Fig. 4. Histone H3 K4 methylation on the ATH5 and ß3 promoters during retina and optic tectum development. Chromatin from E3-E18 retinas and optic tecta were immunoprecipitated with an antibody specific for the dimethylated K4 of histone H3. ATH5 and ß3 promoters sequences in the precipitates were quantified by real-time PCR. Methylation levels are shown relative to E6 retina in A for the ATH5 promoter (IP efficiency, 0.7%) and to E18 retina in B for the ß3 promoter (IP efficiency, 1.1%). *P=0.02, Student's t-test.