Targeted microarray analysis of three symbiotic cyanobacterial diazotroph strains in the South China Sea

We designed a new specific mRNA microarray targeting a subset of genes (748) of the diazotrophs Richelia intracellularis and Calothrix rhizosoleniae (genomes RintRC01, RintHH01, RintHM01 and CalSC01) which associate with diatom hosts. The aim was to be able to describe the gene expressions of genes related to several metabolic pathways and how they possibly differed between the closely related strains based on environment and host association. To better understand how the different environments might affect gene expressions, the samples were taken in depth profiles, at night and day, during a cruise in the South China Sea. In total 21 samples from 9 stations were collected, where 9 was from the surface (< 5m). Moreover, 12 of the samples were collected during the night. The microarray was designed with one thoroughly cross-hybridization tested probe for each target gene, and printed with a total of 18 probe replicates.