Giannuzzi Giuliana, Migliavacca Eugenia, Reymond Alexandre
Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland;
Center for Integrative Genomics, University of Lausanne, 1015 Lausanne, Switzerland; Swiss Institute of Bioinformatics, 1015 Lausanne, Switzerland.
Genome Res. 2014 Sep;24(9):1455-68. doi: 10.1101/gr.167742.113. Epub 2014 Jun 10.
Human and chimpanzee genomes are 98.8% identical within comparable sequences. However, they differ structurally in nine pericentric inversions, one fusion that originated human chromosome 2, and content and localization of heterochromatin and lineage-specific segmental duplications. The possible functional consequences of these cytogenetic and structural differences are not fully understood and their possible involvement in speciation remains unclear. We show that subtelomeric regions--regions that have a species-specific organization, are more divergent in sequence, and are enriched in genes and recombination hotspots--are significantly enriched for species-specific histone modifications that decorate transcription start sites in different tissues in both human and chimpanzee. The human lineage-specific chromosome 2 fusion point and ancestral centromere locus as well as chromosome 1 and 18 pericentric inversion breakpoints showed enrichment of human-specific H3K4me3 peaks in the prefrontal cortex. Our results reveal an association between plastic regions and potential novel regulatory elements.
人类和黑猩猩的基因组在可比序列内有98.8%的一致性。然而，它们在结构上存在九次臂间倒位、一次导致人类2号染色体形成的融合事件，以及异染色质的含量和定位以及谱系特异性片段重复方面的差异。这些细胞遗传学和结构差异可能产生的功能后果尚未完全明了，它们在物种形成中可能发挥的作用也仍不清楚。我们发现，亚端粒区域——具有物种特异性组织、序列差异更大且富含基因和重组热点的区域——在人类和黑猩猩的不同组织中，显著富集了修饰转录起始位点的物种特异性组蛋白修饰。人类谱系特异性的2号染色体融合点和祖先着丝粒位点，以及1号和18号染色体的臂间倒位断点，在前额叶皮质中显示出人类特异性H3K4me3峰的富集。我们的研究结果揭示了可塑性区域与潜在新调控元件之间的关联。
