dELL, a drosophila homologue of transcription elongation factor ELL (Eleven-nineteen Lysine rich Leukemia), is required for early development

Abstract

ELL (Eleven-nineteen Lysine rich Leukemia) is known to be an elongation factor resembling elongin for RNA polymerase II transcription. A homologue of human ELL (hELL) was identified in Drosophila melanogaster (dELL) and several cDNA clones were isolated from the embryonic cDNA library. We showed that dELL is expressed mainly in the ovaries and early embryonic stages by developmental Northern blot. dELL encodes a protein of 912 amino acids which is substantially longer than the hELL (612 aa). Immunostaining revealed that dELL was localized to nuclei in early embryos and to nuclei of nurse cells and follicle cells in the ovary suggesting its important role in early development of drosophila. To elucidate the function of this gene in drosophila, P-element mobilization was performed by utilizing a P-element inserted upstream of dELL. Southern analysis showed that isolated mutants are internal P-element deletions. These P-element deletions can now be used to isolate dELL mutations by EMS mutagenesis.