylacine genetics. don't worry, you don't need to understand genetics in order to participate! the only time genetics will come into play is when breeding your thylacines. understanding genetics can help you predict the colors and markings that your pups might get which can assist in planning breedings, but it's 100% okay to breed and participate without a knowledge of genetics.
the genetics system in modern thylacines is heavily based on coat color genetics in other mammals, particularly dogs and cats, and each pup is rolled for colors and markings by the artist.
sometimes, getting two copies of a gene in real life can harm an animal (examples of this are merle and bobbed tails). thankfully, modern thylacines has no genes that can harm pups so you are free to breed any unrelated thylacines without worry!
if you have any questions at all, feel free to ask any time - I'd be happy to help or explain it in a different way (:
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check back in later for the complete guide!
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what is genetics? I can't understand the words in the guide! where do I even begin to learn? this seems too complicated...
if these are thoughts crossing your mind, this is the section of the guide for you! I'm here to make genetics easy and fun.
let's start with some basic genetics terms!
genetics: the study of heredity, or how certain features pass from parents to their offspring.
pigment: the thing that gives hair or skin its color.
melanin: the most common type of pigment in animals. thylacines have two types: eumelanin (black) and phaeomelanin (red).
genes: a set of instructions in an animal's dna that tell the cells in the body how to produce pigment.
alleles: different variations in genes that are represented by letters. in dna, they come in pairs. (ie: A, a, ab, ac, a1, a2, etc)
locus (plural locii): the spot on dna where a particular set of alleles is located. represented by a single letter. (ie: the A locus)
heterozygous: a pair of genes that are different. (ie: Cc, Ddb, etc)
homozygous: a pair of genes that are the same. (ie: CC, dbdb, etc)
order of dominance: shows which genes 'lead' over others, or take control when in a heterozygous pair. dominant genes lead over recessive genes. this is usually shown in a chart with the most dominant gene on the left and the least dominant gene on the right.
incomplete dominance / co-dominance: when two genes are both expressed instead of only one taking control. in an order of dominance, these are shown with an equals sign between them.
genotype: what genes an animal has. (ie: Aa b1b2 Cc DD, aa b6b6 cc Ddb, etc)
phenotype: what an animal looks like. (ie: black, red, etc)
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every section in this guide includes a short blurb on what each locus controls, a chart showing the dominance of the alleles, a list of the alleles saying what they do, and picture references. as an example, let's look at a made-up locus, the Z locus. let's say that the Z locus controls what color an animal is.
in an order of dominance chart, we use greater-than (>) and equals (=) signs to show which genes have the most control. the dominance chart for the Z locus is:
read the chart from left to right. this means that:
• Z is greater than za, zb, and z. Z is the most dominant allele.
• za and zb are equal, meaning that they are co-dominant. when these alleles are paired together, a mix of the two will be displayed instead of one being more dominant than the other. za and zb are less dominant than Z, but more dominant than z.
• z is the least dominant allele. Z, za, and zb are all more dominant than z.
next comes a list of what each allele does. in this case, it lists what color each allele corresponds to:
Z - red
za - yellow
zb - blue
z - white
now let's try pairing these alleles a few times to see how they mix and match according to the dominance chart (:
• ZZ: this animal will be red since Z represents red.
• Zz: since Z is dominant over z, this animal will be red, too.
• zbz: since zb is dominant over z, this animal will be blue.
• zazb: this one is a bit trickier. since za and zb are co-dominant, and each represent blue and yellow respectively, this animal will be a mix of the two! in this case, you can expect a green animal!
• zz: finally, tiny z gets to be expressed! this animal will be white since none of the other, more dominant alleles are in this pair.
reading the picture references is a little bit tricker than reading the other charts since we have to fill in some gaps ourselves. when we write down the alleles in each possible pair, we always write the most dominant allele first. because of this, we don't always have to list the second allele. it is implied that the second allele is less dominant than - or even the same as - the first, and therefore any allele of less dominance could be in the pair to get the same result. this is how it works in the picture references; we are implying that there is not an allele more dominant than the one listed, and not a co-dominant allele that would result in a different color.
in this case, we'd have photo references for the following:
• red (Z)
• yellow (za)
• green (zazb)
• blue (zb)
• white (z)
if we were to list out every possible combination of alleles, the charts would get too long, especially for the locii with 6 or more possible alleles on them! here's an example of every combination we can make with the Z locus above, showing how we can use the picture references to fill in the gaps ourselves:
• red (ZZ, Zza, Zzb, Zz)
• yellow (zaza, zaz)
• green (zazb)
• blue (zbzb, zbz)
• white (zz)
now that you understand how to read the charts below, let's get started !!
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together, the A and B locii control what 'main' color a thylacine has. this is the darkest color on a thylacine, found in the stripes and possibly other markings on the body. let's look at these locii one at a time!
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the A locus controls whether or not the thylacine produces both eumelanin (black/brown pigment) and phaeomelanin (red pigment).
