Abstract
BACKGROUND: The question what makes Homo sapiens sapiens (HSA) special among other species is one of the basic questions of mankind. A small contribution to answer this question is to study the chromosomal constitution of HSA compared to other, closely related species. In order to check the types and extent of evolutionary conserved breakpoints we studied here for the first time the chromosomes of Hylobates pileatus (HPI) compared to HSA and Hylobates lar (HLA) by means of molecular cytogenetics. RESULTS: Overall, 68 new evolutionary conserved breakpoints compared to HSA could be characterized in this study. Interestingly, only seven of those were different compared to HLA. However, application of heterochromatic human DNA-probes provided evidence that observed high chromosomal rearrangement rates of gibbons in HPI happened rather in these repetitive elements than in euchromatin, even though most centromeric positions were preserved in HPI compared to HSA. CONCLUSION: Understanding genomes of other species and comparing them to HSA needs full karyotypic and high resolution genomic data to approach both: euchromatic and heterochromatic regions of the studied chromosome-content. This study provides full karyotypic data and previously not available data on heterochromatin-syntenies of HPI and HSA.