Page 79 - 《水产学报》2026年第2期

2 期 水 产 学 报 50 卷

Identification and expression analysis of HIF-1 and PHD2 genes in
razor clam (Sinonovacula constricta) under hypoxia stress

1,2
1,2
3
3
LI Zhiping , YAO Lu , LÜ Liyuan , DONG Yinghui , REN Jianfeng 1,2*
(1. Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs,
Shanghai Ocean University, Shanghai 201306, China;
2. Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education,
Shanghai Ocean University, Shanghai 201306, China;
3. Zhejiang Key Laboratory of Efficient Utilization Technology of Aquatic Germplasm Resources, College of
Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo 315000, China)

Abstract: The HIF (hypoxia-inducible factor) signaling pathway is an oxygen-sensing signaling pathway in animals and
plays important roles in metabolism and energy homeostasis under hypoxic conditions. In this study, four key genes of
HIF signaling pathway—HIF-1α, HIF-1β, PHD2A and PHD2B were cloned from Sinonovacula constricta using PCR. The
physicochemical properties and domains of their encoded proteins were predicted, and their phylogenetic relationships were
analyzed. The results showed that HIF-1 contained typical HLH, PAS, PAC, and C-TAD domains, HIF-1α specific ODDD and
N-TAD domains, and ScPHD2 contained zf-MYND and P4Hc domains; unlike other invertebrates, shellfish including S. con-
stricta PHD2 had two copies. Using real-time quantitative PCR (RT-qPCR), the expression levels of HIF-1 and PHD2 were
further analyzed at different developmental stages, in different tissues of adults and under hypoxia stress (0.5 mg/L and 2.0
mg/L) as well as air exposure stress (21 ℃ and 4 ℃) stresses. The results indicated that S. constricta HIF-1 and PHD2 were
expressed from the egg stage, ScHIF-1α was expressed at higher levels than the other genes in the six tissues examined, with
the highest expression in gill, followed by hepatopancreas, whereas ScPHD2A and ScPHD2B were expressed at very low levels
in all six tissues. Under hypoxia stress, the expressions of ScHIF-1α and ScPHD2 were significantly up-regulated, with a
greater up-regulation in the 0.5 mg/L group than in the 2 mg/L group, while ScHIF-1β expressions did not significantly
changed. Under air exposure stress, ScHIF-1β expression remained unchanged, whereas ScHIF-1α and ScPHD2 expression
were significantly up-regulated, with a stronger up-regulation in the 4 ℃ air exposure group than in the 21 ℃ group. These
findings demonstrate that ScHIF-1 and ScPHD2 possessed typical characteristics of the HIF and PHD family, respectively, and
their expression is induced to be up-regulated under hypoxia, suggesting that they may be involved in the response process of S.
constricta after low oxygen stress. This study provide a reference for further research on the hypoxia signaling pathway and the
adaptation mechanisms of S. constricta to hypoxic conditions.
Key words: Sinonovacula constricta; HIF-1; PHD2; hypoxia; air exposure; gene expression
Corresponding author: REN Jianfeng. E-mail: jfren@shou.edu.cn
Funding projects: Zhejiang Province Science and Technology Major Project (2021C02069-7); Ningbo City “Science and
Technology Innovation 2025” Major Project (2019B10005)

https://www.china-fishery.cn 中国水产学会主办 sponsored by China Society of Fisheries
12