Project description:The whole regulon of the LTTR All3953 was determined at 3 h after Ci deficiency in the cyanobacterium Anabaena sp. PCC 7120 by ChIP-Seq analysis. A TAP-tagged version of the protein was used for the chromatin immunoprecipitation. A total of 142 peaks were found, mainly located in the chromosome of Anabaena.
Project description:In order to examine the response of Anabaena sp. PCC 7120 to an infection of the Cyanophage A1, we have used customized microarrays to identify genes potentially up- or downregulated by the infection. For this we compared cell culture before and after infection.
Project description:To examine Alr3614 influence on the expression of Anabaena sp. PCC 7120, we have used customized microarrays to identify genes potentially regulated by this short DNA-binding protein. We compared the expression of an Alr3614-deletion strain with an Alr3614-complementation strain.
Project description:Crewed missions to Mars are expected to take place in the coming decades. After short-term stays, a permanent presence will be desirable to enable a wealth of scientific discoveries. This will require providing crews with life-support consumables in amounts that are too large to be imported from Earth. Part of these consumables could be produced on site with bioprocesses, but the feedstock should not have to be imported. A solution under consideration lies in using diazotrophic, rock-weathering cyanobacteria as primary producers: fed with materials naturally available on site, they would provide the nutrients required by other organisms. This concept has recently gained momentum but progress is slowed by a lack of consistency across contributing teams, and notably of a shared model organism. With the hope to address this issue, we present the work performed to select our current model. We started with preselected strains from the Nostocaceae family. After sequencing the genome of Anabaena sp. PCC 7938-the only one not yet available-we compared the strains' genomic data to determine their relatedness and provide insights into their physiology. We then assessed and compared relevant features: chiefly, their abilities to utilize nutrients from Martian regolith, their resistance to perchlorates (toxic compounds present in the regolith), and their suitability as feedstock for secondary producers (here a heterotrophic bacterium and a higher plant). This led to the selection of Anabaena sp. PCC 7938, which we propose as a model cyanobacterium for the development of bioprocesses based on Mars's natural resources. IMPORTANCE The sustainability of crewed missions to Mars could be increased by biotechnologies which are connected to resources available on site via primary producers: diazotrophic, rock-leaching cyanobacteria. Indeed, this could greatly reduce the mass of payloads to be imported from Earth. The concept is gaining momentum but progress is hindered by a lack of consistency across research teams. We consequently describe the selection process that led to the choice of our model strain, demonstrate its relevance to the field, and propose it as a shared model organism. We expect this contribution to support the development of cyanobacterium-based biotechnologies on Mars.
Project description:Total RNA was extracted from Anabaena 7120, hetZ mutant and hetP mutant at 24 h after nitrogen stepdown with two independent biological replicates. To maintain the integrity of coding RNAs, total RNA were sequenced without ribosomal RNA elimination. Strand-specific RNA-Seq libraries were prepared and sequenced using the Illumina HiSeq 2500 sequencing instrument to generate paired-end reads with length of 125 bp.