Explain the science behind breeding a homozygous tobiano horse ?

Question

I'm interested in the percentage % of breeding a tobiano homozygot.

What are the chances of breeding one from two heterozygots, one heterozygot and one homozygot, and two homozygots?

I'm only interested in the tobiano pattern, not colour, or any other patterned coat.

Links to back up answers would be very useful, thanks

Answer 1

Have a look at the blog part of my website www.soloequestrian.com.  There is an article there on horse coat colour, with some Punnett squares showing outcomes of breeding various genotypes of tobiano.

Answer 2

Since tobiano coloring requires that there be only one dominant tobiano gene of two for the horse to show the pattern if you breed two heterozygous tobianos together you'll have a 25% chance of getting a homozygous tobiano, 50% chance of getting a heterozygous tobiano, and 25% chance of getting a Homozygous recessive that shows no tobiano pattern at all (either will be solid colored or Overo if that pattern is present)

Any time you breed a homozygous tobiano to anything you will get a tobiano.  Unless the other horse is a tobiano you'll have a heterozygous tobiano, not homozygous.