Fixed bins

FIXED BINS
One way of accommodating the continuous nature
of fragment lengthsis to present a continuouasn alysis.
Methods based on normality of measurement errors and independence of alleles atVNTR loci have been locus, and may be regarded as playing the role of used by BERRY (1991) and BERRYE,V ETT and PIN- alleles. This is not too dissimilar to the more familiar
CHON (19 92). To approachthe situation moreu sually case of electromorphs being composites of several encountered in population genetic analysis, an alter- alleles that may be revealed when electrophoretic native is toconstruct “bins” around the estimated conditions are modified, as reviewed recently by LElengths. These bins contain fragments resulting from WONTIN (1991). Binning has been described as being
severaldifferent numbers of repeat units at a VNTR variable or fixed. Variable bins are centered on par
An analysis is presented of data collected by the Federal Bureau of Investigation at six unlinkedvariable number of tandem repeats (VNTR) loci for the United States population. Databases have been constructed of VNTR profiles of Caucasians, Blacks and Hispanics from Florida, Texas and California. Therewas very little evidence for correlations between lengths for pairs of VNTR fragments, within or between loci. When the fragment lengths were amalgamated into discrete bins, there was also littleevidence for disequilibrium over all genotypes, within or between loci, for the Caucasian database, although some disequilibrium was found for the Black and Hispanic databases. No disequilibrium was foundfor the Caucasian or Black databases when tests were confined to heterozygous individuals. In cases of global disequilibrium, local tests can be applied to specific genotypes. The results suggestthat, at the bin level, frequencies of VNTR profiles can generally be estimated as the products of the frequencies of the constituent elements. This overcomes the problem of estimating population...