Biomaterial Database

Statistical estimate of the total number of operons specific for Bacillus subtilis sporulation. 1974

D Hranueli, and P J Piggot, and J Mandelstam

As an alternative to exhaustive mapping, an attempt has been made to obtain a rough estimate of the total number of sporulation operons by statistical treatment. Sixteen sporulation mutants taken at random were characterized biochemically and morphologically. The mutations they contained were mapped to determine whether they fell into any one of 23 known operons. From the proportion that do so (10/16), it is calculated that the most probable number of sporulation operons is 37 (68% confidence limits of 31 and 46). If allowance is made for the fact that two of the operons apparently contain mutagenic "hot spots" and the calculation is amended accordingly, the most probable numbers of operons becomes 42 (limits 33 and 59).

UI	MeSH Term	Description	Entries
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D009153	Mutagens	Chemical agents that increase the rate of genetic mutation by interfering with the function of nucleic acids. A clastogen is a specific mutagen that causes breaks in chromosomes.	Clastogen,Clastogens,Genotoxin,Genotoxins,Mutagen
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
D009604	Nitrosoguanidines	Nitrosylated derivatives of guanidine. They are used as MUTAGENS in MOLECULAR BIOLOGY research.
D009876	Operon	In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.	Operons
D010641	Phenotype	The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.	Phenotypes
D002874	Chromosome Mapping	Any method used for determining the location of and relative distances between genes on a chromosome.	Gene Mapping,Linkage Mapping,Genome Mapping,Chromosome Mappings,Gene Mappings,Genome Mappings,Linkage Mappings,Mapping, Chromosome,Mapping, Gene,Mapping, Genome,Mapping, Linkage,Mappings, Chromosome,Mappings, Gene,Mappings, Genome,Mappings, Linkage
D003433	Crosses, Genetic	Deliberate breeding of two different individuals that results in offspring that carry part of the genetic material of each parent. The parent organisms must be genetically compatible and may be from different varieties or closely related species.	Cross, Genetic,Genetic Cross,Genetic Crosses
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
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