Tracking the origins of Yakutian horses and the genetic basis for their fast adaptation to subarctic environments.

Yakutia, Sakha Republic, in the Siberian Far East, represents one of the coldest places on Earth, with winter record temperatures dropping below -70 °C. Nevertheless, Yakutian horses survive all year round in the open air due to striking phenotypic adaptations, including compact body conformations, extremely hairy winter coats, and acute seasonal differences in metabolic activities. The evolutionary origins of Yakutian horses and the genetic basis of their adaptations remain, however, contentious.

Is aging recorded in blood Cu and Zn isotope compositions?

Recent isotopic observations of animal samples indicate body accumulation of heavy zinc and light copper throughout life. This hypothesis has never been tested for humans, but the existence of a relationship between blood isotopic composition and age could be promising for age assessment methodologies. Dietary habits can also influence the blood zinc isotope composition, being an additional source of isotopic variation.

Molecular identification of bacteria by total sequence screening: determining the cause of death in ancient human subjects.

Research of ancient pathogens in ancient human skeletons has been mainly carried out on the basis of one essential historical or archaeological observation, permitting specific pathogens to be targeted. Detection of ancient human pathogens without such evidence is more difficult, since the quantity and quality of ancient DNA, as well as the environmental bacteria potentially present in the sample, limit the analyses possible. Using human lung tissue and/or teeth samples from burials in eastern Siberia, dating from the end of 17(th) to the 19(th) century, we propose a methodology that includes the: 1) amplification of all 16S rDNA gene sequences present in each sample; 2) identification of all bacterial DNA sequences with a degree of identity ≥ 95%, according to quality criteria; 3) identification and confirmation of bacterial pathogens by the amplification of the rpoB gene; and 4) establishment of authenticity criteria for ancient DNA.

Population genetics of 17 Y-chromosomal STR loci in Yakutia.

Haplotype and allele frequencies of 17 Y-chromosomal short tandem repeat (Y-STR) markers in a population sample of 133 Yakut male volunteers from two regions: Central (n=41) and Western Yakutia (n=92) were determined using the AmpFlSTR Yfiler PCR Amplification Kit (Applied Biosystems). A total of 65 haplotypes were identified in the Yakut population, with 15 haplotypes in Central sample and 54 haplotypes in Western sample. Haplotype diversity values of 0.

Molecular genetic analysis of 400-year-old human remains found in two Yakut burial sites.

The excavation of five frozen graves at the Sytygane Syhe and Istekh-Myrane burial sites (dated at 400 years old) in central Yakutia revealed five human skeletons belonging to the Yakut population. To investigate the origin and evolution of the Yakut population as well as the kinship system between individuals buried in these two sites, DNA was extracted from bone samples and analyzed by autosomal short tandem repeats (STRs) and by sequencing hypervariable region I (HV1) of the mitochondrial DNA (mtDNA) control region. The results showed a diversity of sepulchral organizations linked probably to the social or genetic background of the subjects.

Genetic analysis of human remains found in two eighteenth century Yakut graves at At-Dabaan.

We extracted DNA from three skeletons belonging to the Yakut population, which were excavated from the At-Dabaan site (dating back 300 years) in the Sakha Republic (Russia). Ancient DNA was analyzed by autosomal STRs (short tandem repeats) and by the sequencing of the hypervariable region 1 (HV1) of the mitochondrial DNA (mtDNA) control region. The results showed that these three skeletons were not close relatives but probably linked to the same clan structure.