Methods Mol Biol
November 2024
The fission yeast Schizosaccharomyces pombe has been used to elucidate meiotic recombination mechanisms for decades. Alongside the budding yeast Saccharomyces cerevisiae, research employing fission yeast has been instrumental in advancing our knowledge of double-stranded DNA break (DSB) formation and repair during meiosis. Genetic recombination assays are the workhorses of gene conversion and crossover frequency analysis; these have been employed to investigate cis and trans determinants of meiotic recombination.
View Article and Find Full Text PDFThe presence of a polymer network and/or the addition of ferroelectric nanoparticles to a nematic liquid crystal are found to lower transition temperatures and birefringence, which indicates reduced orientational order. In addition, the electro-optic switching voltage is considerably increased when a polymer network is formed by in situ polymerization in the nematic state. However, the resulting polymer network liquid crystal switches at similar voltages as the neat liquid crystal when polymerization is performed at an elevated temperature in the isotropic state.
View Article and Find Full Text PDFCandida auris is a fungal pathogen of humans responsible for nosocomial infections with high mortality rates. High levels of resistance to antifungal drugs and environmental persistence mean these infections are difficult to treat and eradicate from a healthcare setting. Understanding the life cycle and the genetics of this fungus underpinning clinically relevant traits, such as antifungal resistance and virulence, is of the utmost importance to develop novel treatments and therapies.
View Article and Find Full Text PDFPathogen-associated molecular patterns (PAMPs) of the fungal cell wall are primary targets for the innate immune system of animals. Therefore, characterizing PAMP exposure of fungal pathogens helps to elucidate how they interact with their hosts at a molecular level. Fluorescent labelling can be used to monitor exposure of multiple fungal cell wall PAMPs in a single experiment.
View Article and Find Full Text PDFReverse genetics is a particularly powerful tool in non-model organisms with known whole-genome sequences enabling the characterization of gene and, thus, protein function via a mutant phenotype. Reverse genetic approaches require genetic manipulation techniques which often need to be specifically developed for non-model organisms; this can be fraught with difficulties. Here, we describe a genetic transformation protocol for the recently emerged human pathogen Candida auris to target the integration of DNA constructs into genomic locations via homology-directed repair using long flanking homologous sequences (>1 kb).
View Article and Find Full Text PDFHeredity (Edinb)
July 2022
Meiosis is undoubtedly the mechanism that underpins Mendelian genetics. Meiosis is a specialised, reductional cell division which generates haploid gametes (reproductive cells) carrying a single chromosome complement from diploid progenitor cells harbouring two chromosome sets. Through this process, the hereditary material is shuffled and distributed into haploid gametes such that upon fertilisation, when two haploid gametes fuse, diploidy is restored in the zygote.
View Article and Find Full Text PDFCandida auris is a recently emerged yeast pathogen of humans causing severe hospital-acquired systemic infections. It is of the utmost importance to understand the genetic and cellular basis of its virulence and pathogenicity. In a recent study, Santana and O'Meara generated forward and reverse genetic tools to manipulate C.
View Article and Find Full Text PDF2009 saw the first description of Candida auris, a yeast pathogen of humans. C. auris has since grown into a global problem in intensive care settings, where it causes systemic infections in patients with underlying health issues.
View Article and Find Full Text PDFCandida auris is a worrisome fungal pathogen of humans which emerged merely about a decade ago. Ever since then the scientific community worked hard to understand clinically relevant traits, such as virulence factors, antifungal resistance mechanisms, and its ability to adhere to human skin and medical devices. Whole-genome sequencing of clinical isolates and epidemiological studies outlining the path of nosocomial outbreaks have been the focus of research into this pathogenic and multidrug-resistant yeast since its first description in 2009.
View Article and Find Full Text PDFEnvironmental stress, reactive oxygen species (ROS), or ionizing radiation (IR) can induce adverse effects in organisms and their cells, including mutations and premature aging. DNA damage and its faulty repair can lead to cell death or promote cancer through the accumulation of mutations. Misrepair in germ cells is particularly dangerous as it may lead to alterations in developmental programs and genetic disease in the offspring.
View Article and Find Full Text PDFChanges in environmental temperature influence cellular processes and their dynamics, and thus affect the life cycle of organisms that are unable to control their cell/body temperature. Meiotic recombination is the cellular process essential for producing healthy haploid gametes by providing physical links (chiasmata) between homologous chromosomes to guide their accurate segregation. Additionally, meiotic recombination-initiated by programmed DNA double-strand breaks (DSBs)-can generate genetic diversity and, therefore, is a driving force of evolution.
