Integration of gene maps: chromosome 21.

Physical, cytogenetic, and genetic data including microsatellite markers and a covering sequence-tagged site (STS) map have been entered into a location database and integrated into a summary map that subsumes a composite physical location, sex-specific genetic locations, cytogenetic and regional assignments, mouse homology, rank, and references. With the omission of 52 loci whose location is known only from cytogenetic assignment to an interval greater than 10 megabases, there are 198 loci in the covering STS map and an additional 145 loci. The physical length is consistent with 11 megabases for 21p and 39 megabases for 21q. With error filtration and allowance for high interference, the genetic length in males corresponds to the chiasma map (54.7 centimorgans), and the genetic length in females is 76.5 centimorgans. The relation between map integration and the STS paradigm is illustrated and discussed.