Q: "Is it true that ferrets can breed with black-footed ferrets?"
A: After watching Mickey Moose--who is currently in rut--for the last
week, I think ferrets can breed with shoes, desk legs, cats....
I do not know of a specific published reference which categorically states
domesticated ferrets can sucessfully breed with the endangered black-footed
ferret and produce sexually viable--or even just viable--offspring. I DO
have references which state domesticated ferrets can successfully breed
with both European and steppe polecats to form sexually viable offspring.
Since steppe polecats and black-footed ferrets easily interbreed (and may
ultimately be listed as sub-species of each other), it would follow that
domesticated ferrets could probably breed with black-footed ferrets. I do
not know how successful such a coupling would be, but would assume it to be
more or less successful as a coupling with the steppe polecat.
Domesticated ferrets have 40 chromosomes. When they breed with European
polecats, who also have 40 chromosomes, they have sexually viable offspring
with 40 chromosomes. When domesticated ferrets breed with steppe polecats
(who have 38 chromosomes), they have sexually viable offspring with 39
chromosomes. The black-footed ferret also has 38 chromosomes, and I would
expect any offspring with the domesticated ferret to have 39 chromosomes;
I don't know if there are enough changes to make offspring sterile or
otherwise non-viable.
Interestingly enough, for you fans of genetics, if you cross an albino
domesticated ferret with a steppe polecat, your offspring will all have
normal color and 39 chromosomes. If you recross the offspring, some will
have 38, some 39 and some 40 chromosomes. None of the offspring with 38
or 39 chromosomes will be albino. That means the gene that determines
albinism has to 1) be on the chromosome that "splint" into two chromosomes
during the speciation of the European polecat, and 2) is near the "division
point" of that modified chromosome. In other words, for a ferret or
chromosome to carry the gene that causes the specific type of albinism
noted in domesticated ferrets, they have to have that specific "split"
chromosome. Since the number of "crossing over" events in the chromosomes
is lower than expected, the gene must be near the point where the original
single chromosome was modified into two, which would make crossing over
difficult; a rare event.
Now, there is an implication here that shouldn't be ignored. It is
possible that the ferret was domesticated from the steppe polecat, and
during domestication the chromosome "broke" or "split" into two separate
chromosomes, mimicking the changes which occurred when the European polecat
split from the steppe polecat lineage. This really muddies the water in
determining the possible ancestor of the domesticated ferret. What this
means is, UNTIL better studies are done, the domesticated ferret COULD be a
domestic version of the European polecat (Mustela putorius furo), it COULD
be a domestic version of the steppe polecat (Mustela eversmanni furo), it
COULD have been domesticated from BOTH the steppe and European polecats
(Mustela eversmanni x Mustela putorius), it COULD have been domesticated
from an unknown and extinct anscestor (Mustela furo), OR the European
polecat COULD be a wild form (or reverted form, like found with wild
camels, sheep and horses) of the domesticated ferret (Mustela furo
putorius).
Until such matters are worked out, it is best to use Mustela furo to
describe the domesticated ferret. Just don't hold your breath until it is
figured out; who knows if any of the five possible scenerios are correct.
Maybe all are correct, maybe only one. Or, maybe something else not even
considered. Yet.
Ain't science fun? The more you learn, the less you realize you know. I
used to think I was pretty smart, but know I realize I'm dumber than a
post. I'm lucky to be able to fire enough synapses to generate movement.
Bob C and 16 MO' Dazed and Confused Ferts of Polecat Heritage
[Posted in FML issue 2919]
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