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
在水温为（16．0±0．5）℃、pH为8．0～8．3、盐度为30．2的条件下，对牙鲆Paralichthys olivaceus单倍体、三倍体和雌核发育二倍体胚胎发育的过程与普通二倍体牙鲆的发育进行了比较。结果表明：单倍体胚胎脊柱弯曲，器官分化不全...在水温为（16．0±0．5）℃、pH为8．0～8．3、盐度为30．2的条件下，对牙鲆Paralichthys olivaceus单倍体、三倍体和雌核发育二倍体胚胎发育的过程与普通二倍体牙鲆的发育进行了比较。结果表明：单倍体胚胎脊柱弯曲，器官分化不全，受精率低，畸形率高，出膜率低；三倍体和雌核发育二倍体胚胎与普通二倍体牙鲆的发育时序基本相同，受精卵经过卵裂、囊胚、原肠胚、神经胚、卵黄栓胚、克氏囊胚、尾芽胚、心跳胚、出膜期等阶段孵化出膜，各阶段除发育时间不同外，发育特征与发育分期没有明显差别；普通二倍体胚胎约61h孵化出膜，而三倍体和雌核发育二倍体分别经66 h 30 min和67 h 50 min孵化出膜，孵化时间比普通二倍体牙鲆长约10％。其中，卵裂期三倍体和雌核发育二倍体在细胞分裂阶段发育特别缓慢，发育时间比普通二倍体长约25％。单倍体出膜率为（16．5±2．2）％，畸形率为（97．2±1．6）％；雌核发育二倍体出膜率为（85．6±3．0）％，畸形率为（13．2±2．3）％；三倍体出膜率为（82．3±3．1）％，畸形率为（16．3±2．5）％。与普通二倍体牙鲆相比，三倍体和雌核发育二倍体胚胎出膜率低，仔鱼畸形率高。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
文摘在水温为（16．0±0．5）℃、pH为8．0～8．3、盐度为30．2的条件下，对牙鲆Paralichthys olivaceus单倍体、三倍体和雌核发育二倍体胚胎发育的过程与普通二倍体牙鲆的发育进行了比较。结果表明：单倍体胚胎脊柱弯曲，器官分化不全，受精率低，畸形率高，出膜率低；三倍体和雌核发育二倍体胚胎与普通二倍体牙鲆的发育时序基本相同，受精卵经过卵裂、囊胚、原肠胚、神经胚、卵黄栓胚、克氏囊胚、尾芽胚、心跳胚、出膜期等阶段孵化出膜，各阶段除发育时间不同外，发育特征与发育分期没有明显差别；普通二倍体胚胎约61h孵化出膜，而三倍体和雌核发育二倍体分别经66 h 30 min和67 h 50 min孵化出膜，孵化时间比普通二倍体牙鲆长约10％。其中，卵裂期三倍体和雌核发育二倍体在细胞分裂阶段发育特别缓慢，发育时间比普通二倍体长约25％。单倍体出膜率为（16．5±2．2）％，畸形率为（97．2±1．6）％；雌核发育二倍体出膜率为（85．6±3．0）％，畸形率为（13．2±2．3）％；三倍体出膜率为（82．3±3．1）％，畸形率为（16．3±2．5）％。与普通二倍体牙鲆相比，三倍体和雌核发育二倍体胚胎出膜率低，仔鱼畸形率高。
