The bisexual natural gynogenetic blunt snout bream lineage derived from the distant hybridization of female blunt snout bream and male Bleeker's yellow tail

Abstract

Distant hybridization often results in the generation of naturally gynogenic offspring. However, there are currently few reports about fertile natural gynogenetic bream. In this study, we established a natural gynogenetic blunt snout bream (NGBSB-YT, F1) through distant hybridization from female blunt snout bream (Megalobrama amblycephala, BSB) × male Bleeker's yellow tail (Xenocypris davidi Bleeker, YT), and further obtained NGBSB1-YT (F2) by self-cross. Except for the morphological characteristics, the DNA content, chromosome numbers, and 5 S rDNA sequences of NGBSB1-YT had no significant difference compared to those of BSB. The results of gonad sections showed that NGBSB1-YT was bisexual. The NGBSB2-YT (F3) obtained by self-cross further proved the fertility of NGBSB1-YT. Interestingly, the results of microsatellite (prime XD007) analysis and sox9 sequence analysis confirmed that paternal DNA fragments were inserted in NGBSB1-YT. This study has established a lineage of natural gynogenetic bream(F1-F3), that provides a reference for improvement of the theory of natural gynogenesis in fish. The NGBSB-YT lineage can be used as a new type of germplasm resource of bream.

Keywords

• Distant hybridization
• Natural gynogenesis
• Megalobrama amblycephala
• 5 S rDNA
• sox gene
• Microsatellite