Study of genes affecting the production of wool fibers in sheep based on ontology analysis

The importance of wool has led to extensive research on its structure and genetic since decades ago. Identifying genes affecting economic traits is one of the most important goals of breeding in sheep. The genetic and functional potential of genes can be used to obtain animal products with the best quality and quantity. For the analysis of large data, sequencing software is cost-effective, which has greatly helped to understand the mechanisms and genetic background of various phenotypic traits in sheep. Identifying different characteristics of candidate genes and types of genotypes related to important phenotypic traits is essential in animal breeding. Therefore, the aim of the present study is to identify the genes affecting the production of wool fibers in sheep based on the functional analysis of those genes.

In order to identify genes affecting wool fibers in sheep, the data used in this research were downloaded from the GEO database with access number GSE85844. In the current study, the criterion for selecting genes is the expression difference in the range 0.3 < LogFC <-0.3 and P-value at the 5% level. After identifying and specifying the genes with significant difference (increased and decreased expression), DAVID database was used to analyze the ontology of genes. In order to investigate the interaction and relationship between the genes, the STRING database was used and the Cytoscape software package was utilized to analyze the created network.

1008 genes with different and significant expression were identified (p<0.05). Genes with Log FC <-0.3, have low expression and their number was 431, and genes with Log FC > 0.3 have high expression and their number is 577. The ontology results for CHRD, PLOD1, BMP4 and ITGA5 genes showed that these genes are effective in the pathways related to hair morphogenesis and construction, hair follicle regeneration and development and density of skin.

selecting to improve the quality of wool produced in sheep by using these findings will accelerate the genetic progress of related breeding programs.