Biomaterial Database

Temperature-sensitive mutations in Drosophila melanogaster. 8. The homeotic mutant, ss a40a . 1971

T Grigliatti, and D T Suzuki

There exists in Drosophila a class of mutations called "homeotic" that cause changes in determination of the imaginal discs. The homeotic mutant, ss(a40a), was found to have a temperature-sensitive transformation of the arista segment of the antennal complex to a tarsus of the leg. In a selected stock penetrance was complete, so that at 29 degrees C normal aristae were produced, whereas at 17 degrees C complete tarsi developed in all flies. "Temperature-shift" studies revealed a temperature-sensitive period in the third larval instar. The temperature-initiated action of ss(a40a) does not appear to result from a simple wave or gradient of determination passing through the disc. Shifts up during the temperature-sensitive period yielded leg tissue proximally, which increased distally with progressively later shifts. Shifts down yielded leg tissue at the aristal base, which retreated with later shifts.

UI	MeSH Term	Description	Entries
D007866	Leg	The inferior part of the lower extremity between the KNEE and the ANKLE.	Legs
D008855	Microscopy, Electron, Scanning	Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.	Scanning Electron Microscopy,Electron Scanning Microscopy,Electron Microscopies, Scanning,Electron Microscopy, Scanning,Electron Scanning Microscopies,Microscopies, Electron Scanning,Microscopies, Scanning Electron,Microscopy, Electron Scanning,Microscopy, Scanning Electron,Scanning Electron Microscopies,Scanning Microscopies, Electron,Scanning Microscopy, Electron
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
D010641	Phenotype	The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.	Phenotypes
D004331	Drosophila melanogaster	A species of fruit fly frequently used in genetics because of the large size of its chromosomes.	D. melanogaster,Drosophila melanogasters,melanogaster, Drosophila
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures