Insertion sites of Ta-1 elements in the human genome. Ta-1 integration sites are shown as tick marks above each chromosome. Tick marks with thinner lines impinging directly on the chromosome diagrams are those identified in the human genome database. Tick marks with heavier lines offset from the chromosomes are the ones that we cloned. Solid circles indicate polymorphic inserts, open circles indicate fixed ones, and tick marks without either are indeterminate (not amenable to PCR, see Methods and Table 1). The number in parentheses indicates the number of Ta-1 insertion sites on each chromosome. Chromosome 15 only shows the positions of 4 of the 5 Ta-1 elements on this chromosome because one of them was located on an unassigned segment. The shaded boxes indicate the number of known genes per 5 Mb segments. The unadjusted k-specific P values for some apparent clusters are given.
