124 MUTATIONS 



produce mutations, and if so, is this true only of organic peroxides, or 

 does it apply also to hydrogen peroxide? 



Auerbach: As far as I know, this has not been tested. To my knowl- 

 edge, the only organisms in which peroxides have been used are 

 Neurospora and Drosophila. 



Glass: And in Drosophila? 



Auerbach: They are effective. 



Glass: Hydrogen peroxide, that is? 



Novick: Not in E. coli. 



Auerbach: Not hydrogen peroxide; this is destroyed almost im- 

 mediately by catalase. 



Glass: These are organic peroxides? 



Auerbach: Yes. 



Glass: They were added to the food? 



Auerbach: No, injected. 



Benzer: Hydrogen peroxide does act to induce lysogenic bacteria. 



Auerbach: It is very weakly mutagenic by itself, but it is very much 

 reinforced by formaldehyde, or the other way around. 



Novick: Be careful about generalizing, because there are all kinds 

 of bacteria. So-called lactic acid bacteria lack it completely. 



Benzer: And people too. There is the story about the Japanese 

 dentist who swabbed his patient with peroxide, and it didn't foam. It 

 turned out to be due to a mutation. 



Neel: We have a paper from that Japanese dentist in the Journal of 

 Clinical Investigation of a few months ago (73). There are now some 

 17 families reported in which there have occurred individuals who 

 apparently are completely lacking in the enzyme catalase. Even more 

 interesting is that the carriers of the responsible gene, which behaves 

 as a recessive, have approximately half normal catalase levels, and, if 

 you take the usual Hardy-Weinberg assumptions, which are not good 

 assumptions at all in human populations but give you a first approxi- 

 mation of what you want, there must be 300,000 or so Japanese with 

 half normal catalase values, and no obvious ill effects. 



As a matter of fact, we suspect that complete absence of catalase 

 may sometimes be compatible with normal health. Some of the cases 

 of acatalasemia have been discovered quite by accident. The first af- 

 fected individuals were detected because of an ulcerating gingivitis, 

 which was really life-threatening, but now it begins to look as if some 

 affected individuals may be quite normal phenotypically and are dis- 

 covered accidentally at the time of unrelated surgery. 



Beam: We have looked for acatalasemia carriers. So far we have 



