Reconstruction of the female <i>Gorilla gorilla</i> karyotype using 25-color FISH and multicolor banding (MCB)

Abstract

The origin of the human and great ape chromosomes has been studied by comparative chromosome banding analysis and, more recently, by fluorescence in situ hybridization (FISH), using human whole-chromosome painting probes. It is not always possible, however, to determine the exact breakpoints and distribution or orientation of specific DNA regions using these techniques. To overcome this problem, the recently developed multicolor banding (MCB) probe set for all human chromosomes was applied in the present study to reanalyze the chromosomes of Gorilla gorilla (GGO). While the results agree with those of most previous banding and FISH studies, the breakpoints for the pericentric inversion on GGO 3 were defined more precisely. Moreover, no paracentric inversion was found on GGO 14, and no pericentric inversions could be demonstrated on GGO 16 or 17.

Homologous sequences at human chromosome 9 bands p12 and q13-21.1 are involved in different patterns of pericentric rearrangements

“…Hybridisation of probe midi36 and posthybridisation slide processing under less stringent conditions results in signals in the pericentromeric regions of most human chromosomes including 1qh and 16qh, and the short arms of the acrocentric chromosomes ( Figure 1E). Cohybridisation of midi36 with a microdissectionderived probe for the p-arms of all acrocentric chromosomes (midi54) 11 highlighted identical regions on chromosome 9 ( Figure 1F). The probe midi54 gave the signals only on the pericentromeric region of chromosome 9 regardless of stringency levels ( Figure 1F).…”

“…11 HSA 9 developed from an acrocentric ancestor by a pericentric inversion with breaks in regions homologous to 9p24.3 and 9q13. 11 During further evolution a satellite III DNA block may have been inserted de novo into the DNA block stained by the probe midi36, and in some cases, it was subsequently amplified (9qh+) or diminished (9qh7) (Figure 4). The finding of homology between the 9p12/9q13-q21.1 regions and acrocentric short arms suggests that these regions might be more prone to chromosomal rearrangements.…”

“…Schematic representation of the origin of HSA 9, based on hybridization of the midi54 probe to chromosomes of the Gorilla gorilla (GGO). 11 The p-arm of acrocentric GGO 13 (homologue to HSA 9) has homologous sequences to the short arm of all human acrocentric chromosomes, 11 the region stained by midi36 (blue). A pericentric inversion (inv) of GGO 13, with breaks in regions homologous to 9q24.3 and 9q13 leads to a human chromosome 9 banding pattern.…”

“…Additionally, a microdissection derived whole chromosome and chromosome arm-specific painting probes, 10 microdissection probe for all human acrocentric chromosomes ('midi'54) (derived from the SMC of an ICSI patient and representing heterochromatin from the short arms of chromosome 13 or 21), 11 and a probe specific for all human centromeres (Q-BIOgene) have been applied in some of the cases. Labelling of the microdissection derived probes and hybridisation were carried out as described.…”

“…10,12 We used a chromosome 9-specific MCB probe set 11 to further characterise the heteromorphic chromosome 9 in case 13 following the published MCB FISH procedure. 11,13 All images were captured on a Zeiss Axioplan microscope (Zeiss, Jena, Germany) with the IKAROS and ISIS digital imaging system (MetaSystems, Altlussheim, Germany) using a CCD camera with on-chip integration (XC77, Sony, Vienna, Austria).…”