Project summary To maintain homeostasis, multicellular eukaryotes have adopted specialized mechanisms to enhance O2 uptake and distribution, resulting in dynamic respiratory and circulatory systems, capable of responding to changes in O2 availability on local, organismal, and temporal levels. The key to hypoxia survival resides in combined physiological responses, such as metabolic depression, protection against oxidative damage and redistribution of blood flow - both nitric oxide and oxidative stress pathways are key players in response to hypoxia, due to its relationship to vascularization and inflammation; thus understanding the role of these players would be key in illuminating such common and detrimental human diseases that are dependent on pathological changes in blood vessels (ie. cardiovascular diseases). The Pathway to Independence Award will enable me to pursue an ambitious research program investigating the convergent adaptive mechanisms associated with oxygen-limited environments and dissecting out the role of those gene-regulatory networks associated with hypoxia, using zebrafish. This proposal will test the hypothesis that (Aim 1) similar genes and regulatory networks underlie the routes for adaptation to oxygen-limited environments, ie. high-altitude, in independent animal lineages, (Aim 2) the plastic response to hypoxia exposure makes use of the genes associated with the nitric-oxide biochemical pathway, and finally (Aim 3) early exposure to hypoxia could allow for preacclimation as an adult and also be passed onto progeny via changes to both the epigenomic and transcriptomic landscape. With 7 first-author publications in journals including recent publications in the Proceedings of National Academy of Sciences (PNAS), and Molecular Biology and Evolution, I have an impeccable track record of research productivity and creativity. The proposed experiments will provide me with valuable training in bioinformatics, genomics, molecular genetics and the use of zebrafish as a model. Under the mentorship of Dr. Nathan Clark, I will gain the experience and training necessary to transition to an independent academic position. To further my career development, I will present at conferences, mentor students, attend relevant courses, and publish my findings. My assembled K99 mentorship committee, composed of Dr. Warren Burggren, Dr. Michael Hiller, Dr. Joseph Prchal and Dr. Kristen Kwan, will provide me the necessary expertise to use large-scale genomic data in performing comparative genomics, fully utilizing the power of zebrafish as a model to characterize the role of the nitric-oxide pathway in mediating the plasticity of hypoxia response, and analyzing how hypoxia exposure affects developmental and transgenerational plasticity. I will participate in formal training opportunities and seek attendance at renowned Marine Biological Laboratory (MBL-UChicago) technical courses for intense training in using zebrafish as a model.

Project Narrative The objective of this project is to prepare Dr. Allie Graham to transition to a position as an independent, tenure- track academic investigator. This project focuses on identifying convergent mechanisms in the adaptation to hypoxia in high-altitude mammal lineages, and also utilizes zebrafish as a model for hypoxia response to specifically probe the roles of nitric-oxide signaling in hypoxia acclimatization, as well as understanding how hypoxia exposure during development primes future response, both in the adult and in its offspring. This proposal represents an opportunity to improve our understanding of which mechanisms hypoxia-adapted lineages use to mitigate the long-term detrimental physiological effects of long-term hypoxia exposure, like pulmonary hypertension, erythrocytosis/polycythemia, and cardiovascular disease.