Fig. 5. Effect of SUF4 on H3K4 trimethylation and gene expression at the FLC and FLM loci. (A) Schematic drawing of the FLC and FLM loci. White boxes represent the regions of FLC amplified in ChIP analysis (B and A), black boxes represent exons. (B) ChIP analysis of the histone H3-K4 trimethylation state of FLC chromatin in suf4 and related lines. The input is Col FRI chromatin before immunoprecipitation. `No AB' refers to the control sample lacking the anti-trimethyl H3-K4 antibody. `A' and `B' refer to the regions of FLC indicated in 5A. ACTIN served as an internal control. The results shown are representative of three replicates. (C) Effect of various mutations on the expression of FLC, FLM and neighboring genes, as determined by RT-PCR.