- The Large Isoform of Drosophila melanogaster Heterochromatin Protein 2 Plays a Critical Role in Gene Silencing and Chromosome Structure. Shaffer, C.D., Cenci, G., Thompson, B., Stephens, G.E., Slawson, E.E., Adu-Wusu, K., Gatti, M., Elgin, S.C. Genetics (2006)