Почему белеют взрослые фиолеты?

[valkeryne]

Собственно, сабж.
Почему-то некоторые фиолеты на 2, 3, 4м и так далее году жизни начинают белеть в области носа и вокруг ушей, образуя белую "окантовку", как у черных бархатов. Как думаете, можно ли проследить какую-нибудь закономерность в этом? И еще я не понимаю, почему этих шиншилл причисляют к калифорнийским рецессивных белым, на основании чего это делают? Действительно ли фиолеты имеют отношение к этой мутации или же это брак по окрасу?

[kapushka]

Марин, ну фиолеты же могут быть и носителями какого-то рецессивного гена, и гомозиготными по этому рецессивному гену, так?
Вот уродился фиолет, который меняет окрас в точности как CRW...логичнее считать его фиолетовым СRW, чем каким-то, до сих пор никому не встречавшимся браком по окрасу)

[valkeryne]

Могут конечно, но не все обладают белыми хвостами и очками вокруг глаз. У кого-то просто белый нос и на этом всё. Интересно было бы изучить родословную таких мышей, понять, как этот ген передается (вроде как он не такой же как фиолет\сапфир, а скорее вроде эбони), являются ли белоносые и с очками одной мутацией или это 2 разных гена, отвечающих за окрас. Как оценивают таких на выставке? Снимают ли баллы за окрас или же судят как отдельную мутацию?

[kapushka]

а просто белый нос в каком возрасте?
у них, насколько я понимаю, еще и с возрастом "побеление" усиливается.

[valkeryne]

В 3-4 года только нос, а у кого-то в те же 3 года и вокруг глаз есть. А у Наташи Nightly Edelweiss в 11 месяцев уже у шуши очки и носик белые. Как-то у всех по-разному))) Более взрослых (старше 4-5 лет) шиншилл, чьи фотки новые есть в базах, я не нашла.

[kapushka]

ну если предполагать, что ген по типу эбони передается, с каким-то "накопительным" эффектом)))в общем ясно, что дело темное))
Таня Копатыч недавно фото Текилы выкладывала, у мыхи к 5 годам все тело сбледнуло) а когда-то только полосочки вокруг ушей были...

[valkeryne]

Вот еще кое-что скопипастю с англ. форума, но в целом инфы немного
язык изложения не сложен

I purchased an extreme white violet chinchilla from Vin Somavia a couple of years ago and the pedigree puzzled me because neither parent was a mosaic. He started out a very deep blue violet shade with white rings around each ear, both eyes and nose. The white rings have become more prominent as he has aged. Recently he has started to get flecked with white all through his coat evenly, lightening. His first litter with a Godin black velvet violet carrier produced a very blue violet male that at age 2 has started to get the white rings in the exact same places. Please post any information that you have on the white tails. Thanks!
Here is a video of him on youtube:

http://www.youtube.com/watch?v=iWrDSubhX4M&feature=share&list=ULiWrDSubhX4M

- I have a couple violets here who do that. No white in their lines, but they get the white rings around the ears, eyes, and nose. A white violet gave me a standard vc, no white on the tail. She's an adult now, 2 years old, and her face is turning white.
Chins are weird.

- That's true, strange stuff can happen with breeding. I wouldn't have thought much more about it, but when his son started to develop the exact same markings at an older age, like the white tails do, that's what made me think that this may be from that line. Tabitha has been really helpful in sending me some information on them. It was thought that it may be a recessive trait, but in this case it would prove otherwise. It's very hard to find information on them, so I am hoping some other breeders out there may have some.

- Even when I was first getting into chins and I saw him for the first time I remember saying to you he reminded be of a white tail. I think it would be really awesome if he in fact turned out to be one

- It looks like recessive white (white tail) to me too!

the only information I have on recessive white is this...

"Recessive White or as some call 'White Tail' were uncovered by The PSK ranch in a herd they'd purchased from another rancher. Their Class Champion Standard that had been in breeding for a while, developed white rings around the ears and tail (hence the name "White Tail"). They realized that its color was changing. The chin as well as some others who were showing to be in a lighter color phase were separated from the others and started in a breeding program. Over time, progress was made, the white coloring takes a long time to show (they're born Standard and develop growing white markings later). On rare occasions, they noticed some of the offspring starting to change at about 8 months to a year of age, but most of them either change much later, or even not at all. We seem to think it is based on the amount of 'White Tail' the parents have, similar to the Ebony gene. In theory if the parents have a lot of white (once the color changed) and changed early, the kits have a better chance of changing early. No one is sure if they are really recessive. It could be cumulative trait that's not recessive. With White Tails, if the parents are Heterozygous White Tail, the kits are "possible White Tail carriers" AND "possible White Tails" (since any that are Homozygous don't show at birth). PSK ranch moved and most of the herd was sold to the Bowen Ranch. The rest were purchased by the ToV Ranch from the Bowen Ranch, and are at the ToV Ranch in a closed breeding program. "

- I can see how this might be an interesting development for the pet market but I can't really see much use for this in the fur market...Guess it wouldn't matter if they aren't showing rings until 2 years old...

- This is what I got from Laurie today at .com
The original fading whites appeared in the PSK herd, out of some breeding stock they bought from Doug Wilson in Missouri. Sue dabbled with them a little bit, and then some of them may have gome to Bill Booker's herd and elsewhere when they dispersed. I liked them, but the problem with them is that they were born normal standard, and then did not fade until they were close to two years old. So, you had to keep everything you had for two years or more to know if you had a fading white. They didn't turn completely white. They had a distinct pattern of fading. The quality was very good overall in the fading whites I saw at PSK in the 1990's. Yes, they got rings around their ears, and some faded more dramatically than others.

- It's kind of interesting that it only appears with increasing age. I wonder if the mechanism behind it would be similar to that causing greying in other animals (ie. dogs, horses, even humans I guess), the melanocytes in certain areas are producing less melanin, so the chin turns white there due to a loss of pigment. I think it's that the areas that typically fade, round the ears, the base of the tail, the nose, may have less melanocytes (melanin producing cells) to begin with.

So, I suppose in that case it would be a bit different from most mutations, definitely genetic though, same as some humans greying very early (but chins don't normally show the effect at all, do they, so it's still quite different from usual).

А теперь фото эбони:
http://diamondchinchillas.webs.com/SDC10565.JPG

http://diamondchinchillas.webs.com/SDC10568.JPG

В общем, пусть пока эти избранные посты тут полежат, может потом переведу

[*Nastenka*]

А у Наташи Nightly Edelweiss в 11 месяцев уже у шуши очки и носик белые.так если я не путаю она ее как СRW изначально и покупала, там родители такие же, если мы об одном и том же животном