scholarly journals MATING-TYPE EFFECT ON CIS MUTATIONS LEADING TO CONSTITUTIVITY OF ORNITHINE TRANSAMINASE IN DIPLOID CELLS OF SACCHAROMYCES CEREVISIAE

Genetics ◽  
1979 ◽  
Vol 92 (3) ◽  
pp. 749-758
Author(s):  
Jacqueline Deschamps ◽  
Jean-Marie Wiame
Keyword(s):  
Mating Type ◽  
Second Step ◽  
Cis Acting ◽  
Classical Operator ◽  
Different Types ◽  
Ornithine Transaminase ◽  
Regulatory Mutations ◽  
Constitutive Mutation ◽  
Constitutive Synthesis ◽  
Diploid Cells

ABSTRACT Cis-acting regulatory mutations have been isolated that affect L-ornithine transaminase (OTAse), an enzyme catalyzing the second step of arginine breakdown in yeast. These mutations lead to constitutive synthesis of OTAse at various levels. Two different types of mutations have been recovered, both of which are tightly linked to the structural gene (cargB) for this enzyme. One type behaves as a classical operator-constitutive mutation similar to the cargB+O-—l mutation previously described (DUBOIS et al. 1978) .—The second type is peculiar in two respects : the higher level of constitutive OTAse synthesis and the expression of constitutivity in diploid cells. These mutations are designated curgB+Oh. They behave as usual operator-constitutive mutations in diploid strains homozygous for mating type (a/a or α/α), but the constitutivity is strongly reduced in a/α diploid cells.

scholarly journals Mating Type in Chlamydomonas Is Specified by mid, the Minus-Dominance Gene

Genetics ◽  
1997 ◽  
Vol 146 (3) ◽  
pp. 859-869 ◽  
Author(s):  
Patrick J Ferris ◽  
Ursula W Goodenough
Keyword(s):  
Transcription Factor ◽  
Mating Type ◽  
Codon Bias ◽  
Leucine Zipper ◽  
Laboratory Strain ◽  
Leucine Zipper Motif ◽  
Type Locus ◽  
Diploid Cells ◽  
Necessary And Sufficient

Diploid cells of Chlamydomonas reinhardtii that are heterozygous at the mating-type locus (mt  +/mt  –) differentiate as minus gametes, a phenomenon known as minus dominance. We report the cloning and characterization of a gene that is necessary and sufficient to exert this minus dominance over the plus differentiation program. The gene, called mid, is located in the rearranged (R) domain of the mt  – locus, and has duplicated and transposed to an autosome in a laboratory strain. The imp11 mt  – mutant, which differentiates as a fusion-incompetent plus gamete, carries a point mutation in mid. Like the fus1 gene in the mt  + locus, mid displays low codon bias compared with other nuclear genes. The mid sequence carries a putative leucine zipper motif, suggesting that it functions as a transcription factor to switch on the minus program and switch off the plus program of gametic differentiation. This is the first sex-determination gene to be characterized in a green organism.

The HML mating-type cassette of Saccharomyces cerevisiae is regulated by two separate but functionally equivalent silencers

1989 ◽  
Vol 9 (11) ◽  
pp. 4621-4630
Author(s):  
D J Mahoney ◽  
J R Broach
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Binding Sites ◽  
The Other ◽  
Functional Domains ◽  
Gene Products ◽  
Cis Acting ◽  
Full Expression ◽  
Mating Type Genes ◽  
Chromosome Iii

Mating-type genes resident in the silent cassette HML at the left arm of chromosome III are repressed by the action of four SIR gene products, most likely mediated through two cis-acting sites located on opposite sides of the locus. We showed that deletion of either of these two cis-acting sites from the chromosome did not yield any detectable derepression of HML, while deletion of both sites yielded full expression of the locus. In addition, each of these sites was capable of exerting repression of heterologous genes inserted in their vicinity. Thus, HML expression is regulated by two independent silencers, each fully competent for maintaining repression. This situation was distinct from the organization of the other silent locus, HMR, at which a single silencer served as the predominant repressor of expression. Examination of identifiable domains and binding sites within the HML silencers suggested that silencing activity can be achieved by a variety of combinations of various functional domains.

