RESUMO
Histochemical staining of the hypoderm ofDrosophila larvae for aldehyde-oxidase activity allowed detection of a row of cells destined to form the operculum seam, along which the pupal case opens when the adult ecloses. Analysis ofmal clones in hypoderms of gynandromorph larvae showed that the prospective operculum seam coincides, in part, with a line of clonal restriction that divides the thorax into dorsal and ventral halves. We propose that this line represents the embryonic dorsal/ventral compartment boundary.
RESUMO
The aldehyde oxidase staining pattern in wing discs ofDrosophila melanogaster bearing the genotypesap blt /ap blt andap blt andap blt /ap 73n showns changes from the wild-type pattern. Extensive areas of the presumptive dorsal posterior wing blade, which are normally unstained, have enzyme activity in these mutants. In wings of these genotypes, dorsal posterior structures are replaced by dorsal anterior wing structures. A strong correlation has been found between the frequencies of various staining patterns in the discs and the extent of transformation in the cuticular structures of the wing, which is consistent with the idea that aldehyde oxidase activity can be used as an indicator in the wing disc of this transformation. Unlike the homoeotic mutationengrailed, apterous has not been interpreted as a selector gene yet the work reported here shows thatapterous alleles can cause changes resembling those of theengrailed phenotype both in aldehyde oxidase staining behaviour and in the cuticular transformation.