scholarly journals Loss of heterozygosity results in rapid but variable genome homogenization across genetic backgrounds in yeast

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Abhishek Dutta ◽  
Fabien Dutreux ◽  
Joseph Schacherer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genetic Diversity ◽  
Genome Evolution ◽  
Loss Of Heterozygosity ◽  
Genome Sequencing ◽  
Mutation Rate ◽  
Genetic Variants ◽  
Vegetative Growth ◽  
Essential Role ◽  
Large Set

The dynamics and diversity of the appearance of genetic variants play an essential role in the evolution of the genome and the shaping of biodiversity. Recent population-wide genome sequencing surveys have highlighted the importance of loss-of-heterozygosity (LOH) events and have shown that they are a neglected part of the genetic diversity landscape. To assess the extent, variability, and spectrum, we explored the accumulation of LOH events in 169 heterozygous diploid Saccharomyces cerevisiae mutation accumulation lines across nine genetic backgrounds. In total, we detected a large set of 22,828 LOH events across distinct genetic backgrounds with a heterozygous level ranging from 0.1 to 1%. LOH events are very frequent with a rate consistently much higher than the mutation rate, showing their importance for genome evolution. We observed that the interstitial LOH (I-LOH) events, resulting in internal short LOH tracts, were much frequent (n = 19,660) than the terminal LOH (T-LOH) events, i.e., tracts extending to the end of the chromosome (n = 3,168). However, the spectrum, the rate, and the fraction of the genome under LOH vary across genetic backgrounds. Interestingly, we observed that the more the ancestors were heterozygous, the more they accumulated T-LOH events. In addition, frequent short I-LOH tracts are a signature of the lines derived from hybrids with low spore fertility. Finally, we found lines showing almost complete homozygotization during vegetative progression. Overall, our results highlight that the variable dynamics of the LOH accumulation across distinct genetic backgrounds might lead to rapid differential genome evolution during vegetative growth.

scholarly journals Saccharomyces cerevisiaestrain YH166: a novel wild yeast for the production of tropical fruit sensory attributes in fermented beverages

2017 ◽  
Author(s):  
Kara Osburn ◽  
Robert Caputo ◽  
Justin Miller ◽  
Matthew L. Bochman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genetic Diversity ◽  
Genome Sequencing ◽  
Sensory Profile ◽  
Whole Genome ◽  
Brewing Industry ◽  
Tropical Fruit ◽  
Fermented Beverages ◽  
Wild Yeast ◽  
Phenotypic Variations

AbstractAll ales are fermented by various strains ofSaccharomyces cerevisiae.However, recent whole-genome sequencing has revealed that most commercially available ale yeasts are highly related and represent a small fraction of the genetic diversity found amongS. cerevisiaeisolates as a whole. This lack of diversity limits the phenotypic variations between these strains, which translates into a limited number of sensory compounds created during fermentation. Here, we characterized a collection of wildS. cerevisiae,S. kudriavzevii, andS. paradoxusstrains for their ability to ferment wort into beer. Although many isolates performed well,S. cerevisiaestrain YH166 was the most promising, displaying excellent fermentation kinetics and attenuation, as well as a tropical fruit sensory profile. Use of this strain in multiple styles of beer suggested that it is broadly applicable in the brewing industry. Thus, YH166 is a novel ale strain that can be used to lend fruity esters to beer and should pair well with citrusy hops in hop-forward ales.

Crossover promotion and prevention

2006 ◽  
Vol 34 (4) ◽  
pp. 537-541 ◽  
Author(s):  
A. Lorenz ◽  
M.C. Whitby
Keyword(s):  
Genetic Diversity ◽  
Homologous Recombination ◽  
Loss Of Heterozygosity ◽  
Chromosome Segregation ◽  
Vegetative Growth ◽  
Double Strand Breaks ◽  
Chromosome Rearrangements ◽  
Crossing Over ◽  
Vegetative Cells ◽  
Strand Breaks

Homologous recombination is an important mechanism for the repair of double-strand breaks in DNA. One possible outcome of such repair is the reciprocal exchange or crossing over of DNA between chromosomes. Crossovers are beneficial during meiosis because, as well as generating genetic diversity, they promote proper chromosome segregation through the establishment of chiasmata. However, crossing over in vegetative cells can potentially result in loss of heterozygosity and chromosome rearrangements, which can be deleterious. Consequently, cells have evolved mechanisms to limit crossing over during vegetative growth while promoting it during meiosis. Here, we provide a brief review of how some of these mechanisms are thought to work.

