RT-PCR analysis of reassembled carotenoid cluster genes
E . coli harbouring recombinant pYS71, pYS69, or pYS76 was grown in LB medium to exponential growth phase (12 h after inoculation). The following primers were used for RT reactions: RT3 (crtZ ); RT4 (crtI ); and RT5 (crtY ). The following PCR primers were used: PCR6f and PCR6r; PCR7f and PCR7r; and PCR8f and PCR8r (Supplementary Table S3). Southern hybridisation and DNA sequencing were carried out to confirm the RT-PCR products. As positive controls, pYS71, pYS69, and pYS76 were used. As a negative control, PCR reactions with the same primer sets were performed using RNA samples that had not been reverse transcribed.