Abstract: In order to investigate the expression of gonad-inhibiting hormone (GIH) gene (PhGIH) in tissue distribution of scalloped spiny lobster Panulirushomarus in different ovarian development cycles and response of GIH to different photoperiods, the full-length cDNA sequence of PhGIH in eyestalk of scalloped spiny lobster were cloned by RACE, expressed of PhGIH in different tissues and ovary stages by qPCR,and the effects of different photoperiods (12L∶12D, 13L∶11D and 14L∶10D ) on the ovarian development of scalloped spiny lobster were compared through ovarian color and morphology, histological section and gonadosomatic index. The results showed that the length of PhGIH was 1 206 bp including a 354 bp open reading frame (ORF) encoding 117 amino acids. The amino acids sequence of PhGIH consisted of signal peptide with 39 amino acids and mature peptide with 78 amino acids, which had the typical characteristics of CHH family type II peptide hormones. The homology analysis showed that the gene PhGIH had the maximal identity (56.76%) with Cape rock lobster Jasuslalandii. Phylogenetic tree revealed that the PhGIH has the shortest evolutional distance with Cape rock lobster. The Quantitative Real-time PCR analysis showed that PhGIH was widely expressed in various organizations, with the maximal expression in the eyestalk(P<0.01), and the expression of PhGIH in the eyestalk was as the maturation of ovary. The results of photoperiod experiments indicated that ovarian development was progressed smoothly at 14L∶10D. At 92 days, the GSI was significantly increased (P<0.05) and PhGIH expression in the eyestalk was significantly decreased (P<0.05). The paraffin tissue sections showed that the ovary was orange in color and mainly composed of mature oocytes. The findings indicated that the GIH gene might play an important role in the development of ovary in scalloped spiny lobster. The photoperiod of 14L∶10D had the most obvious effect on promoting ovarian development.
2021, Vol. 36 
