Large tandem repeats of Mesocricetus auratus in silico and in situ

Abstract

The class of tandemly repeated sequences exists only in eukaryotic genomes and absent in prokaryotes. The tens percent of eukaryotic genome are built up of the tandem repeats. The whole set of different tandem repeats is not revealed to any of the eukaryote species in spite of the half century history of its investigation by molecular biology methods. Previously we found the set of tandem repeats in the database of well assembled mouse genome with the bioinformatics methods. In the current work we applied the same methods to the poorly assembled hamster Mesocricetus auratus genome. 19 tandem repeats families have been found in hamster genome by bioinformatics (in silico). Only one of tandem repeats' families found have been cloned previously and exists in the Repbase, the database of all known repetitive fragments. The rest of the families are new and need the experimental verification by FISH (in situ). Oligo probes were designed at the base of in silico found sequences. Oligo probe for the known tandem repeat gives the same signal as the cloned probe, i.e., probes designed are suitable for oligo-FISH. All four oligo probes tested give signal at the heterochromatic centromeric region as expected, though with different intensities and at different number of chromosomes. The results show the power of the in silico methods for the mostly mysterious genome component, tandem repeats, investigation.