滞长刺参恢复生长的分子机制研究OA

The frequent occurrence of growth retardation in Apostichopus japonicus has significantly increased aquaculture production losses,highlighting the urgent need to promote growth recovery in stunted individuals.This study employed 16S rRNA gene sequencing and transcriptome sequencing at 0 weeks(T0 group),4 weeks(T2 group),and 12 weeks(T6 group)during the recovery phase to investigate the underlying molecular mechanisms.The 16S rRNA results revealed the following:(1)Within the intestinal microbiota of sea cucumbers,the Shannon and Chao indices in the T0 group slightly were lower than those in the T2 group,whereas the Simpson index was slightly higher than that in the T2 group(P>0.05),indicating that there was no significant in the intestinal microbiota diversity of sea cucumbers between the T2 group and the T0 group.Similarly,the Shannon and Chao indices in the T2 group were slightly lower than those in the T6 group,whereas the Simpson index was slightly higher than that in the T6 group(P>0.05),indicating that there was no significant difference in the intestinal microbiota diversity of sea cucumbers between the T6 group and the T2 group.Furthermore,the Shannon and Chao indices in the T0 group were significantly lower than those in the T6 group,whereas the Simpson index was significantly higher(P<0.05),demonstrating the intestinal microbiota diversity in the T6 group was markedly greater than that in the T0 group.(2)Across the T0,T2,and T6 groups,the abundances of beneficial bacteria associated with energy supply,including Bacteroidetes and Firmicutes,gradually increased.In contrast,the abundance of pathogenic bacteria associated with disruption of immune homeostasis,such as Proteobacteria,progressively decreased.The transcriptome sequencing results showed the following:(1)The numbers of significantly differentially expressed genes in T2 vs T0 and T6 vs T2 comparisons were 2028 and 829,respectively.(2)In the T2 vs T0 comparison,genes including cathepsin B(ctsb)and legumain(lgmn)were downregulated in immune-related pathways,such as the lysosome pathway.Meanwhile,NADH dehydrogenase subunit 5(nd5)were upregulated in the oxidative phosphorylation pathways.(3)In the T6 vs T2,laminin subunit alpha 3(lama3)was upregulated in the PI3K-Akt signaling pathway,whereas pyruvate dehydrogenase E1 subunit beta(pdhb)was upregulated in the glycolysis and gluconeogenesis pathways.This study demonstrates that growth recovery in stunted A.japonicus is associated with alterations in energy expenditure and immune responses.These findings provide important insights into further elucidating the mechanisms underlying growth recovery in stunted sea cucumbers.