These OSI-906 chemical structure intron sequences from B. bassiana were compared with other fungal intron sequences available in databases for their placement in previously reported subgroups . The introns inserted at positions
2 and 4 were placed in the IC1 subgroup (one of the 15 subgroups, based on their secondary structure, described within the group I introns), and that inserted at position 1 was placed in the IE subgroup. As previously observed in group I introns [25–27], those inserted at the same site all belonged to the same subgroup. The intron sequences obtained in this work were compared with other B. bassiana intron sequences representing different subgroups LCZ696 to examine their polymorphisms (data not shown). Intron size and nucleotide identity differences were observed but P, Q, R and S motif elements, Erastin purchase which are needed for the formation of the secondary structure of group I introns , were highly conserved among the introns inserted at the same site, particularly for position 1. The highest polymorphism was observed in introns inserted at 2, the P1-P3 helices being the source of this variation,
and at 4, in the P5, P6 and P8 helices. The MP tree obtained after an alignment of the 7 different intron sequence types identified from 57 B. bassiana isolates and another 24 GenBank-deposited sequences, which represent intron sequences from M. anisopliae, B. bassiana and Cordyceps profilica, together with the subsequent phylogenetic analysis are shown in Figure 1. The tree reveals the Resveratrol separation of four independent groups, supported by high bootstrap values, corresponding to the four positions reported previously : Ec1921 (position 4), Ec2066 (position 3), Ec2449 (position 2) and Ec2563 (position 1), where intron insertions occurred. The tree shows that the sequence group located at position 4 is closer to those
at position 2 and both contain IC1 subgroup introns. Similarly, position 3 sequences are closer to position 1 sequences, and both groups have IE subgroup introns. Within position 4, Cordyceps and Metarhizium were separated from Beauveria sequences and formed an independent group, supported by a bootstrap value of 100%. In addition, the five different Beauveria sequences obtained here were separated into two of the four observed groups at this position, supported by bootstrap values of 94% and 60%. This separation was in accordance with the two sequence sizes detected: 443 and 427-bp in length. However, the four different sequence types detected for 443-bp-sized introns were not separated after phylogenetic analysis. Figure 1 Phylogenetic analysis of group I introns inserted in the LSU rDNA genes of entomopathogenic fungi. The MP tree was generated by parsimony analysis after heuristic searches (TBR option).