Genomic study reveals complex origins of people living in Tibetan-Yi
corridor

Date:
April 26, 2022
Source:
Cell Press
Summary:
China's mountainous southwestern area is home to one of the
country's most ethnically diverse populations. In the most
comprehensive genetic analysis of the native people there to date,
researchers reveal that the ethnic groups' peopling and migration
history is more complex than previously concluded.



FULL STORY ========================================================================== China's mountainous southwestern area is home to one of the country's most ethnically diverse populations. In the most comprehensive genetic analysis
of the native people there to date, researchers reveal that the ethnic
groups' peopling and migration history is more complex than previously concluded. The study appears April 26 in the journal Cell Reports.


==========================================================================
The Tibetan-Yi corridor (TYC), named after two main ethnic groups in
the region, on the eastern edge of Tibet Plateau in southwestern China
is thought to have served as an important area for ethnic migration
and diversification.

The corridor's corrugated landscape of deep river valleys and tall ridges formed natural passages and barriers for gene flow.

Scientists have previously analyzed how people in the region are
genetically related to the Tibetans, who live mostly west of the region,
and the Han, China's main ethnic group. But prior studies had limited
gene samples from the region, which inhabit over a dozen of different
ethnic groups.

To gain a better understanding of ethnic groups in the TYC, Shengbin
Li, the paper's co-corresponding author at Xi'an Jiaotong University in
central China, spent a decade collecting blood samples from more than
200 people from all 16 ethnic groups in the region.

"The steep mountains that contributed to the high levels of ethnic
diversity in the area also made data collection extremely difficult,"
says Li. "Most of the places were inaccessible by car, so we had to
travel on horseback. And some groups were so isolated that we had to
walk for hours to get there." The team selected individuals from each
ethnic group with at least three generations of history living in a
relatively fixed area. By comparing the genomes of different ethnic
groups, and those of Han and Tibetan populations, the team found that
all ethnic groups in the region are genetically similar, suggesting that
they shared a common ancestor. But people living in the northern TYC
are related more closely to Tibetan Highlanders living on the plateau,
while southern TYC inhabitants have a closer genetic relationship with southeast Asians, such as Thai people and Cambodians.

Previous research suggests that the region's earliest settlers came from
the upper reaches of the Yellow River region in northern China during
the Neolithic period, and the corridor was gradually populated as the
settlers expanded southward. The new study, while not contradicting the previous conclusion, found that the migration pattern is more complex
than a simple north-to-south movement. For example, new data suggest
that the ancestors of some southern TYC populations might have originated
from southeastern Asia.

"More studies are needed to further understand the origin and flow
of the region's population, especially a more comprehensive analysis
that incorporates not only genetic but also archaeological, cultural, linguistic and geographical evidence," says Shuaicheng Li, the study's co-corresponding author at City University of Hong Kong.

Next, the team hopes to study the gut microbiota of the TYC people. "The
region has no air pollution, and locals don't eat processed food with chemicals. Their microbiota has the potential to reveal more connections between gut and health," Shuaicheng Li says.


========================================================================== Story Source: Materials provided by Cell_Press. Note: Content may be
edited for style and length.


========================================================================== Journal Reference:
1. Zhe Zhang, Yanlin Zhang, Yinan Wang, Zicheng Zhao, Melinda Yang, Lin
Zhang, Bin Zhou, Bingying Xu, Hongbo Zhang, Teng Chen, Wenkui Dai,
Yong Zhou, Shuo Shi, Rasmus Nielsen, Shuai Cheng Li, Shengbin
Li. The Tibetan- Yi region is both a corridor and a barrier
for human gene flow. Cell Reports, 2022; 39 (4): 110720 DOI:
10.1016/j.celrep.2022.110720 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/04/220426153711.htm

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