Work

Genomic and transcriptomic analyses reveal the molecular mechanism of heterosis in hybrid largemouth bass (Micropterus salmoides)

Year: 2025

Type: article

Abstract: Populations of largemouth bass ( Micropterus salmoides ) are showing diminishing genetic diversity and degradation of valuable traits, so it is important to enhance their genetic diversity. Two geographically isolated populations of largemouth bass — the protospecies from the United States and the farmed population in Jiangsu, China — were used to produce hybrids. Two hybrid populations (NC and CN) were produced, and the growth performance, genetic diversity, and transcriptomes were compared between the hybrids and purebred groups (CC and NN). The weight gain rate and specific growth rate were significantly higher in the hybrid groups than in the purebred groups, and the hybrids showed significant growth heterosis. The values of diversity indices (observed and expected heterozygosity, polymorphism information content, and nucleotide diversity) were higher in the hybrid groups than in the purebred groups. Differentially expressed genes (DEGs) in the hybrids predominantly exhibited dominant expression patterns; 544 and 180 DEGs in NC and CN, respectively, showed overdominant expression. In NC, genes with overdominant expression were enriched in pathways associated with the synthesis and metabolism of various materials, including amino acids, lipids, and carbohydrates. Many DEGs between the hybrid and purebred groups were significantly enriched in the protein processing in endoplasmic reticulum pathway, which is associated with non-specific immune regulation. Genes in regions under strong selection pressure played important roles in material metabolism and synthesis. Thus, hybridization enhances the genetic diversity of largemouth bass and improves its growth performance. Our findings provide new information about the mechanisms of heterosis, offering insights for future breeding research. • Hybrid largemouth bass were bred from two geographically isolated populations. • The growth performance of the hybrid group was better than that of the parents. • The genetic diversity of the hybrid group was increased. • Genes under strong selection pressure contributed to heterosis. • Genes highly expressed in the hybrids promoted physiological metabolic capacity.

Source: Aquaculture Reports

DOI: 10.1016/j.aqrep.2025.103254

Authors: Qingchun Wang, Ning Zhao, Siqi Lu, Jixiang Hua, Yifan Tao, Yan Zhuge, Wenhua Chen, Jie He, Jun Qiang

Institutions: Ministry of Agriculture and Rural Affairs, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Nanjing Agricultural University

Language: English

Topic: Genetic and phenotypic traits in livestock

Subfield: Genetics

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

SDG: Zero hunger

Open Access status: gold

Estimated APC paid: $2,640