Two Divergent Intragenomic rDNA ITS2 Types within a Monophyletic Lineage of the FungusFusariumAre Nonorthologous

O’Donnell, Kerry; Cigelnik, Elizabeth

doi:10.1006/mpev.1996.0376

Cited by 1,848 publications

(727 citation statements)

References 61 publications

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“…For amplification of part of the beta-tubulin (βT) gene, the primers Bt2a and Bt2b (Glass and Donaldson 1995) were used, which were replaced in some cases with the primer pair Bt2b and T10 (O'Donnell and Cigelnik 1997). PCR amplification of the calmodulin gene region (CAL) was done using the primers CL2F and CL2R (Duong et al 2012) and in cases where amplification was difficult, CL2R2 (Duong et al 2012) was used instead of CL2R.…”

Section: Fungal Identificationmentioning

confidence: 99%

Wounds on Rapanea melanophloeos provide habitat for a large diversity of Ophiostomatales including four new species

Musvuugwa

Beer

Duong

et al. 2016

Antonie van Leeuwenhoek

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Rapanea melanophloeos, an important canopy tree in Afromontane forests, is commonly utilised for medicinal bark harvesting. Wounds created from these activities provide entrance for many fungi, including arthropod-associated members of the Ophiostomatales and Microascales (ophiostomatoid fungi). In this study we assess the diversity of wound-associated Ophiostomatales on storm-damaged R. itsvoense sp. nov., S. rapaneae sp. nov., S. utae) while O. noisomeae groups basal in the Ophiostomatales alongside the S. lignivora complex and Graphilbum. In addition to other taxa known from this host, the present study shows that there is a rich, yet still poorly explored, diversity of Ophiostomatales associated with R. melanophloeos in Afromontane forests. More taxa are likely to be discovered with increased research effort. These must be assessed in terms of pathogenicity towards this ecologically and economically important tree.

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Section: Fungal Identificationmentioning

confidence: 99%

Wounds on Rapanea melanophloeos provide habitat for a large diversity of Ophiostomatales including four new species

Musvuugwa

Beer

Duong

et al. 2016

Antonie van Leeuwenhoek

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“…Intragenomic polymorphisms of the ITS region have also been reported in other eukaryotes, including plants (Baldwin et al 1995; Alvarez and Wendel 2003), beetles (Vogler and DeSalle 1994), nematodes (Zijlstra et al 1995), sponges (Wörheide et al 2004) and filamentous fungi (O’Donnell and Cigelnik 1997; Wang and Yao 2005). The divergent ITS types in the same individual genomes of these organisms are usually described as nonorthologous and attributed to the origin of ancient interspecific hybridisation (xenologous origin) or gene duplication (paralogous origin), but direct evidences have not been presented.…”

Section: Discussionmentioning

confidence: 92%

“…One possible explanation is the defect in gene conversion mechanisms required for concerted evolution of rRNA genes in strain CBS 215. The hypotheses proposed to explain long-term persistence of rDNA polymorphsims following hybridisation or polyplodisation have been summarised by O’Donnell and Cigelnik (1997) as (1) their chromosomal location may not be telomeric, (2) the sequences may have diverged beyond the point that interchromosomal conversion can occur and (3) concerted evolution may be more efficient within a chromosomal locus than between repeats dispersed on non-homologous chromosomes. Rooney (2004) has shown that the intragenomic heterogeneous 18S rRNA genes in apicomplexan protists undergo birth-and-death rather than concerted evolution.…”

Section: Discussionmentioning

confidence: 99%

“…Intragenomic ribosomal DNA (rDNA) sequence polymorphisms have also been reported in fungi. Divergent ITS types have been found in single genomes of Fusarium and Ganoderma species (O’Donnell and Cigelnik 1997; Wang and Yao 2005). In a yeast species, Clavispora lusitaniae , intragenomic variations in the 26S rDNA D1/D2 domain have been reported (Lachance et al 2003).…”

Section: Introductionmentioning

confidence: 99%

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Intragenomic polymorphism and intergenomic recombination in the ribosomal RNA genes of strains belonging to a yeast speciesPichia membranifaciens

Wang

Liu

et al. 2016

Mycology

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A concerted evolution model has been proposed to explain the observed lack of sequence variation among the multiple ribosomal RNA (rRNA) gene copies in many different eukaryotic species. Recent studies on the level of intragenomic variations in the rRNA gene repeats of fungi resulted in controversial conclusions. In this study, we clearly showed that significant polymorphisms of the internal transcribed spacers (ITS1 and ITS2) of ribosomal DNA (rDNA) exist within the genome of a strain of the yeast species Pichia membranifaciens. More interestingly, we showed that the intragenomic ITS sequence polymorphisms were formed by intergenomic rDNA recombination among different P. membranifaciens strains with significantly different ITS sequences. Intergenomic rDNA recombination was also responsible for the diversification of rDNA sequences in different strains of the species. After the events bring together different rDNA types in individual genomes of the P. membranifaciens strains compared, rDNA sequence heterogeneity has remained in the genome of one but eliminated by homogenisation in the genomes of other strains. Our findings show new clue for further investigation on the mechanism of concerted evolution of rRNA genes in eukaryotes.

