scholarly journals Social wasps are aSaccharomycesmating nest

2016 ◽  
Vol 113 (8) ◽  
pp. 2247-2251 ◽  
Author(s):  
Irene Stefanini ◽  
Leonardo Dapporto ◽  
Luisa Berná ◽  
Mario Polsinelli ◽  
Stefano Turillazzi ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Interspecific Hybridization ◽  
Environmental Conditions ◽  
Reproductive Ecology ◽  
Social Wasps ◽  
Polistes Dominula ◽  
Yeast Ecology ◽  
In The Wild ◽  
Prion Transmission ◽  
Insect Gut

The reproductive ecology ofSaccharomyces cerevisiaeis still largely unknown. Recent evidence of interspecific hybridization, high levels of strain heterozygosity, and prion transmission suggest that outbreeding occurs frequently in yeasts. Nevertheless, the place where yeasts mate and recombine in the wild has not been identified. We found that the intestine of social wasps hosts highly outbredS. cerevisiaestrains as well as a rareS. cerevisiae×S. paradoxushybrid. We show that the intestine ofPolistes dominulasocial wasps favors the mating ofS. cerevisiaestrains among themselves and withS. paradoxuscells by providing a succession of environmental conditions prompting cell sporulation and spores germination. In addition, we prove that heterospecific mating is the only option for EuropeanS. paradoxusstrains to survive in the gut. Taken together, these findings unveil the best hidden secret of yeast ecology, introducing the insect gut as an environmental alcove in which crosses occur, maintaining and generating the diversity of the ascomycetes.

scholarly journals Effects of Mutations of RAD50, RAD51, RAD52, and Related Genes on Illegitimate Recombination in Saccharomyces cerevisiae

Genetics ◽  
1996 ◽  
Vol 142 (2) ◽  
pp. 383-391 ◽  
Author(s):  
Yasumasa Tsukamoto ◽  
Jun-ichi Kato ◽  
Hideo Ikeda
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Quantitative Analysis ◽  
Structural Analysis ◽  
Recombination Rate ◽  
Type Strain ◽  
Negative Selection ◽  
Wild Type Strain ◽  
Illegitimate Recombination ◽  
Wild Type ◽  
In The Wild

Abstract To examine the mechanism of illegitimate recombination in Saccharomyces cerevisiae, we have developed a plasmid system for quantitative analysis of deletion formation. A can1 cyh2 cell carrying two negative selection markers, the CAN1 and CYH2 genes, on a YCp plasmid is sensitive to canavanine and cycloheximide, but the cell becomes resistant to both drugs when the plasmid has a deletion over the CAN1 and CYH2 genes. Structural analysis of the recombinant plasmids obtained from the resistant cells showed that the plasmids had deletions at various sites of the CAN1-CYH2 region and there were only short regions of homology (1-5 bp) at the recombination junctions. The results indicated that the deletion detected in this system were formed by illegitimate recombination. Study on the effect of several rad mutations showed that the recombination rate was reduced by 30-, 10-, 10-, and 10-fold in the rad52, rad50, mre11, and xrs2 mutants, respectively, while in the rud51, 54, 55, and 57 mutants, the rate was comparable to that in the wild-type strain. The rad52 mutation did not affect length of homology at junction sites of illegitimate recombination.

scholarly journals Mitochondrial DNA duplication, recombination, and introgression during interspecific hybridization

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Silvia Bágeľová Poláková ◽  
Žaneta Lichtner ◽  
Tomáš Szemes ◽  
Martina Smolejová ◽  
Pavol Sulo
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mitochondrial Dna ◽  
Interspecific Hybridization ◽  
Mobile Elements ◽  
Variable Length ◽  
Mitochondrial Genomes ◽  
Free Standing ◽  
Saccharomyces Paradoxus ◽  
Mtdna Recombination

AbstractmtDNA recombination events in yeasts are known, but altered mitochondrial genomes were not completed. Therefore, we analyzed recombined mtDNAs in six Saccharomyces cerevisiae × Saccharomyces paradoxus hybrids in detail. Assembled molecules contain mostly segments with variable length introgressed to other mtDNA. All recombination sites are in the vicinity of the mobile elements, introns in cox1, cob genes and free standing ORF1, ORF4. The transplaced regions involve co-converted proximal exon regions. Thus, these selfish elements are beneficial to the host if the mother molecule is challenged with another molecule for transmission to the progeny. They trigger mtDNA recombination ensuring the transfer of adjacent regions, into the progeny of recombinant molecules. The recombination of the large segments may result in mitotically stable duplication of several genes.

scholarly journals Influences of Histone Stoichiometry on the Target Site Preference of Retrotransposons Ty1 and Ty2 in Saccharomyces cerevisiae

