RNA Sequencing Analysis In Gonads Of Male And Female Chicken Embryos

Chicken is an important model organism and agricultural animal, Sexuality of which is an important developmental trait and economic character in poultry industry. However, Compared with mammals, the molecular mechanism of sex determination and differentiation remain elusive in avian. It is well known that avian sex phenotype is determined by genes on a dichotomous ZZ/ZW sex chromosome system, the gonads formation and body gender of which is facility to be changed by environmental factors, for instance hormone of estrogen.There are two hypotheses for avian sex determination and differentiation referred as W-linked ovary determinant and Z dosage for testis determination, which are both lack of convincing evidence. Using the next-generation high-throughput sequencing technology, we detected and analyzed the profile of mRNA and small RNA expression of developing gonads in male and female chick embryos at the 6.5d after incubation. 984 genes were indicated to be differentially expressed in male and female gonads and 43 miRNAs were identified to be differentially expressed.In further analysis of expression profile data, those differentially expressed genes mainly focus to 44 GO terms. Steroid hormone biosynthesis, aminoacyl-tRNA biosynthesis and pentose phosphate pathways were considered to be involving in sex determination. The target genes prediction with three tools showed 11 miRNAs may target to important sex determinants. All target genes predicted were analyzed using GO and pathway enrichment and 53 GO terms and 17 pathways were found. Those above-mentioned results will contribute to explore the mechanism of avian sex determination and differentiation.