scholarly journals Whole-genome sequencing from the New Zealand Saccharomyces cerevisiae population reveals the genomic impacts of novel microbial range expansion

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Peter Higgins ◽  
Cooper A Grace ◽  
Soon A Lee ◽  
Matthew R Goddard
Keyword(s):  
Saccharomyces Cerevisiae ◽  
New Zealand ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Range Expansion ◽  
Copy Number ◽  
Small Scale ◽  
Whole Genome ◽  
Copy Number Changes ◽  
The Impact

Abstract Saccharomyces cerevisiae is extensively utilized for commercial fermentation, and is also an important biological model; however, its ecology has only recently begun to be understood. Through the use of whole-genome sequencing, the species has been characterized into a number of distinct subpopulations, defined by geographical ranges and industrial uses. Here, the whole-genome sequences of 104 New Zealand (NZ) S. cerevisiae strains, including 52 novel genomes, are analyzed alongside 450 published sequences derived from various global locations. The impact of S. cerevisiae novel range expansion into NZ was investigated and these analyses reveal the positioning of NZ strains as a subgroup to the predominantly European/wine clade. A number of genomic differences with the European group correlate with range expansion into NZ, including 18 highly enriched single-nucleotide polymorphism (SNPs) and novel Ty1/2 insertions. While it is not possible to categorically determine if any genetic differences are due to stochastic process or the operations of natural selection, we suggest that the observation of NZ-specific copy number increases of four sugar transporter genes in the HXT family may reasonably represent an adaptation in the NZ S. cerevisiae subpopulation, and this correlates with the observations of copy number changes during adaptation in small-scale experimental evolution studies.

scholarly journals Whole genome sequencing reveals high differentiation, low levels of genetic diversity and short runs of homozygosity among Swedish wels catfish

Heredity ◽  
2021 ◽  
Author(s):  
Axel Jensen ◽  
Mette Lillie ◽  
Kristofer Bergström ◽  
Per Larsson ◽  
Jacob Höglund
Keyword(s):  
Genetic Diversity ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Whole Genome Sequencing Data ◽  
Peripheral Populations ◽  
Whole Genome ◽  
Runs Of Homozygosity ◽  
Sequencing Data ◽  
Isolated Populations ◽  
Native Populations

AbstractThe use of genetic markers in the context of conservation is largely being outcompeted by whole-genome data. Comparative studies between the two are sparse, and the knowledge about potential effects of this methodology shift is limited. Here, we used whole-genome sequencing data to assess the genetic status of peripheral populations of the wels catfish (Silurus glanis), and discuss the results in light of a recent microsatellite study of the same populations. The Swedish populations of the wels catfish have suffered from severe declines during the last centuries and persists in only a few isolated water systems. Fragmented populations generally are at greater risk of extinction, for example due to loss of genetic diversity, and may thus require conservation actions. We sequenced individuals from the three remaining native populations (Båven, Emån, and Möckeln) and one reintroduced population of admixed origin (Helge å), and found that genetic diversity was highest in Emån but low overall, with strong differentiation among the populations. No signature of recent inbreeding was found, but a considerable number of short runs of homozygosity were present in all populations, likely linked to historically small population sizes and bottleneck events. Genetic substructure within any of the native populations was at best weak. Individuals from the admixed population Helge å shared most genetic ancestry with the Båven population (72%). Our results are largely in agreement with the microsatellite study, and stresses the need to protect these isolated populations at the northern edge of the distribution of the species.

