Page 63 - 《水产学报》2025年第11期

胡利，等 水产学报, 2025, 49(11): 119105

Identification of chitinase family members in the Crassostrea gigas and
the expression patterns of Cgamcase-1 under ocean acidification

1,2
1,2
1,2*
1,2
HU Li , LIU Chang , LI Qingsong , WANG Lingling , SONG Linsheng 1,2*
1. Liaoning Key Laboratory of Marine Animal Immunology and Disease Control,
Dalian Ocean University, Dalian 116023, China;
2. Liaoning Key Laboratory of Marine Animal Immunology, Dalian Ocean University, Dalian 116023, China

Abstract: Chitinase, as a crucial enzyme for the degradation of chitin, is involved in the construction of the chitin framework
during the process of shell formation. In order to identify the members of the chitinase gene family in Crassostrea gigas and
investigate their response to acidification, bioinformatic methods were employed to identify the chitinase family members and
analyze their expression patterns. Eleven members of the chitinase family were identified from the C. gigas genome. All gene
members contained the Glyco-18 domain, and some genes also contained the chitin-binding domain ChtBD2. These genes were
predominantly located on chromosome 2, 5, 6, and 7. In the C. gigas, the chitinase family genes were clearly divided into two
branches which were endochitinases and exochitinases. The chitinase family expressed across all developmental stages of the C.
gigas larvae. With the development of larva, the expression level of five genes increased gradually. The expression levels of
most chitinase family genes were higher in the mantle compared to other tissues. The acidic mammalian chitinase (Cgamcase-1)
exhibited high expression level in the mantle, with the highest expression level in the outer fold (OF). The expression patterns
of Cgamcase-1 in response to acidification were analyzed. After 3, 7, and 14 days of acidification stress, the mRNA expression
of Cgamcase-1 in the mantle was 3.010-fold (P < 0.05), 4.557-fold (P < 0.001) and 4.129-fold (P < 0.001) of that in the control
group, respectively. After 7 days of acidification stress, the mRNA expression of Cgamcase-1 in OF was 3.598-fold of that in
the control group (P < 0.05). In situ hybridization results revealed that the positive signals for the Cgamcase-1 probe were
primarily concentrated in the epithelial cell region of the outer fold, and the intensity of the positive signals significantly
increased after 7 days of acidification stress, while it significantly decreased after 14 and 28 days. The study suggested that chit-
inase family genes might be involved in the process of larval development and adult shell formation. Cgamcase-1 participated
in chitin degradation and responding to ocean acidification. This research provided important theoretical evidence and refer-
ence for understanding the role of chitinase in the shell formation process of the C. gigas and their response mechanisms under
ocean acidification.

Key words: Crassostrea gigas; chitinase; ocean acidification; gene family
Corresponding authors: LIU Chang. E-mail: liuchang@dlou.edu.cn;
SONG Linsheng. E-mail: lshsong@dlou.edu.cn
Funding projects: Dalian High Level Talent Innovation Support Program (2022RG14); Liaoning Department of Education
(LJKMZ20221123)

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