Life Lines by Dr. Dolittle

Sponsored by the American Physiological Society

Nature’s Solutions

Extreme tolerance of dehydration stress

Talk about an extreme animal. During the rainy season annual killifish, Austrofundulus limnaeus, lay eggs that are resistant to droughts. This is an important attribute for a fish that lives in temporary pools of water. The stress-resistant embryos within the eggs literally shut down their metabolism to survive months – possibly years without water. For many fish, exposure to air (and oxygen) can cause profound oxidative stress. Remarkably, this is […]

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Scientists discover gene that may protect from hypertension

Giraffes are extreme. Given their long necks, their blood pressure is 2.5 times higher than ours, which ensures that oxygenated blood makes it all the way up to their head. Having high blood pressure, however, is simply a normal characteristic of being a giraffe. A new study published in Science Advances explored the giraffe genome to identify genes that might help protect the cardiovascular system of giraffes by comparing their […]

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Anoxia tolerance in goldfish

The reason mammals are not very good at tolerating hypoxic (i.e. low oxygen) environments, is because the brain relies heavily on oxygen for metabolism. It is so stingy, it uses about 20% of the oxygen in the body to make ATP. Without oxygen, the brain has to rely on glycolysis to make ATP and this process is not good at meeting the energy requirements of the neurons, ultimately resulting in […]

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Metabolic costs of reproduction, eating, and increasing temperatures

Planarians are rather cute little flatworms, although they tend to wreak havoc in fish tanks. Researchers have long been fascinated by their ability to regenerate body parts when injured with the help of adult stem cells. More recently, they have gained attention for their ability to survive long periods of time without eating by “degrowing”, i.e. getting smaller but still keeping their shape and functions intact. I would shrink too […]

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Could the ocean hold a cure for Covid-19?

In searching for treatments for Covid-19, researchers discovered that a cancer drug called Aplidin (aka: Plitidepsin), originally isolated from Mediterranean sea squirts, was up to 27.5 times more effective at killing the virus in cell cultures than the FDA-approved drug Remdesivir! Importantly, it was also shown to be effective at preventing the virus from replicating in mice. Sources: Youtube KM White, R Rosales, S Yildiz, T Kehrer, L Miorin, E […]

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How exercise training and diet may impact exercise performance

Both diet and exercise training are associated with muscle performance and endurance. Migratory birds undergo intense endurance exercise. In fact, a recent review indicated that flapping flight costs more energy (9 x increase from basal metabolic rate) than required by elite athletes competing in the Tour de France (4.3 x increase from basal metabolic rate) (Butler, 2016). Unlike running animals, migratory birds fuel endurance exercise with fats as opposed to […]

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Extreme Fasting

While giant pandas roll in horse manure to stay warm in the winter (that’s a different story), other animals spend up to 8 months hibernating to conserve energy during times of reduced food availability and freezing temperatures. During their long winter’s nap, animals such as the Arctic ground squirrel and 13-lined ground squirrel go without food or water while at the same time avoiding muscle wasting – a rather impressive […]

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Staying warm on a chilly day

Giant panda bears have a very unusual trick to staying warm. This unusual behavior was first noted by scientists at the Chinese Academy of Sciences in Beijing who observed a giant panda rolling around in horse manure in the Qinling mountains in central China during the winter of 2007. To see whether this was just a rogue panda or a more common behavior, scientists set up camera traps and observed […]

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Long sperm, short sperm, fast sperm, slow sperm

I read an interesting review published in Physiology that examined how sperm from different species are especially evolved to help promote fertilization, which if successful, results in the creation of an offspring. It is simply amazing to think of the multitude of ways this process occurs in nature. Take marine invertebrates and fish for example. These animals release eggs and sperm into the water. In contrast, fertilization happens internally in […]

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New study may help shed light on avian diversity

An international team of scientists have characterized the genome of 363 species of birds representing 92.4% of avian families. 267 of these species were newly released sequences as part of the Bird 10,000 Genomes (B10K) Project. The goal of this project is to find both similarities as well as unique genome variations among lineages of birds that might contribute to their amazing biodiversity. The study also confirmed that the common […]

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