Biology Projects 2007

The Scorpion's Glow: Understanding the function of an unusual biological trait

Faculty Mentor - Carl Kloock

Scorpions, when exposed to Ultra-violet light, fluoresce, or "glow". To date, only a few possible functions of this unusual trait have been explored experimentally. Using a combination of field and laboratory experiments, I am investigating the general question of what function, if any, fluorescence serves in Scorpions. This summer's research will focus on 3 areas: 1) Determination of the source of fluorescent contamination encountered in a previous experiment; 2) Testing for an effect of fluorescence on intraspecific interactions including mating, cannibalism, and competitive interactions; 3) Testing for the possibility that fluorescence functions as either a form of camouflage or aposematic (warning) coloration.

Kloock Group Poster

Geographic Origin of the Glassy-Winged Sharpshooter in Easter Island, Chile: Analysis of Mitochondrial DNA Gene Sequences

Faculty Mentor - Paul Smith

The glassy-winged sharpshooter, Homalodisca coagulata (Homoptera: Cicadellidae), is a highly polyphagous insect species that is distributed throughout most of the southern regions of the United States. In the last 10 years, H. coagualta has become established in California and represents a significant threat to the state's $35 billion wine and table grape industries. In a previous study, Smith (2005) utilized DNA sequencing analysis to characterize a portion of the mitochondrial cytochrome oxidase I gene from 20 natural populations of H. coagulata distributed in Tahiti, California, Texas, Louisiana, Mississippi, Alabama, and Florida. The results indicated that populations of H. coagulata are geographically structured into two groups of haplotypes; a group of populations from east of the Mississippi River including Louisiana, Mississippi, Alabama and Florida and a group comprised of populations west of the Mississippi River from Texas and California, and from Tahiti. The purpose of the present research is to ascertain the geographic origin of a glassy-winged sharpshooter infestation in Easter Island, Chile. To this end, workers in my lab will utilize the scientific method and a variety of molecular biology techniques (e.g., DNA extraction, gel electrophoresis, polymerase chain reaction, DNA sequencing and phylogenetic analysis) to investigate this question under my supervision. Ultimately, the faculty mentor and the assigned research group will submit the results for publication in a peer-reviewed scientific journal.

Smith Group Poster

Examination of Gene Expression in Arabidopsis thaliana

Faculty Mentor - Kathleen Szick-Miranda

The synthesis of proteins is an absolute requirement for growth and development in all biological organisms, yet our understanding of the core component (the ribosome) and its constituents (ribosomal proteins [r-proteins]) in plants remains limited. In the genetic model plant Arabidopsis thaliana (Ath) the r-protein known as S15a Type II two different genes correspond to the S15a Type II protein. The immediate question that arises is "Why are there two different genes in Ath that encode the same protein?" One possible explanation is differential expression, a condition where one gene may be turned on (expressed) in a specific portion of the plant (the leaf for example), while another may be turned on in another portion of the plant (such as the root). We are currently analyzing the expression of the two genes which code for the S15a Type II protein by isolating total RNA (a molecule that links genes to protein production) from Ath 6-day old seedlings and a variety of other tissue types (leaf, stem, floral bud, roots, etc.) and utilizing a molecular technique known as Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR). Our preliminary results indicate that the two genes that encode Type II S15a are differentially expressed during development. The goal of this project is to analyze the expression of the two genes encoding S15a Type II in Ath seedlings in response to various environmental conditions which plants are normally subjected to, such as flooding, dehydration and extreme heat or cold. Participants in this research project will learn about the processes involved in gene expression (transcription and translation) as well as the fundamentals of research design, analysis and interpretation. In addition, they will acquire hands-on research experience by learning: 1) to handle, germinate, plant and grow Arabidopsis, 2) to prepare Petri plates containing nutrient media, 3) Arabidopsis plating techniques, 4) to isolate total RNA from Arabidopsis seedlings, 5) RT-PCR and 6) how to perform agarose gel electrophoresis

Szick-Miranda Group Poster