Transcriptome sequencing analysis of individual muscle tissues with differences in growth rate of Chinese sturgeon（Acipenser sinensis）

【Objective】 Based on transcriptome sequencing technology, genes and signaling pathways related to the growth of Chinese sturgeon（Acipenser sinensis） were excavated, and the molecular regulatory mechanisms of individual growth differences in Chinese sturgeon were revealed, which could provide technical references for the breeding of Chinese sturgeon, the cultivation of artificial conservation populations and the construction of population echelons. 【Method】 The F₂ generation individuals of Chinese sturgeon from the same batch and cultured under the same environmental and nutritional conditions were divided into a fast-growing group（FGM） and a slow-growing group（SGM）. Three Chinese sturgeons were randomly selected from each group, and their dorsal muscle samples were collected. Differentially expressed genes（DEGs） were screened through transcriptome sequencing, followed by GO functional annotation analysis and KEGG metabolic pathway enrichment analysis. Additionally, real-time fluorescence quantitative PCR was performed to validate the sequencing results. 【Result】 A total of 34.86 Gb of clean data were obtained through sequencing from the muscle tissue samples of 6 Chinese sturgeons in the FGM and SGM groups. Using the Chinese sturgeon genome sequence as the reference genome, 16037 new genes were identified, of which 6953 were annotated in databases such as COG, GO, KEGG, KOG, Pfam, SWISS-PROT, TrEMBL, EggNOG and Nr. According to the screening criteria of FDR ＜ 0.01 and Fold Change ≥ 2, 247 DEGs were identified in the muscle tissues of Chinese sturgeon, including 142 up-regulated and 105 down-regulated DEGs. A total of 191 DEGs were annotated with GO functions, mainly annotated to functional terms such as cellular processes, metabolic processes, cellular structural components, binding, and catalytic activity. Additionally, 100 DEGs were enriched in 88 specific KEGG metabolic pathways, including glycolysis/gluconeogenesis, amino acid biosynthesis, carbon metabolism, proteasome and pentose phosphate pathway. Through comprehensive GO functional annotation and KEGG metabolic pathway enrichment analysis, 20 candidate genes related to the growth of Chinese sturgeon were identified: PKM, PGML1, TPI, GAPDH, LDH, GPI, FBPase, PGK1, ALDOA, enolase, TTN, MYBPC3, PLA2G6, CXCL10, MICALL1, GPC6, CLASP1, CARNS1, PSMD7 and CDO1. The results of real-time fluorescence quantitative PCR were consistent with those of transcriptome sequencing, indicating the reliability of the DEGs identified through transcriptome sequencing. 【Conclusion】 Chinese sturgeon takes carbohydrate utilization efficiency and energy allocation strategy as the leading factors, couples the gene functions such as muscle growth, nutritional metabolism and signal transduction, and coordinately regulates the differentiation of individual growth rates.