Understanding Macrobrachium rosenbergii ovarian maturation control at the genome level is an important aspect for increasing larvae production. In this study, an ovarian maturation related gene, M. rosenbergii vWD domain and three Kazal-type domains of a gene (MrvWD-Kazal) have been studied. The MrvWD-Kazal gene was isolated using a rapid amplification of cDNA end (RACE) method and the relative abundances of MrvWD-Kazal mRNA in the ovary, hepatopancreas, stomach, intestine and gill were determined by using the quantitative PCR technique. The MrvWD-Kazal gene is composed of 2194 bp with an open reading frame (ORF) of 1998 bp encoding 665 amino acids and has great similarity to the M. nipponense vWD-Kazal gene (91%). The qPCR analyses indicated the relative abundance of MrvWD-Kazal mRNA transcript varied among different stages of ovarian function (P < 0.05), but there were no differences abundance in hepatopancreas, stomach, intestine and gill (P> 0.05). In the ovary, relative abundance of MrvWD-Kazal mRNA transcript gradually increased with ovarian maturation from Stages 1 (Spent; 1.00-fold), to 2 (Proliferative; 3.47-fold) to 3 (Premature; 6.18-fold) and decreased at Stage 4 (Mature; 1.31-fold). Differential relative abundances of MrvWD-Kazal mRNA transcript in the ovary indicate the MrvWD-Kazal protein may have an important function in ovarian maturation of M. rosenbergii. The results of this study also indicate the MrvWD-Kazal is not involved in regulation of the reproductive related function of the hepatopancreas, digestive system (stomach and intestine) and respiratory system (gill).
This article investigated how crabs responded to different culture salinities through ovarian maturation stages using combination of external morphology (ovarian coloration and gonadosomatic index), and histological assessment (oocyte structures and diameter sizes). A total of sixty immature crabs were sampled from coastal water of Setiu Wetlands, Kuala Nerus, Terengganu, Peninsular Malaysia, and were introduced to limb autotomy technique in order to induce molt. Crabs were reared until successfully molted, and leaves prior to hardened shell, before proceed with salinities acclimatization prior to salinity treatments (10, 20 and 30 ppt). Five crabs were randomly selected every 15 days throughout 60-day of culture (Day 15, 30, 45 and 60) for the assessment. The different between each ovarian maturation stages was recorded based on the color appearances, and Kruskal-Wallis analysis were done between gonadosomatic index and oocyte diameter sizes with different salinity treatments. Part of the data is associated with the recent articles [1], [2] and provided here as raw data of Supplementary materials.