Research Of Interspecific Cross And Gynogenesis In Several Kinds Of Economic Sea Urchin

Sea urchin is a kind of familiar invertebrate,which arrribute to Echinodermata, Eleutherozea,Echinoidea.There are 850 species of sea urchin in the world,but a little could be used and economic species less than 30.The gonad of sea urchins is regarded as delicious food and restorative medicine in Asian,Mediterranean countries,as well as in some Western Hemisphere countries.Seed breeding and culture of echinoderms has been studied in China since the 1980s.Great progress is made in the mid 1990s.At least 10,000,000 seeds(1.0-1.5 cm)are produced every year in Liaoning province and Shandong province,which are the main production areas for echinoderms in China.Mariculture of sea urchins involves culture in cages suspended in the sea,land-based indoor culture,and release within restricted areas. The main cultured species of sea urchin in China are Strongylocentrotus intermedius, Anthocidaris crassispina,Strongylocentrotus nudus,Glyptocidaris crenularis and Hemicentrotus pulcherrimus.In this study,the cross breeding has been researched among Strongylocentrotus intermedius,Anthocidaris crassispina,Strongylocentrotus nudus,and Hemicentrotus pulcherrimus.6 cross bred sea urchins are gained,after 22 months of culture,4 species cross bred sea urchins appear heterosis in test diameter,test height,body weight,gonad weight and gonad index,which have potential in production.This study also analyses the component of nutrition component and fatty acid in Strongylocentrotus intermedius,Hemicentrotus pulcherrimus and their cross bred sea urchins,the results show that the content of coarse proteid of cross bred sea urchins is higher than that of parental control.The content of some fatty acid is different between cross bred sea urchins and parental control too,from these research,some clues could be obtained about the material metabolizability of cross bred sea urchins.In addition,the coelomocyte types and enzyme activity of cross bred sea urchins and parental control sea urchins are researched,The results show that there are 4 kinds of cells in the coelom of sea urchin,which are pigment cells,colorless spherule cells,Vibratile cell and amoeboid phagocytes,and the activities of ACP,ALP,SOD and LSZ are different in 6 kinds of sea urchins,but the difference isn't significiently(p＞0.05%).In this study,gynogenesis of sea urchins is studied and monoploid embryos of Strongylocentrotus intermedius and Hemicentrotus pulcherrimus are obtained by irradiating sperms with UV.Some monoploid embryos of Hemicentrotus pulcherrimus are doubled by restraining mitosis I with hydrostatic pressure shock.The diploid rate of monoploid embryo relates to starting time,hydrostatic pressure intensities and durations of treatment.The effective treatment of doubling the monoploid embryos is 60-65 MPa of hydrostatic pressure for 3-5 min at 185-210 min after fertilization(a.f.).The treatment of 60 Mpa of hydrostatic pressure for 5 min shock at 195 a.f.could make the diploid rate of 58.62%haploid group increased by 17.23%,and the treatment of 60 Mpa of hydrostatic pressure for 5 min shock at 205 a.f.could make the diploid rate of 89.73%haploid group increased by 12.09%.The UV irradiating could destroy the configuration of sperms;The DCB is existent in monoploid embryos of Strongylocentrotus intermediu and Hemicentrotus pulcherrimus.Microsatellite DNA is isolated and enriched from sea urchin genome by magnetic beads in this paper.103 microsatellite sequences are obtained in this experiment.Base on the flanking sequence of the microsatellite DNA,30 pairs of microsatellite primer are designed and amplified in 4 species sea urchin(Strongylocentrotus intermedius,Strongylocentrotus nudus,Glyptocidaris crenularis and Hemicentrotus pulcherrimus).The results show that 27 pairs of primer generat PCR amplification products,and 8 of them yield polymorphic products.At the same time,680 microsatellite sequences are found with SSR hunter soft from the genome DNA sequences of S.purpuratus(publicized in 2006)and the 160 effective primers are obtained.In this study,the parentage relationship of 30 sea urchis belonging to 3 ancestry has been checkuped with 3 microsatellites primers successfully,which establishes the base for kindred identification and individual identification of sea urchin.