Figure  6.

Use of ATLAS to identify SNPs within older L1s. a, Segregation of a dimorphic 5′ (Ta-1d) ATLAS product in CEPH family 1331. A dimorphic 5′ ATLAS display product (see “D” in fig. 5) is shown. b, Identification, through sequencing, of a cosegregating SNP at the L1 primer site. Primers placed outside the AseI restriction site and Ta-1d L1 primer-annealing site enabled PCR amplification of the product from each individual (1–16) in CEPH family 1331. Direct sequencing of the products revealed that an ATLAS display product occurred only when an individual inherited an allele, of the L1, containing an exact match to the Ta-1d primer-annealing site. Individuals 3 and 5 are heterozygous for the matched/mismatched sequence (arrows indicate the double G/C peak). In contrast, individuals 10 and 14 are homozygous for the mismatched allele (arrows indicate the single G peak).