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Recently, in collaboration with researchers at the University of Bern and the University of California, Davis, and others we have identified unambiguous tests for a total of eight A locus alleles. The new tests are based in large part on variations in two promoter regions of the ASIP (Agouti Signaling Protein)gene which dictate when and where black pigment gets expressed in the coat. Our result documents will include both an allelic designation as well as the pertinent promoter haplotypes. Our new tests will include dominant yellow versus shaded yellow which will let breeders with dogs previously tested as AY/AY know if their fawn or red/yellow dogs carry shaded yellow. Dominant yellow ASIPDY is dominant to shaded yellow ASIPSY. We have changed the terminology for these two alleles to avoid confusion with the long standing use of Ay. We have also identified three distinct “black and tan” mutations, only one of which is linked to the current AT Sine marker. These will be reported as ASIPBB1, ASIPBB2 and ASIPBB3. We have changed the terminology for these three alleles to avoid confusion with results for the widely available and long standing AT test. We will continue to offer the traditionally available tests for AY, at, and a. The results will mean the same things they always have but offer a less detailed analysis than the promoter haplotype testing. An Ay result can be considered a very good marker for ASIPDY and ASIPSY but cannot distinguish between the two. An “at” result can be considered as a marker for both ASIPBB1 and ASIPa but cannot distinguish between the two, nor can it identify the ASIPBB2 and ASIPBB3 alleles.. We have a definitive test for agouti or wild type, ASIPag which replaces the default aw. We have a definitive test for black saddle, ASIPBS which is different from the presently available RALY marker. We have a test for complete analysis of the A locus In total there are eight alleles with the following dominance hierarchy:


NEW A Allele   Promter Haplotype   Phenotype Name   Legacy A allele 
ASIPDY VP1_HCP1 Dominant Yellow Ay
ASIPSY VP2_HCP1 Shaded Yellow Ay
ASIPBS VP1_HCP4 Black Saddle AT
ASIPBB1 VP2_HCP3 Black Back 1 AT
ASIPBB2 VP2_HCP4 Black Back 2 Phenotype AT tested as Aw
ASIPBB3 VP2_HCP5 Black Back 3 Phenotype AT tested as Aw
ASIPa VP2_ HCP3 Recessive Black a
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