scholarly journals Genetic Analysis of Default Mating Behavior in Saccharomyces cerevisiae

Genetics ◽  
1997 ◽  
Vol 146 (1) ◽  
pp. 39-55 ◽  
Author(s):  
Russell Dorer ◽  
Charles Boone ◽  
Tyler Kimbrough ◽  
Joshua Kim ◽  
Leland H Hartwell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genetic Analysis ◽  
Mating Behavior ◽  
Cell Fusion ◽  
Yeast Cells ◽  
Stringent Requirement ◽  
Mating Partner ◽  
Mating Efficiency ◽  
Multiple Copies ◽  
Mating Pathway

Haploid Saccharomyces cerevisiae cells find each other during conjugation by orienting their growth toward each other along pheromone gradients (chemotropism). However, when their receptors are saturated for pheromone binding, yeast cells must select a mate by executing a default pathway in which they choose a mating partner at random. We previously demonstrated that this default pathway requires the SPA2 gene. In this report we show that the default mating pathway also requires the AXL1, FUS1, FUS2, FUS3, PEAZ, RVS161, and BNI1 genes. These genes, including SPA2, are also important for efficient cell fusion during chemotropic mating. Cells containing null mutations in these genes display defects in cell fusion that subtly affect mating efficiency. In addition, we found that the defect in default mating caused by mutations in SPA2 is partially suppressed by multiple copies of two genes, FUS2 and MFA2. These findings uncover a molecular relationship between default mating and cell fusion. Moreover, because axl1 mutants secrete reduced levels of a-factor and are defective at both cell fusion and default mating, these results reveal an important role for a-factor in cell fusion and default mating. We suggest that default mating places a more stringent requirement on some aspects of cell fusion than does chemotropic mating.

scholarly journals A and alpha supernatant pretreatment of Saccharomyces cerevisiae cells affects both the kinetics and efficiency of mating.

1982 ◽  
Vol 2 (8) ◽  
pp. 897-903 ◽  
Author(s):  
E P Sena
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Fusion ◽  
Large Scale ◽  
Culture Supernatant ◽  
Treatment Procedure ◽  
Logarithmic Growth Phase ◽  
Future Studies ◽  
Mating Efficiency ◽  
Potential Applications ◽  
Logarithmic Growth

The effects of culture supernatant treatment on subsequent matings between pretreated a and alpha Saccharomyces cerevisiae cells were studied. For each experiment, pairs of a and alpha [rho+] or [rho- rho0] cells in the logarithmic growth phase in defined minimal medium were pretreated for a total of 15 min (by exchanging their cell-free supernatants or by mixing samples of a and alpha cell cultures) and then mated in defined minimal (YNB) or enriched (YEP) liquid medium. All pretreated cells, regardless of treatment procedure, initiated cell fusion 15 to 35 min faster than did their nontreated counterparts. In all cases, pretreated cells mated 8 to 20% more efficiently than did nonpretreated ones. Regardless of the strains, the hierarchy of mating efficiency was always treated YEP greater than untreated YEP greater than treated YNB greater than untreated YNB. The cell fusion kinetics in alpha [rho+] X a [rho-] crosses were most affected by pretreatment (delta 30 to 35 min), whereas [rho+] X [rho+] crosses were least affected (delta 15 min). These results are discussed in relation to the functions known for a and alpha pheromones. The successful pretreatment regimes were used to design new rapid and efficient techniques for mating YNB-grown log-phase cells in either YNB or YEP liquid media. These techniques can be used for small- or large-scale mating, and because of their inherent media flexibility, they have many potential applications to future studies on mating-specific or intrazygotic phenomena.

