1Programa de Genética Humana, ICBM, Universidad de Chile, 2Departamento de Antropología, Universidad de Chile
Friday All day, Plaza Level
The diversity and evolution of human populations have been systematically analyzed through polymorphisms in the human and microbiome genomes. In fact, several microorganisms have been used to infer microevolutionary events of their human hosts.
The aim of this investigation is contribute to the study of human bacterial flora as an indirect genetics marker of human populations from a new source of genetic material: dental calculus. This material can be analyzed in current and ancient samples, and it has not been genetically analyzed before.
Recent and archaeological DNA samples, as old as 4,000 YBP, were successfully extracted and amplified following all the required controls for ancient DNA. Species-specific PCR primers were designed in order to identify five species (Actinomyces naeslundii, Fusobacterium nucleatum, Streptococcus gordonii, Streptococcus mutans and Porphyromonas gingivalis). Of these species, F. nucleatum was the most frequent, founded in all the recent samples and around 40% from ancient samples. Also, in this bacterium we observed the presence of two o more genetic variants from the same individual, which were detected through DNA cloning.
Genomic analysis of bacteria from dental calculus is a promising source of evidence for paleopathological and microevolutionary studies, focused either on microorganisms or their human hosts.
Grant support: FONDECYT 1110461, 1100643, Anillo ACT-96.