Similar results were obtained when the ldh gene, encoding the lactate dehydrogenase, was used for normalization [40]. Data are expressed as mean ± SD. Statistical analysis was performed with Student’s E test. A p value < 0.05 was considered statistically different. Sequence analysis Protein and nucleic acid sequences from the recombination, regulation and conjugation modules of ICESt1 and ICESt3 were compared with sequences from Firmicutes on the NCBI server http://​www.​ncbi.​nlm.​nih.​gov using BLASTP, BLASTN and/or tBLASTN. Identified sequences are from ICESpn8140 of S. pneumoniae [GenBank:FR671412[22]] and from

the partially Ro 61-8048 supplier or completely sequenced genomes of S. parasanguinis F0405 [GenBank:NZ_AEKM00000000] and ATCC15912 [GeneBank:NZ_ADVN00000000], S. australis ATCC700641 [GeneBank:NZ_AEQR00000000] S. infantis ATCC700779 [GeneBank:NZ_AEVD00000000],

S. agalactiae ATCC13813 [GenBank:AEQQ01000089], S. dysgalactiae ATCC12394 [GenBank:CP002215], S. downei F0415 [GenBank:NZ_AEKN01000010], Streptococcus sp. 2_1_36FAA [GenBank:NZ_GG704942] Mdivi1 clinical trial and S. gallolyticus UCN34 [GenBank:NC_013798]. Acknowledgements We thank S. Payot-Lacroix and J.B. Vincourt for critical reading of the manuscript. NC is supported by MNERT fellowship from the Ministère de l’Education et de la Recherche. The authors are grateful to X. Bellanger for CNRZ368ΔSt1 and M. Mourou for help with the CNRZ368 ICESt3cat. Electronic supplementary material Additional file 1: Fig. S1: Determination of transcriptional units of the ICE core region in stationary phase. ICESt1 (A, B) and ICESt3 (C, D). For (A) and (B), location and orientation of ORFs and a truncated IS are indicated by arrowed boxes and rectangle, respectively. Above, ORF names beginning with “”orf”"

are abbreviated with the corresponding letter or number. The pattern of the arrowed boxes depicts the putative function and/or Tideglusib relationships of each ORF deduced from functional analyses or from BLAST comparisons. White arrowed boxes correspond to unrelated ORFs of the two elements. Black arrowed box is the chromosomal fda gene. Star represents the putative origin of transfer. Horizontal lines delimitate functional modules with their names above. Arrows Org 27569 below each ICE represent transcripts deduced from the results given in B and D. For (B) and (D), RT-PCR amplification was used to determine if RNA spans the ORF end and the beginning of the following or next ORF. For each amplifications, the positive control performed on genomic DNA is presented on the left and the amplification obtained on cDNA is showed on the right. ORFs named above indicate the examined region and numbers below indicate the calculated amplicon size. Similar results were generated with RNA from three independent biological replicates and cells in exponential growth phase.