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Full-Text Articles in Life Sciences
The Role Of Dksa In The Stringent Response In The Lyme Disease Spirochete Borrelia Burgdorferi, Britney Cheff
The Role Of Dksa In The Stringent Response In The Lyme Disease Spirochete Borrelia Burgdorferi, Britney Cheff
Graduate Student Theses, Dissertations, & Professional Papers
Borrelia burgdorferi, the bacterium that causes Lyme disease, is maintained in nature through an enzootic cycle that includes a tick vector and a vertebrate host. The bacterium is acquired by an Ixodes tick from an infected vertebrate. The bacterium alters its gene expression to adapt to different environments of the tick and vertebrate. Between tick feedings, B. burgdorferi must contend with nutrient stress. The stringent response is a physiological mechanism when bacteria switch from “thriving” to “surviving” mode in response to limited nutrient resources; it is mediated by an increase in the nucleotide alarmone guanosine penta- or tetraphosphate, abbreviated …
Chromosomal Rearrangements Directly Cause Underdominant F1 Pollen Sterility In Mimulus Lewisii-M. Cardinalis Hybrids, Angela M. Stathos
Chromosomal Rearrangements Directly Cause Underdominant F1 Pollen Sterility In Mimulus Lewisii-M. Cardinalis Hybrids, Angela M. Stathos
Graduate Student Theses, Dissertations, & Professional Papers
Chromosomal rearrangements can contribute to the evolution of postzygotic reproductive isolation directly, by disrupting meiosis in F1 hybrids, or indirectly, by suppressing recombination among genic incompatibilities. Because direct effects of rearrangements on fertility imply fitness costs during their spread, understanding the mechanism of F1 hybrid sterility is integral to reconstructing the role(s) of rearrangements in speciation. In hybrids between monkeyflowers Mimulus cardinalis and M. lewisii, rearrangements contain all quantitative trait loci (QTLs) for both premating barriers and pollen sterility, suggesting that they may have facilitated speciation in this model system. I used artificial chromosome doubling and …