Gurken-torpedo pathway and spatzle-toll pathway

[Genecks]

Here is a list of what has been bugging me in relation to Drosophila development:

 

We'll take it step by step:

 

Why is it that the gurken mRNA is inhibited from traveling ventrally?

Is it that ventral follicle cells lack the torpedo receptor? If so, why do they lack the torpedo receptor?

 

Perhaps this is all dependent on which materials the mother dumps into the egg first.

Perhaps the concentration is tightly regulated?

 

Also, should this be considered a molecular biology question?

Edited October 9, 2010 by Genecks