Pilot Study Of Phylogeny And Molecular Evolution, In Pleuronectiformes Of Yellow Sea

Since hundreds mollion years of evolution and succession, Pleuronectiformes has been a large, complex group with a worldwide marine distribution, and about extant 570 species are recorded in 123 genera and 14 families (Chapleau, 1993; Nelson, 1994). There are 134 extent species (50 genera, 8 families) recorded in china (Li, 1995), which distributed over Bohai Sea, Yellow Sea, East and South China Sea. The 16S ribosomal RNA (rRNA), cytochrome B gene and the 5'-end partial control region (CR) were sequenced from 12 flatfish species, sequence comparisons of mitochondrial DNA gene were used to infer phylogenetic relationships of flatfishes and the structure of 5'-end partial control region (CR) was described.The mitochongrial 16S rRNA gene were sequenced from 12 flatfish species: Cleisthenes herzensteini, Eopsetta grigorjewi, Kareius bicoloratus, Limanda limanda, Microstomus achne, Pleuronichthys cornutus, Pseudopleuronectes herzensteini, Verasper variegates, Paralichthys olivaceus, Pseudorhombus cinnamomeus, Zebrias zebra and Cynoglossus semilaevis, and their phylogenetic relationships were analyzed by Program MEGA2.1. C. herzensteini, E. grigorjewi, K. bicoloratus, L. limanda, M. achne, P. herzensteini and V. variegates group together closely in Neighbor-Joining (NJ) phylogenetic tree, extraordinary close relationship between C. herzensteini and L. limanda were observed though far geographical distances, V. variegates took a single branch and P. cornutus was found to have far genetic distances to other seven Pleuronectids and group with P. olivaceus (Paralichthyidae). P. olivaceus and P. cinnamomeus were proved belonging to the different subgroups in Paralichthyidae. Cynoglossidae appeared to be the most specialized family of Pleuronectiformes, which consistents with the previousanalysis. The results of Minimum-Evolution (ME) phylogenetic trees is same to NJ, while Maximum-Parsimony (MP) phylogenetic tree has difference in interrelationships of Pleuronectids.The mitochondrial cytochrome b (cyt b) were sequenced from 11 flatfish species: C. herzensteini, E. grigorjewi, K. bicoloratus, L. limanda, M. achne, P. cornutus, P. herzensteini, V. variegates, P. olivaceus P. cinnamomeus and Z. zebra. The results have difference to that of 16S rRNA: E. grigorjewi, V. variegates and P. cornutus group together, while P. cinnamomeus and Z. zebra has close relationship in NJ trees. In MP tree, however, C. herzensteini, K. bicoloratus, L. limanda and P. herzensteini group together, E. grigorjewi, M. achne, P. cornutus, V. variegates and P. cinnamomeus group together. Comparing to the result of cyt b, the phylogenetic tree based on amino acid sequences of partial cyt b gene show difference in inter-relationships of Family Pleuronectidae, however, there are consistences among NJ, ME and MP tree.The 5'-end partial control region were sequenced from 7 Pleuronectids: C. herzensteini, K. bicoloratus, L limanda, M. achne, P. cornutus, P. herzensteini, V. variegates, the relationship among these Pleuronectids did not consistent with the results based on 16S rRNA and cyt b.General speaking, in Pleuronectidea, there are close relationships among C. herzensteini, E. grigorjewi, K. bicoloratus, L. limanda, M. achne and P. herzensteini, V. variegates shows a bigger genetic distance to the six ones and P. cornutus is the mos special one of these Pleuronectids. Three phylogenetic trees were adopted in this study: NJ,ME and MP trees. The results of NJ and ME trees are resemble, while that of MP tree is different to the two trees, especial in inter-relationships of 8 Pleuronectids. Thus the exertion of three trees should be thought over in low level classifications.The conserved sequence blocks (CSBs) in control region of Pleuronectiformes were compared and analysed. Two CSBs: CM and CSB-F were found in 5'-end partial control region: and CSB-F, the sequences of which have similiarities to previous studies, and A GenBank database search was tried , and it was found theCM and CSB-F existed in 16 and 13 more teleost orders, respective...