IDENTIFYING DIFFERENCES IN THE GUT MICROBIOME OF EASY AND HARD KEEPER HORSES

Amy BiddleThe equine gut harbors a diverse community of microbes that are crucial for proper digestion of plant materials and an essential component to the animal’s overall health. As recent studies have found links between the human gut microbiome and obesity, the gut microbiota appears to play in weight and health is further being discovered. The goal of this experiment is to identify differentially abundant bacterial species between horses with differing metabolic tendencies, also known as easy keepers and hard keepers. As a secondary goal, the differences in the microbiome regarding age were also observed to determine the effect of age in addition to keeper status, as metabolic tendency is often seen in horses to change over time. The primary methods of identifying microbial communities were 16S rRNA gene sequencing of DNA extracted from equine fecal matter. A series of analyses were used to compare microbiome data, including differential abundance, alpha diversity, beta diversity, Spearman’s Rank correlation, and LDA Effect Size. All of these were performed to compare the microbiomes of horses of different keeper status, with differential abundance, beta diversity, and a Spearman’s Rank correlation used to analyze and compare age groups. Between horses who were easy and hard keepers, 32 species were found to be differentially abundant, with a definitive correlation between species and keeper status but no significance in diversity. For age, 69 taxa were found to be differentially abundant also with no significance in diversity. The taxa that were different between easy and hard keepers were from the Lachnospiraceae family, along with several others, suggesting a possible difference in nutrient availability for the horse due to the presence or absence of this family.Biological Science

Internalizing Symptoms In Latinos: The Role Of Anxiety Sensitivity

Latin American youth in the United States tend to report more internalizing symptoms than white non-Latino youth, yet little is known about the factors that may contribute to such differences. The present study examined the role that anxiety sensitivity, gender, and ethnic minority status may play in the expression of internalizing symptoms across Latin American adolescents (n = 116) and white non-Latino adolescents (n = 72) in the United States and Colombian adolescents in Colombia (n=163). Results provide evidence that because fear of anxiety related phenomena and physiological symptoms of anxiety in particular may be normative in Latino culture anxiety sensitivity does not amplify somatic complaints for Latin American and Colombian youth as it does for white non-Latino youth. Results further suggest that anxiety sensitivity and being female predicted anxiety and depressive symptoms independent of cultural background. Implications of the findings to our understanding of cultural variability in internalizing symptoms are discussed. © Springer Science+Business Media, LLC 2007

Regulators of rDNA array morphology in fission yeast.

Nucleolar morphology is a well-established indicator of ribosome biogenesis activity that has served as the foundation of many screens investigating ribosome production. Missing from this field of study is a broad-scale investigation of the regulation of ribosomal DNA morphology, despite the essential role of rRNA gene transcription in modulating ribosome output. We hypothesized that the morphology of rDNA arrays reflects ribosome biogenesis activity. We established GapR-GFP, a prokaryotic DNA-binding protein that recognizes transcriptionally-induced overtwisted DNA, as a live visual fluorescent marker for quantitative analysis of rDNA organization in Schizosaccharomyces pombe. We found that the morphology-which we refer to as spatial organization-of the rDNA arrays is dynamic throughout the cell cycle, under glucose starvation, RNA pol I inhibition, and TOR activation. Screening the haploid S. pombe Bioneer deletion collection for spatial organization phenotypes revealed large ribosomal protein (RPL) gene deletions that alter rDNA organization. Further work revealed RPL gene deletion mutants with altered rDNA organization also demonstrate resistance to the TOR inhibitor Torin1. A genetic analysis of signaling pathways essential for this resistance phenotype implicated many factors including a conserved MAPK, Pmk1, previously linked to extracellular stress responses. We propose RPL gene deletion triggers altered rDNA morphology due to compensatory changes in ribosome biogenesis via multiple signaling pathways, and we further suggest compensatory responses may contribute to human diseases such as ribosomopathies. Altogether, GapR-GFP is a powerful tool for live visual reporting on rDNA morphology under myriad conditions

Targeting the adaptability of heterogeneous aneuploids

SummaryAneuploid genomes, characterized by unbalanced chromosome stoichiometry (karyotype), are associated with cancer malignancy and drug resistance of pathogenic fungi. The phenotypic diversity resulting from karyotypic diversity endows the cell population with superior adaptability. We show here, using a combination of experimental data and a general stochastic model, that the degree of phenotypic variation, thus evolvability, escalates with the degree of overall growth suppression. Such scaling likely explains the challenge of treating aneuploidy diseases with a single stress-inducing agent. Instead, we propose the design of an “evolutionary trap” (ET) targeting both karyotypic diversity and fitness. This strategy entails a selective condition “channeling” a karyotypically divergent population into one with a predominant and predictably drugable karyotypic feature. We provide a proof-of-principle case in budding yeast and demonstrate the potential efficacy of this strategy toward aneuploidy-based azole resistance in Candida albicans. By analyzing existing pharmacogenomics data, we propose the potential design of an ET against glioblastoma