DEG Analyses Identifie Differences in Testicular Tissues of Large White and Luchuan Pigs

Small RNAs (sRNAs) play a crucial role in mRNAs for translational repression or degradation, and they also have been reported to be involved in mammalian spermatogenesis. However, little knowledge has been revealed on sRNA and genes differentially expressed in pig breeds during specific stages of spermatogenesis. Illumina GAIIx sequencing technology was employed to profile microRNAs(miRNAs), PIWI-interacting RNAs (piRNAs) and mRNA in Luchuan pigs and Large White at sexually immature and mature testes. A total of 22,289 expressed genes were detected for these two breeds. Within-breed comparison, 9,012 two-times differentially expressed genes (DEGs) between Large White at immature and mature testis, 7,336 DEGs in Luchuan pigs. Inter-breed comparison, there were 1,375 DEGs in Luchuan and Large White at mature testes, and 1,435 DEGs at immature testes. It indicated that gene expression differences during testis maturation processing could mostly explain for difference between breeds. By miRNA profiling comparison, within breed, 54 differentially expressed miRNAs (DEMs) in Large White, and 43 DEMs in Luchuan pigs. Inter-breed comparison, three DEMs in Luchuan and Large White at mature testes, and only one DEM before sexual maturity. 35177 piRNAs were detected, indicating that the human testis has a complex population of small RNAs. In addition, a few of miRNA target genes involved in spermatogenesis and Cell adhesion pathway. This study indicated specific sRNAs expression has an important regulatory role during the processing of developing testicular maturation, as well as differences between pig breeds with sexual maturation differential.