Table 3.

Primers sequences. PCR was performed in a 50 µL-final volume reaction mixture containing 1 µM of each primer, 250 µM of each dNTP, 1.5–2.5 mM of MgCl2 and DNA template, with a Mastercycler Gradient (Eppendorf). Primers Ol35-Eco and Ol252-Xho were used to amplify the DNA fragment encoding the RadA region spanning from L35 to L252. They harbored an EcoRI or XhoI restriction site, respectively, for further cloning. The PCR program used was as follows: (1) initial denaturation at 95 °C for 5 min, (2) denaturation at 95 °C for 40 s, (3) annealing for 40 s at 55 °C, (4) extension at 72 °C for 40 s, and (5) a final extension at 72 °C for 10 min, with the second to fourth steps repeated for 24 cycles. Primers C1L, C1R, C3L, C3R, C5L, C5R, C6L and C6R were used in PCR reactions carried out on R. gnavus E1 cDNA obtained from cells colonizing the caecum of mono-contaminated animals (in situ cDNA) or grown in BHI-YH medium (in vivo DNA). Control experiments were carried out on E1 chromosome DNA. The PCR program used was as follows: (1) initial denaturation at 95 °C for 5 min, (2) denaturation at 95 °C for 40 s, (3) annealing for 40 s at 58 °C, (4) extension at 72 °C for 40 s, and (5) a final extension at 72 °C for 10 min, with the second to fourth steps repeated for 29 cycles.

Primer	Sequence
Ol35-Eco	5′-CCGGAATTCTTAGAACAGTCAGAGAATAAAGCG-3′
Ol252-Xho	5′-CCGCTCGAGATTTAAATATTCTCCGGTAAGATCACCCGG-3′
Ad1F	5′-CGGCTTCTGATTTTAAAGGGATTAC-3′
Ad2R	5′-GTTTTGCACTTGGCTCTTCA-3′
Ad2F	5′-GAAGAGCCAAGTGCAAAAG-3′
Ad3R	5′-CTGAAAGGTGTGTGTAAAAGTG-3′
Ad3F	5′-CACTTTTACACACACCTTTCAG-3′
Ad4R	5′-GTCACCTCATTTAATGGAAG-3′
Ad5F	5′-CATGAGGAACAGGCTCCAAT-3′
Ad6R	5′-TCTTTGTGCGTCTGATTCTC-3′