Date of Award

Spring 4-2022

Degree Type


Degree Name

Master of Science - Biology



First Advisor

Dr. Josephine Taylor

Second Advisor

Dr. Lindsay Porter

Third Advisor

Dr. Zeljko Radulovic

Fourth Advisor

Dr. Keith Hubbard


Amblyomma americanum is a medically important vector in the southeast United States. Cellular and molecular aspects of the immune system of this species were examined. To investigate cellular processes, hemocytes produced in response to gram-negative infection were characterized according to their ultrastructure. Four hemocyte types were identified: prohemocytes, plasmatocytes, type-I granulocytes, and type-II granulocytes. To elucidate molecular processes, we investigated AamTRAF as an immune-related gene by silencing the gene using RNAi then quantifying the hemocytes after inoculation with gram-negative and positive bacteria. It was found that silencing AamTRAF caused a decrease in hemocyte proliferation in response to gram-positive but not gram-negative bacteria. Knowledge gained from this research contributes to the understanding of the Amblyomma americanum immune system, with the long-term goal of determining how human pathogens evade detection in this vector.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.



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