Grown astray

Chemical pollution could cause deformities in frogs in North America

source: Kurt Kleiner
New Scientist April 3 1999 p26

Scripps Research Institute's James La Clair is a molecular biologist who claims that frogs may suffer deformities in North America due to chemicals interfering with an enzyme, acetylcholinesterase (AChE), that affects a neurotransmitter. La Clair is unsure which chemicals are responsible. There have been discoveries of tens of thousands of frogs suffering from deformities in the US and Canada since 1995. La Clair used water from four locations in Vermont. Malformed frogs had been discovered at these sites. La Clair tried to raise tadpoles in his water samples, but they became too malformed to survive. Tadpoles from clean water started twitching if they were placed in the sample water, which indicated that neurotransmitter function was affected. La Clair was able to reproduce the malformations by using tacrine, a drug that inhibits the enzyme AChE. Embryos exposed to AChE inhibitors were found to have little fibroblast growth factor, without which they cannot develop.