Characterisation of the Melanocortin-1 Receptor Gene in Alpaca and Identification of Possible Markers Associated with Phenotypic Variations in ColourThe aim of this study was to determine if any correlation exists between melanocortin-1 receptor (MC1R) polymorphisms and skin and fibre colour in alpacas. Primers capable of amplifying the entire alpaca MC1R gene were designed from a comparative alignment of Bos taurus and Mus musculus MC1R gene sequences. The complete MC1R gene of 41 alpacas exhibiting a range of fibre colours, and which were sourced from farms across Australia, was sequenced from PCR products. Twenty-one single nucleotide polymorphisms were identified within MC1R. Two of these polymorphisms (A82G and C901T) have the potential to reduce eumelanin production by disrupting the activity of MC1R. No agreement was observed between fibre colour alone and MC1R genotype in the 41 animals in this study. However, when the animals were assigned to groups based on the presence or absence of eumelanin in their fibre and skin, only animals that had at least one allele with the A82/C901 combination expressed eumelanin. We propose that A82/C901 is the wild-type dominant ‘E’ MC1R allele, while alpacas with either G82/T901 or G82/Y901 are homozygous for the recessive ‘e’ MC1R allele and are therefore unable to produce eumelanin.
- People who process alpaca fiber into products are well aware that dark fleece behaves differently than lighter fleece in processing as well as in many final products. Even if the fineness and uniformity of a batch of dark fleeces is identical to that of a batch of white, for instance, the yarns made from those fleeces will be denser (and heavier) at the same gauge and exhibit less memory, making its performance in end products different than yarns made from light fiber. The reason for the difference is that the fibers making up the fleeces at the darker end of the spectrum of alpaca colors have less curvature than those from lighter-colored fleeces of similar fineness and length. The question is, why? The analysis below hints at a possible answer.
- Phenotypic and genetic parameters for young Australian Alpacas are presented and compared with Alpaca reports in the literature, as well as with estimates for South Australian (SA) Merino sheep. The traits studied were greasy and clean fleece weight (GFW and CFW), fibre yield (YLD), mean fibre diameter (FD), coefficient of variation of FD (CVFD), staple length (SL) and live weight (LW). Most mean values fell within those found in the literature, except for YLD, which was greater in our study. YLD, FD, SL and LW were greater than for Merino sheep, whereas the opposite was true for GFW and CFW. The heritability was high (0.37 or greater) for all traits. The estimate for LW fell within the range in the literature, whereas for GFW and SL our values were greater. Relative to those for SA Merino sheep our estimates were greater for GFW, CFW, CVFD and LW, whereas they were lower for the remaining traits, except for SL, which had the same value. Phenotypic correlations from the literature were in broad agreement with ours. Those from SA Merino hoggets, except for some correlations involving YLD and SL, were in remarkable agreement with ours. The practical implications of the findings are discussed.