FIG.1.

Four aligned genome images showing transcriptional responses of strain NCM3722 (or its Eut⁺ derivative NCM3954) to N or S limitation in adapted batch cultures. Row 1 (NCM3954), cells grown on ethanolamine (Cy5 label, red) versus cells grown on ammonium (Cy3 label, green); row 2, cells grown on arginine (red) versus cells grown on ammonium (green); row 3, cells grown on taurine (red) versus cells grown on sulfate (green); row 4, cells grown on glutathione (red) versus cells grown on sulfate (green). Glass slide DNA microarrays were probed with mixtures of appropriately labeled cDNAs as described in Materials and Methods. Spots from fluorescent scanning images of microarrays were arranged in genome order to generate the genome images (60, 61). The b number groups are indicated on the left. Blanks represent b numbers that either do not correspond to ORFs or no longer exist. Easily visible red spots are discussed in the text, and green spots will be discussed elsewhere. The eut operon extends from b2437 through b2462 but is interrupted by b2442 to b2450 (3, 44). Spots for b2438, b2440, b2455, and b2458 were problematic (44).