Biomaterial Database

Multiple rRNA operons are essential for efficient cell growth and sporulation as well as outgrowth in Bacillus subtilis. 2013

Koichi Yano, and Tetsuya Wada, and Shota Suzuki, and Kazumi Tagami, and Takashi Matsumoto, and Yuh Shiwa, and Taichiro Ishige, and Yasuhiro Kawaguchi, and Kenta Masuda, and Genki Akanuma, and Hideaki Nanamiya, and Hironori Niki, and Hirofumi Yoshikawa, and Fujio Kawamura

Department of Life Science and Research Center for Life Science, College of Science, Rikkyo University, Toshima-ku Nishi-ikebukuro 3-34-1, Tokyo 171-8501, Japan.

The number of copies of rRNA (rrn) operons in a bacterial genome differs greatly among bacterial species. Here we examined the phenotypic effects of variations in the number of copies of rRNA genes in the genome of Bacillus subtilis by analysis of eight mutant strains constructed to carry from two to nine copies of the rrn operon. We found that a decrease in the number of copies from ten to one increased the doubling time, and decreased the sporulation frequency and motility. The maximum levels for transformation activity were similar among the strains, although the competence development was significantly delayed in the strain with a single rrn operon. Normal sporulation only occurred if more than four copies of the rrn operon were present, although ten copies were needed for vegetative growth after germination of the spores. This behaviour was seen even though the intracellular level of ribosomes was similar among strains with four to ten copies of the rrn operon. Furthermore, ten copies of the rrn operon were needed for the highest swarming activity. We also constructed 21 strains that carried all possible combinations of two copies of the rrn operons, and found that these showed a range of growth rates and sporulation frequencies that all fell between those recorded for strains with one or three copies of the rrn operon. The results suggested that the copy number of the rrn operon has a major influence on cellular processes such as growth rate and sporulation frequency.

UI	MeSH Term	Description	Entries
D008124	Locomotion	Movement or the ability to move from one place or another. It can refer to humans, vertebrate or invertebrate animals, and microorganisms.	Locomotor Activity,Activities, Locomotor,Activity, Locomotor,Locomotor Activities
D009154	Mutation	Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.	Mutations
D002455	Cell Division	The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.	M Phase,Cell Division Phase,Cell Divisions,Division Phase, Cell,Division, Cell,Divisions, Cell,M Phases,Phase, Cell Division,Phase, M,Phases, M
D001412	Bacillus subtilis	A species of gram-positive bacteria that is a common soil and water saprophyte.	Natto Bacteria,Bacillus subtilis (natto),Bacillus subtilis subsp. natto,Bacillus subtilis var. natto
D012407	rRNA Operon	Genetic loci which direct transcription of ribosomal RNA in bacterial operons. They are designated rrnB, rrnC, rrnD, etc. according to the structural position of the transcription unit in the DNA sequence.	Operon, rRNA,rrnB Operon,Operon, rrnB,Operons, rRNA,Operons, rrnB,rRNA Operons,rrnB Operons
D013171	Spores, Bacterial	Heat and stain resistant, metabolically inactive bodies formed within the vegetative cells of bacteria of the genera Bacillus and Clostridium.	Bacterial Spores,Bacterial Spore,Spore, Bacterial
D014169	Transformation, Bacterial	The heritable modification of the properties of a competent bacterium by naked DNA from another source. The uptake of naked DNA is a naturally occuring phenomenon in some bacteria. It is often used as a GENE TRANSFER TECHNIQUE.	Bacterial Transformation
D061269	DNA Transformation Competence	The ability of bacterial cells to take up exogenous DNA and be genetically transformed by it.	Competence, DNA Transformation,Transformation Competence, DNA
D018628	Gene Dosage	The number of copies of a given gene present in the cell of an organism. An increase in gene dosage (by GENE DUPLICATION for example) can result in higher levels of gene product formation. GENE DOSAGE COMPENSATION mechanisms result in adjustments to the level GENE EXPRESSION when there are changes or differences in gene dosage.	Gene Copy Number,Copy Number, Gene,Copy Numbers, Gene,Dosage, Gene,Dosages, Gene,Gene Copy Numbers,Gene Dosages,Number, Gene Copy,Numbers, Gene Copy
D020043	Genes, Essential	Those genes found in an organism which are necessary for its viability and normal function.	Genes, House-keeping,Genes, Housekeeping,Essential Gene,Essential Genes,Gene, Essential,Gene, House-keeping,Gene, Housekeeping,Genes, House keeping,House-keeping Gene,House-keeping Genes,Housekeeping Gene,Housekeeping Genes