DNA Barcoding And Phylogenetic Of Medusa And Hyperiid In Chinese Costal Region

DNA barcoding is the biology technique that uses a short DNA fragment to identify species. DNA barcoding addresses the issues of identification of species, connection of life-history stages, and potentially population structure and phylogenetics. For most metazoans the mitochondrial cytochrome c oxidase subunit I (COI) is used for barcoding. We conducted the analysis of DNA barcoding of Medusa and Hypreiid in Chinese costal region, and phylogenetic of Hyperiid. The main contents consist of the following two parts:1. DNA Barcoding the MedusaMedusa plays an important zooplankton community because of its abundance and distribution. Because of its highly diverse forms, larvae being greatly different from adult and so on, the traditional morphological classification method in the application encountered many difficulties; In addition, the mitochondrial cytochrome oxidase subunit (COI) in the accuracy for the identification of Medusa still controversial. We examined the COI, nuclear genome ribosomal RNA spacer (ITS) and mitochondrial ribosomal large subunit (16S) of three fragments in the molecular identification of Medusa as a means of effectiveness. 40 sequences of COI were analyzed, and intra-specific variation ranged from 0-0.046 while inter-specific variation ranged from0.066-0.173; 18 sequences of 16S were analyzed, and intra-specific variation ranged from 0.003-0.010 while inter-specific variation ranged from0.118-0.273; 18 sequences of 16S were analyzed, and intra-specific were 0 while inter-specific variation ranged from0.138-0.344; Found that groups involved in this experiment, the three kinds of sequences can effectively distinguish different types. However, as the analysis of the types and quantities of Medusa cannot cover the vast majority of the group, we cannot identify which sequence is more effective.2. DNA Barcoding and Phylogenetic of HyperiideaHypreiid is an important part of marine food chain, and a lot of relative work has conducted. But no one research their DNA barcoding and phylogeny. A total of 78 DNA sequences, including our sequences and the corresponding sequences on the NCBI, were analyzed for the barcoding of hyperiid. Intra-specific variation ranged from 0.002 to 0.031, while inter-specific variation ranged from 0.083 to 0.410, there was no overlap between intra- and inter-specific. A cluster diagram generated using the Neighbor Joining algorithm reliably putted all barcodes to their correct species. These data suggest that COI is an appropriate barcoding tool for the Hyperiidea.The molecular phylogeny of Sunorder Hyperiidea was revealed by partial 18S rDNA sequences amplified from 16 species in our study in addition to other isopod sequences cited from Genbank.Phylogenetic analysis using Bayesian method indicates that in Amphipoda, Gammaridea is closely related to Caprellidea. Hyperiidea is the sister group to them, and it is monophyly, including Phronimoidea, Platysceloidea and Vibilioidea. Vibilioidea is closely related to Platysceloidea. Paraphronimoidae located far away from the branch of Vibilioidea.