Male tortoiseshell cat 'genetically impossible' (pic of one)

[The Straight Story]

Male tortoiseshell cat 'genetically impossible'
A veterinarian has adopted a tortoiseshell cat that she claims is a "genetic impossibility" because it is male.


Male cats, like human beings, have only one X chromosome in their DNA meaning that they should be unable to inherit different colours.

The cat's new owner owner Karen Horne , 38, said: ''As a vet I can tell you that it is genetically impossible to get a male cat that is tortoiseshell coloured.

''My colleagues and I have 30 years of experience between us and we have never seen anything like this.''

Of eight million pet cats in Britain only a couple a year are born male tortoiseshells.

The eight-week-old kitten was brought into Mrs Horne's veterinary surgery in Harpenden, Herts., with his three tortoiseshell sisters by local charity Cat and Kitten Rescue.

http://www.telegraph.co.uk/earth/wildlife/6092954/Male-tortoiseshell-cat-genetically-impossible.html

[Brigid]

1. It is extremely rare, but possible.

However, this kitten is probably sterile. He's very cute, though. He looks a lot like my tortie, Ophelia.

[wryter2000]

18. That was my understanding, too

So rare as to be almost impossible, but not actually impossible.

[SharonAnn]

61. Sure. XXY genes would do it. Can be Tortoiseshell (Calico) and Male

[cherish44]

69. I had a male cat with tortie-"ish" markings.

He was mostly a brown and white tabby but his fur had tinges of ginger. I don't know if he was sterile we got him fixed. He was a big boy...17 pounds, not fat, just a BIG cuddly kitty (my favorite kind)

[Tansy_Gold]

2. Uh my understanding has always been that it's CALICO cats

that are never male.

But I'm not a cat person.


TG

[mike_c]

22. although they look different, calicoes and torties are caused by the same...

...genetic phenomenon. It's called mosaic X-inactivation during embryogenesis.

[Hekate]

29. Well that rolls trippingly off the tongue, doesn't it?

Thanks for the info.

[Individualist]

66. I had a male calico cat

from 1983-1995.

[jody]

3. "we have never seen anything like this" reminds me of the Black Swan that also could not be true. nt

[OmmmSweetOmmm]

33. lol! The only time I ever ran for my life was from a black swan in Woodstock, NY!

[redqueen]

4. How stupid. She's obviously wrong.

"only a couple a year are born male tortoiseshells"

*sigh*

[SidDithers]

12. +1...nt

Sid

[johnnie]

5. That cat looks bummed out

[The Straight Story]

6. You would be too if someone said you could not exist but you do

:rofl:

[havocmom]

17. Actually, that has happened to me a couple of times. Was bummed at first.

The second time, it just seemed funny.

[Sal Minella]

25. What a great post!

[havocmom]

28. LOL Kinda early in the day

to be drinking, isn't it? ;)

[redqueen]

9. He was handed over to one of the dumbest vets ever.

They're IMPOSSIBLE! (Cause there's only a few born every year.)

:banghead:

[Epiphany4z]

7. interesting and ....

AWWWWWWWWWWWWWWWWWWWWWWWWWWWW HE IS JUST TO DAM CUTE

[Xithras]

8. It could be an XXY

Humans aren't the only creatures that can have interesting genetic combinations, including XXY males and females, chimerism, etc. Pretty much every animal, insect, and plant that uses an XY sex determination system has occasional variations like this.

[Poll_Blind]

34. That's something that popped into my mind too, thanks for bringing it up! n/t

PB

[iris27]

56. That's what I was thinking too - a Klinefelter's kitty, XXY.

http://en.wikipedia.org/wiki/Klinefelter%27s_syndrome

Though I suppose it probably isn't called that in felines.

[beac]

59. Felinefelter's, perhaps?

;)

[GreenPartyVoter]

70. We have that in my family. I got my older son tested for it. Have not tested the younger one.

[Motown_Johnny]

10. if a couple a year are born that way in Britain alone it isn't impossible

[Arugula Latte]

11. That is the most adorable freak of nature ever! ... WANT!!!

:loveya: :bounce:

*sigh* Kitties are the best.

[Brigid]

51. Go to your local shelter.

I'll bet they have several torties (female, anyway) up for adoption. :)

[Arugula Latte]

62. Don't tempt me!

We've got three kitties and a bunny (all strays, including the bun, who showed up in our yard), but I think within the year we will have two more kitties. The in-laws are getting very old and fragile ... I don't know how much longer they'll be in their house and/or able to care for kitties ... so we'll take 'em ... that'll be six furry indoor mammals bopping around here ... I'm on my way to "crazy cat lady" status. :)

[SPedigrees]

13. It's not genetically impossible, just very rare.

Calicos and tortoiseshells have been known to be born male. This little guy aint the first and won't be the last.

[Pavulon]

14. Sterile was my understanding..

but i am not a geneticist..cute cat.

[SPedigrees]

15. I think you're right, if memory serves. nt

[The Straight Story]

16. My Caption: "I can haz existence?" (nt)

[frylock]

20. nice!

:rofl:

[mike_c]

19. of course it's possible-- it's X-Y nondisjunction and it's very rare....

eom

[Orsino]

21. "You keep using that word..."

Improbable, maybe, but also inevitable.

[mrs_p]

23. she must have missed that day in school

we (vet students) are taught this is possible - though rare. the cat is most likely XXY.

