MHC <i>DRB</i> allele diversity in Alpine ibex and chromosomal localization of genetic markers.

<p>(A) Frequency distribution of the two MHC <i>DRB</i> exon 2 alleles in Alpine ibex populations across the Swiss Alps. The marker OLADRB1 was used to assess the frequency of <i>Caib-DRB</i>*2. All populations with n≥12 are shown except for Weisshorn (n = 9; marked by an asterisk). See <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004438#pgen.1004438.s008" target="_blank">Table S1</a> for complete allele frequency data. (B) Genetic diversity of MHC <i>DRB</i> alleles in different Caprinae species. The proportions of sites that differ between each pair of sequences are shown based on 227 bp sequence length. (C) Chromosomal locations of MHC genes and genetic markers were mapped to the goat chromosome 23 using the homologous cattle (<i>Bos taurus</i>) chromosome 23 as a reference (for further details see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004438#pgen.1004438-Dong1" target="_blank">[40]</a>). The MHC <i>DRB</i> exon 2 is shown in orange. Marker distances between the microsatellites OLADRB1 and OLADRB2 are based on cattle chromosome 23 and sheep chromosome 20. (D) Observed linkage disequilibrium (connected lines) between sequence and microsatellite alleles. <i>Caib-DRB*2</i> was completely associated to allele 184 of microsatellite OLADRB1 (previously shown for a subset of 98 individuals in Alasaad et al. <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004438#pgen.1004438-Alasaad1" target="_blank">[28]</a>) and allele 277 of OLADRB2 (except 2 individuals out of 707).