Application of multicolor banding combined with heterochromatic and locus-specific probes identify evolutionary conserved breakpoints in Hylobates pileatus.

Wiwat Sangpakdee,Xiaobo Fan,Alongklod Tanomtong,Thomas Liehr,Anja Weise,Krit Pinthong

doi:10.1186/s13039-016-0228-x

Abstract

BackgroundThe 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.ResultsOverall, 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.ConclusionUnderstanding 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.Electronic supplementary materialThe online version of this article (doi:10.1186/s13039-016-0228-x) contains supplementary material, which is available to authorized users.

Highlights

The question what makes Homo sapiens sapiens (HSA) special among other species is one of the basic questions of mankind
We report the characterization of 68 evolutionary conserved breakpoints (ECBs) in Hylobates pileatus (HPI) based on fluorescence in situ hybridization (FISH) applying high resolution multicolor banding (MCB), locus-specific probes and all human repetitive probes apart from centromeric ones
One locus-specific probe based FISH result for a region being homologous in HPI to human chromosome 2 can be found there

Summary

Introduction

The question what makes Homo sapiens sapiens (HSA) special among other species is one of the basic questions of mankind. As Hominoidea superfamily includes great apes (chimpanzees, bonobos, orangutans, gorillas, humans) as well as lesser apes (gibbons; Hylobatidae), studies on chromosomal evolution should include all groups of the superfamily HSA belongs to. For lesser apes it has been shown. In Hylobates there were studied yet by FISH with a whole genomic view Hylobates lar (HLA) [8, 9], H. klossii [10], H. moloch [11], and H. pileatus (HPI) [11]. For H. muelleri, and H. agilis (HAG) it was only shown that alphasatellite sequences as present in HSA are not detectable in those species, including in HLA and HPI [9]. There are FISH-studies on H. leucogenys ( called Nomascus leucogenys) [14], H. concolor ( called Nomascus concolor) [15], H. syndactylus (renamed to Symphalangus syndactylus) [16]

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