Presentation on theme: "Y CHROMOSOME VARIATION Males from Cis-Baikal Sites of Lokomotiv, Shamanka II, and Ust’-Ida Examine the genetic relationships between prehistoric Cis- Baikal."— Presentation transcript:
Y CHROMOSOME VARIATION Males from Cis-Baikal Sites of Lokomotiv, Shamanka II, and Ust’-Ida Examine the genetic relationships between prehistoric Cis- Baikal hunter-gatherer groups, specifically, indicating whether there was biological continuity or discontinuity between Kitoi (pre-) and Serovo-Glazkovo (post-hiatus) cultures Which group best reflects the source population of contemporary Siberians Address the question of whether one or both groups represent the ancestral gene pool of Native American populations
STEPS 1.Acquire and Prepare Bone Samples for DNA Extraction 2.DNA Extraction 3.Molecularly Assign or Confirm Sex of Individuals 4.Characterize Individual Y Chromosome Genotypes 5. Assign Genotypes to Y Chromosomal Haplogroups, or Paternally Inherited Genetic Lineages 6.Sequencing 7.Determine Phylogenetic Relationships 8.Compare with mtDNA Data
DETERMINATION OF SEX OF EACH INDIVIDUAL Osteological Evidence Amelogenin Gene Some males may lack the Y copy of this gene due to a deletion and would therefore be incorrectly typed as female. SRY Gene Male sex determining gene
Y Chromosome Genotypes Short tandem repeats (STRs), or microsatellites Useful in population studies because of their polymorphic character A set of these informative mutations will be analyzed in the Lokomotiv, Shamanka II, and Ust’-Ida samples, and the resulting data compared to those from modern Siberian and Native American populations Single nucleotide polymorphisms (SNPs) Reflect unique mutational events Characterize paternal lineages or haplotypes The frequencies with which these SNPs appear in populations illustrate levels of genetic affinities.
IMPLICATIONS OF Y CHROMOSOME VARIATION Test hypotheses of biological continuity vs. discontinuity between Kitoi and Serovo Glazkovo cultures Determine further genetic affinities between one or both of these prehistoric cultures and contemporary Siberians between one or both of these prehistoric cultures and contemporary Native American populations Comparative study with mtDNA research conducted on same samples.
By focusing on the levels of male homogeneity within and between pre- and post-hiatus populations, the Y chromosome data set will enable comparisons with parallel mtDNA work to study: differential male/female mobility and migration patterns, burial organization, kinship relationships, exogamy/endogamy practices demographic structure Differential levels of genetic affinities between prehistoric Cis- Baikal males and modern populations. Comparisons with mtDNA Results
MY 2 MONTH TRAINING IN THE LAB OF HUMAN IDENTIFICATION FOR ARCHAEOLOGY Became acquainted with Lake Baikal mortuary sites, skeletal samples, and current research underway by BAP members. Learned anti-contamination procedures and protocols in place for the retrieval of DNA from ancient samples. Re-extracted 11 samples, in duplicate, from Lokomotiv and Ust’-Ida, which were previously determined to be male by osteological data and molecularly typed as male using Amelogenin. Attempted to confirm their sex by testing for the male specific SRY gene. Extracted 11 samples, in duplicate, from Shamanka II site, which were osteologically determined to be male. Attempted to confirm their sex by testing for the male specific SRY gene.