Transcription profiles of the hydrogenases structural genes versus the putative specific endopeptidases genes in Lyngbya majuscula CCAP 1446/4. Transcription profiles of hoxH (A), hoxW (B), hupL (C), and hupW (D) genes in L. majuscula, evaluated by Real-time RT-PCR (graphs) and RT-PCR (pictures below). The filaments were grown in N2-fixing or non-N2-fixing conditions during a 12 h light/12 h dark cycle, and the samples were collected at 6 h intervals during a complete 24 h cycle (L6 and L12 – light samples, D6 and D12 – dark samples). The cDNAs were produced with random primers, and used in PCR amplifications performed with specific primer pairs (see Methods). For the Real-time experiments, the Mean Normalized Expression (± standard errors) of the target genes was calculated relative to the transcription of the reference gene (16S rDNA) and the reaction internal normalization was performed using the sample L6 from non-N2-fixing conditions. In the RT-PCRs two sets of experiments were performed using 30 and 40 cycles, and the 16S rDNA detection is not shown.