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Participants and Projects 1997
Participants and Projects 1998
Participants and Projects 1999

Greg Bowling

Heat shock proteins (HSPs) are thought to protect cells from the stress of acute hyperthermia. HSP 70 is thought to bind and protect partially denatured proteins during and after a heat stress condition. In this study, HSP 70 antibody was applied to the medial giant axon of the crayfish prior to heat shock conditions in order to deplete intracellular HSP 70. Resting membrane potentials were decreased compared to control MGAs, antibody-only MGAs, and heat shocked-only MGAs. Values for action potentials were not able to be obtained from the MGAs which were pretreated with the HSP 70 antibody prior to heat shock, possibly because of the denaturation of membrane proteins in the absence of HSP 70.

Cassandra Carberry

Michelle Delaney

In this experiment, the affect of changes in environment on the search and oviposition behavior of the parasitoid wasp, Xanthopimpla stemmator was examined. Contents of the straws presented to X. stemmator for parasitism were varied, and the waspıs behavior was noted. When presented with just diet plugs, wasps did fewer thrusts of their abdomen, wiggled their abdomen upon insertion into the straw, held their antennae in a variety of positions during insertion, and had a much shorter average length of insertion. When a pupa was present in the straw, wasps had a much longer insertion time, an increased number of thrusts, and their antennae remained straight during the insertion more so than when there was no pupa. The few number of thrusts into the straw and short insertion time when presented with just diet plugs is indicative of the waspıs ability to discern the absence of a pupa. The increased number of thrusts and increased time spent with their ovipositor in the straw are a direct result of the waspıs continued attempts to pierce and parasitize the pupa. I therefore concluded that the contents of the straw do affect X. stemmatorıs behavior once she has inserted her ovipositor into the straw, but does not affect behavior during the search.

Gladice Go

Several studies of pollen flow have shown that a plant's position is an important component in measuring male fitness (Handel, 1983). In previous analyses gene flow was measured by means of dyes, powders, radio-active labels, and pollinator activity. Unfortunately the movement of pollen analogs does not always correlate with gene flow. A more accurate means of studying male fitness, is to use a masking technique in order to resolve the dilemma of assortative pollination and of the use of pollen analogs. If a phenotype is masked to disguise a homozygous dominant genetic marker in a recessive population, then one may measure the fitness of the homozygous dominant marker when it is both masked and unmasked revealing a greater level of fitness for the masked marker.

Angelyn Kenyon

The levels of Heat Shock Protein 70 (HSP 70) in the hemolymph, Ventral Nerve Cord (VNC), and extracellular bath of crayfish were measured by heat shocking crayfish for two hours at 37 degrees Celcius in a water bath. The hemolymph was removed from the crayfish and the VNC dissected. The VNC was then homogenized and run on an SDS-Page electrophoresis gel along with the hemolymph samples. No detectible constituitive or inducible HSP 70s were found by Immunoblotting and color detection of hemolymph samples (n=6). A positive result was found for HSP 70 in the heat shocked VNC (n=3). Heat shocked and control VNCs were further tested by radiolabeling with 35-S methionine. The extracellular bath of the in vitro labeling as well as the homogenized VNC were run on an SDS-Page electrophoresis gel with Immunoblotting and color detection. A positive result for inducible HSP 70 was detected in the extracellular bath of the heat shocked VNC (n=1). Autoradiography was performed and showed positive results for inducible HSP 70 in the VNC (n=2). The Autoradiography and radiolabeling experiments provide data supporting the mechanism of glia to axon transfer ultimately beginning with gene transcription during times of stress to the organism.

Vi Nguyen

Xanthopimpla stemmator (Hymenoptera: Ichnuemonidae) are solitary endoparastoids of stalkborers. In this study, we looked at the incidence of superparasitization, when females lay multiple eggs in a single host, by the female X. stemmator in the pupa of the corn stalkborer Diatraea saccharalis. Female wasps were presented daily with two pupa that were inserted into a paper drinking straw for a period of six hours. Pupa were dissected and the eggs were counted daily. We discovered that X. stemmator do superparasitize and that more eggs are laid by each female wasp at mid life than at any other time.

Karen Okimoto

The purpose of this project was to determine if developmental instability is manifested through meristic variation of floral formula and through asymmetry in Phlox drummondii. Sepals, petals, stamens, and stigmatic lobes were the floral parts scored to determine merism. Six different cultivars (Chanal, Premium Pink, Globe, Twinkle, Premium Pastel, and petticoat mix) of Phlox were compared to determine that Chanal showed 100% abnormality in petal numbers. Floral inconstancy varied between the two sites used for this experiment, greenhouse and field. Petal number was the most variable flower part.

Brent Patterson

Due to superficial resemblances, fungi have traditionally been classified in the plant kingdom; however, due to their lack of chlorophyll and external mode of digestion, they now have their own kingdom: Kingdom Fungi (Solomon, 1993). Fungi, based on characteristics of sexual spores, have been divided into four divisions: Zygomycota, Ascomycota, Basidiomycota, and Deuteromycota (Prescott, 1996). The organism of interest to this experiment is the Zygomycete Mucor rouxii. Zygomycetes are coenocytic meaning that their hyphae have no divisions or septa, and the organisms essentially exist as multinucleated volumes of cytoplasm moving through an extensive tube system made of hyphae called mycelium. Mucor rouxii, depending on environmental conditions, will grow as either a yeast or a mold (Dow et al. 1983). Only the mold form will be examined in this study. It has been shown that the specific activity of proteinases, during mycelial development in M. rouxii, increases and decreases intermittently as a function of time (Weselman, 1991). Aerobic growth can be divided into two phases. Phase I, the first eight hours, consists of the spore swelling due to water uptake and to biosynthesis of macromolecules. The beginning of phase II is marked by the emergence of germ tubes from the swollen spore, and by continual mycelial development. It has been suggested that the proteolytic activity observed in phase II is a response to stress caused by a lack of nutrients and buildup of waste products (Personal communication, Villa).

One mechanism by which eukaryotic cells degrade damaged or unneeded proteins is through a ubiquitin-dependent proteolytic pathway (Shang, 1997). Ubiquitin is a very highly conserved 76-amino acid polypeptide that varies in primary structure by only 3 amino acids from yeast to man. Multiple ubiquitin molecules are conjugated onto the e-amino functional group of lysine residues in the protein that is to be destroyed (Tiao 1997). The protein is in effect 'tagged' and can now enter the hollow center of a proteasome where it is hydrolyzed. If the proteolytic activity observed in Mucor rouxii is ubiquitin mediated, then the concentration of ubiquitin should coincide with the increases and decreases in the proteolytic activity.

Shannon Webb

The courtship and mating behavior of the parasitoid wasp Xanthopimpla stemmator (Hymenoptera:Ichneumonidae) was observed and analyzed using continuous and focal sampling. Focus centered on the role of the male antenna in courtship. Possible roles include use of the antenna for locating the female, for orientating correctly in order to copulate, and for the release of a pheromone which may have a calming effect on the female. By shortening the antenna of the males, identification of the roles of the male X. stemmator antenna was attempted. Comparison of unaltered and altered pairs, with attention to mating success, time spent in certain activities, and recovery time of the altered wasp indicate that the male antennae do indeed play a significant role in courtship and mating. The area near the middle of the antenna appeared to have a strong effect on the male's ability to locate and successfully court the female. Further study in which segments of the antenna are covered while the entire antenna are kept intact is necessary to corroborate the findings, and will be carried out in the fall.