Tracing the origin of 'blue Weimaraner' XXXX by molecular genetics.

@entity575 @entity235 @entity19 @entity73002 @entity73003
Weimaraner @entity235 are defined by light brown coat colour termed grey including several shadings ranging from @entity575 and deer to @entity19 grey. In contrast, the so-called blue Weimaraners (BW) with lightened black-pigmented coat have been proposed to represent spontaneous revertants in the Weimaraner breed. In order to investigate the genetic determinants of the characteristic grey coat colour versus those of BW, known variation in coat colour genes including @entity73002 and @entity73003 were analysed in a number of grey and blue @entity235 . Variations at the B locus cause grey coat colour in Weimaraners via two non-functional @entity73002 copies (bb) including the b(s), b(d) and b(c) alleles. In all BW, at least one functional @entity73002 allele (Bb or BB genotype) was identified. Defined microsatellite alleles in @entity73002 intron 4 are linked to this functional B allele in BW. These alleles were also detected in various other @entity235 breeds, but not in grey Weimaraners. The combination of a dominant trait for blue versus grey together with a specific @entity73002 haplotype in BW suggests that blue coat colour is not the result of spontaneous (back-) mutation in grey Weimaraners. This inference is even emphasized by the presence of a unique Y-chomosomal haplotype in a male offspring of the supposed ancestor of the BW population which - according to pedigree information - carries a copy of the original Y chromosome. Thus, molecular genetic analyses of coat colours combined with Y-chromosomal haplotypes allow tracing the origin of atypical @entity235 in respective @entity235 populations.
