Part 1 (Base Colors): 


 There are multiple cat genetics tutorials about, but they tend to only cover the basics (base colors, dilutions, tabby, white-spotting, pointism, & tortie/orange). In-depth cat genetics tutorials tend to be lacking. So thus, this. I have no idea how long this will take to be completed. Hopefully before 2016. 

    The first locus we'll learn about is the B locus. It has three genes: black (B), chocolate (b), and cinnamon (b1). B is dominant over b, and b is dominant over b1. Thus, any cat with B/B, B/b, or B/b1 is black. Any cat with b/b or b/b1 is chocolate, and only cats with b1/b1 are cinnamon. However, most cats are B/B, because chocolate and cinnamon are found almost exclusively in pedigreed and purebred cats. The Havana Brown and British Shorthair both have chocolate, and the Abyssinian and Somali both have cinnamon. 

    The red gene is interesting because it is only carried on the X chromosome. Since toms and gibs (male cats unable to breed) only have one X gene, they are either non-red, or red. Queens and mollies (female cats unable to breed) have two copies of the X chromosome, they also have two copies of the red gene. So a female cat needs O/O to be red and o/o to be non-red. If a female cat has O/o, then they become a tortie, which are covered in the next part, part 1.5.

    And a quick word on ghost-markings. Every cat has ghost-markings, or the faintest tabby markings. For some reason, red cats tend to have the largest contrast in ghost-markings. Few cats have noticeable ghost-markings (excluding red cats). Ghost-markings tend to appear and disappear as a cat ages, and tend to be the most visible on the legs and faces of kittens. Adult cats and older rarely show ghost-markings (excluding red cats). Sometimes, a black cat with ghost-markings will develop little dark brown spots on the inside of the legs with black stripes on them that fade. These tend to just one large spot on each leg, or only on the front legs.

      Oh, and the colored circles on the right side for chocolate are highlight colors.

Key: 
Red W - Wildtype
Grey G - Ghost-markings
Colored Circle - Color variations/suggestions
Colored Triangles - Nose leather colors



Part 1.5 (Torties): 

There are multiple cat genetics tutorials about, but they tend to only cover the basics (base colors, dilutions, tabby, white-spotting, pointism, & tortie/orange). In-depth cat genetics tutorials tend to be lacking. So thus, this. I have no idea how long this will take to be completed. Hopefully before 2016.

    In part 1 we learned about the B locus and the red gene. In this picture we get to see tortie acting on all the black variations. There really isn't much to say other than it cause patches of red on the base color, or patches of the base on red if you prefer. Ghost-markings are not shown, but basically put patches of red on the ghost-marked base for what it would look like.

Key:
Colored Circle - Color variations/suggestions
Colored Triangles - Nose leather colors



Part 2 (Dilutions): 

There are multiple cat genetics tutorials about, but they tend to only cover the basics (base colors, dilutions, tabby, white-spotting, pointism, & tortie/orange). In-depth cat genetics tutorials tend to be lacking. So thus, this. I have no idea how long this will take to be completed. Hopefully before 2016.

    Dilutions are next. They reduce the pigment density in the hairs, thus creating a lighter shade. Not much else to say. Ghost-markings are shown, but I forgot the 'G' that's supposed to be next to them. Hopefully you can tell which is ghost-markings and which isn't.

Key:
Colored Circle - Color variations/suggestions
Colored Triangles - Nose leather colors



Part 3 (Tabby): 

There are multiple cat genetics tutorials about, but they tend to only cover the basics (base colors, dilutions, tabby, white-spotting, pointism, & tortie/orange). In-depth cat genetics tutorials tend to be lacking. So thus, this. I have no idea how long this will take to be completed. Hopefully before 2016. 
    
