Research has shown that high fat diets ingested during pregnancy can impair development of the fetus as well as the placenta. The problem is that these perturbations to normal development can have life-long consequences. A new study published in Physiological Reports was interested in whether the volume of amniotic fluid can change with a high fat diet even when the mother does not develop obesity. To examine this, […]
Leptin is a hormone that was discovered in 1994 and was once heavily studied by researchers who had hoped it might be useful in promoting weight loss. It is produced by fat cells and signals to the brain whether those fat cells have sufficient energy, at which time it suppresses hunger and thereby promotes weight loss (WebMD; Klok et al., 2007). One of the reasons it failed as a weight […]
A new review article published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology explored an interesting question: how do prenatal experiences along with the intrauterine environment impact the future development of pediatric and adult obesity in animals? Common marmosets (Callithrix jacchus) are New World monkeys that can spontaneously develop obesity early in life when living in captivity with high food availability and relatively low physical activity. Similar to […]
Several of the posters and talks at the Experimental Biology meeting in San Diego focused on Weddell Seals. They are not only cute, they are really interesting physiologically. Emma Weitzner, a graduate student in the lab of Dr. Heather Liwanag, presented a poster on Weddell seals, which are studied as models of the physiology of diving. Emma and her team recorded diving behavior and collected blood samples from 1 week-old […]
Stress during late pregnancy may result in premature delivery or stillbirth. A new study of pregnant Rambouillet cross ewes, published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology, was designed to understand why lambs succumb to stress late in pregnancy. They found that while arterial blood pressure and heart rates were normal during late gestation (final 2 weeks before birth) in fetuses from pregnant ewes with elevated stress hormones, fetal heart rate and aortic blood pressure declined on the day […]
In honor of Valentine’s Day, let’s talk about prairie voles (Microtus ochrogaster). These animals are often used to study pair bonding because they are one of only a handful of mammalian species that form lifelong socially monogamous pair bonds after mating and cohabitating for at least 6 hours. According to a study published several years ago in Nature Neuroscience, this pair bonding behavior is regulated by specific genes in their […]
Just in case you missed it, I have included a video from YouTube showing research conducted in China that produced the first cloned monkeys using the same techniques that created the cloned sheep Dolly. Some researchers and ethicists worry about this potentially opening the door for human cloning.
Although female northern elephant seals only typically deliver one pup, females will sometimes nurse offspring from other mothers as in this photo by Brocken Inaglory via Wikimedia commons. A situation like this would result in less milk available to each nursing pup. I just read an interesting paper published in Physiology. Animals periodically undergo periods of food deprivation such as during hibernation, mating, molting and migration. During these period of […]
When I think of marsupials, what comes to mind is an image of a mother carrying her young (joey) in a pouch. Contrary to popular belief, however, mother tammar wallabies (Macropus eugenii) have an internal functioning placenta. Albeit, it only develops near the end of their short pregnancy (a mere 26.5 days), just before the developing offspring moves from the uterus to the pouch for further development and nursing. A […]
Samples of fish species from the Poeciliidae family show the diversity in color, fin size and body shape. Kansas State University researchers studied 112 species of these live-bearing fishes and found that males and females evolve differently. Image courtesy of Kansas State University Dr. Michael Tobler and Dr. Zach Culumber at Kansas State University examined 112 species of live-bearing fish (Poeciliidae) and have made some interesting discoveries about their evolution. Their […]
Life Lines by Dr. Dolittle 