Browsing by Subject "genotype"
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Item Open Access Potential Influence of Staphylococcus aureus Clonal Complex 30 Genotype and Transcriptome on Hematogenous Infections.(Open Forum Infect Dis, 2015-09) Sharma-Kuinkel, Batu K; Mongodin, Emmanuel F; Myers, Jason R; Vore, Kelly L; Canfield, Greg S; Fraser, Claire M; Rude, Thomas H; Fowler, Vance G; Gill, Steven RBackground. The contemporary Staphylococcus aureus clonal complex (CC) 30 lineage is associated with complicated infections, including endocarditis and osteomyelitis. This lineage diverged from the phage-type 80/81 S aureus clone responsible for a major bacterial epidemic of the 20th century. The genome and transcriptome features that contribute to complicated infections of the CC30 lineage are unknown. Methods. Twenty-nine clinical methicillin-resistant S aureus (MRSA) strains (8 from CC30 and 21 from other major CCs were evaluated for virulence using murine and Galleria mellonella sepsis models. Genomic features of CC30 were identified by comparative genome sequencing and RNA-Seq transcriptome analysis of the 29 strains and 31 previously sequenced S aureus genomes. Results. The CC30 isolates displayed lower virulence in the sepsis models compared with other CCs [P < .0001]. Comparisons of orthologous proteins and transcriptome analysis identified genes (eg, nitric oxide reductase) and changes in metabolic pathways (eg, pyrimidine metabolism) that contribute to the distinct CC30 phenotype. Previously reported nonsynonymous single-nucleotide polymorphisms (SNPs) were found in accessory gene regulator C (agrC) and α-hemolysin (hla), molecules important for virulence. Additional nonsynonymous SNPs conserved across clinical CC30 isolates when compared with the first sequenced contemporary CC30 clone, MRSA-16, were identified in multiple genes, suggesting continuing evolutionary divergence in this lineage. Conclusions. Genomic and transcriptional analyses suggest that the CC30 lineage has acquired metabolic features that contribute to persistent and complicated infections. Absence of sepsis-induced mortality in animal models may be due in part to its unique genomic profile and suggests that specific genotypes of S aureus elicit distinct types of infection types.Item Open Access The Genetic and Epigenetic Landscape of Oxytocin Signaling in the Social Brain of Humans and Mice(2021) Siecinski, Stephen KennethHuman beings are inherently social. As we grow, the interactions we have with those around us become the foundation of the relationships with our families, friends, educators, and caretakers. Aberrant social behavioral traits can put a strain on these relationships and negatively impact an individual's quality of life. When severe, these disruptions represent core etiological features of many neurodevelopmental and behavioral disorders, including addiction, schizophrenia, and autism spectrum disorder (ASD).
Advances in the fields of psychology, psychiatry, neuroscience, and the behavioral sciences have developed a wide range of techniques to disentangle the biological and behavioral components of complex social traits, often with the goal of developing targeted interventions to improve outcomes for affected individuals. Still, there remains a massive unmet need for pharmaceutical interventions that ameliorate these aberrant social phenotypes, and current interventions are costly and labor intensive. A particularly promising candidate to address this unmet need is \Oxy, an endogenously expressed neuropeptide, with demonstrated pro-social effects in both humans and animal models, and low incidence of adverse effects. However, clinical trials of \oxy in ASD have had mixed results, likely due to a range of issues from inadequately powered study designs, difficulty in quantifying changes in social behavior over time, heterogeneous study populations, and an inadequate understanding of the underlying mechanisms of \oxy signaling in the brain.
The work described in this dissertation aims to address some of these gaps in knowledge. First, the results of a collaboration with a phase-2 clinical trial of \inoxy are discussed, in which I contributed to identifying a number of biological markers that were associated with \enoxy production in human participants. I discuss how this may be an important component of predicting an individuals response to \exoxy.
I will then discuss our findings in the \cd{} mouse model of ASD-like behaviors. These mice exhibit a unique socially divergent phenotype in which some mice will display very little social motivation within litters while the others behave normally. Importantly, these antisocial mice are responsive to treatment with \exoxy, but the mechanisms behind their unique social phenotype and responsiveness to \oxy remain unknown. I quantified broad patterns of differential gene expression and DNA methylation in the brains of \cd{} mice and their closely related but highly social \cs{} counterparts. This work identified a pattern of differential gene expression in the hippocampus of \cs{} mice that may offer insights into the nature of their naturally occurring social divergence.
Collectively, the findings of these two projects provide valuable information to the field of \oxy and ASD research. The results of the human trial can be used to guide new studies into the endogenous regulation of \oxy, providing potential targets for future interventions to responsive candidates. The results of the mouse experiments identified a myriad of underlying biological pathways that distinguish \cd{} from \cs{} mice, which can serve as the foundation for new targeted hypotheses and to test expanded pharmaceutical interventions to enhance the effects of \exoxy.