Figure 6

Mutations in msl1 abolish local Male Specific Lethal (MSL) spreading. In all cases except (c), polytene chromosomes were taken from males carrying one copy of GMroX1-75C inserted on the third chromosome (arrow). In (c) the transgene is homozygous. Chromosomes were stained with anti-MSL1 antibodies (red). In (a)-(c) the X chromosome is roX1^ex6 roX2⁺. (a) msl1⁺/msl1⁺, (b) and (c) msl1^F979Z/msl1⁺. In (d)-(i) the X chromosome is roX1^ex6 roX2⁵². (d) msl1⁺/msl1⁺ the MSL complex covers 73A-77C, (e) msl1⁺/msl1^L60, (f) msl1⁺/msl1^K1009X, (g) msl1⁺/msl1^F979Z, P864L, AFG and K1009X also fail to support local MSL spreading (not shown), (h) mle⁺/mle^null, the mle^I926Z allele was also examined and gave identical results (not shown), (i) msl2⁺/msl2^null. Dense MSL1 staining occurs over the X chromosome.