- The irregular chiasm C-roughest locus of Drosophila, which affects axonal projections and programmed cell death, encodes a novel immunoglobulin-like protein. Ramos, R.G., Igloi, G.L., Lichte, B., Baumann, U., Maier, D., Schneider, T., Brandstätter, J.H., Fröhlich, A., Fischbach, K.F. Genes Dev. (1993)