My understanding of this complicated issue is that the motley gene and the stripe gene are alleles. That means that you could get a cornsnake that is normal looking, we'll say that they have the M gene. (M means the non-motley look, which would be a dominant condition). a motley corn would have the "m" gene, and a pair of them. "mm" because they are homozygous for motley. Now then you have stripe, which is a kind of motley (hence the white belly), which I'll call m(st). A striped corn is m(st)/m(st)... homozygous for both. Turns out that while a non-motley gene M is dominant over the other two genes, the "m" gene is dominant over the stripe gene m(st). With the following "simple" results:
Normal (MM) by motley (mm) will result in all normals het for motley
Motley (mm) by stripe [m(st)m(st)} would result in all motley stripe offspring m/m(st)... but since the motley is a stronger influence than the stripe, you'll get motleys, and you'll get motley stripes in the clutch.
Among my corns I have a lot I can do to play with...
Aphrodite is from Kathy love, and is het for motley M/m. Hermes is a normal stripe. m(st)/m(st). When I cross them all of the offspring should have the stripe gene, and half of them should be a variety of Motley Stripe... anywhere from the motley look all the way to motley stripe.
I also have Athena, an Anery Stripe m(st)/m(st), and Zeus, a Hurricane Snow Motley m/m. When I cross those I should get all anery motley stripes (unless Athena has some hidden recessives I don't know about).
I've heard that crossing Motley with Motley stripe can often result in very odd patterns a couple of generatiosn down the line, and I'm looking forward to seeing what I get.
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~Sasheena