Tuesday, January 3, 2012

Being a Crazy Cat Lady Doesn't Sound Too Bad


Fluff and her unique face
 I know lately you have been inundated with my posts about my pets.  First my horses, then the giant bunny, well I'm not quite finished...  I introduce you to Fluff!  Well technically her name is Penelope, but my dad started calling her "The Fluff" and well, it stuck.  Fluff is a shelter kitty whom I got on my 18th birthday.  She is my constant companion and basically my child.  So how about some fun facts about Fluff and other cats.  Please note this blog contains lots of genetics terms and discussions...

Most know cats come in a variety of colors, calico being a tri-colored cat (Fluff happens to be a calico).  A little known fact is calico coloring is almost exclusively reserved for female cats.  Wait, how is this unusual coloration created, and why do only females get it?  Both questions can be answered by a scientific principle, X inactivation.  Lets break this down to basics, a male has an X and a Y chromosome, where as females have two X's.  The X chromosome is far larger than a Y and contains far more information, including the coding for hair color.  During the developmental process one X chromosome is dominant over the other therefore the other X is inactivated, but not for long.  The two X's take turns.  Now if the X chromosomes code for different colors, they will display the calico pattern as the X's take turns switching on and off.  Depending on the frequency and duration that each X is on/off you get different size patches or even patches that appear interwoven.  This either gives you a brindle colored coat (like Fluff) or a patchwork coat more like a quilt.
Now a few people may argue that thy have seem male calico cats.  They are very likely chimeras, or have two genotypes.  The possible types would be XX XX, XY XX, or XY XY.  This can also create a calico coat pattern through a somewhat similar process except with two completely different sets of chromosomes.  There are a few other genetic disorders that can also lead to calico males but mainly, calico cats are female.

Polydactyl Cat

Cats can have extra toes, this is called Polydactylism.  It can give cats six or even seven claws on each paw.  A normal cat has five toes up front and four on hind feet.  This is caused by a congenital abnormality, basically it is inherited.  It is caused by an autosomal dominant gene in cats.  So the polydactyl factor is located on a chromosome that isn't X or Y and is dominant so you only need to get the one copy to get it. 

Whew, did I overload your brain with all that genetic jargon?  On a lighter note it has been drawn to my attention that I could be considered a crazy animal lady.  My best response is I am 100% one, I love my animals and given enough room and resources would gladly have a zoo or animal center.  My animals will never maliciously hurt me if I didn't provoke it, and love me unconditionally.  Thus far there is no human who can compete, myself included.  That's all for now,
Cass
Sleeping Fluff

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