scholarly journals Understanding genetic changes underlying the molybdate resistance and the glutathione production inSaccharomyces cerevisiaewine strains using an evolution-based strategy

2016 ◽  
Author(s):  
Francesco Mezzetti ◽  
Justin C. Fay ◽  
Paolo Giudici ◽  
Luciana De Vero

AbstractIn this work we have investigated the genetic changes underlying the high glutathione (GSH) production showed by the evolvedSaccharomyces cerevisiaestrain UMCC 2581, selected in a molybdate-enriched environment after sexual recombination of the parental wine strain UMCC 855. To reach our goal, we first generated strains with the desired phenotype, and then we mapped changes underlying adaptation to molybdate by using a whole-genome sequencing. Moreover, we carried out the RNA-seq that allowed an accurate measurement of gene expression and an effective comparison between the transcriptional profiles of parental and evolved strains, in order to investigate the relationship between genotype and high GSH production phenotype.Among all genes evaluated only two genes,MED2andRIM15both related to oxidative stress response, presented new mutations in the UMCC 2581 strain sequence and were potentially related to the evolved phenotype.Regarding the expression of high GSH production phenotype, it included over-expression of amino acids permeases and precursor biosynthetic enzymes rather than the two GSH metabolic enzymes, whereas GSH production and metabolism, transporter activity, vacuolar detoxification and oxidative stress response enzymes were probably added resulting in the molybdate resistance phenotype. This work provides an example of a combination of an evolution-based strategy to successful obtain yeast strain with desired phenotype and inverse engineering approach to genetic characterize the evolved strain. The obtained genetic information could be useful for further optimization of the evolved strains and for providing an even more rapid approach to identify new strains, with a high GSH production, through a marked-assisted selection strategy.

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 345
Author(s):  
Hidemasa Bono

Data accumulation in public databases has resulted in extensive use of meta-analysis, a statistical analysis that combines the results of multiple studies. Oxidative stress occurs when there is an imbalance between free radical activity and antioxidant activity, which can be studied in insects by transcriptome analysis. This study aimed to apply a meta-analysis approach to evaluate insect oxidative transcriptomes using publicly available data. We collected oxidative stress response-related RNA sequencing (RNA-seq) data for a wide variety of insect species, mainly from public gene expression databases, by manual curation. Only RNA-seq data of Drosophila melanogaster were found and were systematically analyzed using a newly developed RNA-seq analysis workflow for species without a reference genome sequence. The results were evaluated by two metric methods to construct a reference dataset for oxidative stress response studies. Many genes were found to be downregulated under oxidative stress and related to organ system process (GO:0003008) and adherens junction organization (GO:0034332) by gene enrichment analysis. A cross-species analysis was also performed. RNA-seq data of Caenorhabditis elegans were curated, since no RNA-seq data of insect species are currently available in public databases. This method, including the workflow developed, represents a powerful tool for deciphering conserved networks in oxidative stress response.


2021 ◽  
Author(s):  
Hidemasa Bono

AbstractData accumulation in public databases has resulted in extensive use of meta-analysis, a statistical analysis that combines the results of multiple studies. Oxidative stress occurs when there is an imbalance between free radical activity and antioxidant activity, which can be studied in insects by transcriptome analysis. This study aimed to apply a meta-analysis approach to evaluate insect oxidative transcriptomes using publicly available data. We collected oxidative stress response-related RNA sequencing (RNA-seq) data for a wide variety of insect species, mainly from public gene expression databases, by manual curation. Only RNA-seq data of Drosophila melanogaster were found and were systematically analyzed using a newly developed RNA-seq analysis workflow for species without a reference genome sequence. The results were evaluated by two metric methods to construct a reference dataset for oxidative stress response studies. Many genes were found to be downregulated under oxidative stress and related to organ system process (GO:0003008) and adherens junction organization (GO:0034332) by gene enrichment analysis. A cross-species analysis was also performed. RNA-seq data of Caenorhabditis elegans were curated, since no RNA-seq data of insect species are currently available in public databases. This method, including the workflow developed, represents a powerful tool for deciphering conserved networks in oxidative stress response.


