The unicellular eukaryote Tetrahymena thermophila has seven mating types. Cells can mate only when they recognize cells of a different mating type as non-self. As a ciliate, Tetrahymena separates its germline and soma into two nuclei. During growth the somatic nucleus is responsible for all gene transcription while the germline nucleus remains silent. During mating, a new somatic nucleus is dif...

The mating-type determination circuit in Saccharomyces yeast serves as a classic paradigm for the genetic control of cell type in all eukaryotes. Using comparative genetics, we discovered a central and conserved, yet previously undetected, component of this genetic circuit: active repression of -specific genes in a cells. Upon inactivation of the SUM1 gene in Saccharomyces bayanus, a close rela...

The polypeptide pheromone Er-1, purified from the ciliate Euplotes raikovi of mating type I and genotype mat-1/mat-1, was iodinated with 125I-Bolton-Hunter reagent to a sp act of 0.45-0.73 mu Ci/microgram of protein. This preparation of 125I-Er-1 bound specifically to high affinity binding sites on the same cells of mating type I. Binding of 125I-Er-1 occurred with an apparent Kd of 4.63 +/- 0....

Saccharomyces cerevisiae, baker’s yeast, can exist in either a haploid (1n) or a diploid (2n) state. Haploids express one of two mating types, a or a (alpha). Haploids of either mating type are capable of mating with haploids of the opposite mating type in response to the action of mating pheromones. Mating results in fusion of haploid cells, forming an a/a diploid, which is no longer capable o...

White-nose syndrome (WNS) of bats has devastated bat populations in eastern North America since its discovery in 2006. WNS, caused by the fungus Pseudogymnoascus destructans, has spread quickly in North America and has become one of the most severe wildlife epidemics of our time. While P. destructans is spreading rapidly in North America, nothing is known about the sexual capacity of this fungu...

A rapid and reliable mating type assay for Fusarium circinatum was created by applying primers specific for the MAT1-1 and MAT1-2 mating type alleles to genomic DNA in a single PCR. A similar approach may be applied to fungi not previously shown to reproduce sexually, thus enabling studies of population structure and inheritance.

Both A1 and A2 mating types of Phytophthora infestans were detected in El-Behera governorate and the surrounding area where potato and tomato were intensively cultivated during the 2005-2006 growing season. The A2 mating type constituted 14.8% of the total isolates recovered (162) while A1 mating type constituted 83.9%. A 7.4% of the total potato and tomato fields (94) surveyed yielded A2 matin...

Fusarium wilt caused by Fusarium oxysporum Schltdl. f.sp. phaseoli (Fop), is one of the important diseases of the common bean in Iran and many of the bean growing countries. Incidence of the disease has been reported in tropical and semi-tropical regions of the world. This study was carried out to characterize genetic diversity of F. oxysporum isolates from the common bean by vegetative compati...

White-nose syndrome (WNS) of bats has devastated bat populations in eastern North America since its discovery in 2006. WNS, caused by the fungus Pseudogymnoascus destructans, has spread quickly in North America and has become one of the most severe wildlife epidemics of our time. While P. destructans is spreading rapidly in North America, nothing is known about the sexual capacity of this fungu...