Comparative transcriptome profiles of four sexually size dimorphic fish.

Sexual size dimorphism is widespread in fish species. Although sex growth differences in multiple species have been studied successively, the commonalities of regulatory mechanisms across sexually dimorphic species are unknown. In this study, we performed RNA-seq analysis of four representative fish (loach, half-smooth tongue sole, yellow catfish, and Nile tilapia) with significant growth differences between females and males. Clean reads were identified from four fish species, ranging from 45,718,052 to 57,733,120. Following comparison transcriptome analysis, there were 1,132 and 1,108, 1,290 and 1,102, 4,732 and 4,266, 748 and 192 differentially expressed genes (DEGs) in the brain and muscle of loach, half-smooth tongue sole, yellow catfish, and Nile tilapia, respectively. Furthermore, the expression levels were validated by quantitative real-time PCR (qRT-PCR). Comparative transcriptome profiles of four fish described here will provide fundamental information for further studies on the commonalities of sexually size dimorphic fish in regulating growth differences between females and males.