Monday, August 27, 2012

White cats, Star Trek, and deafness

We've fallen into the habit of using Monday's posts to talk about health, medical and safety issues - and even interesting science topics. Lately, we've been looking into the genetics of cat coloring.

You can read about why a Siamese is pointed...

What causes the striking look of a tuxedo kitty...
Even why some cats have blue eyes!

Today is a continuation of the topic from three weeks ago: White Cats

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A truly solid white cat has the White Masking, or "W" gene to thank for its striking coat.  But that's not all a kitty gets from that "W" gene.


photo: Wikimedia Commons
Because that gene is responsible for masking all color everywhere, that means pigment is masked or blocked in the eyes as well.

If you read our post in July about what happens when pigment is blocked in the eye, then you won't be surprised to hear that these "W" kitties have gorgeous blue eyes.

(If you'd like to read a bit more on the science behind why this takes place, click here .)

Interestingly enough, this phenomenon causes white cats who have this "W" gene to be deaf.

But not all blue-eyed white cats are deaf, you say. Most are, but not all. 

Correct!  

For those white cats that are not deaf, there is a different gene at play - the Spotting gene. You can read all about the difference between a White Masking gene and a Spotting gene in the post on Monday, August 6.

So, what makes a white cat with the "W" gene deaf?  Star Trek.
Um. Come again?


Star Trek: the reason
white cats are deaf

Okay, well, maybe we're stretching the truth a little bit. Here's what's going on:

There is a spiral-shaped cavity in the inner ear called the cochlea. This is where sound waves are converted to electrical signals and sent to the brain for processing. In order for those electrical signals to be transmitted upstream to the brain, ion balance needs to be maintained.

(Sounds like some kind of warp drive, doesn't it? Like I said, Star Trek. I rest my case. ;-)

odd-eyed cats are often deaf in only one ear
We have no idea what ion balance is, and if you figure it out please let us know, because we're weird like that and love to get our geek on.

Bottom line here is, the thing responsible for maintaining this mysterious ion balance is a thin layer of pigment called melanin that coats the inside of the cochlea.

Can you see where we're going with this?

If the White Masking gene blocks the production of all pigment in a cat's body...then that melanin isn't going to be there.

No melanin means no ion balance. No ion balance means no sound transmission. No sound transmission means complete deafness.




Oh by the way, our Maxwell’s deafness isn’t caused by that. He’s got plenty of melanin in his ears!  His blue eyes are caused by the albino gene, and while that does turn off pigment in select areas of the coat and eyes, it leaves the melanin in the ears untouched.

(If you’d like to find out what caused Maxie’s deafness, you can read about it in last year’s Less Adoptable series post on deaf cats here.)

So there you have it: Star Trek - the reason white cats are deaf.



We sincerely apologize for our Mommy. She is SUCH a geek.


_______________
sources:
Washington State University Animal Sciences' paper on melanin and ion balance

Pleiotropy: University of Richmond


38 comments:

  1. We have had a white and a black (and a Siamese) cat. Fortunately, our white cat was not deaf, but he did shed more than any other cat we have ever known. My assistant also has noticed that the white cats at the shelter where she volunteers also shed more than the others. I've tried to explain to her that she only thinks this is true because she wears lots of dark clothing and so (duh!) she notices the white fur more. But she insists that white cats shed more ...

    Your pal, Pip

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    1. MOL! Um, hmm, with all three of us having both light and dark furs, we get to leave our calling card on Mommy every morning! SCORE!

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  2. Well that explains it. :) Doc is our deaf white foster kitten - and apparently he is an alien and that is why he is deaf. hahaha

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  3. We like your "medical Monday" posts!!!

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  4. That is very interesting to understand why white cats are often deaf. Thanks!

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  5. Very interesting. Have good Monday.
    Best wishes Molly

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  6. It's the Klingons.. all their fault!! :) I to like these posts, oh so informative.

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  7. Mommy says pure white kitties with blue eyes are so so beautiful, even if they are deaf. :)

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    1. Maxwell: Oh they are! A friend mama volunteers with adopted one and named her Cloudy. She's deaf like me and so very clever AND beautiful!

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  8. I think this is all really fascinating! I had no idea it was the lack of melanin that caused kitty deafness!

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    1. We didn't either - like we said, that tidbit totally had mama gettin' her geek on!

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  9. It's life Jim, but not as we know it!! Furry interesting indeed! White cats are beautiful though we don't see so many now. Maybe because if they are deaf they are generally kept inside!!

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    1. MOL!!! Just so long as no one sez "he's DEAD Jim!" oh wait...maybe it should be "he's DEAF Jim..."??

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  10. We had a deaf white kitty named Chuckles! He was quite the trickster and he loved to knock things off the counter...Mommy lost TWO teapots that way. He had the loudest ME-OW, ever.

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    1. Maxwell: Yes, it seems we deaf kittehs either have sooper LOUD meows, or none at all, since they have no way to gauge volume! Mine's a teensy little "mew" momma sez.

      Funny, I knock things over a LOT. Momma sez I am constantly getting into EVERYthing!

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  11. As Mr. Spock would say ... "Fascinating."

    Thanks for such an interesting post, friends! We really enjoy your medical Mondays!

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    1. MOL! We identify since we's got the pointy ear thingy goin'!

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  12. Mommy had a deaf cat named Toby (but yet he answered whenever his name was called, so maybe he wasn't deaf?)

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  13. That is so interesting and we never knew that before either. We're enjoying your scientific tidbits.

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  14. Huh? Come again? ¿Como? Couldn't hear you! HAH!

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    1. Whut? WHUUUUT??? HUH??? Speak up! *snicker*

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  15. Mom used to have a white kitty named Sheena, but she had green eyes and definitely wasn't deaf.

    EK has blue eyes, but he's not deaf either.

    Genetics makes my little kitty brain spaz out so I'm not even gonna try to figure this out. MOL

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    1. MOL! Us too! After mommy wrote this for us, we needed a good Da Bird session to de-spaz us.

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  16. I always like learning more fascinating stuff like this!

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  17. We like the geekness. Our Sally was pure white and purely deaf but had green eyes. We don't remember her but our mom does.

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  18. can't tell you how useful this is. We have a white blue eyed senior female cat in our shelter and I suspect she has considerable hearing loss. Thank you for your Monday series.I learn lots, Savannah

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  19. Well, we learned something today! Thanks for that!!

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  20. This is so interesting. Thanks for sharing.

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  21. Wow.....well I for one (and Mommy for TWO) find all of this very interesting really. The science of kitties - we ARE truly mysterious aren't we?

    Kitty Hugs, Sammy

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    1. Yup, we don't want the humans to figure us ALL out completely - where's the fun in that?~?

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  22. my Mommy Loves your Mommy's geekiness!
    Kisses
    Nellie

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  23. This was really cool! ....way more interesting than most of our school subjects. : )

    We had no idea Max couldn't hear. ...Glogirly had a poodle growing up that lost his hearing. He did just fine. (well, for a dog I guess)

    So Glogirly wants to know if your mom's got any Trekkie costumes hanging in her closet.
    And I want to know if she can do the funny V thing with her hand.

    ; ) Katie

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Coolio! A comment? For US?