    Now we are into markings. Tabby/Agouti is one of the most common markings. It is a dominant gene that turns a solid cat into a tabby, and is represented by an A/a. Torbies are tortoiseshells that are also tabbies. Most torbies have pelts with less distinct and smaller pelts than is shown here. All the colors exhibit the mackerel tabby pattern. The bottom part shows the other possible patterns. The first is spotted tabby, which has an unknown cause. It might be a dominant gene with a recessive activation gene, or just a dominant gene. To add to the confusion, it might be that spotted tabbies only cause spots on areas that would otherwise be marked (classic and mackerel tabbies would have different spotted variations), or just mask all other tabby patterns with spots. It's even possible that there are two genes, one masking and the other morphing. Classic tabby and mackerel tabby is caused by the Mc/mc gene, with the dominant version causing mackerel and the recessive version causing classic. Ticked tabbies are caused by the T/t gene, with the dominant version being a ticked tabby and the recessive being non-ticked. Ticked tabbies also tend to show primitive or residual markings, namely stripes on the tail, legs, and neck. Only tail markings are shown here, but generally all the primitive markings follow mackerel tabby patterns. Broken mackerel tabbies are another genetic mystery, as are braided, or candle-flame, tabbies. Braided tabbies appear most often in wild/domestic hybrids. Marbled, oceloid, and rosette tabbies are from genes introduced from wild crossbreeding, and we don't know what causes them. However,  on rare occasions, purely domestic cats have exhibited marbled tabby patterning.  Sokoke classic tabbies are classic tabbies with the recessive version of the Sk/sk gene. Notice the faintly lighter insides of the markings on the Sokoke classic tabby.

 Key: 
Colored Circle - Color variations/suggestions
Colored Triangles - Nose leather colors


Part 4 (White-Spotting): 

There are multiple cat genetics tutorials about, but they tend to only cover the basics (base colors, dilutions, tabby, white-spotting, pointism, & tortie/orange). In-depth cat genetics tutorials tend to be lacking. So thus, this. I have no idea how long this will take to be completed. Hopefully before 2016. 

 NOTE: THERE IS A MISTAKE!
There should be no wild type at all on this part. I accidentally added wild type to Grade one and roan/tweed. This will be fixed as soon as possible

     Part four is finally here. White-spotting and other white markings are up next. White-spotting is a very common trait, so a randomly chosen moggy probably has white-spotting. White-spotting is split up into ten grades with increasing amounts of white. Dominant white is a dominant gene, but happens to be rather rare. A dominant white cat is born with a patch of color on top of it's head, and this patch usually fades away before the cat is a year old. Next up are weird and unusual mutations. Quite honestly, no one knows what causes any of these mutations. Sheeted cats occasionally have a much thinner stripe which is called belted. Normally the European mutation has less white speckling, with the white speckling more towards the white points. Sometimes there are no white speckles at all, just the white points. Roan/tweed is unusual, and just adds white hairs intermingled with colored hairs. The amount of white hairs to colored hairs varies, but it tends to lean toward more colored hairs. The Finnish mutation is a mutation that comes from an inbred colony of cats in Finland. This mutation is associated with infertility, and it is unknown whether the mutation causes the pure white markings, or if that comes from white-spotting. The Moscow mutation is a snow leopard-esque mutation originating in Russia. Notice the silver hint to the coat except for the white muzzle. Since white-spotting normally comes from the bottom to the top of a cat, skunk stripes are unusual. Notice the 'frame' of white. Brindled is pretty much a tortie with white instead of red or cream. This could be a somatic mutation or a genetic mutation. Swirled markings are asymmetrical, and it could be a mutation or an unusual expression of white-spotting. The skunk stripe could be that too. And onto the last one: unusual spots. These are strange spots of color in white-spotting. Colored muzzle/chin spots are rather common, but speckles on paws, patches on toes, and reverse lockets not so much. Nose colors tend to turn pink or have pink patches.

     Here are some good white-spotting terms worth noting: 
Locket - Small patch of white on chest (Grade 2)
Button - Small spots of white on belly (Grade 2)
Tuxedo - Black with white paws, belly, chest, and muzzle, white tail tip possible (Grades 3-4)
Mask & Mantle - White with colored head, and back & tail (Grade 6)
Harlequin - White with random white patches (Grades 7-8)
Piebald - 50% white or more (Grades 5-9)
Mitted - White paws, other white markings possible (Grades 2-4)
Van pattern - White with colored tail and head spots (Grades 8-9)
Moorish-Headed - White with colored tail and head (very rare, Grade 9)

Part 5 (Pointism & Albinism): 

There are multiple cat genetics tutorials about, but they tend to only cover the basics (base colors, dilutions, tabby, white-spotting, pointism, & tortie/orange). In-depth cat genetics tutorials tend to be lacking. So thus, this. I have no idea how long this will take to be completed. Hopefully before 2016. 

