>'Pez Head' was a term coined by Wolfy I believe. It occurs when you
>hold the ferret on it's back and rather than holding it's head up, it
>flips it backwards to look at the world upside down. It's now called
>'Neural Crest Disease' (please correct me Sukie!) but was referred to
>as Warburton Syndrome or something similar, again Sukie, please
>correct me!
Well, I don't know what "pez head" is, but MOST of the ferrets we have
had over 26 years have LOVED looking at the world upside down, but NONE
of them have been fully deaf and only one was partly deaf.
Neural Crest Genetic Variants can cause deafness; they also can cause
markings such as LIFE-LONG panda heads or LIFE-LONG head blazes, and
more.
They are not a disease, but a genetic difference. Waardensburg Syndrome
is one type of Neural Crest Genetic Variant but genetics professor and
ferret enthusiast, Dr. Brett Middleton thinks that KIT Syndrome (KIT
oncogene) may be a better fit among the types of Neural Crest Variants.
That makes sense; the only reason WS was latched on to in the first
place was because it was the only one we ferret people knew about at
the time -- and I should know that history because I am the one who
first suggested it way back then. KIT is a better fit!
The Neural Crest is a very early region in the fetus -- before organs
develop -- and altering it genetically can affect pigment cells, ear
formation, neural development, and more.
Here is an excellent, entertaining post on the topic that is easy to
read and very enlightening:
http://ferrethealth.org/archive/YG3069
A couple of segments:
>Sure. But that doesn't mean that the resulting depigmentation isn't
>associated with problems. There are lots of genes involved in the
>development, structure and functioning of pigment cells, and any one
>of them could have one or more alleles that result in some degree of
>depigmentation. Since many (maybe even most) genes affect more than
>one trait, an allele that causes depigmentation is likely to have
>other effects.
>
>White patterns associated with deafness are NOT always caused by the
>genes associated with Waardenburg's Syndrome (WS). There are five
>genes that are implicated in the different types of WS. These genes
>are called PAX3, MITF, EDNRB, EDN3 and SOX10. However, most white
>markings in domestic animals appear to be related to the KIT gene,
>which is often referred to as the "S" ("spotting") locus in
>discussions of coat-color genetics. White markings caused by alleles
>of this gene are also associated with deafness, and can range from
>forehead markings to extreme piebald patterns.
...
>There are a zillion problems (scientifically speaking B-) associated
>with various types of depigmentation. Failure of the neural tube to
>close, cleft palate, enlarged colon, anemia, infertility, behavioral
>disorders, reduced intelligence, limb malformations, problems with
>balance, etc. It all depends on which gene or genes are causing the
>depigmentation.
>
>There are some interesting aspects to hearing problems associated
>with white markings, especially where the KIT gene is involved. For
>example, I mentioned that this gene is involved with both spotting
>and deafness in Dalmatians. However, the incidence of hearing loss
>in Dalmatians with black patches on the ears is much lower.
You have probably also heard the Domestication Research term "Star
Gene". There doesn't really appear to be just one gene, or even one
genetic area (locus) involved in that. The term refers to the way
domestication can at times progress very rapidly in some mammals and
when it does those species also tend to develop certain physical
changes. For example, they become more child-like (neotany) in features
even when adult and they tend to have higher instances of neural crest
genetic types of markings (the "star"). There was fascinating work on
this done in the old USSR and the last I heard the people continuing
the fox project were trying very hard to get enough funding that the
many decades long work can continue while some people outside the USSR
were trying to arrange to get some of the animals if possible to also
continue the work.
There was also a project on-going (in Florida) if my memory serves,
trying to figure out where the primary mutations that establish easy
domestication need to occur. They were honing in on the adrenal gland
as one area to research because they figured that if adrenalin output
was lower in contact situations then the animals would not frighten or
fight. So, it may be that domestic animal adrenal glands and at least
part of their output may already differ from those of wild relatives.
Fascinating reading and great fun:
http://www.floridalupine.org/publications/PDF/trut-fox-study.pdf
(above has photos)
http://reactor-core.org/taming-foxes.html
I can't find the popular press article I wanted to tell you about. The
URL for it might be in a past Ferret-Genetics search:
This is one I can't recall offhand, though, I noticed I already had it
in my files when I went to save it for later reading:
http://reactor-core.org/taming-foxes.html
I know i haven't read this one yet:
http://jhered.oxfordjournals.org/cgi/reprint/95/3/185
(Please, note that this is NOT StAR Gene (Steroidogenic Acute
Regulatory) which is a different one and often -- but not always --
written with all cps except for the "t". It does affect adrenal gland
behavior, though, so the searches can become confusing.)
Hope I made enough sense. I need to go back to sleep soon.
Sukie (not a vet)
Recommended ferret health links:
http://pets.groups.yahoo.com/group/ferrethealth/
http://ferrethealth.org/archive/
http://www.afip.org/ferrets/index.html
http://www.miamiferret.org/fhc/
http://www.ferretcongress.org/
http://www.trifl.org/index.shtml
http://homepage.mac.com/sukie/sukiesferretlinks.html
[Posted in FML 5722]
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