Life Lines by Dr. Dolittle

Sponsored by the American Physiological Society

Nature’s Solutions

It’s getting cold outside…what’s a squirrel to do?

As the weather cools down, animals must find ways to stay warm. This is especially important for small animals as they lose body heat faster than larger animals. One way to stay warm is by increasing your metabolism to create body heat, although this process requires a lot of energy. That can be a problem in areas where food may be scarce in the winter. Although some animals, like the […]

Continue Reading →

Mice have special ‘jumping genes’ that help them survive viral infections

Researchers at the University of New South Wales (UNSW), Sydney discovered a ‘jumping gene’ that prevents the immune system of mice from overreacting to a viral infection. Jumping genes are movable nucleic acids, or transposable elements, that make up nearly 2/3 of the genome in mammals. They help regulate the expression of genes. Some transposable elements in the genome are new and some originated in ancient times. In the new […]

Continue Reading →

Aging and Immortality

Have you ever heard of the ‘immortal’ jellyfish, Turritopsis dohrnii? These tiny creatures (about 4.5 mm) are aptly named for their ability to essentially live forever. According to the Natural History Museum, when these jellyfish are damaged, they can actually revert to a prior life cycle as a polyp and become an adult jellyfish (aka, medusa) all over again. This process is called transdifferentiation. Check out this video from the […]

Continue Reading →

Making heat to lose weight

There are many ways to stay warm on a cold day. We can seek shelter, turn up the thermostat, and huddle close together. Obvious physical adaptations to cold include fur, feathers, and clothing in the case of humans…and some pampered dogs. Blood vessels near the skin may also constrict to prevent heat loss and some animals develop a layer fat under the skin that acts like insulation. We may also […]

Continue Reading →

New study discovers how zebrafish mend a broken heart

A new study has helped unravel the mystery explaining how zebrafish regenerate a broken heart. Their findings, published in Nature Genetics, reveal how these amazing little fish can regrow up to 20% of their heart in only 2 months following an injury. This regeneration is driven by signals released from special cells called fibroblasts. When the heart of zebrafish is injured by a stimulus that mimics a heart attack (using […]

Continue Reading →

Buoyancy and Balance

Existing species of coelacanths (pictured above) are descendants of a group of fish that existed about 410 million years ago, during the early Devonian period. They can be found in the Western Indian Ocean off the coast of Indonesia. These fish are really interesting because they have very low metabolic rates. In fact, their metabolism is among the lowest of any other existing vertebrate. Even sloths are jealous of their […]

Continue Reading →

Turning up the heat

There are several ways to stay warm on a cold day. If you are human, you can turn up the heat in your home, put on a sweater, snuggle, and even produce body heat through shivering as well as non-shivering metabolic pathways – although the ability to produce heat metabolically typically declines with aging. If you are a small mammal, turning up the heat or putting on a sweater are […]

Continue Reading →

EB 2022: Seals, seals, and more seals

Several posters at EB 2022 in Philadelphia this month were focused on understanding the remarkable physiology of diving seals. Although we may think of the image below when we picture seals, they really are quite the athletes in water. Kaitlin Allen (a graduate student working in the laboratory of Dr. José Pablo Vázquez-Medina at the University of California Berkeley) presented her research on Northern elephant seals and how these animals […]

Continue Reading →

EB2022: Facing Oxygen Challenges

I learned a lot about how animals adapt to changing environmental oxygen levels in the Experimental Biology symposium on “Functional Integration across the Oxygen Cascade in the Face of Challenging Environments.” Here is what I learned… The first presenter, Dr. Lara do Amaral-Silva (postdoctoral fellow at the University of North Carolina at Greensboro working with Dr. Joseph (Joe) Santin), spoke about her research on adaptations in the bullfrog “super-brain” that […]

Continue Reading →