On a really hot day, a person may prefer to stay in one place without moving. One UW-Madison professor and his team has isolated a strain of fruit flies that, at elevated temperatures, also cannot move-they become temporarily paralyzed until the temperature drops again.
This strain is just one of more than 100 mutant strains that Dr. Barry Ganetzky and his team have created in the laboratory.
By studying what goes wrong in these mutants, Ganetzky has \discovered novel genes involved in the function and development of the nervous system, including the ion channels and proteins that are involved in transmitting nerve impulses,"" he wrote.
Ganetzky, the Steenbock Professor in Biological Sciences in the Laboratory of Genetics, said he thinks his flies are ""beautiful, simply beautiful."" He created them by feeding DNA-damaging chemicals to a large amount of fruit flies and isolating those flies that inherited observable mutations.
""When you're looking for needles in haystacks, it helps if you increase the number of needles,"" Ganetzky said.
One mutation was particularly easy to observe. In a jar at room temperature, the mutant fruit flies fly, crawl on the glass and clean themselves like ordinary flies. But when the jar is placed in a warm water bath, in a matter of seconds the flies fall to the bottom twitching, unable to move.
Studying these flies enables Ganetzky to determine the specific effects of different genes and the consequences of their variations.
Ganetzky and his team theorized that neurological dysfunction must underlie the paralysis. Nerve impulses are created through the complex movement of sodium and potassium ions through channels in cells, and Ganetzky expected the elevated temperature to impair the function of these channels in the mutants.
After 10 years of research, Ganetzky discovered that the mutation was in a gene that codes for a sodium channel protein.
""We got lucky. It turns out we got the gene that codes for the nuts-and-bolts machinery, the big one,"" Ganetzky said.
Now the task at hand is to relate this research to situations relevant to humans. People may become lazy at high temperatures, but no one becomes paralyzed, right? However, Ganetzky said there are situations relevant to humans.
""Some multiple sclerosis sufferers can't take hot baths-their symptoms become more extreme,"" Ganetzky pointed out.
Still, he is not looking for a direct link quite yet.
""Before we can apply this to humans, we have so many other questions to answer. What is the underlying mechanism? Why do some flies recover immediately and others after several hours? Which specific proteins are involved?"" he said.
While it may be years before this research translates into drugs for human sufferers, Ganetzky knows these flies are special. ""They may be mutants,"" he said, ""But I've learned to follow a mutant wherever it leads me.\
