An asexual fungus has the potential for sexual development

Amir Sharon, Kenichi Yamaguchi, Solveig Christiansen, Benjamin A. Horwitz, O. C. Yoder, B. Gillian Turgeon

Research output: Contribution to journalArticlepeer-review


The availability of cloned genes that control sexual reproduction (mating type genes) in higher fungi has allowed us to consider the causes of failure to mate in asexual fungi. We report here that the asexual fungus Bipolaris sacchari has a homolog of the MAT-2 gene of its sexual ascomycete relative Cochliobolus heterostrophus. The B. sacchari MAT-2 sequence is highly similar to that of C. heterostrophus MAT-2 and, in fact, functions in transgenic C. heterostrophus. Thus, the asexual nature of B. sacchari is not due to absence or mutation of MAT. When either of the C. heterostrophus MAT genes was transformed into B. sacchari, the recipient could neither self nor cross with other B. sacchari strains, in contrast to transgenic C. heterostrophus strains which can do both. Persistent asexuality of B. sacchari, in spite of the presence of complementary functional MAT genes, suggests that this fungus lacks genes other than MAT which are essential for mating. Notably, the transgenic B. sacchari strains were sometimes able to initiate, but not complete, sexual development in interspecific pairings with C. heterostrophus. Transcript analysis showed that the B. sacchari MAT-2 gene is expressed in transgenic C. heterostrophus and that the C. heterostrophus MAT genes are expressed in transgenic B. sacchari. No transcript of the native B. sacchari MAT-2 gene was detected under any growth condition tested.

Original languageEnglish
Pages (from-to)60-68
Number of pages9
JournalMolecular and General Genetics
Issue number1
StatePublished - 1996


  • Bipolaris sacchari
  • Cochliobolus heterostrophus
  • DNA binding
  • Idiomorph
  • Mating type


Dive into the research topics of 'An asexual fungus has the potential for sexual development'. Together they form a unique fingerprint.

Cite this