Page 195 - 《水产学报》2023年第1期

孙东方，等 水产学报, 2023, 47(1): 019614

Expression analysis of Htatip2 and its DNA methylation in sterile triploid
females of the Pacific oyster (Crassostrea gigas)

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1,2
SUN Dongfang , YU Hong , LI Qi 1,2*
(1. Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China;
2. Laboratory for Marine Fisheries Science and Food Production Processes,
Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China)

Abstract: Sexual maturation in triploid Pacific oysters (Crassostrea gigas) varies widely among individuals. In
addition to genetic factors, the influence of the environment on their gonadal development is also crucial. To
investigate the epigenetic regulation mechanism of Htatip2 DNA methylation in gonadal development in the
Pacific oyster, the homology, phylogeny, gene expression and DNA methylation profiles at different develop-
mental stages of fertile and sterile gonads in the oyster were investigated. The results showed that the conserved
structural domain of Htatip2 in the Pacific oyster had the highest homology with the Htatip2-like conserved struc-
tural domain in the Eastern oyster (C. virginica). qPCR analysis showed that Htatip2 was expressed in various tis-
sues, with the highest expression in the female gonads. In addition, the expression of Htatip2 increased with gon-
adal maturation in fertile oysters and did not change significantly in sterile oysters. BS-PCR analysis showed that
the DNA methylation level of Htatip2 in oysters decreased with gonadal maturation and was negatively correl-
ated with the gene’s expression level. Finally, the results of dual luciferase reporter assay indicated that the
methylated Htatip2 promoter fragment significantly inhibited luciferase activity compared to the unmethylated
fragment. This study suggests that DNA methylation of Htatip2 may be involved in the gonadal maturation
through inhibition of gene expression. This study provides an important reference for the involvement of epigen-
etic regulatory mechanisms in gonadal development.

Key words: Crassostrea gigas; triploid sterility; DNA methylation; gene expression
Corresponding author: LI Qi. E-mail: qili66@ouc.edu.cn
Funding projects: China Agriculture Research System (CARS-49); Agriculture Seed Improvement Project of
Shandong Province (2021LZGC027)

https://www.china-fishery.cn 中国水产学会主办 sponsored by China Society of Fisheries
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