Abstract

CHIRINOS, Jenny; CONGRAINS, Carlos; RAMIREZ, Rina  and  RAMIREZ, Pablo. Identification of Yarrowia lipolytica (Ascomycota: Hemiascomycetes) as a contaminant in obtaining amplified 28S rRNA gene of mollusks. Rev. peru biol. [online]. 2010, vol.17, n.1, pp.59-64. ISSN 1727-9933.

In this paper we identify an unexpected DNA sequence from the amplicons of 28S rRNA gene of terrestrial mollusks. DNA extractions were performed from foot tissues of land snails using a modified CTAB protocol. PCRs were carried out with universal primers for COI gene and oligonucleotides designed for molluscs, for the markers 16S rRNA, 28S rRNA, and ITS-2. Amplified lengths were 706 pb for COI, 330 pb for 16S rRNA, 900 pb for ITS-2, and 583 pb for 28S rRNA. One amplicon of the last marker was of an unexpected length, ~340 pb. DNA sequences were compared in the GenBank database through the BLASTn program and the sample, with the unexpected length, resulted in 100% identity and 99% query coverage with 26S rRNA gene of the yeast Yarrowia lipolytica. Phylogenetic analysis with Neighbour-Joining and the divergence values confirmed the identification, providing results that support the taxonomic placement of the species within the Hemiascomycetes clade.

Keywords : 26S rRNA; Gastropoda; fungi; DNA barcode.

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