Identification of genes related to growth from transcriptome profiles of the muscle and liver of Chinese longsnout catfish (Leiocassis longirostris)

Abstract

The Chinese longsnout catfish (Leiocassis longirostris) is a commercially important freshwater fish species in China. To understand the molecular mechanisms underlying its growth, we performed a comparative transcriptomic analysis of muscle and liver tissues of fast- and slow-growing L. longirostris. A total of 580 and 511 differentially expressed genes (DEGs) were obtained in the muscle and liver tissues, respectively. We selected 10 DEGs each from muscle and liver tissues by qRT-PCR to verify the reliability of RNA-seq, and it was found that the expression patterns of these genes were consistent with RNA-seq analysis results. According to the differential expression and functional enrichment analysis of genes, we found differences in the expression of several growth-related genes between fast- and slow-growing individuals. These genes may contribute to the differences in the growth of L. longirostris by influencing muscle growth and the metabolism of substances and energy. In particular, the pk and fabp genes were highly expressed in fast-growing individuals, while the cart, leptin, pepck, murf1, trim32, and pparα genes exhibited higher levels in slow-growing individuals. It was speculated that genes related to feeding behavior might be the key genes in regulating the growth of L. longirostris, while glycolytic/gluconeogenic metabolic pathway, lipid metabolism, and ubiquitin-proteasome pathway might be the main pathways involved in regulating body weight of L. longirostris. This study could enrich the available gene resources and provide a valuable basis for further studies on the regulatory mechanisms of growth in L. longirostris.