Spiroplasma Biodiversity/Biocontrol Project: Only a few thousand microorganisms have been described in detail. However, according to current estimates, there may be several hundred thousand species yet to be discovered. There are several reasons why it is important to characterize microbes. These include: 1) microbes are of central importance to biosphere sustainability; 2) microbial resources have biotechnological value; 3) microbes can be used to monitor environmental change; and, 4) microbes represent important models for understanding principles of ecology and evolution. This study will use the genus Spiroplasma to explore microbial biodiversity. Spiroplasmas are helical, motile bacteria associated primarily with insects and ticks. As a result of a large survey of insect families for specifies of Spiroplasmas, taxonomic diversity was estimated using the observation that one new spiroplasma had been found in every 10 insects examined—as there are more than 10 million insect specific, spiroplasmas may be one of the largest genera of microorganisms! The continued characterization of novel species is therefore critical to improving our understanding of microbial diversity in the biosphere. Of importance to agriculture is the observation that many pest insects (e.g. mosquitoes, biting flies, corn rootworm to name a few) have been found to be spiroplasma hosts. Most of these spiroplasmas are commensals in that they do not harm their host insect, however the fact that they are both host-specific and readily transmissible makes them potentially useful as biocontrol agents. If spiroplasmas can be genetically altered to express insect lethal toxins (biocontrol) then only those specific pest insects could be targeted eliminating the destruction of beneficial insects (pollinators) and the need for pesticide applications (which often leaches in the water system). This part of the project will focus on the development of the molecular tools needed to genetically modify the spiroplasmas.
Cellular Responses of a Stream fish, Blacknose Dace (Rhinichthys atromaculatus) to Urbanization: Urbanization leads to habitat loss and fragmentation, which results in reduced communities of organisms that are better able to cope with the novel selection pressures of the urban environment through rapid evolution. To address this question we will use populations of a widely-distributed stream fish, the blacknose dace, as a model system. Comparative studies to date have documented increased growth rates, younger age and size at maturity, increased swimming performance and reduced predator avoidance behavior in populations occupying streams draining heavily urbanized watersheds as compared to those obtained from more rural streams. The broad goal of this project will be to investigate the relative roles of these physical differences and evolution in producing the differences observed in urban populations. Specifically we will be looking for differences in gene expression levels for specimens collected at different sample sites (ranging from rural to urban). If we can determine which genes are expressed differentially in the different specimens then we may begin to get a better understanding of the genetic differences behind the physiological and developmental differences observed along the urban-rural gradient. As more and more rural land is converted to housing and more industrial applications it is critical to understand how organisms adapt to these urban conditions and this study will begin to look at those adaptations with a native species.