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Archive - Jun 8, 2009

Genetic Roots of Animal Tameness Discovered in Rats

In breeding studies conducted in rats, an international team of researchers has identified genomic regions associated with tameness. The discovery could help animal breeders, farmers, zoologists, and anyone else who handles and raises animals to more fully understand what makes some animals interact with humans better than do others. It may also lead to more precise breeding strategies designed to pass specific genes from one generation to the next as a way to produce tame animals. “I hope our study will ultimately lead to a detailed understanding of the genetics and biology of tameness," said Dr. Frank Albert, the lead author of the research report. "Maybe we'll then be able to domesticate a few of those species where humans have historically not been successful, like the wild African Buffalo." For this study, two groups of rats, one bred for tameness toward humans and the other bred for aggressiveness toward humans, were mated with each other and genomic regions associated with tameness and with aggressiveness were identified. The senior author of this study was Dr. Svante Paabo. The research was published in the June issue of Genetics. [Press release] [Genetics abstract]

New Class of Alkaloids Found in Amazonian Poison Frogs

Scientists have identified a new class of alkaloids in some Amazonian poison frogs (family Dendrobatidae). The class of alkaloids, N-methyldecahydroquinolines, has not been previously identified in the frogs or, it is believed, in nature. Senior author Dr. H. Martin Garraffo and colleagues noted that there are more than 500 alkaloids, potentially toxic substances, known to exist in the skin of poison frogs of the family Dendrobatidae. The frogs use the alkaloids as a chemical defense to discourage predators from biting and eating them. Western Colombian natives have used skin extracts from another group of frogs, unrelated to those in the new study, to coat blow-darts for hunting. The frogs obtain nearly all of the alkaloids from their diet--removing the chemicals from ants, mites, small beetles, millipedes, and possibly other small arthropods; concentrating them with incredible efficiency; and storing them in their skin. Although the researchers speculate that the frogs could get the new alkaloids from ants, they are, in fact, not certain about the origin of the chemicals, which could also be produced in the frogs' own bodies. Feeding experiments with alkaloids fed to captive frogs are planned, which might settle this point. This work was published online ahead-of-print in the American Chemical Society’s Journal of Natural Products and is scheduled for publication in the June 26 issue of the journal. [Journal of Natural Products article]