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Blood of King Louis XVI Reveals Genetic Risk for Bipolar Disorder

• Because ornate box turtles (Terrapene ornata ornata) are endangered in Wisconsin, the Department of Natural Resources (DNR) has been evaluating how many remain in the state. These handsome turtles are terrestrial and widely scattered in grassland areas. About five inches in length when fully grown, they are characterized by yellow bands radiating downward from the top of the shell (carapace) to its margins. The DNR has done field work trying to find and count these rare turtles, but their camouflage makes this a difficult task.

Finally the agency turned to dogs to solve the problem. Boykin Spaniels can be trained to search out ornate box turtles and gently take them back to their handler. Dog trainer John Rucker arrived at the DNR’s research site with four Boykins and said to them, “O.K, find the turtles.” Using their sensitive noses to pick up the turtles’ scent trail, within minutes they started finding them, and in an hour and a half the dogs found 19 of the rare turtles. Previously, 15 humans searching the same area had found only one turtle. Thanks to John Rucker and his turtle dogs, the DNR now has a much better understanding of how many ornate box turtles live in Wisconsin. (Milwaukee Journal Sentinel, June 13, 2013)

• Some mosquitoes prefer biting humans over other animals, probably because humans often live in groups near bodies of water. They are specifically attracted to our body odor and heat, as well as the carbon dioxide we exhale. At Rockefeller University the DNA of one people-loving mosquito species was modified by removing a single gene for the odor receptor that responded to human scent. Allowed to reproduce, the resultant mosquitoes did not seek out humans for a meal. Perhaps this finding will lead to better repellents. (The Week, June 21, 2013)

• In 1793 King Louis XVI of France was beheaded, along with his wife Marie Antoinette. A witness soaked up some of the king’s blood in a handkerchief and stored the cloth in a gourd. Recently researchers found the gourd and salvaged enough dried blood to analyze the king’s DNA. They discovered that he had genetic risk factors for diabetes, obesity and bipolar disorder. Historians have written that the king was inept and often indecisive, and the new information, especially as regards bipolar disorder, is in keeping with this kind of behavior. (Science, March 24, 2013)

• Cicadas (Magicicada septendecim) are the loud, red-eyed singers of the insect world. Cicada populations can spend 17 years maturing underground, feeding by sucking fluids from tree roots. After they have undergone about five larval stages underground, warm weather coaxes them out of the ground, where they molt one more time and begin short flights and mate. Biologists have been baffled by the fact that in a given region of the eastern U.S. they all emerge at once after 17 years, a phenomenon one biologist described as a “frenzied horde.” Their density may reach 350 individuals per square yard, and the males’ raspy singing can reach 95 decibels, enough to harm human hearing.

Biologists would like to know how they communicate and synchronize their emergence while underground. And why do they wait 17 years to emerge? Many entomologists theorize that the massive emergence is a way to overwhelm predators, for the cicadas have no real defense mechanisms. Not many biologists study adult cicadas, since 17 years elapse before the next study group emerges. (Nature, May 30, 2013)