The control of mating type heterokaryon incompatibility by vib-1, a locus involved in het-c heterokaryon incompatibility in Neurospora crassa.
The mating-type (mat) locus of Neurospora crassa has a dual function. It is required for mating during sexual development, but it also mediates heterokaryon incompatibility following hyphal fusion during vegetative growth. Previously, it was determined that mutations in vib-1, which encodes a putative transcriptional regulator, suppress het-c heterokaryon incompatibility. This study showed that mutations in vib-1 suppress mat heterokaryon incompatibility in A/a partial diploids; suppression in (A+a) heterokaryons was variable and affected by unknown genetic factors. tol, a gene required for mat heterokaryon incompatibility, is epistatic to vib-1 in mediating mat heterokaryon incompatibility. vib-1 and tol also display a hierarchical order of strength of heterokaryon incompatibility that affected fertilization patterns. In addition to its role in heterokaryon incompatibility, vib-1 also negatively regulates conidiation. This study shows that FL, a positive regulator of conidiation, may partially activate conidiation by repressing VIB-1 function. VIB-1 may also partially regulate heterokaryon incompatibility mediated by genetic differences at het-e and het-8 because mutations in vib-1 increased the survival rate of self-incompatible het-8 and het-e partial diploid progeny.
Xiang
Qijun
Q
Department of Plant and Microbial Biology, University of California, 111 Koshland Hall, Berkeley, CA 94720-3102, USA.
Glass
N Louise
NL
D003433:Crosses, Genetic; D005656:Fungal Proteins / Q000235:genetics* / Q000502:physiology; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D049770:Genes, Mating Type, Fungal; D016153:Genes, Suppressor; D009154:Mutation; D009492:Neurospora crassa / Q000235:genetics* / Q000254:growth & development*; D014157:Transcription Factors / Q000235:genetics* / Q000502:physiology
C112649:FL protein, Neurospora crassa; D005656:Fungal Proteins; C117550:TOL protein, Neurospora crassa; D014157:Transcription Factors