Ask A Scientist Molecular Biology Archive

name Mark P. 
status student 
age 40s 

Question - I have heard about a particular experiment where fruit 
flies were genetically altered to make them blind. After several 
generations, eye sight returned. Is there any truth to such a 
story? Can we really control genes so that we can make a fruit fly blind? 
-----------------
I don't know of what experiment you speak, so I don't know if this is true or not.  But I do 
know that if a gene mutates at random, a certain number of generations later, a mutation could 
happen in the same place that will revert the gene to its original state. So IF there is a 
single gene that can cause blindness in a fruit fly, and it was mutated, it is possible that 
down the line a spontaneous mutation could occur that would put that gene back the way it was 
and restore the fly's sight.

vanhoeck
=====================================================
We have been genetically studying Drosophila for so long we know an enormous amount about its 
genetics. We also use it to understand the biology of humans and other animals.  We often 
understand genes by mutations of those genes.  When a mutation prevents a gene from working 
properly it gives us an idea of what the normal gene dies. Drosophila mutant strains that 
exhibit age-related retinal degeneration become blind prematurely.  We also know that gene N63 
is important to eye development in the fruit fly.  Genetic engineers are able to manipulate 
incredible numbers of genes in fruit flies.  We can even crudely manipulate development by 
manipulating homeotic genes.  Homeotic genes were identified early on as dominant mutations 
affect the identity of body structures.
=====================================================