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“…Entre as técnicas moleculares utilizadas para discriminação de Fusarium spp. destacam-se: Polimorfismo de DNA amplificado ao acaso (RAPD) (Duteau & Leslie, 1991;Ouellet & Seifert, 1993;Voigt et al, 1995;Viljoen et al, 1997), Polimorfismo no comprimento de fragmentos de restrição (RFLP) (Correll et al, 1992;Nicholson et al, 1993), espaços intergênicos transcritos (ITS 1 e ITS 2) (O'Donnell & Cigelnik, 1997;Waalwijk et al, 1996) e dados de seqüências gênicas conservadas (Steenkamp et al, 2000a), Polimorfismo no comprimento de fragmentos amplificados (AFLP) (Jurgenson et al, 2002) e Reação de Polimerase em Cadeia (PCR) (Hue et al, 1999;Steenkamp et al, 2000b). Steenpkamp et al (1999) combinaram as técnicas de PCR-RFLP para a diferenciação dos fungos de F. subglutinans associados a vários hospedeiros (cana-de-açúcar, pinheiro, mangueira e milho).…”

Section: Introductionunclassified

Utilização de marcador molecular SCAR na identificação de Fusarium subglutinans, agente causal da malformação da mangueira

et al. 2007

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RESUMO-O gênero Fusarium é responsável por doenças em diversas plantas economicamente importantes. Entre estas doenças, destaca-se a malformação da mangueira, causada pelo fungo Fusarium subglutinans. O objetivo deste trabalho foi desenvolver oligonucleotídeos iniciadores para reação em cadeia da polimerase (PCR), específicos para o fungo F. subglutinans da mangueira. A amplificação de DNA de oito Fusarium spp. de diferentes hospedeiros, usando o oligonucleotídeo randômico UBC-41 (TTAACCGGGG), produziu um fragmento de aproximadamente 1.300 pb somente para o fungo da mangueira. Tendo em vista que padrões de bandeamento por RAPD não são considerados confiáveis devido à baixa reprodutibilidade dos resultados, o fragmento diferencial foi eluído do gel de agarose, purificado, clonado e seqüenciado. As seqüências nucleotídicas foram utilizadas para identificar e sintetizar quatro pares de oligonucleotídeos específicos, denominados Fs 5, Fs 13, Fs 14 e Fs 15. DNAs de Fusarium spp. de outros hospedeiros (alho, amendoim, cana-de-açúcar, ciclâmen, ervilha, melão e trigo), da planta de mangueira cv. Tommy Atkins sadia e de outros cinco isolados de F. subglutinans de mangueira sintomática, foram submetidos à amplificação com os pares de oligonucleotídeos. Fragmentos amplificados foram visualizados somente para F. subglutinans de mangueira, demonstrando assim a especificidade dos oligonucleotídeos SCAR desenhados. Termos de Indexação: oligonucleotídeos iniciadores, Mangifera indica, marcadores moleculares, RAPD-PCR. USE OF MOLECULAR MARKER SCAR IN THE IDENTIFICATION OF Fusarium subglutinans,CAUSAL AGENT OF MANGO MALFORMATIONABSTRACT-The Fusarium genus is responsible for serious diseases in many economically important crops. Among these diseases it is distinguished the mango flower malformation, caused by the fungus Fusarium subglutinans. The objective of this work was to develop specific oligonucleotide primers for the polymerase chain reaction (PCR) targeting the mango flower malformation by fungus F. subglutinans. The DNA amplification of eight Fusarium spp. collected from different hosts making the use of a random oligonucleotide primer UBC-41 generated a fragment of approximately 1300 pb in size, specifically for the mango flower malformation fungus (Fusarium subglutinans). Since standard RAPD banding patterns are not considered reliable because of their low results of reproducibility, the distinctive fragment was eluted off the agarose gel, purified, cloned and then sequenced. The nucleotide sequences were used to identify and also to synthesize four pairs of specific oligonucleotide named herein Fs 5, Fs 13, Fs 14 and Fs 15. Other Fusarium spp. DNAs sampled from other hosts (garlic, peanut, sugarcane, cyclamen, pea, melon and wheat), from a healthy mango tree cv. Tommy Atkins and other six isolates from symptomatic mango plants were submitted to PCR amplification with these pairs of oligonucleotide. Only fragments from the mango tree fungus Fusarium subglutinans were visualized, showing this way the SCAR oligonucleotid...

show abstract

Two Divergent Intragenomic rDNA ITS2 Types within a Monophyletic Lineage of the FungusFusariumAre Nonorthologous

Cited by 1,848 publications

References 61 publications

Wounds on Rapanea melanophloeos provide habitat for a large diversity of Ophiostomatales including four new species

Wounds on Rapanea melanophloeos provide habitat for a large diversity of Ophiostomatales including four new species

Intragenomic polymorphism and intergenomic recombination in the ribosomal RNA genes of strains belonging to a yeast speciesPichia membranifaciens

Utilização de marcador molecular SCAR na identificação de Fusarium subglutinans, agente causal da malformação da mangueira

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