Excavation of Genes Related to the Mining of Growth, Development, and Meat Quality of Two Crossbred Sheep Populations Based on Comparative Transcriptomes

SIMPLE SUMMARY: In this study, we measured the performance parameters of two crossbred sheep breeds, using Masson staining of the muscle tissue, and using the Illumina high-throughput sequencing platform to determine the differentially expressed genes (DEGs) in Dorper (DP) × Small-tailed Han (STH) sheep and Mongolia (MG) × Small-tailed Han sheep (STH). New transcripts of the muscle transcriptome were examined for the first time. DP × STH sheep were superior to MG × STH sheep in terms of meat quality and muscle morphology. In addition, 13 DEGs were found to play important roles in growth, development, and meat quality. The findings of this work may provide valuable resources for future research on muscle development in sheep. ABSTRACT: Crossbreeding can improve production performance and meat quality in sheep. The objective of this study was to look for genes related to sheep growth, development, and muscle. In this study, Dorper (DP) × Small Tailed Han (STH) sheep and Mongolia (MG) × Small-tailed Han (STH) sheep were used to estimate the productive performance and meat quality in a crossbreed. Subsequently, transcriptome analysis and bioinformatic analysis were performed on the Longissimus dorsi muscles of DP × STH and MG × STH sheep to identify differentially expressed genes (DEGs) related to growth, development, and meat quality. The presence of DEGs was confirmed by real-time PCR (qPCR). Productive performance and meat quality of the DP × STH sheep were better than the MG × STH sheep. Compared to DP × STH, a total of 1445 DEGs were identified in MG × STH sheep (1026 DEG were up-regulated and 419 DEG were down-regulated). Of these, 38 DEGs were related to growth, 161 to development, and 43 to muscle. In addition, 13 co-expressed genes (FGFRL1, SIX1, PLCB1, CRYAB, MYL2, ADIPOQ, GPX1, PPARD, GPC1, CDC42, LOC101106246, IGF1, and LARGE) were identified. The expression of DEGs was consistent with the comparative transcriptome analysis. This work provides genetics resources for future research on muscle development in sheep.