scholarly journals Towards a Systems Approach in the Genetic Analysis of Archaea: Accelerating Mutant Construction and Phenotypic Analysis inHaloferax volcanii

Archaea ◽  
2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
Ian K. Blaby ◽  
Gabriela Phillips ◽  
Crysten E. Blaby-Haas ◽  
Kevin S. Gulig ◽  
Basma El Yacoubi ◽  
...  

With the availability of a genome sequence and increasingly sophisticated genetic tools,Haloferax volcaniiis becoming a model for both Archaea and halophiles. In order forH. volcaniito reach a status equivalent toEscherichia coli, Bacillus subtilis, orSaccharomyces cerevisiae, a gene knockout collection needs to be constructed in order to identify the archaeal essential gene set and enable systematic phenotype screens. A streamlined gene-deletion protocol adapted for potential automation was implemented and used to generate 22H. volcaniideletion strains and identify several potentially essential genes. These gene deletion mutants, generated in this and previous studies, were then analyzed in a high-throughput fashion to measure growth rates in different media and temperature conditions. We conclude that these high-throughput methods are suitable for a rapid investigation of anH. volcaniimutant library and suggest that they should form the basis of a larger genome-wide experiment.

2018 ◽  
Author(s):  
Xiaobo Li ◽  
Weronika Patena ◽  
Friedrich Fauser ◽  
Robert E. Jinkerson ◽  
Shai Saroussi ◽  
...  

2018 ◽  
Author(s):  
Timothy J. de Wet ◽  
Irene Gobe ◽  
Musa M. Mhlanga ◽  
Digby F. Warner

AbstractHigh-throughput essentiality screens have enabled genome-wide assessments of the genetic requirements for growth and survival of a variety of bacteria in different experimental models. The reliance in many of these studies on transposon (Tn)-based gene inactivation has, however, limited the ability to probe essential gene function or design targeted screens. We interrogated the potential of targeted, large-scale, pooled CRISPR interference (CRISPRi)-based screens to extend conventional Tn approaches in mycobacteria through the capacity for positionally regulable gene repression. Here, we report the utility of the “CRISPRi-Seq” method for targeted, pooled essentiality screening, confirming strong overlap with Tn-Seq datasets. In addition, we exploit this high-throughput approach to provide insight into CRISPRi functionality. By interrogating polar effects and combining image-based phenotyping with CRISPRi-mediated depletion of selected essential genes, we demonstrate that CRISPRi-Seq can functionally validate Transcriptional Units within operons. Together, these observations suggest the utility of CRISPRi-Seq to provide insights into (myco)bacterial gene regulation and expression on a genome-wide scale.


Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 888
Author(s):  
Xuejiao Jin ◽  
Jie Zhang ◽  
Tingting An ◽  
Huihui Zhao ◽  
Wenhao Fu ◽  
...  

Lithium hexafluorophosphate (LiPF6) is one of the leading electrolytes in lithium-ion batteries, and its usage has increased tremendously in the past few years. Little is known, however, about its potential environmental and biological impacts. In order to improve our understanding of the cytotoxicity of LiPF6 and the specific cellular response mechanisms to it, we performed a genome-wide screen using a yeast (Saccharomyces cerevisiae) deletion mutant collection and identified 75 gene deletion mutants that showed LiPF6 sensitivity. Among these, genes associated with mitochondria showed the most enrichment. We also found that LiPF6 is more toxic to yeast than lithium chloride (LiCl) or sodium hexafluorophosphate (NaPF6). Physiological analysis showed that a high concentration of LiPF6 caused mitochondrial damage, reactive oxygen species (ROS) accumulation, and ATP content changes. Compared with the results of previous genome-wide screening for LiCl-sensitive mutants, we found that oxidative phosphorylation-related mutants were specifically hypersensitive to LiPF6. In these deletion mutants, LiPF6 treatment resulted in higher ROS production and reduced ATP levels, suggesting that oxidative phosphorylation-related genes were important for counteracting LiPF6-induced toxicity. Taken together, our results identified genes specifically involved in LiPF6-modulated toxicity, and demonstrated that oxidative stress and ATP imbalance maybe the driving factors in governing LiPF6-induced toxicity.


