Page 98 - 《渔业研究》2025年第5期

第 5 期 付胜利等： 陵水才女虫自然感染程度对香港牡蛎凋亡及免疫相关基因表达的影响 639

The effects of Polydora lingshuiensis natural infection on the apoptotic and
immune functions of Hong Kong oyster (Crassostrea hongkongensis)

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FU Shengli ，JIANG Haoyi ，WANG Yuxiang ，LU Jie ，YAO Tuo ，YE Lingtong 1,2*
(1. Key Laboratory of Aquatic Product Processing, Ministry of Agriculture and Rural Affairs, Key Laboratory of South China Sea
Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute,
Chinese Academy of Fishery Sciences, Guangzhou 510300, China;
2. Sanya Tropical Fisheries Research Institute, Sanya 572426, China)
Abstract: [Background] As an important economic mollusc along the coastal areas of South China, the Hong Kong
oyster (Crassostrea hongkongensis) holds a crucial position in aquaculture and significantly contributes to the
local fishery economy. Polydora spp. is a kind of common shell-boring parasites of C. hongkongensis. Severe
infestation of Polydora spp. can cause the “black shell disease”. The parasites even bore through the shell and
invade the soft parts, triggering an immune response, which affecting the quality and economic value of
C. hongkongensis. [Objective] To explore the effects of different Polydora spp. infestation degrees on the ap-
optosis and immune-related genes of C. hongkongensis. [Methods] In this study, a total of 49 C. hongkongen-
sis samples were collected from Hebao Island, Zhuhai City, and Guangdong Province. Firstly, the worms were
identified by the morphological observations and molecular approach. Then, the image processing technology of
Photoshop (PS) was used to count the percentage of the black shell areas of C. hongkongensis caused by the in-
fection of Polydora spp. and classify the infection degrees. Combined with the real-time quantitative poly-
merase chain reaction technology, comparison of the apoptosis and immune-related gene expression differences
were carried out in the mantle and hepatopancreas tissues of C. hongkongensis with different Polydora spp. in-
festation grades. [Results] The results showed that the worms were identified as Polydora lingshuiensis based
on morphological and molecular charateristics. The percentage of the black shell areas within the right shell of
C. hongkongensis caused by Polydora lingshuiensis infestation ranged from 4.07% to 53.59%. Among them,
there were 0 sample with the infestation level of Grade Ⅰ, 3 samples with Grade Ⅱ, 25 samples with Grade Ⅲ,
and 21 samples with Grade Ⅳ. Compared with the oyster’s infestation at Grade Ⅱ, it was up-regulated in the
apoptosis-related genes (Caspase-2, Caspase-3, Caspase-8, FasL, IAP, BAX) in the mantle and hepatopancreas
of the oysters infested with Grade Ⅳ, and down-regulated in the immune-related genes (SABL, defension, lyso-
zme, C3) were. The Spearman correlation analysis showed that the percentage of the black shell areas was posit-
ively correlated with the expressions of Caspase-3 and Bax in the mantle and hepatopancreas, and negatively
correlated with the expression of SABL, especially the positive correlation with the expression of Caspase-3 was
particularly strong. [Conclusion] The percentage of the black shell areas can be used to assess the status of the
C. hongkongensis, and it is related to the expression of apoptosis and immune genes. The study provides a theor-
etical basis and exploration direction for the prevention and treatment of the “black shell disease” and the pro-
tection of the development of C. hongkongensis aquaculture industry.
Key words: Polydora lingshuiensis; Crassostrea hongkongensis; mantle; hepatopancreas; apoptosis; immune
response