Limits...
Genetic analyses place most Spanish isolates of Beauveria bassiana in a molecular group with word-wide distribution.

Garrido-Jurado I, Márquez M, Ortiz-Urquiza A, Santiago-Álvarez C, Iturriaga EA, Quesada-Moraga E, Monte E, Hermosa R - BMC Microbiol. (2011)

Bottom Line: A number of parameters such as thermal growth or origin (host, geographic location and climatic conditions) were also examined but in general no association could be found.However, high phylogenetic diversity was also detected among Spanish isolates from close geographic zones with low climatic variation.In general, no correlation was observed between the molecular distribution and geographic origin or climatic characteristics where the Spanish B. bassiana isolates were sampled.

View Article: PubMed Central - HTML - PubMed

Affiliation: Centro Hispano-Luso de Investigaciones Agrarias (CIALE), Departamento de Microbiología y Genética, Universidad de Salamanca, Río Duero 12, Campus de Villamayor, 37185 Salamanca, Spain.

ABSTRACT

Background: The entomopathogenic anamorphic fungus Beauveria bassiana is currently used as a biocontrol agent (BCA) of insects. Fifty-seven Beauveria bassiana isolates -53 from Spain- were characterized, integrating group I intron insertion patterns at the 3'-end of the nuclear large subunit ribosomal gene (LSU rDNA) and elongation factor 1-alpha (EF1-α) phylogenetic information, in order to assess the genetic structure and diversity of this Spanish collection of B. bassiana.

Results: Group I intron genotype analysis was based on the four highly conserved insertion sites of the LSU (Ec2653, Ec2449, Ec2066, Ec1921). Of the 16 possible combinations/genotypes, only four were detected, two of which were predominant, containing 44 and 9 members out of 57 isolates, respectively. Interestingly, the members of the latter two genotypes showed unique differences in their growth temperatures. In follow, EF1-α phylogeny served to classify most of the strains in the B. bassiana s.s. (sensu stricto) group and separate them into 5 molecular subgroups, all of which contained a group I intron belonging to the IC1 subtype at the Ec1921 position. A number of parameters such as thermal growth or origin (host, geographic location and climatic conditions) were also examined but in general no association could be found.

Conclusion: Most Spanish B. bassiana isolates (77.2%) are grouped into a major phylogenetic subgroup with word-wide distribution. However, high phylogenetic diversity was also detected among Spanish isolates from close geographic zones with low climatic variation. In general, no correlation was observed between the molecular distribution and geographic origin or climatic characteristics where the Spanish B. bassiana isolates were sampled.

Show MeSH
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). A bootstrap full heuristic analysis, with bootstrap intervals from 1000 replications and nodes supported in >50% of bootstrap replicates, was generated using the PAUP 4.0 program. Branch lengths are proportional to the number of changes. Seven different intron sequence types (bolded) identified from 57 B. bassiana isolates were aligned with 24 representative intron sequences from Metarhizium anisopliae (Ma), Beauveria bassiana (Bb) and Cordyceps profilica (Csp), and an intron sequence from Naegleria sp. (Nsp) was used as outgroup. The four group I intron insertion positions are shown as Ec1921 (position 4), Ec2066 (position 3), Ec2449 (position 2) and Ec2563 (position 1).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3111375&req=5

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). A bootstrap full heuristic analysis, with bootstrap intervals from 1000 replications and nodes supported in >50% of bootstrap replicates, was generated using the PAUP 4.0 program. Branch lengths are proportional to the number of changes. Seven different intron sequence types (bolded) identified from 57 B. bassiana isolates were aligned with 24 representative intron sequences from Metarhizium anisopliae (Ma), Beauveria bassiana (Bb) and Cordyceps profilica (Csp), and an intron sequence from Naegleria sp. (Nsp) was used as outgroup. The four group I intron insertion positions are shown as Ec1921 (position 4), Ec2066 (position 3), Ec2449 (position 2) and Ec2563 (position 1).

Mentions: 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 separation of four independent groups, supported by high bootstrap values, corresponding to the four positions reported previously [25]: 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.


