Detection of potentially valuable polymorphisms in four group I intron insertion sites at the 3'-end of the LSU rDNA genes in biocontrol isolates of Metarhizium anisopliae

• Published in: BMC microbiology 2006-09, Vol.6 (1), p.77-77, Article 77
• Main Authors: Márquez, Marcela, Iturriaga, Enrique A, Quesada-Moraga, Enrique, Santiago-Alvarez, Cándido, Monte, Enrique, Hermosa, Rosa
• Format: Article
• Language: English
• Subjects: 3' Untranslated Regions; Base Sequence; DNA Primers; DNA, Fungal - genetics; DNA, Ribosomal - genetics; Escherichia coli; Genes, Fungal; Hypocreales - genetics; Introns; Metarhizium anisopliae; Polymerase Chain Reaction; Polymorphism, Genetic
• ISSN: 1471-2180; 1471-2180
• DOI: 10.1186/1471-2180-6-77

The entomopathogenic anamorphic fungus Metarhizum anisopliae is currently used as a biocontrol agent (BCA) of insects. In the present work, we analyzed the sequence data obtained from group I introns in the large subunit (LSU) of rDNA genes with a view to determining the genetic diversity present in an autochthonous collection of twenty-six M. anisopliae isolates selected as BCAs. DNA fragments corresponding to the 3'-end of the nuclear LSU rDNA genes of 26 M. anisopliae isolates were amplified by PCR. The amplicon sizes ranged from 0.8 to 3.4-kb. Four intron insertion sites, according to Escherichia coli J01695 numbering, were detected--Ec1921, Ec2066, Ec2449 and Ec2563--after sequencing and analysis of the PCR products. The presence/absence of introns allowed the 26 isolates to be distributed into seven genotypes. Nine of the isolates tested showed no introns, 4 had only one, 3 two, and 10 displayed three introns. The most frequent insertion sites were Ec1921 and Ec2449. Of the 26 isolates, 11 showed insertions at Ec2563 and a 1754-bp sequence was observed in ten of them. The most-parsimonious (MP) tree obtained from parsimony analysis of the introns revealed a main set containing four-groups that corresponded to the four insertion sites. Four insertion sites of group I introns in the LSU rDNA genes allowed the establishment of seven genotypes among the twenty-six biocontrol isolates of M. anisopliae. Intron insertions at the Ec2563 site were observed for first time in this species.