Paternal heritage of the Han Chinese in Henan province (Central China): high diversity and evidence of in situ Neolithic expansions.

Background: Due to their long history, complex admixture processes and large population sizes, more research is required to explore the fine genetic structure of Han populations from different geographic locations of China. Aim: To characterise the paternal genetic structure of the Han Chinese in Henan province, which was once the central living region of the ancient Huaxia population, the precursors of the Han Chinese. Subjects and methods: We sequenced Y chromosomes of 60 males from Zhengzhou, Henan Province, and reconstructed a phylogenetic tree for these samples with age estimation. Results: We observed high diversity of paternal lineages in our collection. We found that the in situ Neolithic expansion of the "Major lineages" contributed to a large portion of the paternal gene pool of the Han population in Henan Province. We also detected a large number of "Minor lineages" that diverged in the Palaeolithic Age. Conclusion: We suggest that the high genetic diversity in the paternal gene pool of modern Han populations is mainly attributed to the reservation of a larger number of lineages that diverged in the Palaeolithic Age, while the recent expansion of limited lineages contributed to the majority of the gene pool of modern Han populations. We propose that such a structure is a basal characteristic for the genetic structure of modern Han populations. [ABSTRACT FROM AUTHOR]