Perng-Kuang Chang1. 1. Southern Regional Research Center, Agricultural Research Service, U. S. Department of Agriculture, 1100 Robert E. Lee Boulevard, New Orleans, LA, 70124, USA. perngkuang.chang@usda.gov.
Abstract
OBJECTIVE: The use of genome sequences from strains authenticated to correct species level is a prerequisite for confidently exploring the evolutionary relationship among related species. Aspergillus strains erroneously curated as Aspergillus oryzae and Aspergillus fumigatus have been noticed in the National Center for Biotechnology Information (NCBI) genome database. Aspergillus parasiticus is one of several aspergilli that produce aflatoxin, the most potent carcinogenic mycotoxin known up to now. To ensure that valid conclusions are drawn by researchers from their genomics-related studies, molecular analyses were carried out to authenticate identities of A. parasiticus strains in the NCBI genome database. RESULTS: Two of the nine supposedly A. parasiticus strains, E1365 and NRRL2999, were found to be misidentified. They turned out to be Aspergillus flavus based on genome-wide single nucleotide polymorphisms (SNPs) and genetic features associated with production of aflatoxin and cyclopiazonic acid. NRRL2999 lacked the additional partial aflatoxin gene cluster known to be present in its equivalent strain, designated as SU-1, and shared a very low total SNPs count specifically with A. flavus NRRL3357 but not with other A. flavus isolates. Therefore, the mislabeled NRRL2999 strain actually is a clonal strain of A. flavus NRRL3357, whose genome was first sequenced in 2005.
OBJECTIVE: The use of genome sequences from strains authenticated to correct species level is a prerequisite for confidently exploring the evolutionary relationship among related species. Aspergillus strains erroneously curated as Aspergillus oryzae and Aspergillus fumigatus have been noticed in the National Center for Biotechnology Information (NCBI) genome database. Aspergillus parasiticus is one of several aspergilli that produce aflatoxin, the most potent carcinogenic mycotoxin known up to now. To ensure that valid conclusions are drawn by researchers from their genomics-related studies, molecular analyses were carried out to authenticate identities of A. parasiticus strains in the NCBI genome database. RESULTS: Two of the nine supposedly A. parasiticus strains, E1365 and NRRL2999, were found to be misidentified. They turned out to be Aspergillus flavus based on genome-wide single nucleotide polymorphisms (SNPs) and genetic features associated with production of aflatoxin and cyclopiazonic acid. NRRL2999 lacked the additional partial aflatoxin gene cluster known to be present in its equivalent strain, designated as SU-1, and shared a very low total SNPs count specifically with A. flavus NRRL3357 but not with other A. flavus isolates. Therefore, the mislabeled NRRL2999 strain actually is a clonal strain of A. flavus NRRL3357, whose genome was first sequenced in 2005.
Entities:
Keywords:
Aspergillus flavus; Aspergillus parasiticus; Genome; NRRL2999; NRRL3357; SU-1; Single nucleotide polymorphism; Species identification
Authors: J Yu; P K Chang; J W Cary; M Wright; D Bhatnagar; T E Cleveland; G A Payne; J E Linz Journal: Appl Environ Microbiol Date: 1995-06 Impact factor: 4.792
Authors: William C Nierman; Jiujiang Yu; Natalie D Fedorova-Abrams; Liliana Losada; Thomas E Cleveland; Deepak Bhatnagar; Joan W Bennett; Ralph Dean; Gary A Payne Journal: Genome Announc Date: 2015-04-16