人类基因组拷贝数变化的起源和功能影响
Donald F Conrad1, Dalila Pinto, Richard Redon
1The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA UK.
Nature
|October 9, 2009
概括
这项研究绘制了人类基因组中的11000多个副本数变异 (CNV),揭示了它们的突变机制和与疾病易感性的潜在联系. 常见的CNV不能解释全基因组关联研究发现的复杂特征的遗传差距.
科学领域:
- 基因组学就是基因组学.
- 人类遗传学 人类遗传学
- 分子生物学分子生物学
背景情况:
- 结构变异,特别是复制数变异 (CNVs) >1千基,是人类基因组多样性的重要来源.
- 尽管它们对基因组变异有很大影响,但CNV的确诊不足.
- 了解CNV的分布和起源对于人类遗传学研究至关重要.
研究的目的:
- 在人类基因组中创建复制数变异 (CNVs) 的全面地图.
- 为了研究不同CNV大小类的基因突变机制.
- 确定与疾病易感性相关的CNV,并评估它们对复杂特征遗传性的贡献.
主要方法:
- 使用了带有4200万个探针的片寡核酸微阵列来检测CNVs.
- 通过独立的方法验证了大量已识别的CNV.
- 在各种祖先群体 (欧洲,非洲,东亚) 中为数千种CNV生成参考基因型.
主要成果:
- 创建了11700个CNV (>443个基对) 的地图,其中8599个独立验证.
- 对不同的CNV大小类确定了不同的突变机制,包括逆转换.
- 发现了30个位置,其中CNV与特征相关的单核酸多态 (SNP) 相对应,这表明在疾病易感性中可能发挥作用.
结论:
- 这项研究为人类基因组变异研究提供了宝贵的资源.
- 常见的CNV无法解释在复杂特征的全基因组关联研究中观察到的遗传差距.
- 需要进一步的研究才能充分理解结构变异在人类疾病中的作用.
更多相关视频
相关概念视频
Gene Families
Gene families consist of groups of genes proposed to have originated from a common ancestor. Typically these arise through events in which a gene or genes are mistakenly duplicated during cell division. Unlike their parent genes (which are subject to selection pressure to maintain function), these gene copies do not need to preserve their sequences and may evolve at a relatively faster rate.
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...
Genome Copying Errors
DNA replication is a well-evolved process that copies millions of base pairs with high fidelity during each cell division. Occasionally a wrong base or a long stretch of wrong bases may get added to the daughter strands. If the errors are left unchecked, cells might accumulate several mutations that might endanger their survival. Therefore, the copying errors are checked and repaired at three levels.
Gene Duplication and Divergence
The seminal work of Ohno in 1970 popularized the idea of gene duplication and divergence. DNA sequence comparison studies reveal that a large portion of the genes in bacteria, archaebacteria, and eukaryotes was generated by gene duplication and divergence, indicating its critical role in evolution.
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.
Comparing Copy Number Variations and SNPs
Sequencing of the human genome has opened up several best-kept secrets of the genome. Scientists have identified thousands of genome variations that exist within a population. These variations can be a single nucleotide or a larger chromosomal variation.
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Copy number variations or CNVs are the structural variations that cover more than 1kb of DNA sequence. The single nucleotide polymorphism (SNP), on the other hand, is a single nucleotide change or a point mutation that is found in more than 1%...
Single Nucleotide Polymorphisms-SNPs
A single nucleotide polymorphism or SNP is a single nucleotide variation at a specific genomic position in a large population. It is the most prevalent type of sequence variation found in the human genome. Point mutations that occur in more than 1% of the population qualify as SNPs. These are present once every 1000 nucleotides on an average in the human genome. Replacement of a purine with another purine (A/G) or a pyrimidine with another pyrimidine (C/T) is known as a transition. In contrast,...
Principles of Pharmacogenetics: Types of Genetic Variants
The human genome is over 99.9% identical between individuals, yet genetic differences exist at millions of bases. The human genome contains approximately 3 million variant positions per individual, many of which are heterozygous, contributing to genetic diversity and individual traits. Genetic variations include single-nucleotide polymorphisms (SNPs), insertions, deletions, and copy number variations (CNVs).SNPs, the most common variation, involve single-base changes in DNA. These can be...


