Project description:In Gram-positive bacteria, the direct quorum sensing activation pathway involves sensing a autoinducing peptide (AIP) inside the cell after its maturation, export and re-internalization. Once internalized, the AIP interacts with a transcriptional regulator belonging to the RRNPP family. In Streptococcus thermophilus, AIPs are matured by a protease called Eep, exported by an ABC transporter called PptAB, and re-imported by another ABC transporter called Ami. We used a deep sequencing approach (RNAseq) to identify all genes whose expression is controlled by a quorum sensing mechanism involving the three partners PptAB, Eep and Ami. Thus, we studied the mRNA transcriptional profiles in Streptococcus thermophilus strain LMD-9 and 3 mutants deleted for the pptAB, eep and amiCDE genes. The four strains were also deleted for the comR gene in order to get rid off the genes whose expression is controlled by ComR. Indeed, ComR is a RRNPP regulator and its regulon has been already identified. The four strains were grown in a chemically defined medium and cell were harvested at the end of the exponential phase (OD600 1).
Project description:Comr protein was found to be a major regulator of gene activity in drosophila spermatocytes. We obtained Comr binding profile to determine targets of Comr. Comr binding in drosophila male germ line cells was determined using DamID technique. Comparison of Dam-Comr binding to Dam-alone signal in duplicate for each sample type.
Project description:Comr protein was found to be a major regulator of gene activity in drosophila spermatocytes. We obtained Comr binding profile to determine targets of Comr. Comr binding in drosophila male germ line cells was determined using DamID technique.
Project description:Streptococcus thermophilus strain ND03 is a Chinese commercial dairy starter used for the manufacture of yogurt. It was isolated from naturally fermented yak milk in Qinghai, China. We present here the complete genome sequence of ND03 and compare it to three other published genomes of Streptococcus thermophilus strains.
Project description:Streptococcus thermophilus relies heavily on two type II-A CRISPR-Cas systems, CRISPR1 and CRISPR3, to resist siphophage infections. One hallmark of these systems is the integration of a new spacer at the 5' end of the CRISPR arrays following phage infection. However, we have previously shown that ectopic acquisition of spacers can occur within the CRISPR1 array. Here, we present evidence of the acquisition of new spacers within the array of CRISPR3 of S. thermophilus. The analysis of randomly selected bacteriophage-insensitive mutants of the strain Uy01 obtained after phage infection, as well as the comparison with other S. thermophilus strains with similar CRISPR3 content, showed that a specific spacer within the array could be responsible for misguiding the adaptation complex. These results also indicate that while the vast majority of new spacers are added at the 5' end of the CRISPR array, ectopic spacer acquisition is a common feature of both CRISPR1 and CRISPR3 systems in S. thermophilus, and it can still provide phage resistance. Ectopic spacer acquisition also appears to have occurred naturally in some strains of Streptococcus pyogenes, suggesting that it is a general phenomenon, at least in type II-A systems.
