The structures of four major transcripts from the homeotic gene Antennapedia of Drosophila melanogaster were determined. These transcripts constitute two RNA classes, each class initiating from a unique promoter but sharing 3' exons. Within the shared sequences is a major open reading frame encoding a 378-amino-acid protein as well as alternative polyadenylation sites. Although the RNA classes differ in their 5' sequences, both leaders contain many AUGs upstream of the major open reading frame. For the two RNA classes, neither gross tissue nor temporal specificity was observed. However, the second poly(A) site is preferred in neural tissue. The structural diversity of the RNAs is discussed in relation to biological functions of the Antennapedia locus.