MiR-34b/c play a role in early sex differentiation of Amur sturgeon, Acipenser schrenckii

Xiujuan Zhang; Wenhua Wu; Jiabin Zhou; Linmiao Li; Haiying Jiang; Jinping Chen

doi:10.1186/s12983-022-00469-6

MiR-34b/c play a role in early sex differentiation of Amur sturgeon, Acipenser schrenckii

Front Zool. 2022 Sep 26;19(1):23. doi: 10.1186/s12983-022-00469-6.

Authors

Xiujuan Zhang¹, Wenhua Wu², Jiabin Zhou¹, Linmiao Li¹, Haiying Jiang¹, Jinping Chen³

Affiliations

¹ Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Sciences, Guangzhou, China.
² Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Harbin, China.
³ Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Institute of Zoology, Guangdong Academy of Sciences, Guangzhou, China. chenjp@giz.gd.cn.

Abstract

Background: Sex differentiation can be viewed as a controlled regulatory balance between sex differentiation-related mRNAs and post-transcriptional mechanisms mediated by non-coding RNAs. In mammals, increasing evidence has been reported regarding the importance of gonad-specific microRNAs (miRNAs) in sex differentiation. Although many fishes express a large number of gonadal miRNAs, the effects of these sex-biased miRNAs on sex differentiation in teleost fish remain unknown. Previous studies have shown the exclusive and sexually dimorphic expression of miR-34b/c in the gonads of the Amur sturgeon (Acipenser schrenckii), suggesting its potential role in the sex differentiation process.

Results: Using quantitative real-time PCR (qPCR), we observed that miR-34b/c showed consistent spatiotemporal expression patterns; the expression levels significantly increased during early sex differentiation. Using in situ hybridization, miR-34c was found to be located in the germ cells. In primary germ cells in vitro, the group subjected to overexpression and inhibition of miR-34c showed significantly higher proliferation ability and lower apoptosis, respectively, compared to the corresponding control group. Luciferase reporter assays using the ar-3'UTR-psiCHECK-2 luciferase vector suggested a targeted regulatory interaction between miR-34b/c and the 3'UTR of the androgen receptor (ar) mRNA. Furthermore, miR-34b/c and ar showed negative expression patterns during early sex differentiation. Additionally, a negative feedback regulation pattern was observed between foxl2 expression in the ovaries and amh and sox9 expression in the testes during early sex differentiation.

Conclusions: This study sheds new light on the roles of miR-34b/c in gonad development of Amur sturgeon, and provides the first comprehensive evidence that the gonad-predominant microRNAs may have a major role in sex differentiation in teleost fish.

Keywords: Amur sturgeon (Acipenser schrenckii); Germ cell culture; Sex differentiation; miR-34b; miR-34c.

Grants and funding

[31802279]/the National Natural Science Fund of China