Telomere Disruption Results in Non-Random Formation of De Novo Dicentric Chromosomes Involving Acrocentric Human Chromosomes (original) (raw)
Figure 3
Heterogeneity in iROB structure: only half of induced dicentrics are true telomere-telomere fusions.
(A, A′) FISH with PNA-telomere (green) and acrocentric painting (red) probes illustrated that an irob(14;14) lacked detectable telomeric repeats at the short arm fusion point. (B) Almost 20% of iROBs, and >50% of non-acrocentric-acrocentric fusions lacked telomeric FISH signals at the fusion breakpoints. (C) Schematic of acrocentric genomic organization. Multiple satellite repeats are located on all of the short arms of each acrocentric. (C′) FISH with acrocentric short arm specific probes revealed that an irob(14;15) retained distal ß-satellite array (green), implying that all repeats between the centromere (α-satellite, red) and the distal ß-satellite array were present on the iROB. (C″) Conversely, an irob(13;15) retained only a small amount of proximal ß-satellite (green) on only one of the acrocentrics, indicating heterogeneity in molecular structure of iROBs. (D) In three induced T19 subclones, FISH was used to assess the presence of acrocentric sequences on individual ROBs. Between 20% and 50% of iROBs lacked one or more short arm repeats.