    Part five, pointism and albinism. This modifier is a series of alleles that more or less goes like C (Full color) > cb (tonkinese) > cs (siamese) > ca (blue-eyed albinism) > c (pink-eyed albinism). This part also introduces eyes colored separately because the albinism & pointism allele series affects eye color. cb/cb causes copper/amber eyes, cs/cs blue eyes, cb/cs aqua eyes, ca/ca paler blue eyes, and c/c colorless eyes that look pink/red due to blood vessels being more visible. Cats with pointism can also have agouti, leading to lynx point cats. Their striping shows full blown on the darker extremities, but much paler on the rest of the body. Speaking of said extremities, they are dark due to the fact that pointism is basically temperature controlled albinism with lighter color occurring in warm areas, leading to the fact that pointed cats are born white/very pale, gradually gaining their darker points.

    On another side note, some find the word albino offensive, so it is generally better to use the term albinistic or albinism.



Part 6 (Silver & Gold Series): 

There are multiple cat genetics tutorials about, but they tend to only cover the basics (base colors, dilutions, tabby, white-spotting, pointism, & tortie/orange). In-depth cat genetics tutorials tend to be lacking. So thus, this. I have no idea how long this will take to be completed. Hopefully before 2016. 

     And here is part 6. Silver & gold series are mostly found in Persians and burmillas, and their genes are kind of hard to understand, at least for me. The first gene in this series is the inhibitor gene (I/I). Any cat without silver/gold will have i/i. A silver cat has I/-, and a gold cat i/i. Next gene is one you should be familiar with, Agouti (A/a). Silver tabbies & chinchillas (also known as tipped or shell) have A/-, and shaded and smoke cats have a/a. The final gene is wide band (Wb/wb). A silver tabby would have I/-, A/-, and wb/wb, a silver chinchilla I/-, A/-, and Wb/-, a silver shaded I/-, a/a, Wb/-, and a silver smoke I/-, a/a, and wb/wb. A golden tabby would have i/i, A/-, and Wb/-, a golden chinchilla i/i, A/-, Wb/Wb, a golden shaded i/i, a/a, Wb/Wb, and a golden smoke i/i, a/a, Wb/wb. I hope that makes sense. The base color changes with those genes.

     Since this gene series can be difficult to understand, here some additional resources:


 Part 7 (Color Changes): 

There are multiple cat genetics tutorials about, but they tend to only cover the basics (base colors, dilutions, tabby, white-spotting, pointism, & tortie/orange). In-depth cat genetics tutorials tend to be lacking. So thus, this. I have no idea how long this will take to be completed. Hopefully before 2016. 

At long last, part 7. Amber is a late color change first recorded in Norwegian Forest Cats. The gene mutation is caused by an extension gene that essentially causes melanin (black pigment) to gradually be restricted only to the skin and not show in the hair, thus leaving behind pheomelanin and creating a reddish cat. They are born with full pigmentation, but at around 3 months 0f age they start to change color, starting with a patch on the back that expands to cover the entire cat. Since it is red pigment, tabby striping is seen when they finish their color change. It is caused by a recessive gene that has thus far only been identified in Norwegian Forest Cats. Russet is a color only identified in a few Burmese cats, and thus far has only been seen in chocolate and seal points. They are born as 'odd looking lilacs', but then start to grow darker (maintaining a lighter underside and tail tip throughout their lives). After that, they gradually turn redder until they are what appears to be a red ticked tabby (even if they do not carry agouti) with pink nose, paw pads, and lighter underbelly and tail tip. It takes about one and a half years for this color change to finish. The first image shown is based off newborn kittens, the second off a 12 week old kitten, and the third upon a six month old kitten.


Part 8 (Weirdos): 


 There are multiple cat genetics tutorials about, but they tend to only cover the basics (base colors, dilutions, tabby, white-spotting, pointism, & tortie/orange). In-depth cat genetics tutorials tend to be lacking. So thus, this. I have no idea how long this will take to be completed. Hopefully before 2016 2017. 

 Stuff happens, even in cat genetics. The first image shows sunshine, a posited gene for high amounts of a bit more golden rufousism seen in some Siberians. It is theorized to be a recessive gene brightening up the background color of tabbies. Thus far it has only been seen in brown tabbies. The second... I honestly have no idea how to explain it. My best guess is a solid red (naturally showing ghost-markings) with a genetic error that turns off some turning off of eumelanin production. The third and fourth are chimeras, which are caused by two embryos fusing in the womb, creating a cat with two genomes that both express themselves on the coat. Normally, only one of the genomes is ever passed on, depending on which one the reproductive tissues are made of. Chimeras can be male-male, female-female, or male-female. 

