Functional Analysis of Hyaluronidase-like Genes in Ovarian Development of Macrobrachium nipponense and Comparative Evaluation with Other Key Regulatory Genes.

This study conducted a bioinformatic analysis of two Hyaluronidase-like isoforms (Mn-HyaL1 and Mn-HyaL2) in Macrobrachium nipponense and investigated their phylogenetic relationships. The open reading frames of Mn-HyaL1 and Mn-HyaL2 were 1101 bp (encoding 366 amino acids) and 1164 bp (encoding 387 amino acids), respectively. Both isoforms exhibited similar conserved domains, with an amino acid sequence similarity of 60.21%. Quantitative PCR analysis revealed that the expression levels of Mn-HyaL1 and Mn-HyaL2 increased during the mid-to-late phase of each developmental stage, were higher during the reproductive season than in the non-reproductive season, and were more abundant in the hepatopancreas than in other tissues. RNA interference experiments targeting both genes simultaneously demonstrated that knockdown of Mn-HyaL2 significantly accelerated ovarian development in M. nipponense, indicating that Mn-HyaL genes function as negative regulators of ovarian maturation. A comparative analysis of multiple genes revealed the following descending order of potency in promoting ovarian development in M. nipponense: Mn-Cholesterol 7-desaturase > Mn-Cathepsin L1. The order of potency in inhibiting ovarian development in M. nipponense, from strongest to weakest, was determined to be Mn-Gonad-inhibiting hormone > Mn-HyaL2.