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International audience; The human methylome is dynamically influenced by psychological stress. However, its responsiveness to stress management remains underexplored. Meditation practice has been shown to significantly reduce stress level, among other beneficial neurophysiological outcomes. Here, we evaluated the impact of a day of intensive meditation practice (t2-t1 = 8 h) on the methylome of peripheral blood mononuclear cells in experienced meditators (n = 17). In parallel, we assessed the influence of a day of leisure activities in the same environment on the methylome of matched control subjects with no meditation experience (n = 17). DNA methylation profiles were analyzed using the Illumina 450 K beadchip array. We fitted for each methylation site a linear model for multi-level experiments which adjusts the variation between t1 and t2 for baseline differences. No significant baseline differences in methylation profiles was detected between groups. In the meditation group, we identified 61 differentially methylated sites (DMS) after the intervention. These DMS were enriched in genes mostly associated with immune cell metabolism and ageing and in binding sites for several transcription factors involved in immune response and inflammation, among other functions. In the control group, no significant change in methylation level was observed after the day of leisure activities. These results suggest that a short meditation intervention in trained subjects may rapidly influence the epigenome at sites of potential relevance for immune function and provide a better understanding of the dynamics of the human methylome over short time windows.

The southwestern and Central Asian corridor has played a pivotal role in the history of humankind, witnessing numerous waves of migration of different peoples at different times. To evaluate the effects of these population movements on the current genetic landscape of the Iranian plateau, the Indus Valley, and Central Asia, we have analyzed 910 mitochondrial DNAs (mtDNAs) from 23 populations of the region. This study has allowed a refinement of the phylogenetic relationships of some lineages and the identification of new haplogroups in the southwestern and Central Asian mtDNA tree. Both lineage geographical distribution and spatial analysis of molecular variance showed that populations located west of the Indus Valley mainly harbor mtDNAs of western Eurasian origin, whereas those inhabiting the Indo-Gangetic region and Central Asia present substantial proportions of lineages that can be allocated to three different genetic components of western Eurasian, eastern Eurasian, and south Asian origin. In addition to the overall composite picture of lineage clusters of different origin, we observed a number of deep-rooting lineages, whose relative clustering and coalescent ages suggest an autochthonous origin in the southwestern Asian corridor during the Pleistocene. The comparison with Y-chromosome data revealed a highly complex genetic and demographic history of the region, which includes sexually asymmetrical mating patterns, founder effects, and female-specific traces of the East African slave trade.