Abstract:

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.

Key words: molecular marker, InDel, SNP, SSR