IDENTIFICATION OF OVARIAN ENHANCER-BINDING FACTORS WHICH BIND TO OVARIAN ENHANCER-1 OF THE DROSOPHILA GENES YP1 AND YP2

It has been reported that three different DNA regions - the fat body e nhancer and ovarian enhancers 1 and 2 - direct the tissue-specific exp ression of yp1 and yp2 in Drosophila melanogaster. In the present stud y, we identified ovarian enhancer 1-specific binding proteins. Electro phoretic mobility shift assay revealed that these proteins are present in the adult ovary, but not in adult testis or fat body. Southwestern blot analysis showed that about 130 kDa and 40 kDa proteins, designat ed OEF1 and OEF2, respectively, from ovarian nuclear or crude extracts bind specifically to the ovarian enhancer 1. The two proteins were pa rtially purified by streptavidin/agarose-DNA affinity chromatography, and. their binding activity was confirmed by electrophoretic mobility shift assay. These ovarian enhancer factors may play an important role in the regulation of transcription of yp1 and yp2 in the ovary.