A genome-wide association study of morphometric traits in dromedaries.

BACKGROUND: Investigating genomic regions associated with morphometric traits in camels is valuable, because it allows a better understanding of adaptive and productive features to implement a sustainable management and a customised breeding program for dromedaries. OBJECTIVES: With a genome-wide association study (GWAS) including 96 Iranian dromedaries phenotyped for 12 morphometric traits and genotyped-by-sequencing (GBS) with 14,522 SNPs, we aimed at identifying associated candidate genes. METHODS: The association between SNPs and morphometric traits was investigated using a linear mixed model with principal component analysis (PCA) and kinship matrix. RESULTS: With this approach, we detected 59 SNPs located in 37 candidate genes potentially associated to morphometric traits in dromedaries. The top associated SNPs were related to pin width, whither to pin length, height at whither, muzzle girth, and tail length. Interestingly, the results highlight the association between whither height, muzzle circumference, tail length, whither to pin length. The identified candidate genes were associated with growth, body size, and immune system in other species. CONCLUSIONS: We identified three key hub genes in the gene network analysis including ACTB, SOCS1 and ARFGEF1. In the central position of gene network, ACTB was detected as the most important gene related to muscle function. With this initial GWAS using GBS on dromedary camels for morphometric traits, we show that this SNP panel can be effective for genetic evaluation of growth in dromedaries. However, we suggest a higher-density SNP array may greatly improve the reliability of the results.

Polymorphism of Myostatin Gene in Intron 1 and 2 and Exon 3, and Their Associations with Yearling Weight, Using PCR-RFLP and PCR-SSCP Techniques in Zel Sheep.

The aim of present study was to investigate myostatin gene polymorphism and its association with yearling weight records in Zel sheep using PCR-RFLP and PCR-SSCP methods. Blood samples were collected from 200 Zel sheep, randomly, and DNA was extracted using modified salting out method. Polymerase chain reaction was carried out to amplify 337, 222, and 311 bp fragments, respectively, comprising a part of exon 3, intron 1, and intron 2 of myostatin gene. In addition, exon 3 was digested by HaeIII enzyme under RFLP method, and introns 1 and 2 were studied using SSCP. Under RFLP method, all samples showed mm genotype. Under SSCP method, intron 1 was also monomorph but intron 2 was polymorph (AA, AB, and BB). The allelic frequencies for A and B were 75.5 and 24.5%, respectively. This locus was not in Hardy-Weinberg equilibrium (P < 0.05), and there was no significant effect of myostatin gene on yearling weights.