Functional Characterization of Tret1-like Gene and Its Critical Role in Regulating Growth in Macrobrachium nipponense by RNA Interference

Abstract

Macrobrachium nipponense is a commercially significant freshwater prawn species in China, with larger individuals commanding higher market prices than smaller ones. Previous transcriptomic analyses have shown that a facilitated trehalose transporter gene Tret1-like (Tret1) exhibits significantly elevated expression levels in fast-growing individuals compared to their slow-growing counterparts, suggesting a potential involvement of this gene in modulating growth performance. In the present study, we explored the functional roles of Mn-Tret1 in growth regulation using reverse transcription quantitative real-time PCR (RT-qPCR) and RNA interference (RNAi) techniques. The full-length cDNA sequence of Mn-Tret1 spans 1605 bp and encodes a 535 amino acid (aa) protein. Phylogenetic analysis indicated that the deduced amino acid sequence of Mn-Tret1 shares the closest evolutionary relationship with that of Macrobrachium rosenbergii. Tissue distribution analysis via RT-qPCR revealed that Mn-Tret1 is ubiquitously expressed across all examined tissues, implying its potential involvement in multiple physiological processes. Notably, the highest transcript abundance was detected in muscle tissue, further suggesting its putative role in governing growth performance in M. nipponense. Subsequent RT-qPCR analysis validated the knockdown efficacy of the synthesized dsTret1 on Mn-Tret1 expression. Compared with the dsGFP-injected control group, the dsTret1-injected group exhibited a statistically significant reduction in body mass gain percentage, with the divergence becoming apparent from day 6 in females and day 12 in males (p < 0.05). Moreover, histopathological examination revealed abdominal muscle atrophy in individuals subjected to dsTret1 treatment. Collectively, these findings substantiate a positive regulatory role of Mn-Tret1 in governing growth performance. This study thereby contributes to a deeper mechanistic understanding of growth regulation in M. nipponense.