Lineage: Bacteria[3914]; Firmicutes[795]; Bacilli[433]; Bacillales[223]; Bacillaceae[95]; Bacillus[54]; Bacillus subtilis group[7]; Bacillus subtilis[1]Bacillus subtilis. This organism was one of the first bacteria studied, and was named Vibrio subtilis in 1835 and renamed Bacillus subtilis in 1872. It is one of the most well characterized bacterial organisms, and is a model system for cell differentiation and development. This soil bacterium can divide asymmetrically, producing an endospore that is resistant to environmental factors such as heat, acid, and salt, and which can persist in the environment for long periods of time. The endospore is formed at times of nutritional stress, allowing the organism to persist in the environment until conditions become favorable. Prior to the decision to produce the spore the bacterium might become motile, through the production of flagella, and also take up DNA from the environment through the competence system.The sporulation process is complex and involves the coordinated regulation of hundreds of genes in the genome. Environmental signals are sensed by bacterial two-component systems that initiate a phosphorelay that transfers phosphate to one of the key early transcriptional regulators, Spo0A. This initial step results in the coordinated asymmetric cellular division and endospore formation through multiple stages that produces a single spore from the mother cell. This cascade of gene regulation is intensively studied. [Source: NCBI Genome ]