A and alpha supernatant pretreatment of Saccharomyces cerevisiae cells affects both the kinetics and efficiency of mating

1982 ◽  
Vol 2 (8) ◽  
pp. 897-903
Author(s):  
E P Sena
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Fusion ◽  
Large Scale ◽  
Culture Supernatant ◽  
Treatment Procedure ◽  
Logarithmic Growth Phase ◽  
Future Studies ◽  
Mating Efficiency ◽  
Potential Applications ◽  
Logarithmic Growth

The effects of culture supernatant treatment on subsequent matings between pretreated a and alpha Saccharomyces cerevisiae cells were studied. For each experiment, pairs of a and alpha [rho+] or [rho- rho0] cells in the logarithmic growth phase in defined minimal medium were pretreated for a total of 15 min (by exchanging their cell-free supernatants or by mixing samples of a and alpha cell cultures) and then mated in defined minimal (YNB) or enriched (YEP) liquid medium. All pretreated cells, regardless of treatment procedure, initiated cell fusion 15 to 35 min faster than did their nontreated counterparts. In all cases, pretreated cells mated 8 to 20% more efficiently than did nonpretreated ones. Regardless of the strains, the hierarchy of mating efficiency was always treated YEP greater than untreated YEP greater than treated YNB greater than untreated YNB. The cell fusion kinetics in alpha [rho+] X a [rho-] crosses were most affected by pretreatment (delta 30 to 35 min), whereas [rho+] X [rho+] crosses were least affected (delta 15 min). These results are discussed in relation to the functions known for a and alpha pheromones. The successful pretreatment regimes were used to design new rapid and efficient techniques for mating YNB-grown log-phase cells in either YNB or YEP liquid media. These techniques can be used for small- or large-scale mating, and because of their inherent media flexibility, they have many potential applications to future studies on mating-specific or intrazygotic phenomena.

scholarly journals Molecular analysis of GPH1, the gene encoding glycogen phosphorylase in Saccharomyces cerevisiae.

1989 ◽  
Vol 9 (4) ◽  
pp. 1659-1666 ◽  
Author(s):  
P K Hwang ◽  
S Tugendreich ◽  
R J Fletterick
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glycogen Phosphorylase ◽  
Glucose Repression ◽  
Essential Gene ◽  
Yeast Cells ◽  
Exponential Growth Phase ◽  
Phosphorylase Activity ◽  
Glycogen Accumulation ◽  
Multiple Copies ◽  
Diploid Cells

In yeast cells, the activity of glycogen phosphorylase is regulated by cyclic AMP-mediated phosphorylation of the enzyme. We have previously cloned the gene for glycogen phosphorylase (GPH1) in Saccharomyces cerevisiae. To assess the role of glycogen and phosphorylase-catalyzed glycogenolysis in the yeast life cycle, yeast strains lacking a functional GPH1 gene or containing multiple copies of the gene were constructed. GPH1 was found not to be an essential gene in yeast cells. Haploid cells disrupted in GPH1 lacked phosphorylase activity and attained higher levels of intracellular glycogen but otherwise were similar to wild-type cells. Diploid cells homozygous for the disruption were able to sporulate and give rise to viable ascospores. Absence of functional GPH1 did not impair cells from synthesizing and storing trehalose. Increases in phosphorylase activity of 10- to 40-fold were detected in cells carrying multiple copies of GPH1-containing 2 microns plasmid. Northern (RNA) analysis indicated that GPH1 transcription was induced at the late exponential growth phase, almost simultaneous with the onset of intracellular glycogen accumulation. Thus, the low level of glycogen in exponential cells was not primarily maintained through regulating the phosphorylation state of a constitutive amount of phosphorylase. GPH1 did not appear to be under formal glucose repression, since transcriptional induction occurred well in advance of glucose depletion from the medium.

