• Journal of Mushroom
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• v.9 no.1
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• pp.3-16
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• 2011

In the bipolar basidiomycete Pholiota nameko, a pair of homeodomain protein genes located at the A mating-type locus regulates mating compatibility. In the present study, we used a DNA-mediated transformation system in P. nameko to investigate the homeodomain proteins that control the clamp formation. When a single homeodomain protein gene (A3-hox1 or A3-hox2) from the A3 monokaryon strain was introduced into the A4 monokaryon strain, the transformants produced many pseudo-clamps but very few clamps. When two homeodomain protein genes (A3-hox1 and A3-hox2) were transformed either separately or together into the A4 monokaryon, the ratio of clamps to the clamp-like cells in the transformants was significantly increased to approximately 50%. We, therefore, concluded that the gene dosage of homeodomain protein genes is important for clamp formation. When the sip promoter was connected to the coding region of A3-hox1 and A3-hox2 and the fused fragments were introduced into NGW19-6 (A4), the transformants achieved more than 85% clamp formation and exhibited two nuclei per cell, similar to the dikaryon (NGW12-163 ${\times}$ NGW19-6). The results of real-time RT-PCR confirmed that sip promoter activity is greater than that of the native promoter of homeodomain protein genes in P. nameko. So, we concluded that nearly 100% clamp formation requires high expression levels of homeodomain protein genes and that altered expression of the A mating-type genes alone is sufficient to drive true clamp formation.

• The Korean Journal of Mycology
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• v.26 no.4 s.87
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• pp.574-582
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• 1998

Five basidiocarps of Pholiota species have been collected from the areas of BubJu Temple for last two years, and identified to those of P. adiposa or Pholiota species. The taxonomy of these basidiocarps with the morphological aspects was compared with the analysis obtained from the polymorphisms of PCR-RAPD bands made after reacted with the random primers. The polymorphic variations were observed within the species of the basidiocarps, but not between genomic DNA's of the mycelia obtained and the basidiocarps. Several different bands made from the primers (28 and 36) in PCR-RAPD reactions were identified within the genus of Pholiota and speculated to be specific for the individual basidiocarp of P. adiposa collected. The primers employed here were considered to be very useful for distinguishing the individual isolates or basidiocarps collected from the fields. Also, the basidiospores were obtained from the sporeprints of the above basidiocarps as a simple agar and confirmed with observations of clamp connection under microscopes. The matings of them indicated the 'tetrapolar' type, being different from the 'bipolar' type reported by Japanese basidiocarps of P. adiposa or P. nameko. Based on our work, the edible fungi collected were speculated to be a new breeding resource for those of Pholiota commercialized in Japan.