As if sucking our blood wasn’t bad enough, I was horrified to learn that mosquitoes also pee on us while they’re drinking. Yuck! In this time machine, we revisit a 1987 paper published in Physiology that explains why. Female mosquitoes require blood meals to obtain the proteins necessary for egg production. During a single meal, they can consume up to twice their body mass in blood. That’s like a 150-pound […]
Predators with a taste for blood abound on the remote Galapagos Islands… Meet the Vampire Ground Finch 19 different species of finches can be found on the Galapagos Islands. Observations of their various beak shapes, specialized for different diets and purposes, helped Charles Darwin develop the theory of evolution. One species I do not recall learning about in Biology class, however, is the vampire ground finch (Geospiza septentrionalis), which can […]
Humans have occupied high altitude environments for over 10,000 years, allowing ample time for some remarkable adaptations to hypoxia. Such adaptations we have already discussed in people living on the Tibetan Plateau (elevation: 4,500 meters on average) include higher breathing rates combined with lower levels of hemoglobin, the molecule that carries oxygen in the blood, compared to lowland populations, which helps prevent mountain sickness as well as the formation of […]
Just in time for Halloween: I came across a preprint in bioRxiv that identified 13 genes missing from vampire bats (Desmodus rotundus), but found in other bat species. Animals that drink blood, or sanguivores, have to deal with a diet that is high in protein but typically lower in fat and sugar. Many of the missing genes are thought to be related to their ability to drink blood and obtain […]
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 […]
As you may already know, bone marrow contains cells that specialize in both bone as well as blood maintenance. Stem cells destined to become white blood cells, red blood cells and platelets are called hematopoietic stem cells (aka: HSCs). CXCL12 is a special ligand that helps keep HSCs in the bone marrow by acting as a chemical attractant for the chemokine receptor C-X-C (CXCR4) found on HSCs. Some researchers are […]
Researchers have known that some lizards have green blood due to bile pigments: In fact, six species of lizards found in New Guinea are known to have green blood. The levels of bile found in their blood are four times higher than the toxic level for humans. New research shows that green blood evolved independently 4 times in evolutionary history. These findings suggest that high levels of circulating green bile […]
Researchers studying komodo dragons (Varanus komodoensis) at George Mason University discovered 48 previously unknown peptides in their blood that might have antimicrobial properties. Their findings were published in the Journal of Proteome Research. For the largest lizard, these peptides may help prevent the animals from getting infections from their own saliva, which is host to at least 57 species of bacteria. With this number of bacteria, it is easy to understand why they evolved so many […]
Life Lines by Dr. Dolittle 