Dissertation > Excellent graduate degree dissertation topics show

Studies on the Populatin Genetic Structure of Mactora Chinenis and Hylogeny of Mactridea

Author: NiLeHai
Tutor: LiZuo
School: Ocean University of China
Course: Aquaculture
Keywords: Mactra chinensis population genetic structure marine currents phylogenetic analysis DNA barcoding
CLC: S917.4
Type: Master's thesis
Year: 2011
Downloads: 98
Quote: 2
Read: Download Dissertation

Abstract


The Chinese surf clam (Mactra chinensis) is a commercially important bivalve in China. For its advantages of fast growth rate, high living density and high nutritional value, the Chinese surf clam is suitable for extensive breeding in Northern China, and has broad development prospects for aquaculture. However, due to over-exploitation and changes in environmental conditions, wild populations of the Chinese surf clam is threatened in recent years. At present, seeds for Mactra chinensis aquaculture mainly depend on collecting wild seeds, so insufficiency of seeds hampered the development of Mactra chinensis aquaculture industry. To protect current wild resources and formulate effective protective measures, it is essential to investigate genetic diversity of the Chinese surf clam with molecular techniques. It will also help promote the process of artificial breeding, and achieve sustainable development in aquaculture of Mactra chinensis. In the present study, polymorphic microsatellite markers were isolated from the Chinese surf clam by magnetic selective hybridization. To provide information for fisheries management and artificial breeding, genetic variation and population structure of Mactra chinensis in Northern China were investigated using these microsatellite loci. Phylogenetic relationships of Mactridae were analyzed based on partial sequences of mitochondrial COI and 16S rRNA genes. The main results are as follows:Nineteen polymorphic microsatellite loci were developed from genomic DNA of Mactra chinensis using magnetic selective hybridization. Polymorphism of the microsatellite loci were estimated with 30 Chinese surf clam individuals. The number of alleles varied from 3 to 24 per locus. The expected and observed heterozygosities ranged from 0.419 to 0.953 and from 0.000 to 1.000, respectively. The polymorphic information content (PIC) per locus ranged from 0.353 to 0.933, with an average of 0.790.Genetic diversity and population structure of nine Mactra chinensis populations in Northern China were investigated with microsatellites. Nine microsatellites revealed high allelic diversity with 14-36 alleles per locus. Observed and expected heterozygosity varied from 0.593 to 0.945 and from 0.638 to 0.958, respectively. Pairwise FST values indicated that all population pairs had small but significant genetic differentiation. Results of AMOVA analysis revealed that most of the variance was distributed within populations (97.50 %). A Mantel test showed statistically significant correlations between genetic distance and geographical distance, indicating that genetic differentiation of the Chinese surf clam conformed to a pattern of isolation-by-distance. Cluster analysis using neighbor-joining separated the eight populations into three groups. The three areas of low gene flow identified by barrier analysis corresponded with local oceanographic features, suggesting that marine currents and peninsulas play an important role in population structuring of this species.The partial sequences of mitochondrial COI and 16S rRNA genes from 36 specimens of 11 species of Mactridae were sequenced to infer the phylogenetic relationships and species-level identifications of the family Mactridae. Sequences of two other species in this family gathered from GenBank were included. In the analysis of COI gene, genetic variation between species exceeds variation within species, demonstrating that DNA barcoding gap existed in Mactridae. The barcoding gap based on 16S rRNA gene was not obvious. Except for X3 individual in Coelomactra antiquata, all species of Mactridae fell into reciprocally monophyletic clades with high bootstrap values in neighbour-joining and BI trees. The results indicate that Mactridae species can be efficiently identified through DNA barcoding. Phylogenetic relationships of Mactridae constructed with COI and 16S rRNA genes are almost consistent with traditional morphological classification.

Related Dissertations

  1. The Preliminary Study on DNA Barcoding of Animal Chinese Traditional Medicine Earthworm,R282.5
  2. Identification Technology of Green Tides Forming Algae along the Coast of Qingdao,Q949
  3. China Offshore common jellyfish and ( worms Rong ) like DNA barcoding and phylogenetic studies,Q951
  4. Studies on Reproductive Biology of Mactra Chinensis and Meretrix Meretrix,S917.4
  5. Evaluation of Molecular Markers in Identification of Poisonous Plants,Q943
  6. Application of CO1 for Rapid Identification of Pleurotus Species,Q949.32
  7. Application of DNA Barcoding in Umbilicaria Species,Q949
  8. Studies on Qualitative Identification Methods for Animal-derived Ingredients in Foods,TS207.3
  9. DNA Barcoding and Molecular Phylogeny of the Spider Mites in China (Acari: Tetranychidae),S433.7
  10. DNA Barcoding of Hainan Island Orchid Species Based on matK and ITS Sequences,S682.31
  11. Use of DNA Barcoding to Identify Chinese Medicinal Plants of Zingiberaceae,S567.239
  12. Tardigrade DNA barcoding,Q953
  13. Research on Identification of Small Mammals and Parasitic Fleas by DNA Barcoding in Qinghai Province, China,Q95-3
  14. Application of DNA Barcoding in the Plants of Lauraceae and Caprifoliaceae Family,R284
  15. DNA Barcoding and Molecular Phylogeny of Holcoglossum Schltr. (Orchidaceae),Q941
  16. Germplasm Identification and Tissue Culture and Propagation of Tetrastigma Hemsleyanum, a Medicinal Plant,S567.239
  17. DNA Barcoding of Epinephelinae in Coastal Waters of China,S917.4
  18. Pleurotus eryngii media screening, genetic diversity and related taxa Preliminary barcode,S646
  19. Application of DNA Barcoding in Species Identification of Colocasieae (Araceae),Q943
  20. Cloning and Analysis of Partial Genomic Sequence of Duck Enteritis Virus and Construction of Transfer Vector for Recombinant Virus,S852.65
  21. Avian influenza virus and Newcastle disease virus by RT-PCR and dual source of avian influenza virus Mallard M gene sequence analysis,S852.65

CLC: > Agricultural Sciences > Aquaculture, fisheries > Aquatic basic science > Aquatic Biology > Aquatic Zoology
© 2012 www.DissertationTopic.Net  Mobile