Highlights from the morning sessions

Hypoxia inducible factors in health and disease
G. Haddad, “Genomic information controlling the adaptation to long term hypoxia: insights from flies and humans”
Dr. Haddad’s laboratory has discovered that hypoxia tolerance is inherited in flies. When naive flies are exposed to anoxia (no oxygen) for 1-3 hours, they become immobile but recover fully with subsequent exposure to room air. His team exposed generations of flies to decreasng oxygen conditions and after more than 32 generations, the flies were able to function well in only 3.5% oxygen and had developed significant genetic mutations that support life in low oxygen along with smaller body masses. This is relevant to humans as well since many of the genes that control tracheal branching are conserved between flies and humans.

Sodium and water homeostasis

K. Choe, “Non-mammalian models of salt and water homeostasis: Advantages and examples of success”
Dr. Choe discussed the utility of c. elegans in the study of osmotic stress because these nematodes are able to tolerate very high osmotic environments (high salt) by losing water seemingly without significant pathologies. Very little information exists on how the kidney (a single-celled organ) compensates, which is currently a focus of his research.

J. Donald, “Appetite regulation in desert adapted Spinifex hopping mice during water deprivation”
These desert mice are remarkably well-adapted for life in the desert and can tolerate long bouts of water deprivation without significant pathology. In fact, Dr. Donald’s team has found that 30 days of water deprivations results in weight loss, due mainly to a loss in body fat as it is being used to make metabolic water. What was really interesting was that levels of the appetite stimulating hormone ghrelin were elevated during this time presumably allowing the animals to pull water from their diet.

A. Barbaria, “Comparative studies of the desert rodent Dipodomys merriami and the Munich Wistar vrat urine concentrating mechanisms”
A. Barbaria described work in her lab on the kangaroo which has likewise evolved well-adapted kidneys that are able to lproduce highly concentrated urine allowing the animals to survive 2 months of water deprivation!

P. Bie, “Renal hemodynamics in the anesthetized giraffe”
Dr. Bie described his work with giraffes, which have very high blood pressure that is necessary to ensure delivery to the brain. He focused on how the kidneys are protected from the very high blood pressure conditions. **He has promised to bring a plastinated giraffe kidney to his poster tomorrow!**