fullbloods double muscling

i can't remember if i posted this exact paper or not, but it is a nice summary of the double muscle mutations and their locations.  i had a few fullbloods tested, including some from a carrier bull.  those calves tested clean as did some others that were sons of old import bulls.  one cow tested for E226x that has many north american generations.  fyi, maine's have E226x and NT419.  the numbers mean the amino acid position or the nuceotide position.  amino acids have 3 nucleic acids so E226x is at nucleotide position 678.  maine's are known to have both at once.  don't know what one looks like that are homo for both, but i wouldn't expect them to be "doubly" bad.  also, the calves were tested with igenity and pfizer panels and they don't agree for what it's worth.  not that i didn't expect that either though as the population used to find the markers probably never included maine's so any across breed causation is probably a crapshoot.  i also had a few high accuracy epd old maine's tested as angus, and their epds don't match their "score".  kinda bringing this up because the amaa is trying to get something going to test the breed for markers and there was an article about it in last month's voice.

http://www.biomedcentral.com/content/pdf/1297-9686-35-1-103.pdf

  knabe, I recently saw What I believe to be a double muscled calf from the bull Ground Zero. Ground Zero is a Strictly Business son. Where does the double muscle gene come from in this pedigree?