Monday, January 18, 2010

Epigenetics and the Calico Cat

This is our friendly calico cat. She lives on the farm where we are staying. Almost all calico cats are female—do you know why? It has something to do with epigenetics.

See: Calico Cats—it's one of my most popular postings.

Can anyone explain how some very rare calico cats might be male?

[Photo by Ms. Sandwalk]
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6 comments:

  1. AnonymousMonday, January 18, 2010 4:07:00 PM

    XXY cat? Does that count as male in cats? It does in humans.

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  2. UnknownMonday, January 18, 2010 6:17:00 PM

    could be chimeric

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  3. RaulFelixMonday, January 18, 2010 8:18:00 PM

    Maybe a dispermic embryo, giving rise to an XX/XY chimera.

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  4. TwoYaksTuesday, January 19, 2010 1:12:00 PM

    If x-inactivation is now considered "epigenetic," the term has become so wish-washy and overly broad that it has ceased to have any meaning. I can understand some variation in terminology, but this is reaching absurd heights.

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  5. Larry MoranTuesday, January 19, 2010 4:36:00 PM

    TwoYaks says,

    If x-inactivation is now considered "epigenetic," the term has become so wish-washy and overly broad that it has ceased to have any meaning.

    I agree.
     

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  6. Ralf MuschallThursday, January 21, 2010 8:34:00 AM

    If this happens as early as in the 20-cell-stage, the ovaries should have essentially all the same X active. Do the Barr bodies get unpacked completely during meiosis, or is there a correlation between the Xs of the offspring?

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