title: Three-dimensional architecture of tandem repeats in chicken interphase nucleus.
abstract: Tandem repeats belong to a class of genomic repetitive elements that form arrays of head-to-tail monomers. Due to technical difficulties in sequencing and assembly of large tandem repeat arrays, it remains largely unknown by which mechanisms tandem-repeat-containing regions aid in maintenance of ordered radial genome organization during interphase. Here we analyzed spatial distribution of several types of tandem repeats in interphase nuclei of chicken MDCC-MSB1 cells and somatic tissues relative to heterochromatin compartments and nuclear center. We showed that telomere and subtelomere repeats generally localize at the nuclear or chromocenters periphery. A tandem repeat known as CNM, typical for centromere regions of gene-dense microchromosomes, forms interchromosome clusters and occupies DAPI-positive chromocenters that appear predominantly within the nuclear interior. In contrast, centromere-specific tandem repeats of the majority of gene-poor macrochromosomes are embedded into the peripheral layer of heterochromatin. Chicken chromocenters rarely comprise centromere sequences of both macro- and microchromosomes, whose territories localize in different radial nuclear zones. Possible mechanisms of observed tandem repeats positioning and its implication in highly ordered arrangement of chromosome territories in chicken interphase nucleus are discussed.
authors: Saint Petersburg State University, Saint Petersburg, 198504, Russia.
authors: Antonina
authors: A
authors: Maslova
authors: Saint Petersburg State University, Saint Petersburg, 198504, Russia.
authors: Anna
authors: A
authors: Zlotina
authors: Institute of Human Genetics, Jena University Hospital, Friedrich Schiller University, Jena, Germany.
authors: Nadezhda
authors: N
authors: Kosyakova
authors: Saint Petersburg State University, Saint Petersburg, 198504, Russia.
authors: Marina
authors: M
authors: Sidorova
authors: Saint Petersburg State University, Saint Petersburg, 198504, Russia. alla.krasikova@gmail.com.
authors: Alla
authors: A
authors: Krasikova
mesh_terms: D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000235:genetics*; D002503:Centromere / Q000235:genetics; D002645:Chickens / Q000235:genetics*; D002875:Chromosomes; D016678:Genome; D023281:Genomics; D006570:Heterochromatin / Q000235:genetics; D017404:In Situ Hybridization, Fluorescence; D007399:Interphase / Q000235:genetics*; D020080:Tandem Repeat Sequences; D016615:Telomere / Q000235:genetics
chemical_list: D006570:Heterochromatin
keywords: Centromere; Chicken genome; Chromocenters; Genome architecture; Heterochromatin; Interphase nucleus; MDCC-MSB1; Subtelomere; Tandem repeats; Telomere