Molecular analysis of GPH1, the gene encoding glycogen phosphorylase in Saccharomyces cerevisiae

1989 ◽  
Vol 9 (4) ◽  
pp. 1659-1666 ◽  
Author(s):  
P K Hwang ◽  
S Tugendreich ◽  
R J Fletterick
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glycogen Phosphorylase ◽  
Glucose Repression ◽  
Essential Gene ◽  
Yeast Cells ◽  
Exponential Growth Phase ◽  
Phosphorylase Activity ◽  
Glycogen Accumulation ◽  
Multiple Copies ◽  
Diploid Cells

In yeast cells, the activity of glycogen phosphorylase is regulated by cyclic AMP-mediated phosphorylation of the enzyme. We have previously cloned the gene for glycogen phosphorylase (GPH1) in Saccharomyces cerevisiae. To assess the role of glycogen and phosphorylase-catalyzed glycogenolysis in the yeast life cycle, yeast strains lacking a functional GPH1 gene or containing multiple copies of the gene were constructed. GPH1 was found not to be an essential gene in yeast cells. Haploid cells disrupted in GPH1 lacked phosphorylase activity and attained higher levels of intracellular glycogen but otherwise were similar to wild-type cells. Diploid cells homozygous for the disruption were able to sporulate and give rise to viable ascospores. Absence of functional GPH1 did not impair cells from synthesizing and storing trehalose. Increases in phosphorylase activity of 10- to 40-fold were detected in cells carrying multiple copies of GPH1-containing 2 microns plasmid. Northern (RNA) analysis indicated that GPH1 transcription was induced at the late exponential growth phase, almost simultaneous with the onset of intracellular glycogen accumulation. Thus, the low level of glycogen in exponential cells was not primarily maintained through regulating the phosphorylation state of a constitutive amount of phosphorylase. GPH1 did not appear to be under formal glucose repression, since transcriptional induction occurred well in advance of glucose depletion from the medium.

scholarly journals Specification of sites for polarized growth in Saccharomyces cerevisiae and the influence of external factors on site selection.

1992 ◽  
Vol 3 (9) ◽  
pp. 1025-1035 ◽  
Author(s):  
K Madden ◽  
M Snyder
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Types ◽  
Growth Conditions ◽  
Yeast Cells ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Polarized Growth ◽  
Mating Partner ◽  
Polarized Cell Growth ◽  
External Conditions

Many eucaryotic cell types exhibit polarized cell growth and polarized cell division at nonrandom sites. The sites of polarized growth were investigated in G1 arrested haploid Saccharomyces cerevisiae cells. When yeast cells are arrested during G1 either by treatment with alpha-factor or by shifting temperature-sensitive cdc28-1 cells to the restrictive temperature, the cells form a projection. Staining with Calcofluor reveals that in both cases the projection usually forms at axial sites (i.e., next to the previous bud scar); these are the same sites where bud formation is expected to occur. These results indicate that sites of polarized growth are specified before the end of G1. Sites of polarized growth can be influenced by external conditions. Cells grown to stationary phase and diluted into fresh medium preferentially select sites for polarized growth opposite the previous bud scar (i.e., distal sites). Incubation of cells in a mating mixture results in projection formation at nonaxial sites: presumably cells form projections toward their mating partner. These observations have important implications in understanding three aspects of cell polarity in yeast: 1) how yeast cell shape is influenced by growth conditions 2) how sites of polarized growth are chosen, and 3) the pathway by which polarity is affected and redirected during the mating process.

scholarly journals BISEXUAL MATING BEHAVIOR IN A DIPLOID OF SACCHAROMYCES CEREVISIAE: EVIDENCE FOR GENETICALLY CONTROLLED NON-RANDOM CHROMOSOME LOSS DURING VEGETATIVE GROWTH

Genetics ◽  
1974 ◽  
Vol 78 (3) ◽  
pp. 843-858
Author(s):  
James E Haber
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Behavior ◽  
Mating Type ◽  
Vegetative Growth ◽  
Nuclear Gene ◽  
Chromosome Loss ◽  
Type Locus ◽  
Mating Efficiency ◽  
Single Mating ◽  
Chromosome Iii

