- The Drosophila SSL gene is expressed in larvae, pupae, and adults, exhibits sexual dimorphism, and mimics properties of the beta subunit of casein kinase II. Karandikar, U., Anderson, S., Mason, N., Trott, R.L., Bishop, C.P., Bidwai, A.P. Biochem. Biophys. Res. Commun. (2003)