sex determination

[Joe Kunkel]

Andrea,

I am not sure about the timing of the sex of butterflies, but
_Drosophila_ sex is determined tissue by tissue at different times. 
This has been established using temperature sensitive sex determination
genes such as tra2^ts.  By switching growing-cultures of tra2 from a
permissive temperature (18 C) to a non-permissive temp (29 C) and
following the sex of the emerging adults one can determine when each
tissue has its sex determined.  The genetics of most lepidoptera are
little known or developed to the degree as in _Drosophila_.  Perhaps an
expert in the moth _Ephestia kuhniella_ might be able to comment on sex
determination timing in leps.  I think it is the Lep with the best
genetics.

You can read more about _Drosophila_ sex determination at URL:

http://marlin.bio.umass.edu/biology/kunkel/drosoph.html

joe kunkel

ANDREA KNEBEL wrote:
> 
> Hi all,
> 
> does anybody klnow when the sex of a butterfly is determined? Is it
> set in the egg right after laing? Or is it possible to change the sex by
> e.g. temperature after the egg is laid like in some fish?
> 
> Thanks in advance,
> Andrea Knebel
> University Bielefeld,
> Germany

-- 
--------------------
Joseph G. Kunkel, Professor
Biology Department             joe at bio.umass.edu
University of Massachusetts    http://www.bio.umass.edu/biology/kunkel
Amherst MA 01003