Project Title

Collaborative Research: Role of Endothelial Cell Activation in Hypoxia Tolerance of an Elite Diver, the Weddell Seal

Summary

Event Number:
B-464-M
NSF/OPP Award 2020664

Program Director:
Dr. William Ambrose

ASC POC/Implementer:
Ryan Steiner / Randolph Jones

Principal Investigator(s)

Dr. Jose Pablo Vazquez-Medina
jpv-m@berkeley.edu
University of California Berkeley
Berkeley, California

Location

Supporting Stations: McMurdo Station
Research Locations: McMurdo Sound Sea Ice

Description

The Weddell seal is a champion diver with a high natural tolerance for low blood oxygen concentration (hypoxemia) and inadequate blood supply (ischemia). The processes unique to this species protects their tissue from the inflammation and oxidative stress observed in other mammalian tissues exposed to such physiological conditions. Weddell seals’ repetitive short dives before long ones are hypothesized to precondition the tissues and activate the protective processes. This project aims to understand the signatures of these processes through the use of molecular, cellular, and metabolic tools. In the field, blood samples will be taken after seals are isolated in a dive hole, and their diving performance will be recorded. It is expected that the blood will contain metabolites that can be related to molecular pathways identified in the lab experiments. This study newly investigates endothelial cells (i.e., cells in a single-cell layer lining blood vessels) that can relate directly to seal breathing and how breath hold affects cellular function. Collaborators on the team will provide field support, with the ice camp, dive hole for the seals, and telemetry associated with the seals’ dives.

Field Season Overview

Five participants (including a veterinarian) will deploy to McMurdo Station from mid-October through mid-December to focus on three objectives: (1) collecting tissue, both from expelled placentas and opportunistic necropsies of animals who die of natural causes within the Erebus Bay colony; (2) collecting serial blood samples from seals holding their breath during sleep, to validate blood sampling protocols planned for isolated dive hole studies in a second field season; and (3) deploying instruments to measure heart rate and blood oxygen levels in up to 12 free-ranging Weddell seals. Crary Lab resources will be heavily relied upon to maximize on-site experiments that can be performed on the limited samples collected without an isolated dive hole. The McMurdo Station-based field plan shifts logical support plans away from a sea ice-based field camp and toward vehicle support (e.g., snowmachines and a PistenBully), plus helicopter support for reconnaissance flights (recces) in early and late season and contingency flights as needed to recover any wayward seals.

Deploying Team Members