Abstract:The ridgetail white prawn Exopalaemon carinicauda belongs to the suborder Pleocyemata, in the family Palaemonidae, and is one of the most economically important pond-reared shrimp. At present, most of the egg-carrying broodstock are harvested from natural sea areas, which considerably restricts the development of E. carinicauda aquaculture. Thus, artificial propagation methods are required to enhance the productivity of E. carinicauda in aquaculture systems. To develop these systems, there is a need for a greater knowledge base encompassing the mechanism of ovarian and embryonic development of E. carinicauda. Ubiquitin C-terminal hydrolases (UCHLs) are a subset of deubiquitinating enzymes that are involved in numerous physiological processes. Many studies have shown that the UCH family of deubiquitinating enzymes plays an important role in reproduction. In this experiment, the full-length cDNA of UCHL5 was identified and characterized using an approach that combines transcriptome data and rapid amplification of cDNA ends (RACE). The expression profile of UCHL5 in different developmental stages of the ovary and various tissues was determined using real-time quantitative PCR. The pET32a-UCHL5 prokaryotic expression recombinant plasmid was constructed and induction expression was carried out. The cloned UCHL5 gene was 1440 bp in length, encoding 329 amino acids. Isoelectric point (pI) of UCHL5 protein was 5.51, and molecular weight was 37.57 kDa Homology and phylogenetic analysis showed that the deduced amino acid sequence of UCHL5 shared high homology in different species and the highest conservation with Litopenaeus vannamei (83%). Real-time quantitative PCR results indicated that the expression quantity of UCHL5 was the highest in the gill tissue of E. carinicauda, followed by that in the ovary. The expression quantities of UCHL5 at different ovary developmental stages (Ⅰ~Ⅳ) were progressively upregulated, and the expression of UCHL5 was the lowest in stageⅤ. The fusion protein UCHL5 obtained through prokaryotic expression was 52 kDa. From the results of this study, we may conclude that UCHL5 is possibly playing an important role in the ovarian development of E. carinicauda.