ABSTRACT A diploid strain of Saccharomyces cerevisiae has been isolated which exhabits bisexual mating behavior. The strain mates with either a or α strains with a relative mating efficiency of 1 to 2%. The efficiency of mating is correlated with the frequency with which subclones of this strain revert to a single mating type. Crosses of the bisexual diploid with a/a or α/α diploids yield bisexual segregants with a frequency of approximately 3%. Analysis of the segregation of the mating type alleles and other markers on chromosome III indicates that the primary event which leads to the bisexual phenotype is the loss of one homolog of chromosome III during vegetative growth to produce a monosomic (2n-1) diploid. Evidence is presented that the loss of chromosome I11 and possibly of other chromosomes during vegetative growth is affected by a recessive nuclear gene-her (hermaphrodite)—which is not closely linked to the mating type locus.

Courtship in Saccharomyces cerevisiae: an early cell-cell interaction during mating

1990 ◽  
Vol 10 (5) ◽  
pp. 2202-2213
Author(s):  
C L Jackson ◽  
L H Hartwell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Interaction ◽  
Yeast Cells ◽  
Induced Response ◽  
Specific Gene ◽  
Gene Products ◽  
Alpha Cells ◽  
Wild Type ◽  
Opposite Mating Type ◽  
Mating Partner

During conjugation in Saccharomyces cerevisiae, two cells of opposite mating type (MATa and MAT alpha) fuse to form a diploid zygote. Conjugation requires that each cell locate an appropriate mating partner. To investigate how yeast cells select a mating partner, we developed a competition mating assay in which wild-type MAT alpha cells have a choice of two MATa cell mating partners. We first demonstrated that sterile MAT alpha 1 cells (expressing no a- or alpha-specific gene products) do not compete with fertile MATa cells in the assay; hence, wild-type MATa and MAT alpha cells can efficiently locate an appropriate mating partner. Second, we showed that a MATa strain need not be fertile to compete with a fertile MATa strain in the assay. This result defines an early step in conjugation, which we term courtship. We showed that the ability to agglutinate is not necessary in MATa cells for courtship but that production of a-pheromone and response to alpha-pheromone are necessary. Thus, MATa cells must not only transmit but must also receive and then respond to information for effective courtship; hence, there is a "conversation" between the courting cells. We showed that the only alpha-pheromone-induced response necessary in MATa cells for courtship is production of a-pheromone. In all cases tested, a strain producing a higher level of a-pheromone was more proficient in courtship than one producing a lower level. We propose that during courtship, a MAT alpha cell selects the adjacent MATa cell producing the highest level of a-pheromone.

scholarly journals High-Throughput Flow Cytometry Combined with Genetic Analysis Brings New Insights into the Understanding of Chromatin Regulation of Cellular Quiescence

2020 ◽  
Vol 21 (23) ◽  
pp. 9022
Author(s):  
Yasaman Zahedi ◽  
Mickael Durand-Dubief ◽  
Karl Ekwall
Keyword(s):  
Flow Cytometry ◽  
Genetic Analysis ◽  
High Throughput ◽  
Yeast Cells ◽  
Mating Partner ◽  
Nucleosome Remodeling ◽  
Mrn Complex ◽  
Cellular Environment ◽  
Genes Encoding ◽  
Cellular Quiescence

Cellular quiescence is a reversible differentiation state when cells are changing the gene expression program to reduce metabolic functions and adapt to a new cellular environment. When fission yeast cells are deprived of nitrogen in the absence of any mating partner, cells can reversibly arrest in a differentiated G0-like cellular state, called quiescence. This change is accompanied by a marked alteration of nuclear organization and a global reduction of transcription. Using high-throughput flow cytometry combined with genetic analysis, we describe the results of a comprehensive screen for genes encoding chromatin components and regulators that are required for the entry and the maintenance of cellular quiescence. We show that the histone acetylase and deacetylase complexes, SAGA and Rpd3, have key roles both for G0 entry and survival during quiescence. We reveal a novel function for the Ino80 nucleosome remodeling complex in cellular quiescence. Finally, we demonstrate that components of the MRN complex, Rad3, the nonhomologous end-joining, and nucleotide excision DNA repair pathways are essential for viability in G0.

scholarly journals Courtship in Saccharomyces cerevisiae: an early cell-cell interaction during mating.

