Affiliation:
1. School of Life Sciences and Health, Hunan University of Science and Technology
2. State Key Laboratory of Developmental Biology of Freshwater Fishes, Hunan Normal University
Abstract
Abstract
Background Distant hybridization is an important breeding technique for creating new strains with superior traits by integrating two different genomes. Successful hybridization of Megalobrama amblycephala (BSB, 2n = 48) and Culter alburnus (TC, 2n = 48) was achieved to establish hybrid lineages (BT and TB), which provide valuable materials for exploring the mechanisms of distant hybridization fertility. In this study, the gonadal tissue transcriptomes of BSB, TC, BT-F1, and TB-F1 were sequenced using Illumina high-throughput sequencing technology to analyze the reproductive characteristics of BT and TB.Results Differential gene expression analysis showed that the differentially expressed genes in BT vs BSB and BT vs TC were mainly enriched in signaling pathways not directly associated with meiosis. The differentially expressed genes of TB vs BSB and TB vs TC were mainly enriched in pathways related to meiosis, and most of them were down-regulated, indicating that meiosis is suppressed in TB. UD (under-dominance) genes were enriched in pathways related to meiosis and DNA repair in TB. OD (over-dominance) genes were enriched in MAPK signaling pathway, and ELD-B (expression level dominance-BSB) genes were enriched in pathways related to steroid hormone synthesis in both BT and TB.Conclusions These results suggest that meiotic progression may not be affected in BT, whereas it is clearly inhibited in TB. Offspring of M. amblycephala maternal parent may have better genomic compatibility and fertility. Our study provides important information on the molecular mechanisms of breaking reproductive isolation in distantly hybridized fertile lineages.
Publisher
Research Square Platform LLC