FRIZZLED GENE-EXPRESSION AND DEVELOPMENT OF TISSUE POLARITY IN THE DROSOPHILA WING

Almost every cell in the Drosophila pupal wing forms a single, distall y pointing cuticular hair. The function of the frizzled (fz) gene is e ssential for the elaboration of the normal wing hair pattern. in the a bsence of fz function hairs develop, but they display an abnormal pola rity. We have examined the developmental expression of the fz gene at the RNA level via in situ hybridization and at the protein level via W estern blotting. We have found that fi is expressed in all regions of the epidermis before, during, and after the fz cold sensitive period. We have also found that fz function is not required for normal fz expr ession. We have further found that mutations in several other tissue p olarity genes do not noticeably alter the expression or the modificati on state of the Fz protein. (C) 1994 Wiley-Liss, Inc.