TY - JOUR AU - Lan Anh, Hoang Thi AU - Hong, Dang Diem AU - Thuoc, Chu Van PY - 2014/11/12 Y2 - 2024/03/28 TI - Construction of the phylogenetic tree of Pseudonitzschia sp.g3 isolated from haiphong city basing on the nucleotide sequence of the its1-5.8s-its2 gene fragment JF - Academia Journal of Biology JA - AJB VL - 28 IS - 4 SE - Articles DO - 10.15625/0866-7160/v28n4.5347 UR - https://vjs.ac.vn/index.php/vjbio/article/view/5347 SP - 68-73 AB - <p>Some species belonging to the marine diatom genus <em>Pseudonitzschia</em> were recognized to have capacity to produce domoic acid which caused amnesic shellfish poisoning (ASP). According to the traditional classification, researchers have relied on the morphological characters to identify the species of the genus <em>Pseudonitzschia</em>. In addition, the morphological study of the species belonging to the genus <em>Pseudonitzschia</em> were supported by phylogenetic analyses of the nuclear- encoded internal transcribed spacer 1-5.8S and the internal transcibed 2 rDNA (ITS1-5.8S-ITS2). In this study, the length of the ITS1-5.8S-ITS2 gene fragment of <em>Pseudonitzschia</em> sp.G3 was estimated about 825 bp. After, this fragment was amplified from <em>Pseudonitzschia</em> sp.G3 by using genomic DNA; the PCR products have been cloned into the pCR<sup>Ò</sup>2.1 vector and the recombinant plasmids were transformed into the <em>E. coli</em> strain DH5a T1’. The result of the cloning was confirmed by PCR checking method and the restriction analysis by <em>Eco</em>RI enzyme. By comparing the <em>Pseudonitzschia</em> sp.G3 nucleotide sequence with the published nucleotide sequences of the ITS1-5.8S-ITS2 gene fragments of <em>Pseudonitzschia</em> species in Gene Bank and constructing the phylogenetic tree, the phylogenetic relationships between <em>Pseudonitzschia</em> sp.G3 and 12 other <em>Pseudonitzschia</em> species were established. Our results indicated that <em>Pseudonitzschia</em> sp.G3 collected in Haiphong city had close phylogenetic relationship with <em>Pseudonitzschia</em> <em>pungens</em> (with accession number AY544769) with homological coefficient of 98.8%. The obtained results in this paper allowed us to conclude that may be the studied <em>Pseudonitzschia</em> sp.G3 species was <em>Pseudonitzschia</em> <em>pungens</em>.</p> ER -