A lesson in feline genetics …

As we await the arrival of Sequoia’s kitten, it’s fun to speculate on what its pattern and color might be.  Unlike previous litters, Sequoia brings more genetic possibilities. Breeders should have at least a vague idea of genetics and that’s about what I have — a vague idea.

Simba Kahn is ‘color bred.’  He is pure shaded silver/shaded golden as far back as I can trace his pedigree which is six generations.  He brings only one color to the table.  Black.  Technically shaded silvers and goldens are A. tabbies (agouti) and B. genetically black.  They have a couple of other magical things going on that allow the shading and the gold vs the silver.  But basically, they are black tabbies.

Sequoia, however, is a different story.  Her lineage includes the rare chocolate color, recessive dilute, color point (Himalayan), both basic colors (red and black), tabby (agouti), and piebald (bi-color).  Obviously with Simba Kahn’s genetic short comings, we are not taking advantage of Koi Koi’s diverse capabilities.  We will never see a chocolate nor a dilute.

As I understand it, there are only two colors in cats – red and black.  White is the absence of color and therefor not a color.  There are two basic patterns (not counting bi-color also known as piebald) — tabby (known as agouti,which is dominant) and solid (sometimes called ‘self’ and is recessive).

Both parents are tabbies, so we know that the kitten will be a tabby, but what color and what pattern?  Simba Kahn contributes only black, whereas Sequoia contributes one black gene and one red gene.  Note that black will be perceived as brown.  Females inherit one color gene from each parent so if it’s a female it will have genes ‘black black’ (a brown tabby) or ‘black red’ (a patched tabby or ‘torbie’).  Males inherit only one color gene and that is from the mother.  It is paired with the “Y” gene from the father.  So a male kitten will get either black or red from Sequoia.  Remember all the kittens will be tabbies which means they will have tabby markings interspersed in their coloring.  Sequoia also carries the piebald gene which gives her the large white areas.  The kitten has a 50% chance of inheriting piebald and it can be manifested either lightly (a tiny white dot) or heavily (almost all white).

If my reasoning is correct, these are the possibilities:

Female: red and brown tabby (torbie); red and brown bi-color tabby (same as Sequoia); brown bi-color tabby (brown tabby with white); brown tabby.

Male: red tabby; red bi-color tabby (white with red tabby markings); brown tabby; brown bi-color tabby (white with brown tabby markings.

To the above colors be sure to throw in Simba Kahn’s shading capabilities and you may see the kitten’s markings, whatever they turn out to be, fade to some extend as he or she matures.

I’ve attempted to figure out eye color genetics and find it very confusing.  As I understand it, cats have the greatest variety of shading and eye color of just about any other animal.  Some eye colors are linked to coat color such as the blue eyes in the Himalayans or the green eyes in the shaded goldens/silvers, but unless you breed from cats with strong eye shading you are likely to get a mish mash of colors in between.   Sequoia’s pale orange eyes are the result of breeding a green eyed shaded golden to a blue eyed bi-color.  I suspect that all of her kittens will have a pale orange color to their eyes much like their mother’s.

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26 responses to “A lesson in feline genetics …

  1. I find genetics so fascinating! It’s exciting to be waiting for the unknown! Whatever Sequoia’s kitten looks like, one thing is certain…it with be adorable! :o)

  2. Sounds far more complicated than Mendel’s beans, and way more fun.

  3. Thank you Molly. Before your ‘most helpful’ post I was totallty ignorant (and ignorance is bliss). Now I am marginally less ignorant, and totally confused. Nevertheless, I have decided that this is one thing
    a) I have no control over
    b) I will be fascinated to see evolve
    c) I will not worry my ‘poor little head’ over it.

    As previous people have said, we will love it (and Sequoia) whatever he or she turns out to look like, and watch to see BabyKoi’s characteristics and habits evolve. Perhaps World Cat Basket twirler? Perhaps only Californian Champion? Who can tell.

    Good luck and fortune to KoiKoi, yourself, and BabyKoi for the coming days, weeks and months. And any other kitties who dare poke a whisker in. KF be warned.

    You wouldn’t dare call the baby JoyKoy would you? (Just joyking…) Bobin

  4. Wow…..That was like learning Mendelson’s law all over again. thanks for the refresher… : )
    It will be very interesting to see what actually turns up. I’m excited !!!!

  5. WOW Molly!! This is so fascinating! I am so looking forward to seeing Koi Koi/Simba Kahn’s kitten. Can’t wait. Thanks for the possibilities. I didn’t know that about kittie’s eye colors. Did she have that color when you got her as a kitten (I can’t remember).

