Any suggestions?

WHITEAKER, AMANDA LORRAINE alw9038 at rigel.tamu.edu
Wed Apr 7 12:28:00 EST 1993


I know this bboard is being set up for scientific discussions about
Drosophila.  And I realize that a lot of the people who respond and
post regularly on this bboard will be geneticists of high repute and
people with Doctorates and all that.  So, a question from an
undergraduate genetics student is probably not quite what the bboard
developers had in mind when they set this up.  But, it did seem like 
the right place to ask this question.  And I would realy appreciate
any suggestions/answers any of you could give me.

In my genetics lab, we have been working with Drosophila crosses.
We had several different phenotypic traits we could follow, of which
we were asked to select two.

In the P1 generation, a certified virgin wildtype female was crossed
with a male with vestigial wings and an ebony body:

	v+   e+             v    e
	========  fm   x    =======  m
	v+   e+             v    e

The F1 generation yielded 100% wildtypes, both male and female.

	v+   e+             v+    e+
	========  fm   x    ========  m
	v   e               v    e

But, the F2 generation yielded 100% wildtypes as well.

	v+   e+             v+    e+
	========  fm   x    ========  m
	?    ?.             ?     ?
	
	123 fm		    151 m

So, here's my question.  How could this have happened?  We expected
the recessive traits to surface in the F2 generation, but neither of 
them did.  What forces would cause such a strange result?  Any
input would be greatly appreciated.

					Lorraine Whiteaker
					alw9038 at rigel.tamu.edu



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