[SPedigrees]

47. Thank you for the clarity. Was hoping a qualified vet or vet student would respond.

XXY certainly makes sense.

[Quasimodem]

24. Much to do about naught.

Having spent most of my life in bondage to cats I can tell you that this is not surprising.

If they wish, a cat can defy gravity, it can repudiate the claims of any security device, and can - when frightened - teleport.

Doing something as basic as arranging their fur into a colour and pattern which pleases them is mere kitten’s play.

[StatGirl]

45. They don't actually *defy* gravity . . .

. . . they displace it through time.

My late, great, lapcat weighed 18 lbs normally, 5 lbs when he wanted to be picked up, and 40 lbs when sleeping on my lap. It worked out. :)

[DireStrike]

55. Yeah, "defy" seems to imply a willful contradiction

Cats simply don't care what gravity thinks.

[SpookyCat]

57. Cat: "Shhhhh...don't let me out of the bag...must keep humanz complacent..."

Welcome to DU! :hi: Love the name, btw...

[Crunchy Frog]

26. Maybe it's an XXY, like some male humans.

[Sylvarose]

27. well..being tortie owned

...I have done some research on them. They are truly an interesting class of cats. Like calico's they are tri-colored because they do have an extra chromosome. I've also been told they are the most "bi-polar" of cats.

If you are really interested in the fascinating genetics which go into throwing calicos and torties (and how the very very rare male DOES occur) there's an excellent article here: http://www.messybeast.com/mosaicism.htm

sr

[The Straight Story]

31. Sweet, thanks for that link. Will toss it onto to FB (have a lot of friends that like cats) (nt)

[SPedigrees]

46. I too have lived for 23 yrs with a calico, 10 yrs w/ a tortie, and 16 ys thus far w/ another calico.

Folklore has it that a calico cat is good luck. Our luck has held up over the years.

Interesting thing I recently learned is that in guinea pigs and hamsters the calico/tortoiseshell pattern is also (female) sex linked.

[Withywindle]

60. I'm tortie-owned too.

I just got a regular lady tortie, but there's nothing ordinary about her. "Bi-polar"? Oh yes. She can be very cuddly and then she can also go completely apeshit. Runs around at night like a little meth goblin.

[SidDithers]

30. If I were Karen Horne, I'd be looking for a new vet...nt

Sid

[Posteritatis]

32. If a few are born annually it's obviously not impossible, is it? (nt)

[The Straight Story]

35. If it happens once it is a miracle, if it happens twice it is unique, three is impossible

more than that and it is normal :)

[rox63]

36. That's one very cute genetic improbability

:D

Rox-the-cat-owned.

[yesphan]

37. Perhaps

Mummy cat stood a little too close to the microwave.

[Berry Cool]

38. This is obviously someone who doesn't know the meaning of the word "impossible"

rather like people who speak of something as "very unique."

There are no degrees of uniqueness. Either something is unique (one of a kind) or it's not--in which case it could be called "unusual" or "rare," but not "unique." Not even "rather unique."

[NickB79]

65. "You keep using that word. I do not think it means, what you think it means."

nt

[ashling]

39. Quote from Descarte's cat:

Meowa Ergo Sunt

[ashling]

40. Are we talking "impossible" or

"absolutely impossible"? Exactly the same, only different.:shrug:

[The Straight Story]

41. Impossible to tell

:)

[ashling]

44. What about calico dinosaurs

Jesus rode a calico dinosaur in Leviticus ... its true! :shrug:

[Javaman]

42. Hermaphrocat? nt

[EC]

43. Not impossible, just rare...

but that one pictured is not a tortoiseshell not enough brown in him, he looks like he'd be classified as black...

[The Velveteen Ocelot]

50. Looks like a tortie to me.

They don't have to have a lot of brown or orange -- I see enough on this one to call him a tortie.

[mrs_p]

48. i just have to add

that that cat needs kisses now. so IMPOSSIBLY cute!!

[The Velveteen Ocelot]

49. Schrodinger's male tortoiseshell cat -- he is both impossible and not impossible.

[anneboleyn]

52. And he is in a bit of a predicament, but that is another issue entirely!

A quantum predicament.

[Hansel]

53. We only saw a couple of them when I worked at the Humane Society

over a period of about 7 years. We took in 10 of thousands of cats and kittens a year.

The male tortoise shells were only allow to be adopted by employees or trusted volunteers because of the concern that they would be sold because they are so rare.

[Kaleva]

54. I was expecting to see a cross between a turtle and a cat.

[Pavulon]

71. Sounds like an something that does not destroy furniture..(nt)

[applegrove]

58. I have a female ginger tabby which is also rare. I think one in 200.

[Arugula Latte]

63. I thought they were rare, too, but it seems like lots of people have 'em, including my mom & my sis

[applegrove]

64. One vet I used to see told me she was rare. I wonder how the rumour started.

[cherish44]

67. There's a stray female ginger tabby in my neighborhood

Well I think it's a female anyway. She's dark ginger, practically orange, I call her Pumpkin. She's gorgeous but very shy :)

[Jennicut]

68. I had two tortoiseshell cats growing up...one is still alive and is 18 now.

They are beautiful cats...my Mom still has Maxie and she has some Siamese in her too. Ours were both female, never heard of a male but what a cutie.