Friday, May 16, 2014

"mitotically heritable" arises all the time, and is hard to type!


The definition of epigentics includes mitotic heritability.

I would just like to say that "mitotic" is not that easy to type, nor is "genetic."

My fingers are getting a workout in Epigenetics, which must mean that motor regions of my brain are getting one, too.  (In addition to the "higher functions" parts of my brain!)

This week we are learning in some depth about X inactivation.  X inactivation is what causes/allows a calico cat  to be a calico cat -- displaying, as she does, the coat-color factors she inherited from each of two different-colored parents, in random patches here and there on her body. 

Digression:  A calico cat's coat has patches of color pattern inherited from her mother, and patches of color pattern inherited from her father. Coat color in cats is on the X chromosome.  Any cat displaying two coat-color patterns -- a calico cat -- has two X chromosomes.  Which is why calico cats are essentially always female.  The rare male calico cat is XXY.
End of Digression.

This unit is really interesting, and I'm finding it much more accessible than last week's lecture (for whatever reason).  A pleasure and a surprise -- I was afraid this class might be going to be more and more opaque..........



Jeanie said...

Interesting about the calico cat. I'm curious -- are all multi-colored cats calico? Lizzie seems like a mostly black and white striped tabby, but when you look at her closely she has patches of the golden orange -- not big ones. I love the rear of her tail though -- it's orangey!

I need orange said...

I believe it's the case that any cat that has ginger and black or gray is calico.

As I understand it, her black/gray/white tabby will have come from one parent, and her ginger bits from the other.


Isn't it cool, to see her inheritance printed on her coat? Our skin, likewise, has patches of cells with X chromosomes inherited from our mothers, and other patches of cells with X chromosomes inherited from our fathers, but we can't tell one from the other just by looking, as we can with a calico cat!