...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Genetics Research >The covariance of heterozygosity as a measure of linkage disequilibrium between blocks of linked and unlinked sites in Hapmap
【24h】

The covariance of heterozygosity as a measure of linkage disequilibrium between blocks of linked and unlinked sites in Hapmap

机译：杂合度的协方差作为Hapmap中链接和未链接位点之间的连锁不平衡的量度

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The covariance of heterozygosity serves as a measure of linkage disequilibrium (LD) between genes at two loci, although one that does not have as much information as a parameter such as r(2). However, it may be extended to blocks of loci (single nucleotide polymorphisms, SNPs) along a chromosome. This has two advantages when searching for significant associations between different chromosomal regions. Calculations for a data set such as Hapmap are complicated by the large number of pairs of loci (SNPs) that need to be considered. For example, a search for significant associations between SNPs on different chromosomes involves around 10(12) calculations for a single population. Furthermore, this may not be an efficient way of detecting associations since r(2) values calculated from neighbouring pairs will not be independent of each other. The covariance of heterozygosity provides an average measure of association between blocks of any size, and reduces the number of calculations by a factor of b(2), where his the block size. Unlike the calculation of r(2), the covariance of heterozygosity uses just diploid data and is not biased by sample size. Calculations using a block size of 50 have been used to look for associations in the Hapmap data set between regions within and between chromosomes. Within chromosomes, a signal is detected up to around 10 cM. No obviously significant associations have been detected between regions on different chromosomes, although there is a low level of association consistent with departures from random mating.
机译：杂合度的协方差可用来衡量两个基因座上基因之间的连锁不平衡（LD），尽管该基因不具有像r（2）这样的参数那么多的信息。但是，它可能会扩展到沿染色体的基因座（单核苷酸多态性，SNP）区域。当搜索不同染色体区域之间的显着关联时，这具有两个优点。像Hapmap这样的数据集的计算由于需要考虑大量成对的基因座（SNP）而变得很复杂。例如，对不同染色体上SNP之间重要关联的搜索涉及单个群体的大约10（12）个计算。此外，这可能不是检测关联的有效方法，因为从相邻对计算出的r（2）值将不会彼此独立。杂合度的协方差提供了任何大小的块之间关联的平均度量，并且将计算数量减少了b（2）倍，即块大小。与r（2）的计算不同，杂合度的协方差仅使用二倍体数据，并且不受样本量的影响。使用块大小为50的计算已用于在Hapmap数据集中寻找染色体内以及染色体之间的关联。在染色体内，检测到的信号高达10 cM。尽管与随机交配背离的关联水平较低，但在不同染色体上的区域之间未检测到明显的显着关联。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号