Book Viewer

Short Contents | Full Contents | Other books @ NCBI

Modern Genetic Analysis Glossary
F
F cell In E. coli, a cell having no fertility factor; a female cell.
F+ cell In E. coli, a cell having a free fertility factor; a male cell.
F factor See fertility factor.
F factor A fertility factor into which a part of the bacterial chromosome has been incorporated.
F1 generation The first filial generation, produced by crossing two parental lines.
F2 generation The second filial generation, produced by selfing or intercrossing the F1.
FACS (fluorescence-activated chromosome sorting) Using specific fluorescence signals of stained chromosomes in droplets to activate deflector plates that sort chromosomes into individual tubes of uniform types.
facultative heterochromatin Heterochromatin located in positions that are composed of euchromatin in other individuals of the same species or even in the other homolog of a chromosome pair.
familial trait A trait shared by members of a family.
family selection A breeding technique of selecting a pair on the basis of the average performance of their progeny.
fate map A map of an embryo showing areas that are destined to develop into specific adult tissues and organs.
fate refinement The process by which decisions are fine-tuned so that all necessary cell types are fated in the proper spatial locations and cell numbers.
feedback loop See autoregulatory loop.
fertility factor (F factor) A bacterial episome whose presence confers donor ability (maleness).
filial generations Successive generations of progeny in a controlled series of crosses, starting with two specific parents (the P generation) and selfing or intercrossing the progeny of each new (F1, F2,...) generation.
filter enrichment A technique for recovering auxotrophic mutants in filamentous fungi.
fingerprint The characteristic spot pattern produced by electrophoresis of the polypeptide fragments obtained through denaturation of a particular protein with a proteolytic enzyme.
first-division segregation pattern A linear pattern of spore phenotypes within the ascus for a particular allele pair, produced when the alleles go into separate nuclei at the first meiotic division, showing that no crossover has occurred between the allele pair and the centromere.
FISH (fluorescence in situ hybridization) In situ hybridization using a probe coupled to a fluorescent molecule.
fitness See Darwinian fitness.
fixed allele An allele for which all members of the population under study are homozygous, so that no other alleles for this locus exist in the population.
fixed breakage point According to the heteroduplex DNA recombination model, the point from which unwinding of the DNA double helices begins, as a prelude to formation of heteroduplex DNA.
flow sorting See FACS.
fluctuation test A test used in microbes to establish the random nature of mutation or to measure mutation rates.
fMet See formylmethionine.
focus map A fate map of areas of the Drosophila blastoderm destined to become specific adult structures, based on the frequencies of specific kinds of mosaics.
foreign DNA DNA from another organism.
formylmethionine (fMet) A specialized amino acid that is the very first one incorporated into the polypeptide chain in the synthesis of proteins.
forward mutation A mutation that converts a wild-type allele into a mutant allele.
frame-shift mutation The insertion or deletion of a nucleotide pair or pairs, causing a disruption of the translational reading frame.
frequency-dependent fitness Fitness differences whose intensity changes with changes in the relative frequency of genotypes in the population.
frequency-dependent selection Selection that depends on frequency-dependent fitness.
frequency histogram A "step curve" in which the frequencies of various arbitrarily bounded classes are graphed.
frequency-independent fitness Fitness that is not dependent on interactions with other individuals of the same species.
frequency-independent selection Selection in which the fitnesses of genotypes are independent of their relative frequency in the population.
fruiting body In fungi, the organ in which meiosis takes place and sexual spores are produced.
functional complementation The use of a cloned fragment of wild-type DNA to transform a mutant into wild type; used in identifying a clone containing one specific gene.
functional genomics Studying patterns of gene expression and interaction in the genome as a whole.

© 1999 by W. H. Freeman and Company. All rights reserved.