Fertilization Cytology And SSR Analysis On Hybrid Offspring, Pingxiang Red Transparent Crucian Carp (♀)×Pengze Crucian Carp (♂)

Pingxiang red transparent crucian carp(Carassius auratus var.pingxiangnensis) is a wildness mutant crucian carp species founded in Pingxiang area of Jiangxi Province.For seven years,the sixth generation of the fish has been breeded now. The offsprings of this generation has advantageous traits which are fast growing, strong adaptability,high nutritional value,easy to breed and strong disease resistance,etc.Furthermore we found this fish which exists as a bisexual population is another triploid gynogenetic natural mutant similar to the Carassius auratus gibelio Bloch origined in Shuangfen reserovir of Heilongjiang Province.Because the fish is a unique potencial population being lacked of its genetic characteristics,it is very important to know the gynogenetic reproduction mode of the fish.it is also significative to know the homology and the difference from the Carassius auratus gibelio Bloch.The offsprings's biological characteristics which from different mate groups,changing of the early fertilizatized eggs,embryo development and reproduction biology were observed under light and electronic microscope. Microsatellite markers(SSR)was used to analyze the relationship between the parents with offspring in different mate groups.Main results show:1.Early sperm entry into the egg,embryonic development process of two different mate groups,Pingxiang red transparent crucian carp(♀)×Pingxiang red transparent crucian carp((?))and Pingxiang red transparent crucian carp(♀)×Pengze crucian carp((?)),has been observed by optical microscopy and SEM..The results showed that sperm penetration into eggs and embryonic development of both mating groups did have essentially difference.The micropylar region is funnel shape.Only one sperm can entry the micropylar canal.A series of intracellular reaction produced including cortical reaction,fertilizationg membrane hunching,maturation division restarting with extrusion of a single polar,the plasma memebrane testoration and reorgenizastion.The result show that the modalities of embryos of crossbreeding and inbreeding looked the same,but there was a little difference on the hatching time of early stage of embrogenesis.2.The fusion of male pronuleus and female pronuleus were observed by paraffin slice,The heterologous sperm nucleus remained condensed after entering the egg,it did not transform into female pronuleus and fuse with female pronuleus. The homologous sperm nucleus transform into female pronuleus and decondensates to fuse with the female pronuleus.3.SSR DNA marker was used to analysis the relationship between parent and offspring in different mate groups and to conform the reproduction mode of Pingxiang red transparent crucian carp.The amplified patterns clearly indicated that the genotype of the F1 progeny triggered by the male Carassius auratus var.pengze and xingguo red carp was similar to the female parent but different from the male parent.4.The morphologic characteristics of the offspring from different mate groups has also been in full accord with the female parent. In conclusion,the Pingxiang red transparent crucian carp as a multiple tiploid and bisexual reproduction strain did reproduce by both gynogenesis and bissexual.