duly 2553 1955

Dr. Hobart Briggs
Lankenaug Cancer esearch Institute
Philadelphia ll, Pa.

Dear Bob:

ether and I have been putting the final tceches for the ms. for the

symposium paper, whence some questions came to aind about your studies with
toludfine blue.

I was particularly intrigued by your account of fertiliszations with par-
tially inactivated sperm. Do you ascribe the abnormal embryos to aneuploidy?
If so, do you think each chromosome is a unit of response to the dye? Then some
kind of "multiplicity reactivation" experiment might be possible. Anyhow,
you had a footnda which implied that a more detailed cytclogical study might
be forthcoming— have you anything that bears on the history of the partially
inactivated sperms?

«@ were inmediately re~interested in this because there is a recent claim
of partial fertilization in E. coli-~ these French workers disrupted mating
cultures prematurely and claim to have induced (orf revealed) the transmission
of partial ganetes. The evidence there is not very convincing, and they are
somewhat confused as to whether they are inducing the effect (as seems mre
likely) or uncovering a normal process, But I was curious about possible ana-
logies. Muller and Pontecorvo had something similar with UV'd sperm, but never
published more extensively than a note in Science (92:418, '40). I ama little
surprised that no one (as far as I know) has followed your dye effects in Dro-
sophila, wheres a more complete genetic analysis would be possible, but I am
sending a copy of this letter to Herskowitz to see what he thinks about it.

Yours sincerely,

Jos wi Lederborg