A team of researchers has found that nocturnal lemurs thought to belong to different species because of their strikingly different coat colors are not only genetically alike, but belong to the same species. The team, which includes Laurie R. Godfrey, professor of anthropology at the University of Massachusetts Amherst, and UMass graduate student Emilienne Rasoazanabary, has just published its findings in the open access journal BMC Evolutionary Biology.
The lemurs they tested had three different coat colors and lived in different types of forest locations in southern Madagascar -- classic characteristics of separate nocturnal species. Surprisingly, the researchers found that although the lemurs appeared to be different species because they were visually distinct, they did not differ genetically. According to the sequence of this specific gene, all belong to the same previously identified species, Microcebus griseorufus.
The authors also show that lemurs with each of the three different coat colors could be found in all three geographical locations in similar proportions. They note that lemurs are nocturnal animals and tend to depend on auditory cues, or smell, more than on visual cues to recognize each other. They say that this could explain why a certain amount of variation in coat color does not affect species recognition in the mouse lemurs.
Using cooler water to wash shell eggs during a second washing can help cool them quicker. This reduces the potential of foodborne pathogen growth both inside the eggs and on the eggshell surface, according to scientists with the Agricultural Research Service (ARS).
Airborne volatile compounds that attract plant-feeding insects to alfalfa could help growers control cotton pests with fewer pesticides.
Another study combined the chemical cues with a green-light-emitting diode (LED), which imitated a visual cue that attracts plant-feeding insects. Alone, the LED drew several females, but when combined with volatile or synthetic cues, it attracted both males and females at all stages of maturity. In some tests, the LED-synthetic compound combination drew positive responses of 80 percent or higher.
Fruit flies' ability to discern one sex from another may depend on the number of receptors on the surface of nerve cells, and the number of receptors is controlled by levels of a ubiquitous brain chemical, University of Illinois at Chicago researchers have found.
A UIC research team led by David Featherstone, assistant professor of biological sciences, has discovered that receptor numbers are controlled by the brain's level of glutamate. But it is not the same glutamate that most neuroscientists think about -- the neurotransmitter that moves in message packets across the synapse. Instead, it is what Featherstone calls ambient extracellular glutamate, which just floats around the nervous system and has generally been ignored because no one knew where it came from or what it was doing.
For years, scientists failed to identify glutamate as a key neurotransmitter precisely because there was so much of it.
"It made no sense," said Featherstone. "People figured you couldn't use glutamate to send messages because there was too much glutamate background noise in the brain. It turns out that this background noise plays an important part in regulating information transfer."
Featherstone and his lab team found that glia cells are the source of the excess ambient glutamate. Along with neurons, these poorly understood "support" cells fill the brain.