> BTW: The cat in the first two is actually a she, as all calicos are
> female, or so I am told.
AG writes:
Hmm... I didn't think that was necessarily true, but sufficient to say, rare.
Well, to be a bit more precise all are female or are phenotypic males with an
abnormal sex chromosome complement---usually XXY or Klinefelter's syndrome. I
certainly have a substantial number of such patients
but none are currently cats. Recently diagnosed one patient at age 60. None
to pleased, but did appreciate being repeleted with testosterone. I don't know
why the random inactivation of X chromosomes in female placental mammals is
deemed a "hypothesis", though it was so in 1961.
Not all the genes are silenced either---those homologous to the Y chromo are
often still active.
Former long time denizen of molecular biology lab, Mike
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