Heterothallism inCordyceps takaomontana

Abstract

Perithecium formation of an entomopathogenic fungus Cordyceps takaomontana was promoted by treating the mycelia with cell wall-degrading enzymes and PEG 4000. Perithecia were formed in the mixed culture of both mating-type strains MAT1 and MAT2, and not in the culture of MAT1 or MAT2 alone. The MAT1 strains did not possess a mating-type gene MAT1-1-3, but could produce perithecia. These results strongly suggested that C. takaomontana is heterothallic, and does not need MAT1-1-3 for the perithecium formation. MAT1-1-3 was also not found in another entomopathogenic fungus Cordyceps militaris. On the other hand, phytopathogenic fungi Balansia sp., Claviceps purpurea and Epichloë typhina possessed MAT1-1-3. The structures of mating-type locus MAT1-1 of these phytopathogenic fungi in the family Clavicipitaceae were similar to that of a phytopathogenic fungus Gibberella fujikuroi in the family Nectriaceae, which is closely related to Clavicipitaceae. These results suggested that phytopathogen might be more ancestral group than entomopathogen in Clavicipitaceae, and that MAT1-1-3 might be lost in the course of the host shift from plants to insects.

Both mating types in the heterothallic fungus Ophiostoma quercus contain MAT1-1 and MAT1-2 genes

“…The predicted protein sequence for this region showed high similarity to the MAT1-1-3 sequences for other species, e.g. O. novo-ulmi (accession ACZ53925), Claviceps purpurea (BAD72602) (Yokoyama et al 2005) and Epichloe species (BAD72610, BAD72606) (Yokoyama et al 2005). …”

Asexual fungus Verticillium dahliae is potentially heterothallic

“…We used a DNA fragment including part of a DNA lyase gene homologue (nt 6780-7881 of accession AB505214) (Fig. 2) as a screening probe because this gene was often found outside the MAT idiomorph (Kanematsu et al 2007;Yokoyama et al 2005Yokoyama et al , 2006Yun et al 2000) and probably exists adjacent to the MAT1-1 idiomorph of V. dahliae. Detailed procedures for library construction and screening are described by Usami et al (2007).…”

“…Alternaria alternata and Cochliobolus heterostrophus contain only MAT1-1-1 in their MAT1-1 idiomorphs. On the other hand, many fungal species contain three genes, MAT1-1-1, MAT1-1-2, and MAT1-1-3 Kanamori et al 2007;Kanematsu et al 2007;Pöggeler et al 2008;Turgeon and Yoder 2000;Yokoyama et al 2005Yokoyama et al , 2006Yun et al 2000). Pyrenopeziza brassicae contains MAT1-1-4 instead of MAT1-1-2 (Singh and Ashby 1998).…”

Selection of Superior Strains ofCordyceps militariswith Enhanced Fruiting Body Productivity

“…Very recently, heterothallism has been confirmed in C. takaomontana by both cultural and molecular studies (Yokoyama et al, 2005). To develop C. militaris as an important component of oriental medicine as well as modern medicine, it is very necessary to understand genetic and environmental factors to produce high potential fruiting bodies.…”