Life Lines by Dr. Dolittle

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Extreme Animals

Adults are better adapted to survive without oxygen

Adult fruit flies (Drosophila melanogaster) are more tolerant of environments devoid of oxygen than their larvae. In fact, they are able to survive up to 12 hours without oxygen by becoming paralyzed, which enables them to dramatically reduce metabolism and the need for oxygen. In contrast, Drosophila larvae expend a lot of energy trying to escape and are only able to tolerate a couple of hours without oxygen. This is surprising […]

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Remarkable hypoxia and cold tolerance of rodents native to the Tibetan plateau

The plateau zokor (Eospalax baileyi) is an underground dwelling rodent species native to the Tibetan plateau (2000-4200 meters in elevation). A new study published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology explored how these animals were adapted to extract oxygen from an environment with very low levels (83-88% of atmospheric). Hemoglobin molecules found in red blood cells are responsible for binding oxygen and transporting it to tissues […]

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High altitude deer mice have less stress?

Animals that live at high altitude have evolved a number of physiological adaptations to deal with the low atmospheric oxygen concentrations (hypoxia). For low altitude acclimated animals, short exposures to high altitude results in activation of the sympathetic nervous system (i.e. the fight or flight response). This is a good thing because activation of this system results in more blood flow, especially to the heart and brain to help protect oxygen […]

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Animals that eat plastic?

Have you seen this? A video just released by Yellowstone National Park talks about how some heat-loving microorganisms can break down plastics. Pretty cool.   Not so cool was the recent finding published in the Proceedings of the Royal Society B: Biological Sciences that Astrangia poculata coral polyps are eating microplastics instead of brine shrimp eggs…on purpose. In the lab, the team were able to observe the corals consuming nearly […]

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Rapid switches in metabolism of hibernating animals

  In a new study published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology, researchers examined how changes in metabolism during torpor are regulated in 13-lined ground squirrels (Ictidomys tridecemlineatus). During hibernation, these animals cycle between bouts of torpor (about 2 weeks each) when their metabolism is reduced by 95% and body temperature can drop to 5degC and short states of interbout euthermia when both temperature […]

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Blood flow shifts during diving

In many mammals exposure to hypoxic conditions results in the release of a vasodilator called nitric oxide, which improves blood flow and protects oxygen delivery to tissues throughout the body. Diving animals appear to be unique in that some of their blood vessels stay constricted while they are diving even though they experience hypoxia. A new study published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology explored […]

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Working towards prolonged spaceflight

Spaceflight has always fascinated me. While long distance spaceflight looks so routine in science fiction shows, the reality is much different as we have yet to conquer the complications surrounding long duration deep-space flight. One issue is how to feed astronauts traveling long distances as we do not yet have replicator technologies. If we did, I would have coffee whenever I wanted it. In a new article published in Physiology, […]

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Highlights from the last day in Orlando

Today marked the final day of the 2019 Experimental Biology meeting in Orlando. As usual it was a great day for Physiology. Crupi et al., from the University of Messina and the Universita della Magna Grecia in Italy put up a poster presentation describing their research on how red blood cells respond to environmental toxins. Their research showed that isolated red blood cells from rabbits are more sensitive to venoms […]

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Highlights from EB 2019

There were so many poster presentations on comparative and evolutionary physiology today at the 2019 Experimental Biology conference that it was impossible to see them all. Here are some highlights: Dr. Michael Hedrick from California State University – East Bay, presented his research on African cheetahs (Acinonyx jubatus) examining adaptations that cheetahs have evolved to supply their muscles with oxygen so efficiently, given they maintain the world record for being […]

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Dietary carotenoids and oxidative stress- What can we learn from birds?

Congratulations to this year’s Dr. Dolittle Travel Award winner, Alex Mohr from Arizona State University! Alex is presenting his research at the annual Experimental Biology conference in Orlando, FL (Mohr AE, Girard M, Rowe M, McGraw KJ, Sweazea KL. Varied Effects of Dietary Carotenoid Supplementation on Oxidative Damage in Tissues of Two Waterfowl Species).  Here is his award-winning blog entry describing his research on carotenoids in ducks: In relation to tissue […]

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