Fig. 2. Impact of snf mutations on SXL-SNF complex formation. SXL/SNF complex assembly was tested by GST pull-down assays. Equal amounts of GST::SXL fusion protein, or GST alone, bound to glutathione sepharose beads were incubated with embryonic extracts of the indicated genotype followed by western blotting using an antibody directed against SNF. Because a substantial amount of maternally produced SNF protein is supplied to the embryo, we carried out crosses (described in the Materials and Methods) to obtain a homogeneous population of embryos whose only source of SNF protein (both maternal and zygotic) is the mutant protein. The lane marked 10% input, is a control in which the amount of snf¹⁴⁸ extract loaded corresponds to 10% of the material applied to the glutathione affinity beads.