Scabrous Background Information
Drosophila melanogaster is a proven and effective model for studying developmental and cellular processes common to higher eukaryotes. Approximately 13,600 genes have been elucidated from more than 120 megabases of euchromatin, and they are organized among the chromosomes 2, 3, 4, X and Y, with the Y chromosome being predominately heterochromatic (1). Drosophila genes can be categorized based on the type of protein for which they encode and are represented by six major classifications, which include intracellular signaling proteins, transmembrane proteins, RNA binding proteins, secreted factors, transcription regulators (basic helix-loop-helix, homeodomain-containing, zinc finger-containing, and chromatin- associated) or other functional proteins (2). Drosophila scabrous (sca) gene encodes a secreted dimeric glycoprotein with putative coiled-coil domains N-terminally and a C-terminal region related to the blood clot protein fibrinogen (3,4). Scabrous influences ommatidial rotation during eye development by suppressing nemo activity (5). Homozygous sca mutants have extra bristle organs and rough eyes (4).