2015 ◽  
Vol 11 (11) ◽  
pp. 3129-3136 ◽  
Author(s):  
Namal V. C. Coorey ◽  
James H. Matthews ◽  
David S. Bellows ◽  
Paul H. Atkinson

Identifying Saccharomyces cerevisiae genome-wide gene deletion mutants that confer hypersensitivity to a xenobiotic aids the elucidation of its mechanism of action (MoA).


2021 ◽  
Author(s):  
Heather R. Keys ◽  
Kristin A. Knouse

ABSTRACTOur ability to understand and modulate mammalian physiology and disease requires knowing how all genes contribute to any given phenotype in the organism. Genome-wide screening using CRISPR-Cas9 has emerged as a powerful method for the genetic dissection of cellular processes1,2, but the need to stably deliver single guide RNAs to millions of cells has restricted its implementation to ex vivo systems. These ex vivo systems cannot reproduce all of the cellular phenotypes observed in vivo nor can they recapitulate all of the factors that influence these phenotypes. There thus remains a pressing need for high-throughput functional genomics in a living organism. Here, we establish accessible genome-wide screening in the mouse liver and use this approach to uncover the complete regulation of cellular fitness in a living organism. We discover novel sex-specific and cell non-autonomous regulation of cell growth and viability. In particular, we find that the class I major histocompatibility complex is essential for preventing immune-mediated clearance of hepatocytes. Our approach provides the first comprehensive picture of cell fitness in a living organism and highlights the importance of investigating cellular phenomena in their native context. Our screening method is robust, scalable, and easily adapted to examine diverse cellular processes using any CRISPR application. We have hereby established a foundation for high-throughput functional genomics in a living mammal, enabling unprecedented insight into mammalian physiology and disease.


2016 ◽  
Vol 22 (2) ◽  
pp. 155-165 ◽  
Author(s):  
Elizabeth B. Rex ◽  
Nikhil Shukla ◽  
Shenyan Gu ◽  
David Bredt ◽  
Daniel DiSepio

Cellular signaling is in part regulated by the composition and subcellular localization of a series of protein interactions that collectively form a signaling complex. Using the α7 nicotinic acetylcholine receptor (α7nAChR) as a proof-of-concept target, we developed a platform to identify functional modulators (or auxiliary proteins) of α7nAChR signaling. The Broad cDNA library was transiently cotransfected with α7nAChR cDNA in HEK293T cells in a high-throughput fashion. Using this approach in combination with a functional assay, we identified positive modulators of α7nAChR activity. We identified known positive modulators/auxiliary proteins present in the cDNA library that regulate α7nAChR signaling, in addition to identifying novel modulators of α7nAChR signaling. These included NACHO, SPDYE11, TCF4, and ZC3H12A, all of which increased PNU-120596-mediated nicotine-dependent calcium flux. Importantly, these auxiliary proteins did not modulate GluR1(o)-mediated Ca flux. To elucidate a possible mechanism of action, we employed an α7nAChR-HA surface staining assay. NACHO enhanced α7nAChR surface expression; however, the mechanism responsible for the SPDYE11-, TCF4-, and ZC3H12A-dependent modulation of α7nAChR has yet to be defined. This report describes the development and validation of a high-throughput, genome-wide cDNA screening platform coupled to FLIPR functional assays in order to identify functional modulators of α7nAChR signaling.


2019 ◽  
Vol 51 (4) ◽  
pp. 627-635 ◽  
Author(s):  
Xiaobo Li ◽  
Weronika Patena ◽  
Friedrich Fauser ◽  
Robert E. Jinkerson ◽  
Shai Saroussi ◽  
...  

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