Phylogenetic Analysis Of Five Marine Economic Shrimps Basing On The Mtdna Genomes Sequence

The shrmps we studied in this document are as follows: Parapenaeopsis hardwickii, Parapenaeus fissuroides, Solenocera alticarinata, Solencera koelbelide and Trachypenaeus curvirostris. They are all common marine economy shrimp in our contry, and have very high value in fishing and farming economicly. In Late years, with the increasing of ocean development and overfishing, the environment of marine is worsening and becoming deterioration, and resulting in the fishery resources decline significantly. It also leads to the degradation of the shrimp germplasm resources. At present, there is only study about breeding cultivation, the shape and ecological research. However, the information about gene data and genetic diversity of this five shrimps is very less. To investigate the genetic diversity of five shrimps in Xiang Shan harbor, we have 16S rRNA and COI gene amplification of 30 samples in every species. In the later experiment, we get complement mitochondrion genome of P. hardwickii and S. alticarinata by technology of Primer-walking.To investigate the germplasm resources and genetic diversity of the wild population P. hardwickii, 558 base of the 16S rRNA and 688 base of the COI gene sequences were obtained from P. hardwickii wild populations by PCR amplification. T, C, A and G base content of 16S rRNA gene sequences were 35.76%, 19.48%, 26.74% and 17.88%, while COI gene sequences were 35.36%, 12.68%, 30.54% and 21.43%. One haplotypes and none polymorphic sites were detected in 16S rRNA gene sequences, while 7 haplotypes and 6 polymorphic sites were in COI gene sequences, including 5 singleton variable sites and 1 parsimony informative sites. The variations of COI gene sequences were more than 16S rRNA gene sequences, showing that COI gene sequences were adaptive for genetic diversity analysis in P. hardwickii. The molecular phylogentic analysis based on 16S rRNA and COI gene sequences were not consistent with each other, indicating that P. hardwickii was a sole branch in the genus Parapenaeopsis, and had closer relationships with Parapenaeopsis tenella and Parapenaeopsis hungerfordi. Based on the genetic distance of COI gene sequences, the differentiation time of 12 shrimp species were deduced, and the results showed that the radiation differentiation time of genus Parapenaeopsis was between the Evening Miocene Epoch and the Initial Pliocene Epoch.The 16S rRNA gene length of P. fissuroides is 566 bases, the species of which has 4 haplotypes; The COI gene length of P. fissuroides is 726 bases, the species of which has 10 haplotypes. The relationship of species between P. fissuroides and P. lanceolatus is most closed.The molecular phylogentic analysis based on 16S rRNA gene sequences was consistent with result of morphological classification. P. lanceolatus is origined from Penaeus, as well as Parapenaeus.The 16S rRNA gene length of S. alticarinata, S. koelbelide and T. curvirostris is 539 bp, 515 bp and 515 bp, respectively, and the quantity of haplotypes for 16S rRNA gene is 6, 3 and 5 respectively. The COI gene length of S. alticarinata, S. koelbelide and T. curvirostris is 663 bp, 677 bp and 686 bp, respectively, and the quantity of haplotypes is 7, 6 and 6 respectively. S. alticarinata and S. koelbelide are all belong to Solenocera, which is under Penaeidae, and it is parallel structures betwwen the species of Solenocera and Penaeus in the molecular phylogenetic tree. T. curvirostris is belonged to Trachypenaeus, which is the member of Penaeidae.It is closed to P. hardwickii.The complement mitochondrion genome of P. hardwickii and S. alticarinata is 15922 bp and 15968 bp, respectively. The genome is included 13 PCGs, The most stable of which is gene of cox2. The gene arrangement of 13 PCGs is same comepletely. P. hardwickii and S. alticarinata is all origined from Penaeidae in the late age of differentiation, and all make up out group of Penaeidae in the molecular phylogenetic tree.