In PLoS this week, Jonathan Eisen edited a collection of articles, essays, perspectives, and reviews about how genomics, "with all its associated tools and techniques, can provide insights into our understanding of emerging infectious disease." The articles run the gamut, from an essay appearing in PLoS Medicine on establishing genomics approaches to disease testing in developing countries, to reviews studying microevolutionary change in bacteria, emerging zoonotic viral diseases, and the evolution of influenza A virus, among others.
In work published this week in PLoS Genetics, Judith Berman from the University of Minnesota, Minneapolis, is the senior author on work that examines genomic changes that occur in Candida albicans as it acquires resistance to antifungal drugs. "Resistance to fluconazole, the most widely used antifungal, is often associated with acquired aneuploidy," they say in the abstract. In an experiment where they dosed C. albicans populations with fluconazole, they found that all of them developed a specific aneuploidy, isochromosome 5L, which was then associated with increased fitness in the presence of the drugs and "over time, became fixed in independent populations."
Scientists led by first author Nataly Perez at the Methodist Hospital Research Institute in Houston, Texas, used genomic approaches to discover the prevalence of small regulatory RNAs in the human bacterial pathogen group A Streptococcus. With an Affymetrix tiling array, they identified 40 candidate sRNAs within the M1T1 GAS strain MGAS2221, bringing to total number to 75. Taking six from these 40, further study showed "significant variation ... between the six sRNAs with respect to their stability during growth, and with respect to their inter- and/or intra-serotype-specific levels of abundance," they say. Their work appears this week in PLoS One.
Another study in PLoS One takes a look at the relationship between glucocorticoid receptor-mediated transcription in the brain and anxiety disorders. Using a mutated form GR with an inducible transgenic approach, scientists led by researchers at INSERM in Bordeaux, France, saw that in a mouse line where the mutated GR was only expressed in neurons of the dentate gyrus, increased expressed led to increased anxiety-related behaviors as well as up-regulation of the MAPK signaling pathway and Egr-1 protein in the DG.