Distant hybridization makes it possible to transfer the genome of one species to another, which results in changes in phenotypes and genotypes of the progenies. This study shows that distant hybridization or the combi...Distant hybridization makes it possible to transfer the genome of one species to another, which results in changes in phenotypes and genotypes of the progenies. This study shows that distant hybridization or the combination of this method with gynogenesis or androgenesis lead to different ploidy fishes with genetic variation, including fertile tetraploid hybrids, sterile triploid hybrids, fertile diploid hybrids, fertile diploid gynogenetic fish, and their derived progenies. The formations of the different ploidy fishes depend on the genetic relationship between the parents. In this study, several types of distant hybridization, including red crucian carp (Carassius auratus red var.) (2n=100, abbreviated as RCC) (♀)×common carp (Cyprinus carpio L.) (2n=100, abbreviated as CC) (♂), and RCC (2n=100) (♀)×blunt snout bream (Megalobrama amblycephala) (2n=48, abbreviated as BSB) (♂) are described. In the distant hybridization of RCC (♀)×CC (♂), bisexual fertile F3–F18 allotetraploid hybrids (4n=200, abbreviated as 4nAT) were formed. The diploid hybrid eggs and diploid sperm generated by the females and males of 4nAT developed into diploid gynogenetic hybrids and diploid androgenetic hybrids, respectively, by gynogenesis and androgenesis, without treatment for doubling the chromosome. Improved tetraploid hybrids and improved diploid fishes with genetic variation were derived from the gynogenetic hybrid line. The improved diploid fishes included the high-body RCC and high-body goldfish. The formation of the tetraploid hybrids was related to the occurrence of unreduced gametes generated from the diploid hybrids, which involved in premeiotic endoreduplication, endomitosis, or fusion of germ cells. The sterile triploid hybrids (3n=150) were produced on a large scale by crossing the males of tetraploid hybrids with females of diploid fish (2n=100). In another distant hybridization of RCC (♀)×BSB (♂), different ploidy fishes were obtained, including diploid bisexual fertile natural gynogenetic fish (2n=1展开更多
A strategy to improve aquaculture mollusks in genetics, which involve the theory, method, material and application system, is very important for the sustainable development of the marine molluscan breeding and industr...A strategy to improve aquaculture mollusks in genetics, which involve the theory, method, material and application system, is very important for the sustainable development of the marine molluscan breeding and industry. Selection and hybridization as the traditional way have proved effective in the genetic improvement of mariculture mollusks. The growth had increased significantly by selective breeding in oysters as well as the resisitance to MSX and QX disease. A frame chart of genetic improvement of mollusks had been derived from the breeding application of abalone and scallop. The systematic breeding with selection and hybridization has a substantial progress based on the family establishment in Haliotis discus hannai, H. diversicolor, Argopecten irradians, Chlamys farreri and Pinctada martensii. The first self-fertilized family of bay scallop had been established in the 1999 and then a series of family lines with different traits have been succeed and formed the basic element of genetic breeding. The hybridization of Pacific abalone between diffeent populations with a large genetic distance has showed a remarkable traits. The hybrid of Pacific abalone has applied to improve the traits of growth and resistance in the aquaculture and 98% seed used in the farming is hybrid. The hybridization among populations has used in other mariculture mollusks such as zhikong scallop, bay scallop, pearl oyster and small abalone. Hybridization among different populations and systematic and massive selection are the dominant approaches in the genetic improvement of mollusks. So far in China the material system for molluscan genetics and breeding is more considerable as well as the basic theory of heritability, heterosis, inbreeding depression, genetic-environment interaction for the genetic improvement. The different lines have been produced by self-fertilization, inbreeding and crossing and some self-fertilized lines of bay scallop have been bred to F4 successively. The color traits heritable are useful as the marker of selec展开更多
基金supported by the National Natural Science Fund for Distin-guished Young Scholars (Grant No. 30725028)the National Natural Sci-ence Foundation of China (Grant No. 30930071)+1 种基金the State Key Basic Research and Development Program of China (Grant No. 2007CB109200)the Specially-appointed Professor for Lotus Scholars Program of Hunan Province (Grant No. 080648)
文摘Distant hybridization makes it possible to transfer the genome of one species to another, which results in changes in phenotypes and genotypes of the progenies. This study shows that distant hybridization or the combination of this method with gynogenesis or androgenesis lead to different ploidy fishes with genetic variation, including fertile tetraploid hybrids, sterile triploid hybrids, fertile diploid hybrids, fertile diploid gynogenetic fish, and their derived progenies. The formations of the different ploidy fishes depend on the genetic relationship between the parents. In this study, several types of distant hybridization, including red crucian carp (Carassius auratus red var.) (2n=100, abbreviated as RCC) (♀)×common carp (Cyprinus carpio L.) (2n=100, abbreviated as CC) (♂), and RCC (2n=100) (♀)×blunt snout bream (Megalobrama amblycephala) (2n=48, abbreviated as BSB) (♂) are described. In the distant hybridization of RCC (♀)×CC (♂), bisexual fertile F3–F18 allotetraploid hybrids (4n=200, abbreviated as 4nAT) were formed. The diploid hybrid eggs and diploid sperm generated by the females and males of 4nAT developed into diploid gynogenetic hybrids and diploid androgenetic hybrids, respectively, by gynogenesis and androgenesis, without treatment for doubling the chromosome. Improved tetraploid hybrids and improved diploid fishes with genetic variation were derived from the gynogenetic hybrid line. The improved diploid fishes included the high-body RCC and high-body goldfish. The formation of the tetraploid hybrids was related to the occurrence of unreduced gametes generated from the diploid hybrids, which involved in premeiotic endoreduplication, endomitosis, or fusion of germ cells. The sterile triploid hybrids (3n=150) were produced on a large scale by crossing the males of tetraploid hybrids with females of diploid fish (2n=100). In another distant hybridization of RCC (♀)×BSB (♂), different ploidy fishes were obtained, including diploid bisexual fertile natural gynogenetic fish (2n=1
文摘A strategy to improve aquaculture mollusks in genetics, which involve the theory, method, material and application system, is very important for the sustainable development of the marine molluscan breeding and industry. Selection and hybridization as the traditional way have proved effective in the genetic improvement of mariculture mollusks. The growth had increased significantly by selective breeding in oysters as well as the resisitance to MSX and QX disease. A frame chart of genetic improvement of mollusks had been derived from the breeding application of abalone and scallop. The systematic breeding with selection and hybridization has a substantial progress based on the family establishment in Haliotis discus hannai, H. diversicolor, Argopecten irradians, Chlamys farreri and Pinctada martensii. The first self-fertilized family of bay scallop had been established in the 1999 and then a series of family lines with different traits have been succeed and formed the basic element of genetic breeding. The hybridization of Pacific abalone between diffeent populations with a large genetic distance has showed a remarkable traits. The hybrid of Pacific abalone has applied to improve the traits of growth and resistance in the aquaculture and 98% seed used in the farming is hybrid. The hybridization among populations has used in other mariculture mollusks such as zhikong scallop, bay scallop, pearl oyster and small abalone. Hybridization among different populations and systematic and massive selection are the dominant approaches in the genetic improvement of mollusks. So far in China the material system for molluscan genetics and breeding is more considerable as well as the basic theory of heritability, heterosis, inbreeding depression, genetic-environment interaction for the genetic improvement. The different lines have been produced by self-fertilization, inbreeding and crossing and some self-fertilized lines of bay scallop have been bred to F4 successively. The color traits heritable are useful as the marker of selec
