Work

Polymorphisms and Expression Characteristics of the ZSWIM7 Gene Are Associated with the Fertility of Male Allotetraploid of Red Crucian Carp × Common Carp

Year: 2026

Type: article

Abstract: Allotetraploid fish produced by distant hybridization are valuable germplasm for the mass production of sterile triploids. The allotetraploid crucian–carp hybrid (4nAT, 4n = 200) is derived from the intergeneric cross between a female red crucian carp (Carassius auratus red var., 2n = 100) and a male common carp (Cyprinus carpio L., 2n = 100). However, after 33 successive generations, this lineage faces a critical bottleneck in maintaining male fertility. The present study aimed to develop new biomarkers for testicular development and characterize the associated functional gene expression profile in 4nAT. Following whole-genome resequencing and selection signature analysis of 15 male 4nAT individuals from each of the high-development group (HDG) and low-development group (LDG), ZSWIM7 (Zinc Finger SWIM-Type Containing 7), a gene implicated in reproductive development, was selected as a candidate for further fertility association studies. Seven SNPs were screened in the coding region of ZSWIM7 of 70 4nAT males; among these, SNP3 (c.23T/C) exhibited a significant correlation between genotypes and testicular development: individuals with the CT genotype showed a higher gonadosomatic index (1.17 ± 0.68 vs. 0.65 ± 0.50) and greater counts of mature spermatozoa (2537.67 ± 283.95 vs. 341.56 ± 121.66) compared to those with the TT genotype. Further quantitative PCR and immunofluorescence assays demonstrated that ZSWIM7 was highly expressed in the testis and specifically localized to the nuclei of early meiotic primary spermatocytes. Collectively, these results establish ZSWIM7 as a promising biomarker for 4nAT testicular development, offering a potential molecular tool for maintaining male fertility in allotetraploid fish breeding.

Source: Animals

DOI: 10.3390/ani16020352

Authors: Tao Dai, Minglin Dong, Siyang He, Weiling Qin, Conghui Yang, Yi Zhou

Institution: Hunan Normal University

Language: English

Topic: Reproductive biology and impacts on aquatic species

Subfield: Physiology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $2,896

Funders: National Natural Science Foundation of China, Hunan Normal University, National Key Research and Development Program of China