X-chromosomal STRs in aDNA kinship analysis.

The analysis of ancient DNA (aDNA) from human skeletal remains can provide useful insights when investigating archaeological finds. One popular application of aDNA is to examine genealogical relationships between individuals recovered at the same archaeological site. For the reconstruction of genealogical relationships, several genetic markers are commonly used: autosomal STRs, mitochondrial lineages (based on SNP-analysis) and Y-chromosomal haplotypes (based on Y-STR-analysis). In this paper, we present the additional opportunities that X-STRs provide in aDNA kinship reconstruction, especially in deficiency cases and for the examination of father-daughter relationships. Possible applications are demonstrated on a range of different kinship reconstructions: confirmation of half-siblingship in the Lichtenstein cave (Germany), exclusion of two potential father-daughter relationships in Goslar (Germany), investigation of three siblingships in Boilstädt (Germany) as well as the confirmation of a father-daughter relationship in Stolpe (Germany). This study shows that the analysis of X-STRs can contribute to the investigation of relationship constellations otherwise difficult to approach (e.g. father-daughter relationships) and that X-STRs are useful to support and complement autosomal STRs, mtDNA and Y-STR data.

The influence of sample quantity and lysis parameters on the success of ancient DNA extraction from skeletal remains.

DNA extraction is of utmost importance in archaeobiology, as it determines the success of further DNA analyses. This study concentrates on the success of ancient DNA extraction using silica spin columns and PCR-based analysis from archaeological skeletal material and investigates the influence of sample quantity, lysis time and lysis temperature during sample preparation. The results show that lysis times ranging from 2 to 48 h are suitable, and that lysis should be carried out at a constant temperature of 56°C. Concerning sample quantity, 10 mg for mitochondrial DNA and 50 mg for chromosomal DNA are sufficient for high quality analyses. Thus invaluable sample material can be saved, and time of sample preparation can be reduced considerably.