Part 9 (Hair): 

There are multiple cat genetics tutorials about, but they tend to only cover the basics (base colors, dilutions, tabby, white-spotting, pointism, & tortie/orange). In-depth cat genetics tutorials tend to be lacking. So thus, this. I have no idea how long this will take to be completed. Hopefully before 2016 2017. 

     Off from (almost all) of the colors, and off into other characteristics. As you might know, not all cats have the same type of fur, and genetics are (normally) to blame. Most common is short hair, which is dominant over long hair (L/l). The long hair depicted here is rather modest, they can get a lot longer. There are also hairless cats, most famously the Sphynx, and this is caused by a recessive gene (Hr/hr). Then there are a whole multitude of rex or curly coated cats. The Cornish (R/r) and Devon (Re/re) varieties are recessive, while LaPerms (Lp/lp)  and Selkirks (Se/se) have dominant mutations. Last on my list is the Lykoi, which has a rather unique appearance and coat development, LykoCat



Part 10 (Tail): 

There are multiple cat genetics tutorials about, but they tend to only cover the basics (base colors, dilutions, tabby, white-spotting, pointism, & tortie/orange). In-depth cat genetics tutorials tend to be lacking. So thus, this. I have no idea how long this will take to be completed. Hopefully before 2016 2017. 

     And from hair to tails. The first mutation shown here is the tailess manx, a dominant gene that is fatal in its homozygous form, and even when heterozygous can cause some spinal deformations. The gene is also responsible for stumpy/rump riser style manx and manx cats with shorter than normal tails. The second one is the Japanese Bobtail, a recessive mutation that causes short tails that are very kinky and knotted up. Speaking of kinky tails, sometimes cats just happen to have kinks in their tail. Siamese are known to be especially prone to this. Curled tails can also happen, and is often seen as a chance mutation. It is possible that there are multiple mutations that cause curled tails. They can curl in various ways, and in some they are able to be straightened. The last mutation here is the kinky half tail best known among Singaporean street cats, but fairly widespread around Asia. These cats have shorter than normal tails with a kinked or knotted end. Although not known for sure, the best current guess is that the mutation is recessive.



Part 11 (Ears): 

There are multiple cat genetics tutorials about, but they tend to only cover the basics (base colors, dilutions, tabby, white-spotting, pointism, & tortie/orange). In-depth cat genetics tutorials tend to be lacking. So thus, this. I have no idea how long this will take to be completed. Hopefully before 2016 2017. 

     The classic cat ear is the round triangle shape, pricked up and listening to everything around. The folded ear gene is most commonly found in Scottish Folds. It is dominant, but lethal in homozygous form. Even in heterozygous form the gene can cause problems due to the weakened cartilage that makes the ear flop down. Two different degrees of folded ear are shown. Curled ears are associated with American Curls, and are dominant, but with no known side effects. Two different degrees of curled ear are shown. Both cats with folded and curled ears tend to be born with straight ears that transition to their final shape within several months. 'Four eared' cats have a double pinnae (the outer part of the ear that sticks up). It can appear in many different forms, and is often a one-off mutation. Weakened cartilage is often caused by external factors (mostly frostbite), and often shows up in wrinkled ears or a floppy tip.



Part 12 (Other): 

There are multiple cat genetics tutorials about, but they tend to only cover the basics (base colors, dilutions, tabby, white-spotting, pointism, & tortie/orange). In-depth cat genetics tutorials tend to be lacking. So thus, this. I have no idea how long this will take to be completed. Hopefully before 2016 2017. 

     I've already covered most things in cat genetics, but here are a few more. The mica effect causes the tips of a cat's hair to look shiny and with a silvery tinge. Russian Blues, such as this one, tend to have this. The actual effect is caused by the tip of the hair being too thin for pigment granules to reach, creating the effect. It also tends to accumulate around the muzzle and paws, making those seem lighter in color. Satin is similar, although it only changes the hair to make it shinier, causing shiny cats. Birman gloving is a theoretical gene that would cause white markings on the paws of cats, specifically the Birman breed which is well known for it. All three of the previous genes are assumed to be recessive. Polydactylism is a condition in where a cat has extra toes, from one or two to essentially another foot growing out of that leg. Generally, polydactyl cats are fine and live normal cat lives. A dominant gene (Pd/pd) causes most polydactylism (though of course random mutation can affect limb development in some cats).

    Like any other animal, cats have mutations and new genes can crop up and change a cat's appearance. Messybeast is a great place to keep up with new mutations, and if anything throughout this tutorial is unclear, feel free to ask me any questions
.