MScottMGP <[EMAIL PROTECTED]> wrote
>If modifying genes affect the amount of spotting on an
>animal carrying Sp, and only one parent of a pair
>carries Sp, does it follow that all spotted offspring
>will be similarly pied?
No.
This would assume there was one dominant modifying gene. Breeding Pieds
has shown that all the following are possible:
PiedxPied
=
Spot
PiedxUnmarked
=
Spot
SpotxUnmarked
=
Pied
In the early days when we first had spots it was possible to do the
following experiment:
PiedxUnmarked
=
Unmarked
If this Unmarked was bred to a spot bred from traditional UK spots some
of the offspring would have extended markings that were previously
unobtainable in the UK.
> If not, how much variation
>can be expected in a litter?
A lot!
Have a look at the first picture, and caption, at:
http://www.gerbils.co.uk/gerbils/pied.htm
> How much is known about
>the inheritance and action of the modifying genes?
Not a lot other than the above. Breeding decedents of well marked
gerbils to other well marked gerbils increases the amount of white -
thereby suggesting more than one modifying gene.
>
>A related question - what is the normal coloration of
>the very tip of a polar fox's tail? My PF's tail tip
>is white, and I'm wondering if this is a possible
>indication of Sp. He doesn't show any other
>indications, such as pink toes or white on the face or
>neck.
The tail of gerbils can be misleading. The hairs are long which
exaggerates any light colours in the fur. For example, nutmegs tend to
have what looks like a yellow tuft.
--
Julian
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* Jackie and Julian *
* [EMAIL PROTECTED] *
* National Gerbil Society *
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