Tandem Repeat-Based Probes Support the Loop Model of Pericentromere Packing.
Constitutive heterochromatin is the most mysterious part of the eukaryotic genome. It forms vital chromosome regions such as the centromeric and the pericentromeric ones. The main component of heterochromatic regions are tandem repeats (TR), and their specific organization complicates assembly, annotation, and mapping of these regions. Unannotated and unmapped TR arrays are still present in database contigs. In this study, we used a set of TR in the genomes of the pig (Sus scrofa) and the Chinese hamster (Cricetulus griseus) identified with the help of bioinformatics techniques and determined the specificity of the designed probes. The signal of the 4 pig TR probes in spermatogenic cells was often ring-shaped, especially in primary spermatocytes. The rings were located in the regions relatively weakly stained with DAPI. The unique assembly of the centromeric region was traced using the hamster meiotic chromosomes. The probe specific to chromosome 5 was used. Two signals, arranged as rings, were seen at the pachytene stage, similar to those in the pig spermatogenic cells. In the spermatogenic cells of both pig and hamster, the rings appeared on the chromosomes with pericentromeric TR probes. Our observations support the loop model of the centromeric region, the size of the loops being about 50 kb.
['Ivanova|Nadezhda G|NG|', 'Ostromyshenskii|Dmitrii|D|', 'Podgornaya|Olga|O|']
D000818:Animals D002503:Centromere D019295:Computational Biology D020451:Contig Mapping D003412:Cricetulus D004276:DNA, Satellite D016678:Genome D006570:Heterochromatin D017404:In Situ Hybridization, Fluorescence D008297:Male D008540:Meiosis D009693:Nucleic Acid Hybridization D013091:Spermatogenesis D034421:Sus scrofa
Centromere Tandem repeats Chromosome organization FISH Satellite DNA