Undergraduate Library Research Award (ULRA): 2015 ULRA Winners
Faculty Mentor: Dr. Jennifer Hernandez Gifford
Project Title: Cattle with Increased Severity of Bovine Respiratory Disease Complex Exhibit Decreased Capacity to Protect Against Histone Cytotoxicity
Project Abstract: Bovine respiratory disease complex (BRDC) is the leading cause of morbidity and mortality in feedlot cattle. Significant inflammation and lesions are often observed in lungs of infected cattle. During acute inflammatory responses, histones contribute to mortality in rodents and humans and serum proteins can protect against histone-induced cytotoxicity. We hypothesized that cattle experiencing chronic or fatal cases of BRDC have reduced ability to protect against cytotoxic effects of histones. Serum samples were collected from 66 bull calves at time of normal feedlot processing procedures. Animals were retrospectively assigned to groups consisting of calves never treated for BRDC (CONT; n = 10), treated with antimicrobials once for BRDC (1T; n = 16), treated twice (2T; n = 13), treated 3 times (3T; n = 14), or treated 4 times (4T; n = 13). Samples were also collected each time animals received antimicrobial treatment; animals within a group were further sorted by those that recovered (R) and died (D) to test histone cytotoxicity. Bovine kidney cells (MDBK) were cultured in duplicate in 96-well plates and exposed to 0 or 50 µg/mL of total histones for 18 h with 1% serum from each animal. Cell viability was assessed by the addition of resazurin for 6 h followed by fluorescent quantification. Fluorescent values from serum alone were subtracted from values obtained for histone treatment for each animal. Serum from CONT, 1T, and 2T calves at initial processing all exhibited a similar (P > 0.10) response to histone treatment with fluorescent values of -312 ± 557, -1059 ± 441, and -975 ± 489, respectively. However, 3T and 4T calves demonstrated an impaired capacity (P < 0.05) to protect against histones (-2778 ± 471 and -3026 ± 489) at initial processing when compared to the other groups. When sorted by mortality within group, 2TR (-847 ± 331) calves demonstrated a greater (P < 0.05) protective capacity than 2TD (-2264 ± 412) indicating calves that contract BRDC and ultimately die might have reduced protective capacity against histone cytotoxicity. Results suggest calves that require multiple treatments for BRDC have reduced ability to protect against cytotoxicity of histones. Understanding the primary mechanism responsible for protecting against histone cytotoxicity could lead to improved identification of animals susceptible to severe cases of BRDC, improved focus and utilization of available resources, or better treatments for severe cases of BRDC.
Upperclassman Honorable Mention
Faculty Mentor: Dr. Polly Campbell
Project Title: Do hybrid mice exhibit behavioral abnormalities?
Project Abstract: Embryos created by crossing M. domesticus and M. spretus show classic signs of interrupted genomic imprinting. Developmental issues arise in the womb as a result. In humans, a loss of genomic imprinting causes disorders like Prader-Willi and Angelman syndromes which are characterized by intellectual, social, and neuropsychiatric abnormalities. The purpose of this study was to determine whether or not the genomic imprinting exhibited by these mice would produce phenotypic effects similar to those of Prader-Willi or Angelman syndrome. It was hypothesized that the hybrid mouse pups would display significant differences in anxiety and social behaviors when compared to pups of either inbred parent strain. This hypothesis was tested by two experiments; an open field trial and an analysis of ultrasonic vocalizations. The open field trial was used to measure exploratory behavior and anxiety. The vocalization analysis was used to measure the pups’ ability to communicate with other mice at a young age. There were significant differences in the behavior of the F1 hybrid mice in comparison to the behavior of mice of the parent species as well as an apparent delay in motor development in the F1 hybrid pups. These results could lead to further studies in the effects of genomic imprinting and its effect on behavior.