摘要
In terms of taxonomic status,common carp(Cyprinus carpio,Cyprininae)and crucian carp(Carassius auratus,Cyprininae)are different species;however,in this study,a newborn homodiploid crucian carp-like fish(2n=100)(2nNCRC)lineage(F1–F3)was established from the interspecific hybridization of female common carp(2n=100)×male blunt snout bream(Megalobrama amblycephala,Cultrinae,2n=48).The phenotypes and genotypes of 2 n NCRC differed from those of its parents but were closely related to those of the existing diploid crucian carp.We further sequenced the whole mitochondrial(mt)genomes of the 2n NCRC lineage from F1 to F3.The paternal mt DNA fragments were stably embedded in the mt-genomes of F1–F3 generations of 2n NCRC to form chimeric DNA fragments.Along with this chimeric process,numerous base sites of F1–F3 generations of 2 n NCRC underwent mutations.Most of these mutation sites were consistent with the existing diploid crucian carp.Moreover,the mt DNA organization and nucleotide composition of 2n NCRC were more similar to those of the existing diploid crucian carp than those of the parents.The inheritable chimeric DNA fragments and mutant loci in the mt-genomes of different generations of 2nNCRC provided important evidence of the mt DNA change process in the newborn lineage derived from hybridization of different species.Our findings demonstrated for the first time that the paternal mt DNA were transmitted into the mt-genomes of homodiploid lineage,which provided new insights into the existence of paternal mt DNA in the mt DNA inheritance.
In terms of taxonomic status, common carp（Cyprinus carpio, Cyprininae） and crucian carp（Carassius auratus, Cyprininae） are different species; however, in this study, a newborn homodiploid crucian carp-like fish（2n=100）（2nNCRC） lineage（F1–F3） was established from the interspecific hybridization of female common carp（2n=100）×male blunt snout bream（Megalobrama amblycephala, Cultrinae, 2n=48）. The phenotypes and genotypes of 2 n NCRC differed from those of its parents but were closely related to those of the existing diploid crucian carp. We further sequenced the whole mitochondrial（mt） genomes of the 2n NCRC lineage from F1 to F3. The paternal mt DNA fragments were stably embedded in the mt-genomes of F1–F3 generations of 2n NCRC to form chimeric DNA fragments. Along with this chimeric process, numerous base sites of F1–F3 generations of 2 n NCRC underwent mutations. Most of these mutation sites were consistent with the existing diploid crucian carp. Moreover, the mt DNA organization and nucleotide composition of 2n NCRC were more similar to those of the existing diploid crucian carp than those of the parents. The inheritable chimeric DNA fragments and mutant loci in the mt-genomes of different generations of 2nNCRC provided important evidence of the mt DNA change process in the newborn lineage derived from hybridization of different species. Our findings demonstrated for the first time that the paternal mt DNA were transmitted into the mt-genomes of homodiploid lineage, which provided new insights into the existence of paternal mt DNA in the mt DNA inheritance.
基金
supported by the National Natural Science Foundation of China(31802287,31730098,31430088)
the China Postdoctoral Science Foundation(2018M632969)
the earmarked fund for China Agriculture Research System(CARS-45)
the Key Research and Development Program of Hunan Province(2018NK2072)
Hunan Provincial Natural Science and Technology Major Project(2017NK1031)
the Cooperative Innovation Center of Engineering and New Products for Developmental Biology of Hunan Province(20134486)
作者简介
Corresponding author:Shaojun Liu(email:lsj@hunnu.edu.cn)。
