AMPLIFYING DINUCLEOTIDE MICROSATELLITE LOCI FROM BONE AND TOOTH SAMPLES OF UP TO 5000 YEARS OF AGE - MORE INCONSISTENCY THAN USEFULNESS

We have studied the feasibility of using dinucleotide-repeat microsate llites in the analysis of DNA from ancient bones and teeth. We have us ed three microsatellites (IVS8CA, IVS17BTA, and IVS17BCA) within the c ystic fibrosis transmembrane conductance regulator gene in 28 DNA samp les from bones and teeth of up to 5000 years of age. PCR amplification was successful in 71.4% of cases. The repeated analysis of each marke r produced different genotypes in 97% of samples, and the same individ ual genotype was reproduced at least once in 45.5% of cases. Alleles d iffering from the originals consisted of additions or deletions of 1-3 9 dinucleotides. The mechanism by which alleles differing from the ori ginals were amplified can be related to the marked degradation of the DNA, with repeat sequences of different length interacting with the pa rtially degraded repeats of the amplified loci. The repeated analysis of each sample allowed us to produce data with some anthropological in terest. Among the haplotypes detected in samples from Easter Island, t wo (16-32-13 and 23-32-13) were found in more than one sample. Similar ly, three haplotypes (16-7-17, 16-7-13, and 16-24-13) were detected mo re than once in samples from the Basque Country. Although haplotypes i n the Basque Country are amongst the commonest in European chromosomes , most of those detected in the Easter Island samples are not frequent in Europeans. Thus, the repeated typing of microsatellites allowed us to postulate the genotypes that might be present in the samples but d inucleotide markers do not seem to be reliable enough for genotyping a ncient bone and teeth samples.