Genetic diversity of FLO1 and FLO5 genes in wine flocculent Saccharomyces cerevisiae strains

2014 ◽  
Vol 191 ◽  
pp. 45-52 ◽  
Author(s):  
Rosanna Tofalo ◽  
Giorgia Perpetuini ◽  
Paola Di Gianvito ◽  
Maria Schirone ◽  
Aldo Corsetti ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genetic Diversity

scholarly journals Loss of Heterozygosity and Base Mutation Rates Vary Among Saccharomyces cerevisiae Hybrid Strains

2020 ◽  
Vol 10 (9) ◽  
pp. 3309-3319 ◽  
Author(s):  
Ajith V Pankajam ◽  
Suman Dash ◽  
Asma Saifudeen ◽  
Abhishek Dutta ◽  
Koodali T Nishant
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Loss Of Heterozygosity ◽  
Mutation Rates ◽  
Single Nucleotide ◽  
Single Nucleotide Mutation ◽  
Genome Wide ◽  
Nucleotide Mutation ◽  
Specific Variation ◽  
Chromosomal Changes ◽  
Species Specific

Abstract A growing body of evidence suggests that mutation rates exhibit intra-species specific variation. We estimated genome-wide loss of heterozygosity (LOH), gross chromosomal changes, and single nucleotide mutation rates to determine intra-species specific differences in hybrid and homozygous strains of Saccharomyces cerevisiae. The mutation accumulation lines of the S. cerevisiae hybrid backgrounds - S288c/YJM789 (S/Y) and S288c/RM11-1a (S/R) were analyzed along with the homozygous diploids RM11, S288c, and YJM145. LOH was extensive in both S/Y and S/R hybrid backgrounds. The S/Y background also showed longer LOH tracts, gross chromosomal changes, and aneuploidy. Short copy number aberrations were observed in the S/R background. LOH data from the S/Y and S/R hybrids were used to construct a LOH map for S288c to identify hotspots. Further, we observe up to a sixfold difference in single nucleotide mutation rates among the S. cerevisiae S/Y and S/R genetic backgrounds. Our results demonstrate LOH is common during mitotic divisions in S. cerevisiae hybrids and also highlight genome-wide differences in LOH patterns and rates of single nucleotide mutations between commonly used S. cerevisiae hybrid genetic backgrounds.

scholarly journals Molecular Characterization of Pathogenicity Locus (PaLoc) and tcdC Genetic Diversity Among tcdA+B+ Clostridioides Difficile Clinical Isolates in Tehran, Iran

2020 ◽  
Author(s):  
Mansoor Kodori ◽  
Zohreh Ghalavand ◽  
Abbas Yadegar ◽  
Gita Eslami ◽  
Masoumeh Azimirad ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Molecular Characterization ◽  
Disease Severity ◽  
Genetic Variants ◽  
Rflp Analysis ◽  
Clostridioides Difficile ◽  
Pcr Rflp ◽  
The Common ◽  
Healthcare Associated

Abstract Background: Clostridioides difficile is the main cause of healthcare-associated diarrhea worldwide. It is proposed that certain C. difficile toxinotypes with distinct pathogenicity locus (PaLoc) variants are associated with disease severity and outcomes. Additionally, few studies have described the common C. difficile toxinotypes, and also little is known about the tcdC variants in Iranian isolates. We characterized the toxinotypes and the tcdC genotypes from a collection of Iranian clinical C. difficile tcdA+B+ isolates with known ribotypes (RTs).Methods: Fifty C. difficile isolates with known RTs and carrying the tcdA and tcdB toxin genes were analyzed. Toxinotyping was carried out based on a PCR-RFLP analysis of a 19.6 kb region encompassing the PaLoc. Genetic diversity of the tcdC gene was determined by the sequencing of the gene.Results: Of the 50 C. difficile isolates investigated, five distinct toxinotypes were recognized. Toxinotypes 0 (33/50, 66%) and V (11/50, 22%) were the most frequently found. C. difficile isolates of the toxinotype 0 mostly belonged to RT 001 (12/33, 36.4%), whereas toxinotype V consisted of RT 126 (9/11, 81.8%). The tcdC sequencing showed six variants (35/50, 70%); tcdC-sc3 (24%), tcdC-A (22%), tcdC-sc9 (18%), tcdC-B (2%), tcdC-sc14 (2%), and tcdC-sc15 (2%). The remaining isolates were wild-types (15/50, 30%) in the tcdC gene.Conclusions: The present study demonstrates that the majority of clinical tcdA+B+ isolates of C. difficile frequently harbor tcdC genetic variants. We also found that the RT 001/ toxinotype 0 and the RT 126/ toxinotype V are the most common types among Iranian isolates. Further studies are needed to investigate the putative association of various tcdC genotypes with CDI severity and its recurrence.

Sign in / Sign up

Export Citation Format

Share Document