Two-step activation of meiosis by the mat1 locus in Schizosaccharomyces pombe.

The mat1 locus is a key regulator of both conjugation and meiosis in the fission yeast Schizosaccharomyces pombe. Two alternative DNA segments of this locus, mat1-P and mat1-M, specify the haploid cell types (Plus and Minus). Each segment includes two genes: mat1-P includes mat1-Pc and mat1-Pm, while mat1-M includes mat1-Mc and mat1-Mm. The mat1-Pc and mat1-Mc genes are responsible for establishing the pheromone communication system that mediates conjugation between P and M cells, while all four mat1 genes are required for meiosis in diploid P/M cells. Our understanding of the initiation of meiosis is based largely on indirect observations, and a more precise investigation of these events was required to define the interaction between the mat1 genes. Here we resolve this issue using synthetic pheromones and P/M strains with mutations in either mat1-Pc or mat1-Mc. Our results suggest a model in which the mat1 locus plays two roles in controlling meiosis. In the first instance, the mat1-Pc and mat1-Mc functions are required to produce the mating pheromones and receptors that allow the generation of a pheromone signal. This signal is required to induce the expression of mat1-Pm and mat1-Mm. This appears to be the major pheromone-dependent step in controlling meiosis since ectopic expression of these genes allows meiosis in the absence of mat1-Pc and mat1-Mc. The mat1-Pm and mat1-Mm products complete the initiation of meiosis by activating transcription of the mei3 gene.

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Analysis of the structural genes encoding M-factor in the fission yeast Schizosaccharomyces pombe: identification of a third gene, mfm3

Molecular and Cellular Biology ◽

10.1128/mcb.14.6.3895-3905.1994 ◽

1994 ◽

Vol 14 (6) ◽

pp. 3895-3905

Author(s):

S Kjaerulff ◽

J Davey ◽

O Nielsen

Keyword(s):

Schizosaccharomyces Pombe ◽

Fission Yeast ◽

Mutational Analysis ◽

M Cells ◽

Gene Products ◽

Structural Genes ◽

Triple Mutant ◽

Isolation And Characterization ◽

Genes Encoding

We previously identified two genes, mfm1 and mfm2, with the potential to encode the M-factor mating pheromone of the fission yeast Schizosaccharomyces pombe (J. Davey, EMBO J. 11:951-960, 1992), but further analysis revealed that a mutant strain lacking both genes still produced active M-factor. Here we describe the isolation and characterization of a third M-factor gene, mfm3. A mutant lacking all three genes fails to produce M-factor, indicating that all functional M-factor genes now have been identified. The triple mutant exhibits an absolute mating defect in M cells, a defect that is not rescued by addition of exogenous M-factor. A mutational analysis reveals that all three mfm genes contribute to the production of M-factor. Their transcription is limited to M cells and requires the mat1-Mc and ste11 gene products. Each gene is induced when the cells are starved of nitrogen and further induced by a pheromone signal. Additionally, the signal transduction machinery associated with the pheromone response is required for transcription of the mfm genes in both stimulated and unstimulated cells.

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Sex Pheromone Communication System in Hawk Moths

Insect Sex Pheromone Research and Beyond - Entomology Monographs ◽

10.1007/978-981-15-3082-1_2 ◽

2020 ◽

pp. 19-33

Author(s):

Takuya Uehara ◽

Hiroshi Honda

Keyword(s):

Sex Pheromone ◽

Communication System ◽

Pheromone Communication ◽

Pheromone Communication System

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The asymmetric chemical structures of two mating pheromones reflect their differential roles in conjugation of Schizosaccharomyces pombe

10.1101/548586 ◽

2019 ◽

Author(s):

Taisuke Seike ◽

Hiromi Maekawa ◽

Taro Nakamura ◽

Chikashi Shimoda

Keyword(s):

Schizosaccharomyces Pombe ◽

M Cells ◽

Opposite Mating Type ◽

Chemical Structures ◽

Mating Pheromones ◽

Fusion Site ◽

Summary Statement ◽

P Factor ◽

P Type ◽

P Cells

AbstractIn the fission yeast Schizosaccharomyces pombe, the mating reaction is controlled by two mating pheromones, M-factor and P-factor, secreted by M- and P-type cells, respectively. M-factor is a C-terminally farnesylated lipid peptide, whereas P-factor is a simple peptide. To examine whether this chemical asymmetry in the two pheromones is essential for conjugation, we constructed a mating system in which either pheromone can stimulate both M- and P-cells, and examined whether the resulting autocrine strains can mate. Autocrine M-cells responding to M-factor successfully mated with P-factor-less P-cells, indicating that P-factor is not essential for conjugation; by contrast, autocrine P-cells responding to P-factor were unable to mate with M-factor-less M-cells. The sterility of the autocrine P-cells was completely recovered by expressing the M-factor receptor. These observations indicate that the different chemical characteristics of the two types of pheromone, a lipid and a simple peptide, are not essential; however, a lipid peptide is absolutely required for successful mating. Our findings allow us to propose a model of the differential roles of M-factor and P-factor in conjugation of S. pombe.Summary statementLipid pheromone peptides secreted locally from one cell may be concentrated at the fusion site with an opposite mating-type cell, which then polarizes to enable successful conjugation in S. pombe.

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