AUTHOR=Jiang Sufei , Xiong Yiwei , Zhang Wenyi , Zhu Junpeng , Cheng Dan , Gong Yongsheng , Wu Yan , Qiao Hui , Fu Hongtuo 

TITLE=A Novel Legumain-Like Protease in Macrobrachium nipponense: Identification, Characterization, and Function Analysis in Ovary Maturation

JOURNAL=Frontiers in Endocrinology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2022.858726

DOI=10.3389/fendo.2022.858726

ISSN=1664-2392

ABSTRACT=<p><italic>Legumain</italic>, also called <italic>aspartic endopeptidase</italic> (AEP), is a member of the cysteine protease family and is involved in various physiological processes. In this study, we analyzed the characteristics of a novel <italic>legumain-like</italic> (named <italic>Mn-Lel</italic>) in the female oriental river prawn, <italic>Macrobrachium nipponense</italic>, which is involved in ovary maturation. The <italic>Mn-Lel</italic> is 1,454 bp in length, including a 1,290-bp open reading frame that encodes 430 amino acids. qPCR analysis indicated that <italic>Mn-Lel</italic> is specifically highly expressed in the hepatopancreas and ovaries of female prawns. It is rarely expressed in embryogenesis, weakly expressed in early larval development stages, and then significantly increased after metamorphosis, which indicated that <italic>Mn-Lel</italic> is not a maternal gene and mainly plays a role in adults. During the different ovarian stages, <italic>Mn-Lel</italic> expression in the hepatopancreas had no obvious rules, while its expression in the ovaries had a significant peak in stage III. <italic>In situ</italic> hybridization studies revealed that <italic>Mn-Lel</italic> is localized in the oocyte of the ovary. Changes in the gonadosomatic index confirmed the inhibitory effects of <italic>Mn-Lel</italic> dsRNA on ovary maturation. These results suggest that <italic>Mn-Lel</italic> has a key role in promoting ovary maturation.</p>