Simcox, A.A., Roberts, I.J.H., Hersperger, E., Gribbin, M.C., Shearn, A., Whittle, J.R.S. (1989). Imaginal discs can be recovered from cultured embryos mutant for the segment-polarity genes engrailed naked and patched but not from wingless.  Development 107(4): 715--722.

FBrf0049570

Research paper

Drosophila embryos homozygous for strong mutations in each of the segment-polarity genes wingless (wg), engrailed (en), naked (nkd) and patched (ptc) form a larval cuticle in which there is a deletion in every segment. The mutant embryos normally fail to hatch but by in vivo culture we were able to show which could produce adult structures. Cultured wg- embryos did not produce any adult structures. Cultured en- embryos produced eye-antennal derivatives and rarely produced partial thoracic structures. nkd- and ptc- embryos produced eye-antennal and thoracic derivatives. The nkd- and ptc- thoracic imaginal discs developed with an abnormal morphology and abnormal pattern of en- expression. Our findings are consistent with the idea that the thoracic imaginal discs derive from two adjacent groups of cells that express wg and en respectively in the embryo.