Life Lines by Dr. Dolittle

Sponsored by the American Physiological Society

Reproduction and Development

Q&A with Dr. Jon Harrison, Meredith Johnson, and Jordan Glass

We recently interviewed Meredith Johnson (graduate student), Jordan Glass (graduate student), and Dr. Jon Harrison from the School of Life Sciences at Arizona State University about the research they presented at the 2021 annual Experimental Biology conference.   Q: You mentioned in one of your presentations that insects have an ‘unusual’ respiratory system. Can you explain how it differs from mammals?  Dr. Harrison: Insects exchange gases through blind-ended air-filled tubes called tracheae. There […]

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New research working towards preventing and treating necrotizing enterocolitis in premature babies

Necrotizing enterocolitis is an inflammatory disease of the intestines. New research suggests that premature babies are at risk of necrotizing enterocolitis in part because they have low levels of arachidonic and docosahexanoic acids in their gut, which regulate inflammation. Doctors routinely administer nutritional supplements to premature babies via an intravenous (i.v.) route until the gastrointestinal tract develops and the babies are able to process oral foods. This parenteral nutrition helps […]

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Frogs are teaching researchers about autism

Dr. Helen Willsey at the University of California San Francisco is seeking to understand how autism develops with the help of frogs. Because frogs produce thousands of embryos at the same time, she is able to quickly study the effects of many different gene alterations in the offspring. While the embryos are at the two-cell stage of development, her laboratory alters genes in just one of the cells using CRISPR-Cas9 […]

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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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Dwarfism documented for first time in wild giraffes

A disorder affecting the normal development of cartilage and bone has been observed in wild giraffes. While skeletal dysplasia, or dwarfism, has been observed in captive and domestic animals such as dogs, cows, rats, pigs and marmosets, it is not often seen in wild animals. In a new study, researchers used photography to document the condition for the first time in a wild Nubian giraffe calf (Giraffa camelopardalis camelopardalis) in […]

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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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Live fast, die young

Researchers have long known that smaller animals have higher metabolisms and tend to die younger than larger animals. Think about it – a mouse typically only lives about 2 years whereas an elephant in the wild may live 50-70 years, depending on the species. After studying over 700 species of birds and 540 species of mammals, scientists discovered that migratory animals also live faster (mature and reproduce earlier) and die […]

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How a really long winter’s nap can impact sperm production

As winter approaches, hibernating animals will finalize their preparations for taking a ‘long winter’s nap’. These remarkable animals reduce their metabolism to help conserve energy at a time when environmental resources are scarce and considerable energy would otherwise need to be spent on just staying warm. For many species of hibernators, periodically entering this state of torpor allows them to reduce their energy needs by 90% compared to intermittent states […]

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How some fish may compensate for low environmental oxygen

     Adult fish rely on gills to extract oxygen from the surrounding water. Larval fish, on the other hand, do not have well-developed gills and instead rely primarily on gas exchange across their skin.      In a new study published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology, researchers examined whether larval fish could use their pectoral fins to increase the flow of water […]

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Researchers explore why fetuses that experienced intrauterine growth restriction have smaller muscles

We have talked several times about the long-lasting issues related to growth restriction of a fetus during pregnancy: Intrauterine growth restriction increases risk of cardiovascular disease as adults Intrauterine growth restriction increases risk of insulin resistance as adults It can also result in offspring that have smaller muscles. New research published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology suggests this may be due to adaptations to […]

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