现代人走出非洲之后，迁移至世界各地并迅速适应当地的环境，在这个过程中，很多表型都经历了适应性进化。骨骼系统在过去10000年间伴随着群体扩张在人群中进化速率非常快，但是与大脑发育认知能力、免疫生殖系统等不同的是，目前有关人群中骨骼系统相关基因所受自然选择作用的研究报道还很少。
据前人的研究报道：LMBR1基因intron5内的多态位点与多种表型的多指症存在相关性，受其调控的SHH基因在骨骼系统发育中具有重要作用，且该基因在灵长类中、特别是在人这一进化枝中受到强烈的正选择作用。基于此，张亚平院士研究组的研究生何芳等检测了LMBR1基因intron 5区域在41个东亚个体中的遗传多样性状况，发现该区域在人群中受到平衡选择的作用。该结果不仅说明一个与骨骼系统发育有关的基因调控元件在进化历程中受到自然选择的作用，同时也为揭示骨骼系统发育过程中出现缺陷的遗传机理及骨骼系统的进化机制提供了重要信息。该研究成果已发表在国际刊物《公共科学图书馆·综合》（PLoS ONE）上。（生物谷Bioon.com）
PLoS ONE，doi:10.1371/journal.pone.0002948，Fang He，Ya-Ping Zhang
Intriguing Balancing Selection on the Intron 5 Region of LMBR1 in Human Population
Fang He1,3, Dong-Dong Wu1,3, Qing-Peng Kong1, Ya-Ping Zhang1,2*
1 State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China2 Laboratory for Conservation and Utilization of Bio-resource, Yunnan University, Kunming, China3 Graduate School of the Chinese Academy of Sciences, Beijing, China
Abstract
Background
The intron 5 of gene LMBR1 is the cis-acting regulatory module for the sonic hedgehog (SHH) gene. Mutation in this non-coding region is associated with preaxial polydactyly, and may play crucial roles in the evolution of limb and skeletal system.
Methodology/Principal Findings
We sequenced a region of the LMBR1 gene intron 5 in East Asian human population, and found a significant deviation of Tajima's D statistics from neutrality taking human population growth into account. Data from HapMap also demonstrated extended linkage disequilibrium in the region in East Asian and European population, and significantly low degree of genetic differentiation among human populations.
Conclusion/Significance
We proposed that the intron 5 of LMBR1 was presumably subject to balancing selection during the evolution of modern human.
