A novel uniquely ovary-expressed insulin-like receptor in the female prawn, Macrobrachium rosenbergii (Decapoda, Palaemonidae)

Abstract

The insulin signalling pathway is one of the most studied pathways, including ovary maturation and female reproduction. However, downstream elements involved in this cascade remain unknown. Here, we identified and characterized an insulin-like receptor (IR) in female Macrobrachium rosenbergii, and named as Mro-IR. The deduced Mro-IR contained conserved domains of IR proteins, including two ligand-binding domains, a furin-like domain, two fibronectin-3 domains, a transmembrane domain and an intracellular tyrosine kinase domain in order. Multiple sequence alignment of the first ligand-binding domain and the tyrosine kinase domain in Mro-IR revealed a high degree of similarity to other representative IRs. Mro-IR was clustered into a separate branch with IRs from decapods by phylogenetic analysis. Additionally, tissue distribution analysis showed that Mro-IR was uniquely expressed in the ovary of M. rosenbergii. This study would possibly provide a new highlight to the molecular mechanism of insulin-like signalling cascade, regulating female sexual differentiation in crustaceans.