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幽门螺杆菌(H.pylori)可引起消化性溃疡,是胃癌的危险因素之一。H.pylori感染普遍存在,而且其基因具有很强的种系地理结构(phylogeographic structure),提示其多态性可反映人类的种系地理特征和迁徙史。2003年,我们将370株H.pylori菌株分为4个主要种群。这些菌株的地理起源反映了人类居留史上的重要事件,如玻里尼西亚和美洲的殖民地化,以及非洲班图人的迁徙。然而,这些种群的离散性似与人类遗传多态性中地理成分的明显连续性相矛盾:人类种群的遗传变异性与地理距离呈线性相关;其遗传多态性随着距东非地理距离的增加而降低。
Helicobacter pylori (H.pylori) can cause peptic ulcer, is one of the risk factors of gastric cancer. H.pylori infection is ubiquitous and its gene has a strong phylogeographic structure suggesting that its polymorphism can reflect the human germ-line geography and migration history. In 2003, we divided 370 H.pylori strains into four major populations. The geographical origin of these strains reflects important events in the history of human habitation, such as the colonization of Polynesia and the Americas and the migration of Bantu in Africa. However, the discreteness of these populations seems to contradict the apparent continuity of geographical elements in human genetic polymorphisms: the genetic variability of human populations is linearly related to geographical distance; and its genetic polymorphism increases with geographic distance from East Africa Lower.