Genetics ◽  
1996 ◽  
Vol 142 (3) ◽  
pp. 761-776 ◽  
Author(s):  
Lori A Rinckel ◽  
David J Garfinkel
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Promoter Region ◽  
Target Site ◽  
Site Preference ◽  
Wild Type ◽  
Histone Proteins ◽  
Protein Levels ◽  
In The Wild ◽  
Type Strains ◽  
Orientation Bias

Abstract In Saccharomyces cerevisiae, the target site specificity of the retrotransposon Ty1 appears to involve the Ty integration complex recognizing chromatin structures. To determine whether changes in chromatin structure affect Ty1 and Ty2 target site preference, we analyzed Ty transposition at the CAN1 locus in mutants containing altered levels of histone proteins. A Δhta1-htb1 mutant with decreased levels of H2A and H2B histone proteins showed a pattern of Ty1 and Ty2 insertions at CAN1 that was significantly different from that of both the wild-type and a Δhta2-htb2 mutant, which does not have altered histone protein levels. Altered levels of H2A and H2B proteins disrupted a dramatic orientation bias in the CAN1 promoter region. In the wild-type strains, few Ty1 and Ty2 insertions in the promoter region were oriented opposite to the direction of CAN1 transcription. In the Δhta1-htb1 background, however, numerous Ty1 and Ty2 insertions were in the opposite orientation clustered within the TATA region. This altered insertion pattern does not appear to be due to a bias caused by selecting canavanine resistant isolates in the different HTA1-HTB1 backgrounds. Our results suggest that reduced levels of histone proteins alter Ty target site preference and disrupt an asymmetric Ty insertion pattern.

Suppressors of Saccharomyces cerevisiae his3 promoter mutations lacking the upstream element

1985 ◽  
Vol 5 (8) ◽  
pp. 1901-1909
Author(s):  
M A Oettinger ◽  
K Struhl
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcriptional Activation ◽  
Tata Box ◽  
Micrococcal Nuclease ◽  
Promoter Element ◽  
Wild Type ◽  
Upstream Promoter ◽  
In The Wild ◽  
Promoter Mutations ◽  
His3 Gene

Transcription of the Saccharomyces cerevisiae his3 gene requires an upstream promoter element and a TATA element. A strain containing his3-delta 13, an allele which deletes the upstream promoter element but contains the TATA box and intact structural gene, fails to express the gene and consequently is unable to grow in medium lacking histidine. In this paper we characterize His+ revertants of his3-delta 13 which are due to unlinked suppressor mutations. Recessive suppressors in three different ope genes allow his3-delta 13 to be expressed at wild-type levels. In all cases, the suppression is due to increased his3 transcription. However, unlike the wild-type his3 gene, whose transcripts are initiated about equally from two different sites (+1 and +12), transcription due to the ope mutations is initiated only from the +12 site, ope-mediated transcription is regulated in a novel manner; it is observed in minimal medium, but not in rich broth. Although ope mutations restore wild-type levels of transcription, his3 chromatin structure, as assayed by micrococcal nuclease sensitivity of the TATA box, resembles that found in the his3-delta 13 parent rather than in the wild-type strain. This provides further evidence that TATA box sensitivity is not correlated with transcriptional activation. ope mutations are pleiotropic in that cells have a crunchy colony morphology and lyse at 37 degrees C in conditions of normal osmolarity. ope mutations are allele specific because they fail to suppress five other his3 promoter mutations. We discuss implications concerning upstream promoter elements and propose some models for ope suppression.

scholarly journals Disruption of the RAD52 gene alters the spectrum of spontaneous SUP4-o mutations in Saccharomyces cerevisiae.

Genetics ◽  
1989 ◽  
Vol 122 (3) ◽  
pp. 535-542 ◽  
Author(s):  
B A Kunz ◽  
M G Peters ◽  
S E Kohalmi ◽  
J D Armstrong ◽  
M Glattke ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Base Pair ◽  
Type Strain ◽  
Wild Type Strain ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Mutator Phenotype ◽  
In The Wild ◽  
Single Base Pair ◽  
Almost All