1990 ◽  
Vol 10 (5) ◽  
pp. 2202-2213 ◽  
Author(s):  
C L Jackson ◽  
L H Hartwell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Interaction ◽  
Yeast Cells ◽  
Induced Response ◽  
Specific Gene ◽  
Gene Products ◽  
Alpha Cells ◽  
Wild Type ◽  
Opposite Mating Type ◽  
Mating Partner

During conjugation in Saccharomyces cerevisiae, two cells of opposite mating type (MATa and MAT alpha) fuse to form a diploid zygote. Conjugation requires that each cell locate an appropriate mating partner. To investigate how yeast cells select a mating partner, we developed a competition mating assay in which wild-type MAT alpha cells have a choice of two MATa cell mating partners. We first demonstrated that sterile MAT alpha 1 cells (expressing no a- or alpha-specific gene products) do not compete with fertile MATa cells in the assay; hence, wild-type MATa and MAT alpha cells can efficiently locate an appropriate mating partner. Second, we showed that a MATa strain need not be fertile to compete with a fertile MATa strain in the assay. This result defines an early step in conjugation, which we term courtship. We showed that the ability to agglutinate is not necessary in MATa cells for courtship but that production of a-pheromone and response to alpha-pheromone are necessary. Thus, MATa cells must not only transmit but must also receive and then respond to information for effective courtship; hence, there is a "conversation" between the courting cells. We showed that the only alpha-pheromone-induced response necessary in MATa cells for courtship is production of a-pheromone. In all cases tested, a strain producing a higher level of a-pheromone was more proficient in courtship than one producing a lower level. We propose that during courtship, a MAT alpha cell selects the adjacent MATa cell producing the highest level of a-pheromone.

scholarly journals Coordination of the mating and cell integrity mitogen-activated protein kinase pathways in Saccharomyces cerevisiae.

1997 ◽  
Vol 17 (11) ◽  
pp. 6517-6525 ◽  
Author(s):  
B M Buehrer ◽  
B Errede
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Map Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Cell Integrity ◽  
Mating Partner ◽  
Kinase Activation ◽  
Mitogen Activated Protein ◽  
Kinase Cascade ◽  
Mating Pathway ◽  
Transcriptional Output

Mating pheromone stimulates a mitogen-activated protein (MAP) kinase activation pathway in Saccharomyces cerevisiae that induces cells to differentiate and form projections oriented toward the gradient of pheromone secreted by a mating partner. The polarized growth of mating projections involves new cell wall synthesis, a process that relies on activation of the cell integrity MAP kinase, Mpk1. In this report, we show that Mpk1 activation during pheromone induction requires the transcriptional output of the mating pathway and protein synthesis. Consequently, Mpk1 activation occurs subsequent to the activation of the mating pathway MAP kinase cascade. Additionally, Spa2 and Bni1, a formin family member, are two coil-coil-related proteins that are involved in the timing and other aspects of mating projection formation. Both proteins also affect the timing and extent of Mpk1 activation. This correlation suggests that projection formation comprises part of the pheromone-induced signal that coordinates Mpk1 activation with mating differentiation. Stimulation of Mpk1 activity occurs through the cell integrity phosphorylation cascade and depends on Pkc1 and the redundant MAP/Erk kinases (MEKs), Mkk1 and Mkk2. Surprisingly, Mpk1 activation by pheromone was only partially impaired in cells lacking the MEK kinase Bck1. This Bck1-independent mechanism reveals the existence of an alternative activator of Mkk1/Mkk2 in some strain backgrounds that at least functions under pheromone-induced conditions.

Sign in / Sign up

Export Citation Format

Share Document