An Evaluation of Heat Shock Protein Expression in the Blood Cells of Free-Living Common Loons (Gavia Immer)
Research Subject Categories::NATURAL SCIENCES , Research Subject Categories::NATURAL SCIENCES::Biology::Organism biology::Animal physiology , Research Subject Categories::NATURAL SCIENCES::Biology::Cell and molecular biology::Toxicology
Common loons in the northeastern United States are subjected to a wide variety of environmental and anthropogenic stressors. Many of the biomarkers currently used to assess individual or population health of common loons are influenced by capture and handling, therefore there is a need to develop new biomarkers of physiological condition that can aid in the management of this species. Heat shock protein 70 (HSP70) is a stress protein found within the red blood cells of many vertebrates that has been used as a biomarker of general stress in avian species. The objective of our study was to evaluate the use of HSP70 as a potential intracellular biomarker of physiological condition of loons from across New England. We collected blood samples from adults and hatch-year chicks across Maine, New York, and Massachusetts during the 2021 breeding season, and measured indicators of stress at the circulatory (% hematocrit, plasma glucose, blood mercury), immune (heterophil to lymphocyte ratio), and cellular level (hemoglobin and HSP70 protein expression). Our results revealed that: (1) HSP70 is present in the red blood cells of common loons; (2) HSP70 expression does not vary significantly with age or sex; (3) HSP70 expression does not appear to be correlated to blood mercury levels, and (4) there is a trend that higher expression of HSP70 in blood cells may be associated with anemia in common loons. Together, the evidence we present suggests that HSP70 should be further investigated as a potential blood biomarker of physiological condition in loons when combined with other measurable factors of environmental and anthropogenic stress.
To begin with, I would like to express my sincere gratitude and appreciation to my thesis advisor Dr. Michelle Y. Monette for giving me the opportunity to work on this project, providing valuable guidance and feedback, and challenging me to grow as a researcher. Dr. Monette provided me with unlimited support and unconditional guidance throughout my master's program. Additionally, I would like to extend my gratitude to Dr. Theodora Pinou for her guidance and mentoring throughout my degree process. Without the support and collaboration of many people, this research would not have been possible. Lucas Savoy and the Biodiversity Research Institute deserve a tremendous thank you for providing funding for this project, helping to collect samples, and providing guidance, support, and feedback throughout the past two years. As well, I want to thank Dr. Nina Schoch and the staff at Adirondack Center for Loon Conservation for the opportunity to be involved in this project and for assistance with sampling. Also, I would like to thank Dr. Randall Walikonis from the Department of Physiology and Neurobiology at the University of Connecticut, Storrs for the use of the Licor Odyssey Infrared Scanner. Lastly, thank you to the members of my committee, Dr. Mark Pokras, Dr. James Paruk, and Dr. Patrice Boily, who provided guidance and support throughout my degree. I am grateful to the National Science Foundation for awarding me a 2021 Graduate Research Fellowship, which has enabled me to complete this research. As a final note, I would like to thank my family, friends, and fellow graduate students for their constant support and love.