The Study Of The Genetic Diversity And Phylogeny Of Sea Urchins Using AFLP And 16SrRNA Gene

Amplified Fragment Length Polymorphism (AFLP)technique and 16SrRNA gene were used to estimate phylogeny and genetic diversity of sea urchins which belong to five species, S. nudu,S. intermedius,H. pulcherrimus,G. crenularis,A. crassispina. The purpose is to offer basic data for the selection of excellent breeds and the protection of idioplasm resource.Sea urchin belongs to Echinodermata, Eleutherozea, Echinoidea. Some reports about biochemistry, genetics and morphology of sea urchins have been seen in some both here and abroad articles at present, but there are few reports about phylogeny and genetic diversity of sea urchin by using molecular marks.AFLP technique was performed to analyze genetic diversity of five species of sea urchins, 4 pairs random primers were chosen and used to amplify the individuals'DNA of five species. Among the five species, H. pulcherrimus has the highest percentage of polymorphic loci which is 46.61%, G crenularis has the lowest one which is 30.77%. The range of alteration of index Shannon is from 0.2511 to 0.1628 , and the index Nei is from 0.1702 to 0.1101 ,the alteration law of two indexes is identical, and this result is also identical with the analysis of the percentage of polymorphic loci. From these we can conclude the intra-species genetic variation of five species: H. pulcherrimus is highest, G crenularis is lowest. The total gene diversity of five species is 0.3020, Gst is 0.5122. AMOVA analysis indicates that 76.91% diversity of five species comes from inter-species, 23.09% diversity comes from intra-species.We use the data which were obtained from AFLP technique and 16SrRNA gene to study the phylogeny of sea urchin. Some biological analysis software such as POPGEN 32 and MEGA3.0 were also used to analysize the data. The UPGMA, NJ and MP phylogenetic tree which were obtained by the data show that S. nudu and H. pulcherrimus are close to each other, then is close to S. intermedius. This indicates that there is closely relationship among S. nudu, H. pulcherrimus and S. intermedius, while G. crenularis and A. crassispina have far relationship with these three species.