Abstract Defects in the RAD52 gene of the yeast Saccharomyces cerevisiae confer a mutator phenotype. To characterize this effect in detail, a collection of 238 spontaneous SUP4-o mutations arising in a strain having a disrupted RAD52 gene was analyzed by DNA sequencing. The resulting mutational spectrum was compared to that derived from an examination of 222 spontaneous mutations selected in a nearisogenic wild-type (RAD52) strain. This comparison revealed that the mutator phenotype was associated with an increase in the frequency of base-pair substitutions. All possible types of substitution were detected but there was a reduction in the relative fraction of A.T----G.C transitions and an increase in the proportion of G.C----C.G transversions. These changes were sufficient to cause a twofold greater preference for substitutions at G.C sites in the rad52 strain despite a decrease in the fraction of G.C----T.A transversions. There were also considerable differences between the distributions of substitutions within the SUP4-o gene. Base-pair changes occurred at fewer sites in the rad52 strain but the mutated sites included several that were not detected in the RAD52 background. Only two of the four sites that were mutated most frequently in the rad52 strain were also prominent in the wild-type strain and mutation frequencies at almost all sites common to both strains were greater for the rad52 derivative. Although single base-pair deletions occurred in the two strains with similar frequencies, several classes of mutation that were recovered in the wild-type background including multiple base-pair deletions, insertions of the yeast transposable element Ty, and more complex changes, were not detected in the rad52 strain.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals The sources of sex differences in aging in annual fishes

2020 ◽  
Author(s):  
Martin Reichard ◽  
Radim Blažek ◽  
Jakub Žák ◽  
Petr Kačer ◽  
Oldřich Tomášek ◽  
...  
Keyword(s):  
Sex Differences ◽  
Social Environment ◽  
Social Factors ◽  
Environmental Conditions ◽  
Natural Populations ◽  
Experimental Results ◽  
Survival Difference ◽  
Captive Populations ◽  
Baseline Mortality ◽  
In The Wild

AbstractSex differences in lifespan and aging are widespread among animals, with males usually the shorter-lived sex. Despite extensive research interest, it is unclear how lifespan differences between the sexes are modulated by genetic, environmental and social factors. We combined comparative data from natural populations of annual killifishes with experimental results on replicated captive populations, showing that females consistently outlived males in the wild. This sex-specific survival difference persisted in social environment only in two most aggressive species, and ceased completely when social and physical contacts were prevented. Demographically, neither an earlier start nor faster rate of aging accounted for shorter male lifespans, but increased baseline mortality and the lack of mortality deceleration in the oldest age shortened male lifespan. The sexes did not differ in any measure of functional aging we recorded. Overall, we demonstrate that sex differences in lifespan and aging may be ameliorated by modulating social and environmental conditions.

scholarly journals A willow drawing from 1786: the earliest depiction of intraspecific trait variation in plants?

2020 ◽  
Author(s):  
Ulrich E Stegmann
Keyword(s):  
Environmental Conditions ◽  
18Th Century ◽  
Elevation Gradient ◽  
Experimental Studies ◽  
Fourth Century ◽  
Trait Variation ◽  
Intraspecific Trait Variation ◽  
Bavarian Alps ◽  
In The Wild ◽  
Unidentified Species

Abstract Background and Aims The study of intraspecific trait variation (ITV) in plants has a long history, dating back to the fourth century BC. Its existence was widely acknowledged by the end of the 18th century, although systematic and experimental studies commenced only a century later. However, the historiography of ITV has many gaps, especially with regard to early observations and visual documents. This note identifies an early depiction of plant ITV. Methods The botanical works of Johann Wolfgang von Goethe (1749–1832), a German writer and naturalist, were subjected to close reading. This included all publications and unpublished sources related to botany between 1785 and 1832 (e.g. notes, drafts, diaries, letters, drawings). This material is accessible in the multi-volume historical-critical edition of Goethe’s studies in natural science (Leopoldina-Ausgabe). Key Results A diary entry from 9 September 1786 described changes in leaf morphology along an elevation gradient in the Bavarian Alps. The leaves of an unidentified species of willow (Spix sp.) and gentian (Gentiana sp.) were said to become narrower with increasing elevation; leaves also stood further apart on twigs, and the latter became thinner. A crude drawing of two willow twigs illustrated the differences. Goethe conjectured that the differences were due to environmental conditions. Conclusions Goethe’s notes were anecdotal, and it is unclear whether the observed plant individuals actually belonged to the same species. Nevertheless, the notes represent an early and clear articulation of the hypothesis that changes in environmental conditions can cause ITV in a natural plant population. The drawing may be the earliest visual record of environmentally caused plant ITV in the wild.

scholarly journals Suppressors of Saccharomyces cerevisiae his3 promoter mutations lacking the upstream element.

