Re: LD50 FOR FRUIT FLIES -Reply

[Andy Hull <hull@mail.sep.bnl.gov>]

Paul,
As I recall from my brief exposure (no pun intended) to radiation biology
in the late 1950s, Drosophila melanogaster were favored radiation research
organisms because they had unusually large chromosomes.  If this is
correct, did this make them somewhat more sensitive than others.  The
findings of BNL's gamma  source exposed forest in the 1960s led to this
conclusion with regard to evergreens, compared to other trees (as was
evident downwind from Chernobyl.
Best regards,
Andy



At 07:32 AM 1/6/98 -0600, you wrote:
>Some time ago, Paul Skierkowski requested info on the LD50 for
>Drosophila melanogaster.
>
>One table I have (of unknown origin) gives the LD50 for Drosophila at
>approximately 100,000 rad.
>
>There is a paper in Nucleonics Dec 1952 p 42 by Hassett and Jenkins
>that provides the following info regarding Drosophila melanogaster:
> "using x-rays found that 180 r killed 50% of young (approximately 3 hr)
>Drosophila eggs. Dittrich et al found that X-rays were more effective
>than fast electrons when Drosophila eggs over 3 hr old were
>treated...resistance to radiation increases steadily with development, for
>the LD-50 was 200 r for 3 hr old eggs, 500 r for 4 hr eggs, 810 r for 7.5
>hr eggs, and 2800 r for pupae"
>
>At 1300 r/hr using Ta 182 as the gamma source "90% of adult Drosophila
>were killed by exposure to 84,000 r".
>
>At 193,000 r/hr using Co-60, all adults were dead within 2 days of
>193,000 r, 
>
>At 64,000 r some survived 3 weeks but were sterile. 
>
>The paper doesn't specify a LD-50  but given all the variables, a guess of
>50,000 to 60,000 r might not be too far off. 
>
>Best wishes
>
>Paul Frame
>Professional Training Programs
>ORISE
>framep@orau.gov
>
>