Meeting Abstract
To maintain homeostasis, multicellular eukaryotes have evolved tight coordination of numerous genes that control specialized mechanisms to enhance O2 uptake and distribution, resulting in dynamic respiratory and circulatory systems, capable of responding to changes in O2 availability. Environmental stressors such as changes in temperature, salinity, and pH are well-studied in intertidal systems, but hypoxia is often overlooked, even though it is an important physiological threat in marine habitats. In this study, we test the ability of the intertidal copepod Tigriopus californicus to withstand low-oxygen conditions for extended periods of time, as well as the impact of hypoxia on developmental time points and survival. We also assay the transcriptional response of T. californicus to hypoxia stress over acute and chronic exposure times, by utilizing RNA-seq to determine which genes/pathways are involved. Ultimately, we show that T. californicus can withstand prolonged exposure to extreme oxygen deprivation with little to no mortality in adults, and no significant change in development in larvae/juveniles. In addition, we show that T. californicus has secondarily lost key HIF-pathway members, and that the transcriptional response to hypoxic stress has been off-loaded to (or co-opted by) other mechanisms, including genes involved in cuticle reorganization and ecdysis, as well as mitochondrially embedded/localized genes associated with pathways of oxidative stress.