1985 ◽  
Vol 5 (8) ◽  
pp. 1901-1909 ◽  
Author(s):  
M A Oettinger ◽  
K Struhl
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcriptional Activation ◽  
Tata Box ◽  
Micrococcal Nuclease ◽  
Promoter Element ◽  
Wild Type ◽  
Upstream Promoter ◽  
In The Wild ◽  
Promoter Mutations ◽  
His3 Gene

Transcription of the Saccharomyces cerevisiae his3 gene requires an upstream promoter element and a TATA element. A strain containing his3-delta 13, an allele which deletes the upstream promoter element but contains the TATA box and intact structural gene, fails to express the gene and consequently is unable to grow in medium lacking histidine. In this paper we characterize His+ revertants of his3-delta 13 which are due to unlinked suppressor mutations. Recessive suppressors in three different ope genes allow his3-delta 13 to be expressed at wild-type levels. In all cases, the suppression is due to increased his3 transcription. However, unlike the wild-type his3 gene, whose transcripts are initiated about equally from two different sites (+1 and +12), transcription due to the ope mutations is initiated only from the +12 site, ope-mediated transcription is regulated in a novel manner; it is observed in minimal medium, but not in rich broth. Although ope mutations restore wild-type levels of transcription, his3 chromatin structure, as assayed by micrococcal nuclease sensitivity of the TATA box, resembles that found in the his3-delta 13 parent rather than in the wild-type strain. This provides further evidence that TATA box sensitivity is not correlated with transcriptional activation. ope mutations are pleiotropic in that cells have a crunchy colony morphology and lyse at 37 degrees C in conditions of normal osmolarity. ope mutations are allele specific because they fail to suppress five other his3 promoter mutations. We discuss implications concerning upstream promoter elements and propose some models for ope suppression.

scholarly journals SPO71 Encodes a Developmental Stage-Specific Partner for Vps13 in Saccharomyces cerevisiae

2013 ◽  
Vol 12 (11) ◽  
pp. 1530-1537 ◽  
Author(s):  
Jae-Sook Park ◽  
Yuuya Okumura ◽  
Hiroyuki Tachikawa ◽  
Aaron M. Neiman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
De Novo ◽  
Ectopic Expression ◽  
Membrane Vesicles ◽  
Specific Gene ◽  
Wild Type ◽  
Protein Mutation ◽  
Prospore Membrane ◽  
In The Wild ◽  
Membrane Morphogenesis

ABSTRACT The creation of haploid gametes in yeast, termed spores, requires the de novo formation of membranes within the cytoplasm. These membranes, called prospore membranes, enclose the daughter nuclei generated by meiosis. Proper growth and closure of prospore membranes require the highly conserved Vps13 protein. Mutation of SPO71 , a meiosis-specific gene first identified as defective in spore formation, was found to display defects in membrane morphogenesis very similar to those seen in vps13 Δ cells. Specifically, prospore membranes are smaller than in the wild type, they fail to close, and membrane vesicles are present within the prospore membrane lumen. As in vps13 Δ cells, the levels of phophatidylinositol-4-phosphate are reduced in the prospore membranes of spo71 Δ cells. SPO71 is required for the translocation of Vps13 from the endosome to the prospore membrane, and ectopic expression of SPO71 in vegetative cells results in mislocalization of Vps13. Finally, the two proteins can be coprecipitated from sporulating cells. We propose that Spo71 is a sporulation-specific partner for Vps13 and that they act in concert to regulate prospore membrane morphogenesis.

scholarly journals Azo Reductase Activity of Intact Saccharomyces cerevisiae Cells Is Dependent on the Fre1p Component of Plasma Membrane Ferric Reductase

2005 ◽  
Vol 71 (7) ◽  
pp. 3882-3888 ◽  
Author(s):  
Patrícia A. Ramalho ◽  
Sandra Paiva ◽  
A. Cavaco-Paulo ◽  
Margarida Casal ◽  
M. Helena Cardoso ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Plasma Membrane ◽  
Azo Dyes ◽  
Reductase Activity ◽  
Redox System ◽  
Ferric Reductase ◽  
Bacterial Reduction ◽  
Azo Reductase ◽  
In The Wild ◽  
Ascomycete Yeast

ABSTRACT Unspecific bacterial reduction of azo dyes is a process widely studied in correlation with the biological treatment of colored wastewaters, but the enzyme system associated with this bacterial capability has never been positively identified. Several ascomycete yeast strains display similar decolorizing behaviors. The yeast-mediated process requires an alternative carbon and energy source and is independent of previous exposure to the dyes. When substrate dyes are polar, their reduction is extracellular, strongly suggesting the involvement of an externally directed plasma membrane redox system. The present work demonstrates that, in Saccharomyces cerevisiae, the ferric reductase system participates in the extracellular reduction of azo dyes. The S. cerevisiae Δfre1 and Δfre1 Δfre2 mutant strains, but not the Δfre2 strain, showed much-reduced decolorizing capabilities. The FRE1 gene complemented the phenotype of S. cerevisiae Δfre1 cells, restoring the ability to grow in medium without externally added iron and to decolorize the dye, following a pattern similar to the one observed in the wild-type strain. These results suggest that under the conditions tested, Fre1p is a major component of the azo reductase activity.

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