Turkey Genetics

Yes, Well, continuing on with our study of wierd genetics, today we consider the Turkey.  The bird, not the country.  I know nothing about Turkish genetics, just turkey genetics.  The Beltsville Small White, specifically.

A long time ago, in a state we shall call Maryland, there were agricultural scientists called breeders.  In Beltsville, MD, some breeders developed a fowl from the turkey which had white feathers.  White is easier on the eyes when you pluck the feathers off a bird on its way to becoming Thanksgiving dinner.   The turkey breeders were massing a bunch of birds into a pen and discarding the  boy turkeys because their meat might be tough to the consumer.  When a wonderous thing happened.  Although the pen consisted of all girl turkeys, they continued to lay eggs.  (That isn’t the wonderous part)  The eggs hatched.  Girl birds lay eggs all the time, just as most females ovulate routinely.  The mystery is how the eggs turned into live turkeys if there were no boy turkeys in there?

And then here we come to the most wonderous part.  Turkeys do not need men turkeys in the short term.  Turkeys are parthenogenic.  Girl turkeys can cook up a perfectly functional baby turkey from NOTHING.  They just lay an egg and out comes a baby turkey.  However, in a cruel twist of fate, all the parthenogenic baby turkeys were boy-turkeys.

Unlike the XY sex determination system in your upper, normal animals like kitties and humans, turkeys are on the ZW system.  Girl turkeys have the genotype of ZW and can make an egg for either a girl (W) or for a boy (Z).   Double u-ness equals girl turkey.  Z-ness is boy.  So a diploid girl turkey is ZW and a diploid boy turkey is ZZ.  In turkeys, WW is a lethal gene combination.  So no parthenogenically created turkeys will ever be WW.  So that leaves ZZ which is a boy.  So turkeys can get one generation from creating fertile eggs without mating.  That generation will be composed entirely of guy turkeys.  The ladies can get away with it at first, but sooner or later, they need the guys.

All us girls are fierce and proud



  1. Kevin said,

    January 15, 2010 at 5:59 AM

    Huh. Never knew that.

    • January 15, 2010 at 4:45 PM

      What are you doing up at 6:00 in the morning, kevin?

      • Kevin said,

        January 15, 2010 at 10:56 PM

        It was most definitely not 6 in the morning when I posted that.

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