The linkage of cell cycle and DNA replication with growth difference in female Chinese tongue sole (Cynoglossus semilaevis): Analysis from transcriptomic study and WGCNA.

In addition to the typical sexual size dimorphism, considerable size differences within the female population of the Chinese tongue sole (Cynoglossus semilaevis) have become a further bottleneck of the improvement of sole aquaculture. To identify the internal mechanism, transcriptomic analysis and weighted gene co-expression network analysis (WGCNA) were employed simultaneously. Transcriptomic analyses of brain, pituitary gland, liver, gonad, and muscle tissues from two female groups with size differences identified 109, 698, 1325, 2299, and 2141 differentially expressed genes (DEGs), respectively. The results of these enrichment analyses suggest that the up-regulation of neuroactive ligand-receptor interaction, cell cycle, DNA replication, and MAPK signaling pathway in the group with larger females may be involved in the regulation of the observed growth differences. WGCNA of DEGs showed that cell cycle and DNA replication might be crucial pathways for accelerating cell growth in the groups with larger females. Finally, a series of hub genes including 6-phosphofructokinase type C (pfkp), ribosome biogenesis protein (wdr12), bleomycin hydrolase (blmh), and semaphorin-3A (sema3a) were recognized by the illustrated network map of modules. The linkage of cell cycle, DNA replication, and hub genes in the growth regulation of C. semilaevis provides further information for a better understanding of growth differences in fish.