The ubiquitin-like, containing PHD and RING finger domains 1 (uhrf1) gene promotes ovarian development in Exopalaemon carinicauda

Ridgetail white prawn, Exopalaemon carinicauda, with high reproductive capacity can reproduce up to three or four generations a year. In exploring the genetic factors affecting the gonadal development of E. carinicauda, we cloned and studied the function of the ubiquitin-like, containing PHD and RING finger domains 1 (uhrf1) gene. The open reading frame of uhrf1 gene was 2286 bp, encoding a total of 761 amino acids. The Uhrf1 has UBL, TTD, PhD, SRA, and ring finger domains that are associated with genome methylation, histone recognition and chromatin modification. According to the phylogenetic analysis, the amino acid sequence of Ec-uhrf1 has the highest similarity with Litopenaeus vannamei uhrf1, and it is a branch of Penaeus monodon and L. vannamei. The real-time quantitative PCR showed that the expression level of uhrf1 was highest in ridgetail white prawn ovarian tissue, which was significantly higher than that of other tissues (P < 0.05). In addition, the expression level gradually increased in stages I-IV of ovarian development, with its expression level in stage IV being significantly higher than that in other stages (P < 0.05). RNAi results showed that a knockdown of uhrf1 gene expression significantly reduced the expression of the cell proliferation-related gene pcna, the DNA methylation-related gene dnmt1 and yolk synthesis related genes vg, indicating that uhrf1 regulates the expression of pcna and dnmt1. The in situ hybridization tests further indicated that the uhrf1 gene plays an important role in oocyte proliferation and accumulation of exogenous nutrients.