Division of Evolutionary Genetics • Akashi Group
Division of Population Genetics • Saitou Group

Cynomolgus macaques (Macaca fascicularis) are important animals for biomedical research and known to be genetically highly heterogeneous. They are mainly distributed throughout Southeast Asia, but a small number of individuals were introduced to the island of Mauritius by humans around the 16th century. The unique demographic history of the Mauritian cynomolgus macaques would be useful for understanding the effect of an extreme population bottleneck on the pattern of polymorphisms in genomes. We sequenced and analyzed the whole genomes of six Mauritian cynomolgus macaques, and found the mild reduction of overall level of nucleotide diversity as well as the strong reduction of low-frequency polymorphisms in the populations. In addition, we confirmed that the Mauritian cynomolgus macaques have been originated from Indonesia-Malaysian cynomolgus macaques. The information of the genome sequences would be useful for future biomedical research using those macaques that have unique population history.

(Left panel) The island of Mauritius is marked by the red circle; (Right panel) a picture of cynomolgus macaque

Biological Macromolecules Laboratory • Maeshima Group

he unbiased identification of proteins associated with specific loci is crucial for understanding chromatin-based processes. The proteomics of isolated chromatin fragment (PICh) method has previously been developed to purify telomeres and identify associated proteins. This approach is based on the affinity capture of endogenous chromatin segments by hybridization with oligonucleotide containing locked nucleic acids. However, PICh is only efficient with highly abundant genomic targets, limiting its applicability. Here we develop an approach for identifying factors bound to the promoter region of the ribosomal RNA genes that we call end-targeting PICh (ePICh). Using ePICh, we could specifically enrich the RNA polymerase I pre-initiation complex, including the selectivity factor 1. The high purity of the ePICh material allowed the identification of ZFP106, a novel factor regulating transcription initiation by targeting RNA polymerase I to the promoter. Our results demonstrate that ePICh can uncover novel proteins controlling endogenous regulatory elements in mammals.

Rules for designing capture probes for the formation of stable oligo-DNA hybrids.