View Article and Find Full Text PDFThe morphogenetic switching between yeast cells and filaments (true hyphae and pseudohyphae) is a key cellular feature required for full virulence in many polymorphic fungal pathogens, such as In the recently emerged yeast pathogen , occasional elongation of cells has been reported. However, environmental conditions and genetic triggers for filament formation have remained elusive. Here, we report that induction of DNA damage and perturbation of replication forks by treatment with genotoxins, such as hydroxyurea, methyl methanesulfonate, and the clinically relevant fungistatic 5-fluorocytosine, cause filamentation in The filaments formed were characteristic of pseudohyphae and not parallel-sided true hyphae.
View Article and Find Full Text PDFHomologues of benzophenone silane, a covalently graftable, photochemically active surface functionalizing agent, are investigated as surface functionalization agents for both small particles and planar substrates. In these homologues, a chlorosilane functional group and a photochemically active benzophenone oxo moiety are separated with an aliphatic spacer of varying length. The species obtained are first investigated by surface grafting on substrates (Si wafers, glass plates, and indium tin oxide coated glass plates).
View Article and Find Full Text PDFMeiotic recombination is essential for producing healthy gametes, and also generates genetic diversity. DNA double-strand break (DSB) formation is the initiating step of meiotic recombination, producing, among other outcomes, crossovers between homologous chromosomes (homologs), which provide physical links to guide accurate chromosome segregation. The parameters influencing DSB position and repair are thus crucial determinants of reproductive success and genetic diversity.
View Article and Find Full Text PDFA fast-switching, tunable color filter was found in a copolymer network liquid crystal (LC), which was in situ generated in a conventional LC test cell with parallel aligned glass plates and investigated with polarized light. Polarization filters were used to convert the tunable optical phase retardance of the test cells to birefringence colors as is always possible in a LC test cell with carefully adjusted cell gap and effective birefringence. The cell gap of the samples could be adjusted to a value of 9 μm, which is not easily possible in a polymer LC composite without creating defects.
View Article and Find Full Text PDFATP-binding cassette (ABC) superfamily members have a key role as nutrient importers and exporters in bacteria. However, their role as drug exporters in eukaryotes brought this superfamily member to even greater prominence. The capacity of ABC transporters to efflux a broad spectrum of xenobiotics represents one of the major mechanisms of clinical multidrug resistance in pathogenic fungi including species.
View Article and Find Full Text PDFCandida auris is a newly emerged pathogenic microbe, having been identified as a medically relevant fungus as recently as 2009. It is one of the most drug-resistant yeast species known to date and its emergence and population structure are unusual. Because of its recent emergence, we are largely ignorant about fundamental aspects of its general biology, life cycle, and population dynamics.
View Article and Find Full Text PDFSchizosaccharomyces pombe, also known as fission yeast, is an established model for studying chromosome biological processes. Over the years, research employing fission yeast has made important contributions to our knowledge about chromosome segregation during meiosis, as well as meiotic recombination and its regulation. Quantification of meiotic recombination frequency is not a straightforward undertaking, either requiring viable progeny for a genetic plating assay, or relying on laborious Southern blot analysis of recombination intermediates.
View Article and Find Full Text PDFDrying under solvent atmosphere (DUSA) was investigated as an experimental technique to generate self-assembled nanowires and needles from solutions of organic molecules under controlled conditions. Experimental observations of twisted nanowires are reported. These twisted nanowires were obtained by drying of solutions of achiral molecules under solvent controlled atmospheres: achiral, amphiphilic copper complexes were dissolved in an achiral solvent and these solutions were dried under controlled conditions.
View Article and Find Full Text PDFCandida auris has recently emerged as a multi-drug resistant fungal pathogen that poses a serious global health threat, especially for patients in hospital intensive care units (ICUs). C. auris can colonize human skin and can spread by physical contact or contaminated surfaces and equipment.
View Article and Find Full Text PDFHop1 is a component of the meiosis-specific chromosome axis and belongs to the evolutionarily conserved family of HORMA domain proteins. Hop1 and its orthologs in higher eukaryotes are a major factor in promoting double-strand DNA break formation and inter-homolog recombination. In budding yeast and mammals, they are also involved in a meiotic checkpoint kinase cascade monitoring the completion of double-strand DNA break repair.
View Article and Find Full Text PDFA chiral nematic (N*) liquid crystal (LC) was hybridized with a z-cut iron doped lithium niobate (Fe:LN) substrate and exposed with a focused continuous wave diode laser beam. The N* LC layer was confined with a cover glass to provide a homogeneous LC layer thickness. Two distinct kinds of test cells were investigated, one with an uncoated glass covering slip and one with an indium tin oxide (ITO) coated cover glass.
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