Graduation Year
2021
Graduation Month
May
Document Type
Thesis
Degree Name
Bachelor of Science
School or Department
Biological Sciences, Division of
Major
Biology – Human Biological Sciences
Faculty Mentor Department
Biological Sciences, Division of
Faculty Mentor
Zachary A. Cheviron
Keywords
Hypoxia, plasticity, placenta, high-elevation
Subject Categories
Other Ecology and Evolutionary Biology
Abstract
High altitude residence causes fetal growth restriction (FGR) during pregnancy in lowland mammals. Highland-adapted mammals do not experience this altitude-dependent FGR, suggesting that adaptation to altitude has produced some protective mechanisms. However, the specific mechanisms by which highland-adapted mammals preserve fetal growth at altitude remain unknown. We hypothesized that highland-adapted populations protect fetal growth through structural changes to the placenta that increase surface area for nutrient and gas exchange. We tested this hypothesis using deer mice (Peromyscus maniculatus), from populations native to low [400 m, Lincoln, NE] and high [4300 m, Mt. Evans, CO] altitudes. We predicted structural adaptation would occur via increases to the relative size of the labyrinth zone (LZ), the layer within the rodent placenta where nutrient and gas exchange occur. Placentas were collected from lowland and highland deer mice undergoing pregnancy under normoxia or hypoxia (60 kPa) to understand how hypoxia-dependent structural plasticity might interact with adaptive remodeling of the placenta (N = 5-7 per strain and treatment). Using immunohistochemistry, we quantified the size of each placenta zone. Our preliminary results show that highlanders have relatively larger placental arteries and LZs under both normoxia and hypoxia (P < 0.05 in generalized linear mixed model), suggesting that blood delivery and area for exchange (as determined by the LZ size) may protect fetal growth in highlanders. Future work will pair histological characterization of placental structure with transcriptomics to guide a mechanistic understanding of how placentation constrains to fetal growth under hypoxia.
Honors College Research Project
Yes
GLI Capstone Project
no
Recommended Citation
Johnson, Hannah C.; Wilsterman, Kathryn; Good, Jeffrey M.; and Cheviron, Zachary A., "Does adaptation to high altitude affect hypoxia-dependent structural plasticity of the placenta?" (2021). Undergraduate Theses, Professional Papers, and Capstone Artifacts. 320.
https://scholarworks.umt.edu/utpp/320
Included in
© Copyright 2021 Hannah C. Johnson, Kathryn Wilsterman, Jeffrey M. Good, and Zachary A. Cheviron