Distant hybridization leads to different ploidy fishes

Area of Science:

• Aquaculture and Genetics
• Fish breeding and hybridization

Background:

• Distant hybridization enables interspecific genome transfer, inducing phenotypic and genotypic changes in offspring.
• Previous studies indicate polyploidy induction is a key factor in fish breeding.

Purpose of the Study:

• To investigate the outcomes of distant hybridization, alone and combined with gynogenesis or androgenesis, on fish ploidy and genetic variation.
• To analyze the formation mechanisms and biological characteristics of various ploidy fish.

Main Methods:

• Performed distant hybridization between red crucian carp (RCC) and common carp (CC), and between RCC and blunt snout bream (BSB).
• Utilized gynogenesis and androgenesis in combination with hybridization to produce diploid and tetraploid fish.
• Analyzed ploidy levels, fertility, and genetic variation in resulting hybrid progenies.

Main Results:

• Achieved fertile allotetraploid hybrids (4nAT) from RCC x CC crosses, producing diploid gynogenetic and androgenetic hybrids.
• Generated sterile triploid hybrids (3n) on a large scale via tetraploid x diploid crosses.
• Obtained diploid gynogenetic fish, triploid hybrids, tetraploid hybrids, and pentaploid hybrids from RCC x BSB crosses.

Conclusions:

• Distant hybridization, especially when combined with gynogenesis or androgenesis, is effective in generating diverse ploidy fish with significant genetic variation.
• The genetic relationship between parental species influences the ploidy and fertility of hybrid offspring.
• This approach can lead to the development of improved fish varieties, such as high-body RCC and goldfish.