Molecular characterization of the diatom, pseudo-nitzschia (bacillariophyceae) using the mitochondrial genetic marker, cytochrome oxidase I
Pseudo-nitzschia is a marine and planktonic chain-forming diatom. Some Pseudo-nitzschia species produce biotoxin, domoic acid (DA) which causes Amnesic Shellfish Poisoning (ASP) in humans and marine mammals. Species of Pseudo-nitzschia are difficult to distinguish under light microscope (LM). In t...
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| Format: | Final Year Project Report / IMRAD |
| Language: | English English |
| Published: |
Universiti Malaysia Sarawak, UNIMAS
2013
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| Online Access: | http://ir.unimas.my/id/eprint/7549/ http://ir.unimas.my/id/eprint/7549/1/Molecular%20characterization%20of%20the%20diatom%2C%20pseudo-nitzschia%20%28bacillariophyceae%29%20using%20the%20mitochondrial%20genetic%20marker%2C%20cytochrome%20oxidase%20I%20%2824pgs%29.pdf http://ir.unimas.my/id/eprint/7549/8/Tan%20Suh%20Nih.pdf |
| Summary: | Pseudo-nitzschia is a marine and planktonic chain-forming diatom. Some Pseudo-nitzschia species produce
biotoxin, domoic acid (DA) which causes Amnesic Shellfish Poisoning (ASP) in humans and marine
mammals. Species of Pseudo-nitzschia are difficult to distinguish under light microscope (LM). In this study,
a total of 22 strains of Pseudo-nitzschia from Malaysian waters were identified based on morphological
characteristics observed under LM and transmission electron microscope (TEM). A total of 17 stains were
successfully identified; they are P. circumpora, P. cuspidata and P. pungens. A pair of genus-specific primer
targeting the mitochondrial cytochrome oxidase I (COI) gene was developed in silico to infer the molecular
phylogeny of Pseudo-nitzschia species. The primer specificity was tested using genomic DNA from clonal
cultures. The designed primer was successfully amplified with a fragment length of 450 bp. A total of 12
strains of Pseudo-nitzschia species were successfully amplified. LSU rRNA gene of the cultures were also
amplified to compare with the COI dataset. Genetic divergences of COI dataset and LSU rRNA dataset
among the Pseudo-nitzschia taxa were ranged from 0 to 20.5 % and from 0 to 5 % respectively. Phylogenetic
reconstruction revealed Pseudo-nitzschia taxa as a monophyletic group. However, the results showed
incongruence in both COI and LSU phylogenies. As conclusion, the cultures and the species identity
obtained in this study provide useful information on Pseudo-nitzschia study, and added to the database of
harmful algal blooms research in the country. |
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