Aquaculture Reports (Jun 2024)
Molecular characterization and functional identification of the insulin-like peptides receptor gene in the oriental river prawn Macrobrachium nipponense
Abstract
The insulin-like signaling pathway plays diverse biological roles in regulating metabolism, immune responses, growth, and development in invertebrates. The insulin-like peptides (ILP) receptor (ILPR) is the pivotal protein in any insulin-like signaling pathway. In our previous study, we cloned the Mn-ILP gene from the oriental river prawn Macrobrachium nipponense and elucidated its function. However, the ILPR has not yet been described in M. nipponense. In the present study, we further examined the function of Mn-ILPR in M. nipponense. The full length of the Mn-ILPR mRNA was 4790 bp, encoding 1412 amino acids. Mn-ILPR was a transmembrane receptor under a subfamily of receptor tyrosine kinases. The Mn-ILPR mRNA was predominantly expressed in muscle and hepatopancreas. To elucidate the function of Mn-ILPR, we investigated its expression in different growth stages of prawns of both sexes, in prawns of different sizes at the same time, and in prawns of the same size at different stages of the molt cycle using qRT-PCR. The expression of Mn-ILPR was markedly higher: (1) in the rapid growth stage than in other stages of male individuals; (2) in the normal growth stage than in the gonad development stage of female individuals; (3) in large male individuals than in small male individuals; and (4) in the intermolt stage than in other stages of the molt cycle. Furthermore, the long-term knockdown of Mn-ILPR by RNAi effectively delayed the growth speed of M. nipponense. Meanwhile, the short-term knockdown of Mn-ILPR revealed that the ILP-ILPR signal pathway played a part in the process of growth of M. nipponense. These findings provide a greater understanding of the molecular mechanisms underlying growth and development in crustaceans.
