In order to develop a comparative map between chicken and quail, we identified orthologous gene markers based on chicken genomic sequences and localized them on the Japanese quail Kobe-NIBS linkage map, which had previously been constructed with amplified fragment length polymorphisms. After sequencing the intronic regions of 168 genes located on chicken chromosomes 1-8, polymorphisms among Kobe-NIBS quail family parents were detected in 51 genes. These orthologous markers were mapped on eight Japanese quail linkage groups (JQG), and they allowed the comparison of JQG to chicken macrochromosomes. The locations of the genes and their orders were quite similar between the two species except within a previously reported inversion on quail chromosome 2. Therefore, we propose that the respective quail linkage groups are macrochromosomes and designated as quail chromosomes CJA 1-8.

Genotype data from eight microsatellite markers were used to assess genetic diversity and relationships among five indigenous Bhutanese sheep populations, Sakten, Jakar, Sarpang, Sipsu and Tsirang. Estimates of mean observed and expected heterozygosities, mean number of alleles per locus/population were obtained. The highest observed heterozygosities were found in Jakar (0.657) and Sakten (0.647), while the lowest one was found in Tsirang (0.539). Genetic distances, pairwise proportion of different alleles, UPGMA tree, and principal component analysis indicate close relationship among Tsirang, Sipsu and Sarpang populations, while Jakar and Sakten populations are located in one cluster. These two clusters are separated geographically, and show distinct phenotypic as well as molecular characters. We therefore recommend that the Bhutanese native sheep populations be classified into at least two distinct breeds, Jakar-Sakten sheep and Sipsu sheep. Since Jakar and Sakten sheep have different morphological phenotypes, further analyses will be required to understand the genetic differences between these two sheep populations.

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