Mating type control in Saccharomyces cerevisiae: a frameshift mutation at the common DNA sequence, X, of the HML alpha locus

1984 ◽  
Vol 4 (1) ◽  
pp. 203-211
Author(s):  
K Tanaka ◽  
T Oshima ◽  
H Araki ◽  
S Harashima ◽  
Y Oshima
Keyword(s):  
Mating Type ◽  
Base Pair ◽  
Reading Frame ◽  
Base Pair Deletion ◽  
A Cell ◽  
Alpha Gene ◽  
The Common ◽  
Type Switch ◽  
Diploid Cells ◽  
Mat Locus

A mutation defective in the homothallic switching of mating type alleles, designated hml alpha-2, has previously been characterized. The mutation occurred in a cell having the HO MATa HML alpha HMRa genotype, and the mutant culture consisted of ca. 10% a mating type cells, 90% nonmater cells of haploid cell size, and 0.1% sporogenous diploid cells. Genetic analyses revealed that nonmater haploid cells have a defect in the alpha 2 cistron at the MAT locus. This defect was probably caused by transposition of a cassette originating from the hml alpha-2 allele by the process of the homothallic mating type switch. That the MAT locus of the nonmater cells is occupied by a DNA fragment indistinguishable from the Y alpha sequence in electrophoretic mobility was demonstrated by Southern hybridization of the EcoRI-HindIII fragment encoding the MAT locus with a cloned HML alpha gene as the probe. The hml alpha-2 mutation was revealed to be a one-base-pair deletion at the ninth base pair in the X region from the X and Y boundary of the HML locus. This mutation gave rise to a shift in the open reading frame of the alpha 2 cistron. A molecular mechanism for the mating type switch associated with the occurrence of sporogenous diploid cells in the mutant culture is discussed.

scholarly journals Specific repression of the yeast silent mating locus HMR by an adjacent telomere.

1994 ◽  
Vol 14 (1) ◽  
pp. 446-455 ◽  
Author(s):  
J S Thompson ◽  
L M Johnson ◽  
M Grunstein
Keyword(s):  
Mating Type ◽  
Chromosomal Location ◽  
Regulatory Genes ◽  
Histone H4 ◽  
Cis Acting ◽  
N Terminus ◽  
Silencer Elements ◽  
Chromosome Iii

The yeast silent mating loci HML and HMR are located at opposite ends of chromosome III adjacent to the telomeres. Mutations in the N terminus of histone H4 have been previously found to derepress the yeast silent mating locus HML to a much greater extent than HMR. Although differences in the a and alpha mating-type regulatory genes and in the cis-acting silencer elements do not appear to strongly influence the level of derepression at HMR, we have found that the differential between the two silent cassettes is largely due to the position of the HMR cassette relative to the telomere on chromosome III. While HML is derepressed to roughly the same extent by mutations in histone H4 regardless of its chromosomal location, HMR is affected to different extends depending upon its chromosomal positioning. We have found that HMR is more severely derepressed by histone H4 mutations when positioned far from the telomere (cdc14 locus on chromosome VI) but is only minimally affected by the same mutations when integrated immediately adjacent to another telomere (ADH4 locus on chromosome VII). These data indicate that the degree of silencing at HMR is regulated in part by its neighboring telomere over a distance of at least 23 kb and that this form of regulation is unique for HMR and not present at HML. These data also indicate that histone H4 plays an important role in regulating the silenced state at both HML and HMR.

scholarly journals Detecting dynamical anomalies in time series from different palaeoclimate proxy archives using windowed recurrence network analysis

2019 ◽  
Author(s):  
Jaqueline Lekscha ◽  
Reik V. Donner
Keyword(s):  
Time Series ◽  
Network Analysis ◽  
Nonlinear Filtering ◽  
Ice Cores ◽  
Second Step ◽  
Different Types ◽  
Output Time ◽  
Input Time ◽  
Past Climate Variability ◽  
Input Time Series

