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Mr. Studds. The gentleman from New York. 



Mr. HocHBRUECKNER. Dr. Eisner, in your testimony, you talked 

 about gene flux. Could you explain that for all of us and give us a 

 few examples? 



Mr. Eisner. The terms that are being used currently are gene 

 flux or horizontal gene transfer. The idea is genetic transfer, not 

 from parent to offspring, but between species. I will give you an ex- 

 ample from work done at Texas A&M. 



There are tiny little parasitic wasps which lay their eggs in cat- 

 erpillars. The eggs hatch and the little baby wasps eventually come 

 out of the dead caterpillar. For these wasps to develop, they have 

 to knock out the immune system of the caterpillar. They use a 

 virus to do that. The virus also lives in the caterpillar and the 

 wasp and the virus divide up the caterpillar's resources for their 

 own benefit. 



Studies were done to investigate how the immune system of the 

 caterpillar is knocked out. That has been unraveled biochemically. 

 Now some wasps have been found that knock out the immune 

 system of the host in the same way but have no free living viruses 

 associated with them. The most logical explanation is that the 

 virus has been incorporated into the genome of the wasp. The wasp 

 and the virus have become symbionts, and coupled in such a way 

 that they are for all intents and purposes one and the same orga- 

 nism. 



Another example: there are some compounds called trichothe- 

 cenes. These are highly complex molecules which if one finds them 

 in nature, one suspects a fungal source. They have been found by 

 investigators from the University of Maryland in the leaves of cer- 

 tain composite plants of the genus Baccharus. 



If you find that kind of compound in the leaf of a plant you say 

 there must be a fungus there somewhere producing it for the plant. 

 Indeed, they looked at the roots of the plant and found a fungus 

 associated with the roots. 



Now they find species of Baccharus that produce trichothecenes 

 but apparently without a fungus. The most logical explanation is 

 that sometime in recent evolution the genes of the fungus have 

 been incorporated into the plant. 



What this means is that gene transfer from one specimen to an- 

 other occurs not only under experimental conditions in the labora- 

 tory but in nature. 



What it tells us further is that by studying the interaction of or- 

 ganisms in nature we have things to learn that we have so far not 

 even been able to imagine. 



It means further that we need to take the long-range view when 

 we are assessing the value of species. Species have "hidden value" 

 that we are often not able to assess on the basis of knowledge now 

 available to us. 



Mr. HocHBRUECKNER. On your first example, is there any evi- 

 dence along this line with regard to the white wasp with its use in 

 attacking the Lyme disease-carrying tick? 



Mr. Eisner. I cannot respond specifically to your question be- 

 cause I am unfamiliar with that particular wasp as an agent of bio- 

 logical control. 



Mr. HocHBRUECKNER. Thank you. 



