Life Sciences Commons^™

A Genetic And Biochemical Analysis Of Sulfolobus Spindle-Shaped Virus 1, Eric Alexander Iverson

Dissertations and Theses

Viruses infecting the Archaea exhibit a tremendous amount of morphological and genetic diversity. This is especially true for crenarchaeal viruses from the family Fuselloviridae, which possess spindle-shaped capsids and genomes that harbor a great number of uncharacterized genes. The functions of these unidentified gene products are of interest as they have the potential to provide valuable insights into the fusellovirus infection cycle and archaeal viruses in general. In an effort to better characterize the genetic requirements of the Fuselloviridae, we have performed genetic and biochemical experiments using the best studied fusellovirus, Sulfolobus spindle-shaped virus 1 (SSV1).

A comprehensive …

Genome Rearrangements Can Make And Break Small Rna Genes, Rahul Raghavan, Fenil R. Kacharia, Jess A. Millar, Christine Demko Sislak, Howard Ochman

Biology Faculty Publications and Presentations

Small RNAs (sRNAs) are short, transcribed regulatory elements that are typically encoded in the intergenic regions (IGRs) of bacterial genomes. Several sRNAs, first recognized in Escherichia coli, are conserved among enteric bacteria, but because of the regulatory roles of sRNAs, differences in sRNA repertoires might be responsible for features that differentiate closely related species. We scanned the E. coli MG1655 and Salmonella enterica Typhimurium genomes for nonsyntenic IGRs as a potential source of uncharacterized, species-specific sRNAs and found that genome rearrangements have reconfigured several IGRs causing the disruption and formation of sRNAs. Within an IGR that is present in …

Recbcd Is Required To Complete Chromosomal Replication: Implications For Double- Strand Break Frequencies And Repair Mechanisms, Justin Courcelle, Brian M. Wendel, Dena D. Livingstone, Charmain T. Courcelle

Biology Faculty Publications and Presentations

Several aspects of the mechanism of homologous double strand break repair remain unclear. Although intensive efforts have focused on how recombination reactions initiate, far less is known about the molecular events that follow. Based upon biochemical studies, current models propose that RecBCD processes double strand ends and loads RecA to initiate recombinational repair. However, recent studies have shown that RecBCD plays a critical role in completing replication events on the chromosome through a mechanism that does not involve RecA or recombination. Here, we examine several studies, both early and recent, that suggest RecBCD also operates late in the recombination process- …

A Coxiella-Like Endosymbiont Is A Potential Vitamin Source For The Lone Star Tick, Todd A. Smith, Timothy Driscoll, Joseph J. Gillespie, Rahul Raghavan

Biology Faculty Publications and Presentations

Amblyomma americanum (Lone star tick) is an important disease vector in the United States. It transmits several human pathogens, including the agents of human monocytic ehrlichiosis, tularemia, and southern tick-associated rash illness. Blood-feeding insects (Class Insecta) depend on bacterial endosymbionts to provide vitamins and cofactors that are scarce in blood. It is unclear how this deficiency is compensated in ticks (Class Arachnida) that feed exclusively on mammalian blood. A bacterium related to Coxiella burnetii, the agent of human Q fever, has been observed previously within cells of A. americanum. Eliminating this bacterium (CLEAA, Coxiella-like endosymbiont of A. americanum) with antibiotics …