A > a
A - produces both eumelanin and phaeomelanin; follow the base colors 1 list below
a - only produces phaeomelanin; follow the base colors 2 list below
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the B locus tells you which number to follow on the list we previously chose for the base color. it controls the dilution levels of the pigment, or how strong are the colors are - are they intense or 'washed out'? remember that the base color is the stripe color, not the background color!
note: this is highly simplified. in real life, multiple genes come into play for dilution, but to make it easier I've combined them all onto one locus (:
b1 > b2 > b3 > b4 > b5 > b6
b1 - follow 1
b2 - follow 2
b3 - follow 3
b4 - follow 4
b5 - follow 5
b6 - follow 6
- - -
from the A and B locii's instructions, we can now see what the base color is:
base colors 1
1 - black
2 - chocolate
3 - liver
4 - gray
5 - isabella
6 - pearl
base colors 2
1 - red
2 - fawn
3 - apricot
4 - peach
5 - cream
6 - chinchilla
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the C locus tells us what the background color underneath the stripes looks like. the background is often a mottled 'agouti' color that's a mix of both black and red pigments, but different genes can affect which color is the most prominent and how dark it is.
remember: if a thylacine can't produce black pigment, the base will always be a shade of red/yellow no matter what! and if a thylacine is gray, it won't have as much red pigment so the base will always be gray, too.
C > cg > cr > cm > c
C - regular (a good amount lighter than the stripes; often a tawny color)
cg - golden (more yellow than usual)
cr - rusty (more red than usual)
cm - muddy (in between regular and dark; often brownish)
cd - dark (a little bit lighter than the stripes; must be noticeable)
c - absent (usually a cream, pale gray, or off-white color; pure white only on a light-colored thylacine)
here's an example on a black thylacine:
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the D locus tells us about stripe variations, like what shape the stripes are and how many of them we'll have. this one is a little bit different from the previous locii - we'll indicate the number of stripes with a symbol next to the two genes representing shape (ie: Ddc+). when breeding, thylacines do not carry a second gene for the number of stripes so a pup will inherit this modifier from only one parent (it will be randomly rolled for which parent they'll get the gene from) (:
D > dz > dc > db > ds > dt
D - regular stripes
dz - zigzag stripes
dc - connected stripes
db - broken stripes
ds - split stripes
dt - tiger stripes
± > + > -
± - around the usual number of stripes (six to twelve)
+ - more stripes (thirteen or more)
- - less stripes (five or less)
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the E locus controls white markings on a thylacine. these markings are co-dominant, meaning that the two genes mix together to create the final marking pattern. certain combinations of low and high white can create pseudo markings for genes in between (for example, pseudo-irish can occur with emep while psuedo-piebald can occur with eiew). see the examples below for a general idea of marking shapes! if the particular gene combo isn't on the chart below, pick the amount of white in between both genes. markings don't have to follow the pictures exactly as white markings are so fluid, but the amounts of white should stay generally the same.
E > em = ei = ep = ew
E - none
em - minimal white
ei - irish
ep - piebald
ew - extreme white
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the F locus controls white modifiers. these genes are only visible if there are white markings on a thylacine.
F > fb > ft > fr > fd
F - none
fb - fleabites (a few round spots of color showing through; on the legs and face)
ft - ticking (round spots of color showing through; scattered around the coat)
fr - roaning (lots of spots of color showing through; throughout the entire coat giving a mottled appearance)
fd - dalmation (large, round spots of color showing through; scattered throughout the coat)
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markings
urajiro (light undersides)
sable
brindle
tan points
saddle
masks
points
spectacles
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overrides
full albinism
partial albinism
melanism
leucism?
isabelline?
abundism
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occasionally, special thylacines will have peculiar markings that aren't quite explained by normal genetics. these markings will not be passed down to pups, but are extremely rare and sought after nonetheless! some oddities include:
• somatic mutations, when a single cell mutates after the embryo has begun to form. as the cell replicates, it passes the mutation onto those new surrounding cells. when pigment is involved, it causes a patch of color on the body, the size depending on how early on the mutation occurred.
• chimerism, when a single organism is composed of the genetically distinct cells of multiple organisms, usually when two embryos merge early on in development. in animals, this often causes a marbled or patched pattern between the two distinct coats.
• vitiligo, when the skin and coat develops a progressive pigment loss, causing speckles or patches of white. the pigment loss is generally concentrated around the head and face, but often spreads to the rest of the body.
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thylacines may have little nuances to keep their designs looking unique. this is completely normal! nuances may be passed down to children as long as it doesn't break any 'rules' in this guide. some nuances include:
• gradients / mottling in fur
• skin showing through in certain places on lighter coats
• a reddish gradient on dark brown or black coats, as if the fur has been bleached slightly by the sun
• tannish areas on the undersides of gray thylacines
• staining on lighter fur
Last edited by
mars on Mon Jul 29, 2019 7:17 pm, edited 22 times in total.
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화성 • 여성 • 레즈 • 감각처리장애 + 광장공포증
hi !! I'm mars, a gal with spd + agoraphobia.
I frequent the oc + adoptables side of cs.
my interests rn include genshin, skz,
learning languages, and drawing !! :3c
my cs inbox is full so please chat w/ me
on discord @ mars_v_e
나는 네가 자랑스럽다. 계속 최선을 다하거라 ♡
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