InDel标记的研究和应用进展

InDel是指在近缘种或同一物种不同个体之间基因组同一位点的序列发生不同大小核苷酸片段的插入或缺失(insertion-deletion), 是同源序列比对产生空位(gap)的现象。InDel在基因组中分布广泛、密度大、数目众多。InDel多态性分子标记是基于插入/缺失位点两侧的序列设计特异引物进行PCR扩增的标记, 其本质仍属于长度多态性标记, 可利用便捷的电泳平台进行分型。InDel标记准确性高、稳定性好, 避免了由于特异性和复杂性导致的后续分析模糊。此外, InDel标记能扩增混合DNA样品和高度降解的微量DNA样品, 并进行有效分型。InDel标记目前已开始应用于动植物群体遗传分析、分子辅助育种以及人类法医遗传学、医学诊断等领域。随着位于功能基因上InDel标记的开发, 结合染色体步移和基因精细定位, 可将这些标记应用于相关物种经济性状的功能基因的筛选, 有利于优良基因的进一步开发和利用。

Progress in research and application of InDel markers

InDel indicates insertions or deletions (insertion-deletion) of nucleotide fragments of different sizes at the same site in the genome sequence between the same or closely related species and is a gap in sequence derived from alignment of the homologous sequence. InDel is widely distributed across the genome and occurs in a high density and large numbers in a genome. The InDel polymorphic molecular marker is a PCR-amplified marker that is based on specific primers designed from both sides of the site of sequence of insertion / deletion. It is essentially a length polymorphic marker still, and one can use the convenient electrophoresis platform for genotyping. InDel molecular markers have the advantage of high accuracy and good stability, which help to avoid confusion in subsequent analysis due to marker specificity and complexity, as is often seen in other length polymorphic markers. Furthermore, mixed or highly degraded DNA samples can be successfully amplified with InDel markers, and effectively typed. Because of its abundance, convenient typing platform and other advantages, InDel molecular markers have been applied to genetic analyses of animal and plant populations, molecular assisted crops and farmed animal breeding, human forensic genetics, medical diagnostics and other research areas. The development of the InDel molecular marker located on functional genes, combined with chromosome walking and fine gene mapping, has enabled the application of these molecular markers in the screening of genes related to important economic traits, which is conducive to the further development and utilization of these valuable genes. In this review, on the basis of an overview of the InDel marker development and applications, we discuss some of the technical limitations of the development and limited efficiency of genetic analysis, as well as potential future applications in the fine mapping and genetic structure of large numbers of individuals.