Genetic analyses place most Spanish isolates of Beauveria bassiana in a molecular group with word-wide distribution.

Garrido-Jurado I, Márquez M, Ortiz-Urquiza A, Santiago-Álvarez C, Iturriaga EA, Quesada-Moraga E, Monte E, Hermosa R - BMC Microbiol. (2011)

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). A bootstrap full heuristic analysis, with bootstrap intervals from 1000 replications and nodes supported in >50% of bootstrap replicates, was generated using the PAUP 4.0 program. Branch lengths are proportional to the number of changes. Seven different intron sequence types (bolded) identified from 57 B. bassiana isolates were aligned with 24 representative intron sequences from Metarhizium anisopliae (Ma), Beauveria bassiana (Bb) and Cordyceps profilica (Csp), and an intron sequence from Naegleria sp. (Nsp) was used as outgroup. The four group I intron insertion positions are shown as Ec1921 (position 4), Ec2066 (position 3), Ec2449 (position 2) and Ec2563 (position 1).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3111375&req=5

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). A bootstrap full heuristic analysis, with bootstrap intervals from 1000 replications and nodes supported in >50% of bootstrap replicates, was generated using the PAUP 4.0 program. Branch lengths are proportional to the number of changes. Seven different intron sequence types (bolded) identified from 57 B. bassiana isolates were aligned with 24 representative intron sequences from Metarhizium anisopliae (Ma), Beauveria bassiana (Bb) and Cordyceps profilica (Csp), and an intron sequence from Naegleria sp. (Nsp) was used as outgroup. The four group I intron insertion positions are shown as Ec1921 (position 4), Ec2066 (position 3), Ec2449 (position 2) and Ec2563 (position 1).
Mentions: 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 separation of four independent groups, supported by high bootstrap values, corresponding to the four positions reported previously [25]: 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.

Bottom Line: A number of parameters such as thermal growth or origin (host, geographic location and climatic conditions) were also examined but in general no association could be found.However, high phylogenetic diversity was also detected among Spanish isolates from close geographic zones with low climatic variation.In general, no correlation was observed between the molecular distribution and geographic origin or climatic characteristics where the Spanish B. bassiana isolates were sampled.

View Article: PubMed Central - HTML - PubMed

Affiliation: Centro Hispano-Luso de Investigaciones Agrarias (CIALE), Departamento de Microbiología y Genética, Universidad de Salamanca, Río Duero 12, Campus de Villamayor, 37185 Salamanca, Spain.

ABSTRACT

Background: The entomopathogenic anamorphic fungus Beauveria bassiana is currently used as a biocontrol agent (BCA) of insects. Fifty-seven Beauveria bassiana isolates -53 from Spain- were characterized, integrating group I intron insertion patterns at the 3'-end of the nuclear large subunit ribosomal gene (LSU rDNA) and elongation factor 1-alpha (EF1-α) phylogenetic information, in order to assess the genetic structure and diversity of this Spanish collection of B. bassiana.

Results: Group I intron genotype analysis was based on the four highly conserved insertion sites of the LSU (Ec2653, Ec2449, Ec2066, Ec1921). Of the 16 possible combinations/genotypes, only four were detected, two of which were predominant, containing 44 and 9 members out of 57 isolates, respectively. Interestingly, the members of the latter two genotypes showed unique differences in their growth temperatures. In follow, EF1-α phylogeny served to classify most of the strains in the B. bassiana s.s. (sensu stricto) group and separate them into 5 molecular subgroups, all of which contained a group I intron belonging to the IC1 subtype at the Ec1921 position. A number of parameters such as thermal growth or origin (host, geographic location and climatic conditions) were also examined but in general no association could be found.

Conclusion: Most Spanish B. bassiana isolates (77.2%) are grouped into a major phylogenetic subgroup with word-wide distribution. However, high phylogenetic diversity was also detected among Spanish isolates from close geographic zones with low climatic variation. In general, no correlation was observed between the molecular distribution and geographic origin or climatic characteristics where the Spanish B. bassiana isolates were sampled.

Show MeSH