Don't know when it first began showing up in the pet population, but I'd
expect it's been around forever (given how many mammals in general have
it). It's didn't get so widely spread till people began strongly wanting
to have one that "looked different". I DO know when it was first realized
that what was seen in ferrets was likely WS, the same as in so many other
mammals. Science News had run a long and detailed article on WS in general
and that led to the first discussion on it by name, though people had
already noticed the hearing loss connection to the markings. If you
search for the first mentions of WS here on the FML you should find it.
(Sometimes in memory I connect first mentions to the cited source; for
instance, ADV was first mentioned on the Internet when members began
getting copies of Fox's first veterinary text book but I don't recall how
long after publication that was. Do recall the WS aspect being discussed
almost as soon as the SN article appeared.)
Safest at this point to think of at least some (possibly as many as all,
but it remains a "who knows?") mitts as something separate from WS, though
some breeders have noticed markings other than the *diagnostic head ones*
in some WS ferrets. At this point it's not known if any of such other
markings have one or more fo the strains of WS as one possible cause, if
any of these other markings might tag along on an allele located near at
least one WS cause, if it's only coincidence when they happen together,
or what. People too often automatically ascribe too much to WS, without
considering the other possibilities.
That said, I do not believe in breeding for the WS group given that WS
is firmly connected with hearing impairments in them (with variable
expression), that WS in connected in studies on other species with
intestinal infirmities, and that there are some numerical suggestions
(which could be only a sampling quirk but are still scary till more is
known) that WS might be associated with a greater risk of reduced
life-spans.
>She had what he described as a 'hooded' look, with a dark cap of colour on
>the top of her head, and two dark markings under her eyes, LIKE A BLAZE,
>but without the blaze markings. Now, I read that the blaze was caused by
>skull deformation and the pigmentation resulting thereof
The markings you describe are seen in a range of types of coats from what
we've seen over the 18 years, and can not be specified to one cause. Aside
from WS individuals sometimes having widely spaced eyes I have NOT --
repeat NOT -- read of skull malformations in them. The blaze happens
because the same early embryonic cells that form into pigment cells for
the head also develop into other structures, such as aspects of the ears.
Remember, in early fetuses there are cell types which have to later
differentiate into multiple other types of cells, so if the original cells
are wrong due to whatever cause then the cells which develop from those
original cells will also have problems in varying degrees.
Cells' genetic material have THOUSANDS of genetic locations in each. There
are many, many, many, many, many, many, many, many, many locations at which
a mutation may be present. Some will have no affect, very likely most will
have no effect, but that still leaves many things that can go wrong and
points out WHY breeders have to follow lines (including those who have been
"petted out") and be observant.
>This seems even more likely because of her horrible time with miscarages,
>and fetal deformeties when paired with a panda hob.
Hope culling of one or both breeding lines was done given the kits born
with deformities IF vet said was likely genetic. Depending on the type of
malformation it's important to find out of the cause is more likely to be
genetic or of another reason. For instance, the current thinking according
to my podiatrist is that "club foot" is more a reflection of lack of room
in the uterus for the fetus than of genetics that directly affect the
foot -- though genetics might affect the uterine size or stretch (as can
things like early large DDT exposure, apparently). There are also problems
that can be caused by disease in utero, ditto ones by poisoning, or by
diet.
>I'm mostly curious if WS could be, I don't know, accumulative.
There are so far three known possible causes, and I gather they are at
different loci (locations). This means that with people purposely breeding
for the markings it would be possible for a given ferret to have multiple
genetic causes of WS at the same time, which might make the health results
grimmer. You can learn more about this and the rest at the genetics page.
Especially read Leigh's posts; she is geneticist.
[Posted in FML issue 3223]
|
