Research Methods in Life Sciences Commons^™

Influence Of Testosterone On Male-Male Competition In The Red-Sided Garter Snake, Thamnophis Sirtalis Parietalis, Isabella M. G. Bukovich

Senior Honors Projects, 2020-current

Female mimicry in the red-sided garter snake, Thamnophis sirtalis parietalis, is described in several well-studied evolutionary advantages, but an aspect that remains elusive is how reproductive traits are linked to the 3-fold higher circulating androgens in males with this phenotype. In this study, we implanted male garter snakes (n=15 per group) with either a blank implant (SHAM; control) or a T implant, the latter simulating the female mimic phenotype. Following simulated low-temperature dormancy, males were scored for courtship intensity over three days of behavioral trials with females housed in the same facility. Males were sacrificed, and sperm were collected …

Effect Of Ambient Temperature On Recovery Of Surgically Instrumented Sprague-Dawley Rats, Gianna Mangone

Senior Honors Projects, 2020-current

Based on current guidelines for housing rodents after surgical instrumentation, rodents may be housed at temperatures that hinder surgical recovery and cause thermal stress– room temperature (21°C) being one of them. Rodents are often housed at room temperature since this temperature is easy for humans to be caring for them. However, if recovering rodents are thermally stressed, experimental results will be confounded. To address this issue, Sprague-Dawley rats were surgically instrumented with radiotelemtry thermoprobes (Data Sciences, #TA-10F40) to monitor their core temperatures, then housed at one of five temperatures to assess the effect ambient temperature had on multiple aspects of …

Decrypting Female Attractivity In Garter Snakes, Holly Rucker

Senior Honors Projects, 2010-2019

Pheromones are utilized by many species as sexual signals driving mate choice, and pheromone production in vertebrates hinges on sex hormone action. Female red-sided garter snakes (Thamnophis sirtalis parietalis) produce a skin-based sex pheromone used by males for mate detection and selection. Estradiol is necessary for pheromone production, yet the specific mechanisms within the skin are unknown. Central to this is the metabolism of testosterone to estradiol via the enzyme aromatase. It is hypothesized that female garter snakes synthesize estradiol locally in the skin and maintain pheromone production via tissue-specific regulation of aromatase. Further, I hypothesize that female …

Microplastics In Full View: Birds As Bioindicators Of Malta's Coastal Ecosystem Health, Dalton Brauer

Masters Theses, 2010-2019

Plastic pollution has recently become a widely studied topic, yet research on microplastics has remained lacking for specific geographic regions. Microplastics are small plastics resulting from degradation or the dumping of raw material and can lead to deleterious impacts on the coastal marine environment and its organisms. To assess Malta’s coastal environmental health, water birds (inshore, offshore and pelagic species) were used as bioindicators by assessing the presence and abundance of plastic within their stomach contents. The project hoped to fill some of the current gaps in knowledge on microplastics within Malta by creating a working baseline, as well as …

Isolation, Sequencing, And Characterization Of Four Transmissible Antibiotic Resistance Plasmids Captured From Bacteria In Stream Sediments, Curtis J. Kapsak

Masters Theses, 2010-2019

Self-transmissible plasmids are key vectors in the transfer of resistance, catabolic, and other genes among bacteria native to environments such as streams and wetlands. The evolution of antibiotic resistance in particular is known to be powerfully affected by conjugative plasmid transfer due to the ease in which some plasmids can be horizontally transferred into a broad range of host bacteria and their ability to exchange mobile genetic elements that often contain antibiotic resistance genes.

In this study, we captured tetracycline resistance plasmids from stream sediments impacted by agricultural runoff. We selected for resistance plasmids using tetracycline, an antibiotic commonly used …

The Effect Of Ambient Temperature On Recovery Of Surgical Stress In Sprague-Dawley Rats, Romie D. Powell

Masters Theses, 2010-2019

Laboratory animals are housed at ambient temperatures ranging from 20°C – 26°C per recommended guidelines. Rats in particular typically prefer ambient temperatures (Tamb) of ~27°C (Brown et al, 2011). When rats undergo surgical instrumentation for experimental use, they often recover at normal room temperature (~21°C). While this is comfortable to those maintaining them, it may lead to a cold thermal stress for the rats. It is hypothesized that housing rats at ambient temperatures away from their preferred Tamb could lead to a thermal stress, which adversely affects surgical recovery. To address this, rats (220g-350g) were surgically instrumented with a radiotelemetry …