Copyright information:Taken from "Specific function of a plastid sigma factor for F gene transcription"Nucleic Acids Research 2005;33(18):5991-5999.Published online 20 Oct 2005PMCID:PMC1266065.© The Author 2005. Published by Oxford University Press. All rights reserved Total RNA was isolated from 7-day-old plantlets that had been grown under 16 h light/8 h dark cycle. RNA was reverse transcribed and cDNAs were separated on 6% polyacrylamide gels under denaturing conditions. The accompanying sequence ladders are established with the same primer that was used for primer extension. () An aliquot of 10 µg (upper part) or 1 µg (lower part) of total RNA prepared from WT (lanes 5 and 1, upper part and lower part, respectively) and plantlets (lanes 6 and 2, upper part and lower part, respectively) have been analysed by primer extension using a primer specific to F (upper part) or by RT–PCR using primers specific for F and N. () An aliquot of 10 µg of total RNA prepared from WT (lane 5) and plantlets (lane 6) have been analysed by primer extension using a primer specific to G. () An aliquot of 10 µg of total RNA prepared from WT (lane 5) and plants (lane 6) have been analysed by primer extension using a primer specific to 4. () The nucleotide sequences upstream of the F, G and 4 precursor RNAs are aligned. Putative promoter sequences are underlined, and 5′ ends of transcripts [positions −320 (F), −213 and −138 (G), −326 and −226 (4)] are marked in bold letters and by vertical arrows.