What’s the News: When mosquitoes finish a piping-hot meal of blood, they have more than your average postprandial snooze, biologists have found: they go into heat shock, producing proteins most organisms only make when something is terribly wrong.
How the Heck:
- A team of biologists slapped tiny temperature sensors on mosquitoes and monitored them before and after they fed on chicken blood. The skeeters’ body temperature climbed by a whopping 20 F (71.6 to 89.6 degrees) in one minute, one of the biggest temperature jumps ever recorded in a cold-blooded creature.
- While the mosquitoes’ body temperatures were elevated, they were also producing nearly eight times the normal amount of heat shock protein 70 (Hsp70), a protein that helps keep crucial enzymes from getting denatured by the heat and usually only shows up in humans when we’re running a fever. The two effects were solely because of the meal’s temperature: they happened when the mosquitoes were fed warm saline solution and didn’t happen with cooler blood.
- When the team knocked down production of Hsp70 and fed the mosquitoes hot blood, the females laid 25 percent fewer eggs and digestion of the blood proteins seemed to slow down, indicating that Hsp70 works to keep those processes safe from the ravages of too much heat.
- And this process isn’t a one-species fluke: The team found that the increases in body temp and Hsp70 production held across three species of mosquitoes and the bedbug, another notorious blood-sucker.
What’s the Context: Heat shock, the production of certain proteins to preserve the structure of heat-sensitive enzymes after a temperature jump, happens in pretty much every organism. But it’s nearly always a survival response in the face of trauma like disease, drought, or stress. The fact that a variety of blood-eating insects go into heat shock on a regular basis, just as a byproduct of having lunch, is unexpected and fascinating. What else are these little suckers hiding?
Reference: Joshua B. Benoit, Giancarlo Lopez-Martinez, Kevin R. Patrick, Zachary P. Phillips, Tyler B. Krause and David L. Denlinger. Drinking a hot blood meal elicits a protective heat shock response in mosquitoes. PNAS, April 25, 2011 DOI: doi:10.1073/pnas.1105195108
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