THE DETECTION OF JONAH GENE TRANSCRIPTS IN DROSOPHILA BY INSITU HYBRIDIZATION

The Jonah genes constitute a family of .apprx. 20 genes expressed at 2 periods during the development of D. melanogaster. They are expressed only in the midgut, where they yield very abundant transcripts of .apprx. 900 bases. The function of their products is not known. In situ hybridization was used to show that transcripts homologous to 2 members of the Jonah family have quite different distributions within the midgut. Transcripts closely homologous to Jon65Aiv are expressed throughout most of the anterior midgut and in the posterior section of the middle midgut. Transcripts closely homologous to Jon99C.beta. are expressed only in the anterior region of the posterior midgut.