2018 ◽  
Vol 1 (4) ◽  
pp. e201800080 ◽  
Author(s):  
Konrad U Förstner ◽  
Carina M Reuscher ◽  
Kerstin Haberzettl ◽  
Lennart Weber ◽  
Gabriele Klug

Bacteria adapt to changing environmental conditions by rapid changes in their transcriptome. This is achieved not only by adjusting rates of transcription but also by processing and degradation of RNAs. We applied TIER-Seq (transiently inactivating an endoribonuclease followed by RNA-Seq) for the transcriptome-wide identification of RNase E cleavage sites and of 5′ RNA ends, which are enriched when RNase E activity is reduced inRhodobacter sphaeroides. These results reveal the importance of RNase E for the maturation and turnover of mRNAs, rRNAs, and sRNAs in this guanine-cytosine-rich α-proteobacterium, some of the latter have well-described functions in the oxidative stress response. In agreement with this, a role of RNase E in the oxidative stress response is demonstrated. A remarkably strong phenotype of a mutant with reduced RNase E activity was observed regarding the formation of photosynthetic complexes and phototrophic growth, whereas there was no effect on chemotrophic growth.


2019 ◽  
Author(s):  
Yuan Fang ◽  
Haoye Wang ◽  
Xia Liu ◽  
Yuchun Rao ◽  
Xin Dedong ◽  
...  

AbstractXanthomonas oryzae pv. oryzicola (Xoc) is the causal agent of bacterial leaf streak in rice. It is known as one of the most severe seed-born bacterial diseases of rice, molecular role governing its interaction with rice is mostly still unexplored. To successfully invade rice, the survival of the Xoc is mandotarory following generating a specific response to its host’s oxidative stress condition. However, the response network of Xoc is still unknown. To address this question, we performed a time-series RNA-seq analysis on the Xoc response to H2O2. Overall, our RNA sequence analysis of Xoc revealed a significant global gene expression profile when it exposed to H2O2. The response of key genes was also noted that soxR triggers and regulates the Xoc oxidative stress response in the early stage of infection, gene expression kinetics among the time-series samples, namely for TonB-dependent receptors and the suf and pst operons. Moreover, a hypothetical protein (XOC_2868) showed significant differential expression following its mutant endorsed RNA-seq findings by clearly displaying a greater H2O2 sensitivity and decreased pathogenicity than the wild-type. Gene location and phylogeny analysis strongly suggests that this gene may have been horizontally transferred from a Burkholderiaceae ancestor. Our study not only provides a first glance of Xoc’s global response against oxidative stress, but it also reveals the impact of horizontal gene transfer in the evolutionary history of Xoc.


2021 ◽  
Vol 9 (6) ◽  
pp. 1116
Author(s):  
Laurens Maertens ◽  
Pauline Cherry ◽  
Françoise Tilquin ◽  
Rob Van Houdt ◽  
Jean-Yves Matroule

Bacteria encounter elevated copper (Cu) concentrations in multiple environments, varying from mining wastes to antimicrobial applications of copper. As the role of the environment in the bacterial response to Cu ion exposure remains elusive, we used a tagRNA-seq approach to elucidate the disparate responses of two morphotypes of Caulobacter crescentus NA1000 to moderate Cu stress in a complex rich (PYE) medium and a defined poor (M2G) medium. The transcriptome was more responsive in M2G, where we observed an extensive oxidative stress response and reconfiguration of the proteome, as well as the induction of metal resistance clusters. In PYE, little evidence was found for an oxidative stress response, but several transport systems were differentially expressed, and an increased need for histidine was apparent. These results show that the Cu stress response is strongly dependent on the cellular environment. In addition, induction of the extracytoplasmic function sigma factor SigF and its regulon was shared by the Cu stress responses in both media, and its central role was confirmed by the phenotypic screening of a sigF::Tn5 mutant. In both media, stalked cells were more responsive to Cu stress than swarmer cells, and a stronger basal expression of several cell protection systems was noted, indicating that the swarmer cell is inherently more Cu resistant. Our approach also allowed for detecting several new transcription start sites, putatively indicating small regulatory RNAs, and additional levels of Cu-responsive regulation.


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