Abstract. Analysing palaeoclimate proxy time series using windowed recurrence network analysis (wRNA) has been shown to provide valuable information on past climate variability. In turn, it has also been found that the robustness of the obtained results differs among proxies from different palaeoclimate archives. To systematically test the suitability of wRNA for studying different types of palaeoclimate proxy time series, we use the framework of forward proxy modelling. For this, we create artificial input time series with different properties and, in a first step, compare the time series properties of the input and the model output time series. In a second step, we compare the areawise significant anomalies detected using wRNA. For proxies from tree and lake archives, we find that significant anomalies present in the input time series are sometimes missed in the input time series after the nonlinear filtering by the corresponding models. For proxies from speleothems, we observe falsely identified significant anomalies that are not present in the input time series. Finally, for proxies from ice cores, the wRNA results show the best correspondence with those for the input data. Our results contribute to improve the interpretation of windowed recurrence network analysis results obtained from real-world palaeoclimate time series.

Regulation of STA1 gene expression by MAT during the life cycle of Saccharomyces cerevisiae

1989 ◽  
Vol 9 (9) ◽  
pp. 3992-3998
Author(s):  
A M Dranginis
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mating Type ◽  
Yeast Cells ◽  
Specific Gene ◽  
Activity Levels ◽  
Sporulation Medium ◽  
Mrna Levels ◽  
Yeast Saccharomyces Cerevisiae ◽  
Type Locus ◽  
Diploid Cells

STA1 encodes a secreted glucoamylase of the yeast Saccharomyces cerevisiae var. diastaticus. Glucoamylase secretion is controlled by the mating type locus MAT; a and alpha haploid yeast cells secrete high levels of the enzyme, but a/alpha diploid cells produce undetectable amounts. It has been suggested that STA1 is regulated by MATa2 (I. Yamashita, Y. Takano, and S. Fukui, J. Bacteriol. 164:769-773, 1985), which is a MAT transcript of previously unknown function. In contrast, this work shows that deletion of the entire MATa2 gene had no effect on STA1 regulation but that deletion of MATa1 sequences completely abolished mating-type control. In all cases, glucoamylase activity levels reflected STA1 mRNA levels. It appears that STA1 is a haploid-specific gene that is regulated by MATa1 and a product of the MAT alpha locus and that this regulation occurs at the level of RNA accumulation. STA1 expression was also shown to be glucose repressible. STA1 mRNA was induced in diploids during sporulation along with SGA, a closely linked gene that encodes an intracellular sporulation-specific glucoamylase of S. cerevisiae. A diploid strain with a MATa1 deletion showed normal induction of STA1 in sporulation medium, but SGA expression was abolished. Therefore, these two homologous and closely linked glucoamylase genes are induced by different mechanisms during sporulation. STA1 induction may be a response to the starvation conditions necessary for sporulation, while SGA induction is governed by the pathway by which MAT regulates sporulation. The strain containing a complete deletion of MATa2 grew, mated, and sporulated normally.

Karakteristik Mazmur Pujian

2021 ◽  
Vol 1 (2) ◽  
pp. 155-164
Author(s):  
Darto Sachius
Keyword(s):  
Research Methods ◽  
Experimental Research ◽  
Qualitative Method ◽  
Second Step ◽  
Hebrew Poetry ◽  
The Third ◽  
Original Meaning ◽  
Language Style ◽  
Different Types

The study is titled characteristics Psalm of Praise. This study will seek and discover the characteristics and principles of psalm praise in the Book of Psalms. To discover the characteristics of the Praise Psalm used qualitative rather than experimental research methods. This qualitative method can also be used for reflective speculators. With four steps: analyzing the passage according to its elements, the second step is to recognize the language style of poetry and stories that are historical, the third reveals the original meaning of Hebrew poetry, the fourth looks for the characteristics of the Hebrew satra of the author's motives and goals. So that preserved by this method can be formulated characteristics from the Psalm of Praise. There are three important things to remember in the Psalm of praise is, first the Psalm of praise begins with an invitation to worship The Lord, The second psalm of praise continues by giving a description of the reasons why God is worthy of praise. Third is the psalm praise usually includes and sometimes ends with a further invitation to praise God therefore the proper title is the characteristics Psalm of Praise so that the awkwardness of distinguishing the interpretation of different types of psalm can be well cleared.