  6. Really interesting. Thanks for sharing.

  7. I know about as much about genetics as to fill a thimble really, even after 22 years of breeding. But I have a breeder in Finland I know who is very knowledgeable and helps me with any questions. I was told my cream and white boys copper eyes are because of his ‘dilute’ color and inheritance but I am not sure why…

    Ps: Still lovin’ the stud pants!

    • Oh, good news about the stud pants working!…. very interesting that eye color is connected to dilute as well as other “stuff.” I have a book an genetics and can decipher about 2 % of it… and eye color is in NOT the small part I understand.

      • I hadn’t heard that dilute affected the eyes directly, but since colorpoint does I suppose it isn’t impossible. I had a dilute cat that had yellow/green eyes so it isn’t a sure thing. Copper eyes are bred for in breeds that like the grey dilute color like Russian Blue and British Blue so you might pick it up that way.

        Your genetics discussion did leave one thing out – there are actually three types of tabby patterns controlled by a different gene – classic tabby which has a swirl on the side, mackerel tabby which are vertical stripes on the side, and the ticked tabby which is only striped on the legs and head – like the Abyssinian breed. So if the Agouti gene allows the pattern to come out, you could display one of three tabby patterns. I gave them in the order of least to most dominant.

        It’s hard to tell but I have the impression that Simba Kahn is a classic
        tabby. If Sequoia has the mackerel tabby gene the kittens might have vertical striping rather than their father’s pattern.

      • Aha! Someone well versed in genetics. I did not know there were more than two tabby patterns… I see in my genetics book that there are four — the ticked tabby you mentioned in the Abyssinian and also the spotted tabby.

      • I wouldn’t call myself a huge expert – I have just tried to read up on it in the last year and a half because I adopted a Himalayan Persian with White and wondered how this came about.

        I left out ‘spotted’ because from what I read, the spots can either be in a mackerel pattern or the classic pattern. So to my way of thinking there should be either 2 spotted tabby ‘versions’ or none. I went with none, and that somewhere else in the genetic map there are factors that determine if spots are solid or broken up. But the real point is that all cats have a tabby pattern in their genes, even if other genes keep it from being expressed on this cat.

        There are quite a few things in a cat genetic map that are controlled either by a number of genes, or factors that are not understood – the level of white spotting on a cat with white spotting like Sequoia is one. The ‘rufousing’ factors that make Simba appear golden versus Tiny Bear appear white are another. Breeders can select for the features, but the genes that they are selecting are not well understood or simple.

  8. Interesting reading Molly !! Not long to wait before we know what colours this little kitten will be. 😀

  9. Are we going to be tested on this?

  10. Wow Molly. Very inyeresting! Thank you for taking the te to share this! I cannot wait to see the newest mythic bell! Is this kitty spoken for?

  11. More to the point, how does your ‘waiting list’ work, Molly? Strictly hierachical by date-of-request? Do previous almni or newbie get priority?

    • Bobin & Lisa – the usual waiting list is in effect and will be sorted through with candidates contacted in turn. One never knows how the list will play out. It’s different every time.

    • As to how it works? Sorry, just re-read your post, Bobin. I don’t require a deposit to be on the list, so it’s notoriously unstable. I do pre-screen people in that they have to fill out my questionnaire and look like good candidates to be on the list. People I don’t hear back from right away after a birth announcement or at all are dropped. I favor people who communicate well with me, who are enthused, and who stay in contact. I frown on people who pass too many times for too many reasons but still want to stay on the list to hedge their bets, as you can pretty much assume they are shopping for a better deal, a different color or breed, or are just not that serious. I shy away from folks who want to find “that perfect kitten” and want to come spend the day to see if they are going to bond with this one or that one. Get real! All of mine are perfect. I have so few kittens a buyer is lucky to get one at all. Some people are just not that comfortable with the idea that they will just get the one they get with very little choice. I understand that and I’m up front with them that I’m not the breeder they should be working with. If you read the blurbs on my available page on my website, you’ll see that I reserve the right to reorder the list to provide the best home for a specific kitten…but, in general, I contact them in turn when I have kittens available.

  12. So pleased to hear your views on future candidates for your kittens Molly. Your kittens have been treated with the best love, care and attention from the day they are born and they, and you deserve that they should have that care for the rest of their lives.

  13. I was going thru old blog posts and came across your comment, so finally I am responding…the necropsy on the kittens I lost in February showed Pasteurella in the lung tissues, nothing else

  14. Thank for posting this, I still think its a bi-color tortie girl but whomever is to be born I hope its full of life nomatter exterior;)

    • For a female
      Odds of being Tortie: 50 percent, rest will be ‘black’

      Odds of bicolor:
      if Sequoia has “double” white spotted genetics: 100%
      If she has only one White Spot gene: 50%

      so yours has a 25 percent overall chance if a female is born.
      so a 12.5 percent chance overall.

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