A mating-type factors of Coprinus cinereus have variable numbers of specificity genes encoding two classes of homeodomain proteins

Mol Gen Genet. 1994 Oct 17;245(1):45-52. doi: 10.1007/BF00279749.


We have identified the seven genes that constitute the A43 mating-type factor of Coprinus cinereus and compare the organisation of A43 with the previously characterised A42 factor. In both, the genes that trigger clamp cell development, the so-called specificity genes, are separated into alpha and beta loci by 7 kb of noncoding sequence and are flanked by homologous genes alpha-fg and beta-fg. The specificity genes are known to encode two classes of dissimilar homeodomain (HD1 and HD2) proteins and have different allelic forms which show little or no cross-hybridisation. By partial sequencing we identified a divergently transcribed HD1 (a1-2) and HD2 (a2-2) gene in the A43 alpha locus. a2-2 failed to elicit clamp cell development in three different hosts, suggesting that it is non-functional. a1-2 elicited clamp cells in an A42 host that has only an HD2 gene (a2-1) in its alpha locus, thus demonstrating that the compatible A alpha mating interaction is between an HD1 and an HD2 protein. The A43 beta locus contains three specificity genes, the divergently transcribed HD1 and HD2 genes b1-2 and b2-2 and a third HD1 gene (d1-1) that was shown by hybridisation and transformation analyses to be functionally equivalent to d1-1 in A42. An untranscribed footprint of a third A42 HD1 gene, c1-1, was detected between the A43 b2-2 and d1-1 genes by Southern hybridisation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Coprinus / genetics*
  • Fungal Proteins / genetics*
  • Genes, Fungal*
  • Genes, Mating Type, Fungal*
  • Homeodomain Proteins / genetics*
  • Molecular Sequence Data
  • RNA, Fungal / genetics
  • Transformation, Genetic


  • Fungal Proteins
  • Homeodomain Proteins
  • RNA, Fungal