An automatic procedure to search highly repetitive sequences in genome as fluorescence in situ hybridization probes and its application on Brachypodium distachyon

Fluorescence in situ hybridization (FISH) is a powerful technique that localizes specific DNA sequences on chromosomes for use in physical and genetic maps assembling, genetic counselling, species identification, etc. Highly repetitive sequences are considered to be suitable FISH probes that can avoid many potential problems of using unique sequences as FISH probes. The distinct chromosomal distributions of these highly repetitive sequences are also ideal for labelling purposes such as karyotyping. In this paper, we present an automatic computational procedure for searching highly repetitive sequences from a whole genome as FISH probes, as well as an experimental protocol to use them in FISH analysis. We successfully applied the method on the newly released genome of Brachypodium distachyon (Brachypodium) and produced satisfactory results of FISH experiment.