Formation of Part Families for Shared Setups Generation in Sheet Metal Bending

1998 ◽  
Author(s):  
Satyandra K. Gupta
Keyword(s):  
Sheet Metal ◽  
Cost Effective ◽  
Second Step ◽  
Setup Planning ◽  
Planning Techniques ◽  
Individual Part ◽  
Part Families ◽  
Different Types ◽  
Sheet Metal Bending ◽  
Different Parts

Abstract Sheet metal bending press-brakes can be setup to produce more than one type of parts without requiring a setup change. To exploit this flexibility, we need setup planning techniques to generate press-brake setups that can be shared among many different parts. In this paper, we describe an algorithm which partitions a given set of parts into setup compatible part families which can be produced on the same setup. Our algorithm is based on a two step approach. The first step is to identify setup constraints for each individual part. The second step is to form setup-compatible part families based on the compatibility of setup constraints. We expect that by producing many different types of parts on the same setup, we can significantly reduce the required number of setups and enable cost effective small batch manufacturing.

Discursive-Linguistic Devices and Strategies in Spam E-Mail Narratives

2018 ◽  
Vol 10 (3) ◽  
pp. 1-13
Author(s):  
Simone Belli ◽  
Miriam Jiménez Bernal
Keyword(s):  
Gender Stereotypes ◽  
Positioning Theory ◽  
Second Step ◽  
Linguistic Expression ◽  
Linguistic Strategies ◽  
Different Types ◽  
Expression Of Emotions ◽  
And Gender ◽  
E Mail

In this article, we aim at relating emotions and gender stereotypes through the analysis of the narratives contained in spam e-mails. We will present four different types of spam e-mails from a corpus consisting of 450 emails, their length being between four and fifty-two lines of extension. They were received between late 2009 and mid-2013, and written in English, Spanish, Portuguese and French. Our analysis will be carried out in two steps. In the first step, the discursive-linguistic strategies will be described. In the second step, the linguistic expression of emotions will be addressed. We will rely on the Positioning Theory of Rom Harré to identify where authors and readers are positioned in the narratives.

scholarly journals Identification of a member of a DNA-dependent ATPase family that causes interference with silencing.

1997 ◽  
Vol 17 (9) ◽  
pp. 5461-5472 ◽  
Author(s):  
Z Zhang ◽  
A R Buchman
Keyword(s):  
Mating Type ◽  
Tandem Repeats ◽  
Specific Interaction ◽  
Cis Acting ◽  
Cellular Processes ◽  
Protein Dna Interactions ◽  
Mating Type Switching ◽  
Silencer Elements ◽  
Dna Template ◽  
Knockout Mutation

DNA in eukaryotic cells is packed in tandem repeats of nucleosomes or higher-order chromatin structures, which present obstacles to many cellular processes that require protein-DNA interactions, such as transcription, DNA repair, and recombination. To find proteins that are involved in increasing the accessibility of specific DNA regions in yeast, we used a genetic approach that exploited transcriptional silencing normally occurring at HML and HMR loci. The silencing is mediated by cis-acting silencer elements and is thought to require the formation of a special chromatin structure that prevents accessibility to the silenced DNA. A previously uncharacterized gene, termed DIS1, was isolated from a screen for genes that interfere with silencing when overexpressed. DIS1 encodes a protein with conserved motifs that are present in a family of DNA-dependent ATPases, the SWI2/SNF2-like proteins. Overproduction of N-terminal half of DIS1 protein interfered specifically with ectopic silencing used in the screen as well as HMR E silencing. Two-hybrid studies revealed a specific interaction between the N terminus of DIS1 and the C-terminal half of SIR4, a protein essential for silencing. Cells with a dis1 knockout mutation had significantly lower mating-type switching rate. These results suggest that DIS1 may contribute to making the silenced DNA template at HM loci more accessible during the mating-type switching process.

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