Transcriptome Analysis Reveals the Molecular Mechanisms Underlying Growth Superiority in a Novel Hybrid, ♀ × ♂.

Artificial hybrid breeding can optimize parental traits to cultivate excellent hybrids with enhanced economic value. In this study, we investigated the growth performance and transcriptomes of (♀) and (♂) and their F1 hybrid fishes. Hatched individuals of (GP) and (GE) of the same size and their F1 hybrids (GH) were separately cultured for eight months in three cement tanks ( = 3). The growth indexes were measured, which showed that the growth rate of the groups was GE > GH > GP, while the survival rate was GH > GE > GP. The RNA-Seq data analysis of the muscles from the three fish strains revealed that gene transcription has a significant impact on F1 hybrid fish and its parents. The differentially expressed genes (DEGs) in GH show less differences with GP, but more with GE. qRT-PCR was used to confirm the expression profiles of the chosen DEGs, and the results showed positive correlations with the RNA-seq data. KEGG enrichment results indicated that the DEGs were related to a variety of molecular functions, such as glycolysis/gluconeogenesis, arachidonic acid formation, citrate cycle, and the MAPK, PI3K-Akt, or mTOR signal pathways. Subsequent analysis indicated that there may be a significant correlation between the differential expression of IGF2 and a difference in the growth of GE and GP.