The normal white (w+) gene in Drosophila is required for production of red pigment in the eyes. In some mutants in which the w+ gene has been moved to a region near the centrosomal heterochromatin due to an inversion in the X chromosome, the eyes are mottled with red and white patches; the w+ gene in the white cells has been silenced due to spreading heterochromatin, while w+ gene in the red cells is active. This phenomenon is called PEV (position-effect variegation), and a number of factors that control epigenetics, such as histone methyltransferases, have been identified by measuring the extent of variegation. Now, in this sliding screen, maple leaves in autumn were drawn with Japanese ink on gold foil background except some in the central oval with a red paint as an accent. A shadow that looks like Drosophila happened to be cast on it, emerging a figure of the w mutant with a mottled eye.
Kappa, a mischievous monster found in Japanese folklore, supposedly lives in a stream or pond, and has webbed hands and feet so that it's good at swimming. Human hands also have an interdigital web in the early embryo, but it disappears by apoptotic programmed cell death like a tadpole's tail. The intracellular signaling pathway that triggers apoptosis has been studied well; the signal flows down the 'cascade' that consists of multiple caspases (Cysteine-ASPartic proteASE) such as caspase 9 or 3 encoded by CASP9 or CASP3, respectively. This poor Kappa in this drawing has been saturated with the water flowing down the caspase cascade, and its vaunted web is in danger of disappearing by apoptosis.