Alteration in synonymous arginine codon preferences of bacillus subtilis during sporulation

• Published in: Journal of theoretical biology Vol. 172; no. 4; pp. 387 - 390
• Main Author: Kunisawa, Takashi
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 21-02-1995
• Subjects: Arginine - genetics; Bacillus subtilis; Bacillus subtilis - physiology; Codon; Spores
• ISSN: 0022-5193; 1095-8541
• DOI: 10.1006/jtbi.1995.0036

How do cells of one type differentiate into dissimilar types of cells? Great progress has been made in elucidating the complex genetic program regulating spore formation in Bacillus subtilis, in which only two cell types-mother cell and prespore-arise that differ from each other and from the progenitor cell. Many of the genetic interactions involved in sporulation can be explained by the action of transcription factors that are confined in mother cell or prespore. However, little is known about regulatory mechanisms that operate at the translational level. Recently, a possible example of this has come to light in another spore-forming bacterium Streptomyces coelicolor A3(2). Although genes required for vegetative growth of S. coelicolor do not contain the leucine codon UUA, this codon is used specifically in a few genes necessary during differentiation, leading to formation of actinospores and production of antibiotics. The distribution of the UUA codon is consistent with the experimental result showing that accumulation of a leucine tRNA species recognizing the UUA codon is temporally regulated. In this note, I report the synonymous codon usage pattern of B. subtilis genes at each stage of sporulation and suggest increased accumulation of an Arg-tRNA species in mother cells during sporulation. It is now generally accepted that major synonymous codon preferences in unicellular organisms such as Escherichia coli and yeast are determined by the abundance of isoacceptor tRNA species in cells. Therefore, from synonymous codon usage data, relative cellular concentrations of isoacceptor species can be inferred.