Segmental genome duplication responsible for our brain power

Genome duplication is the trigger for evolution. Complex multicellular organisms have evolved from simple unicellular organisms by genome duplication and other genome rearrangements. Genome duplication can be of two types: whole genome duplication in which a diploid organism becomes a tetraploid and provide whole set of additional genes i.e for every old gene a new copy is provided. This type of change is considered to be responsible for major changes in organisms including speciation. The second type of duplication is called segmental duplication or copy number variation.  Here only a part of the genome gets duplicated and provide additional copies of only those genes in the duplicated regions. This type of  variation is considered to be responsible for differences among closely related organisms for example between monkeys and humans. Immediately after sequencing genomes of chimp and other primates Scientists were expecting to find a segmental duplication of  genomic regions possessing genes associated with  the brain i.e neural system but were not successful.

Recently  two  groups of Scientists led by Evan Eichler and Franck Polleux have found a part of the missing clue.  They identified segmental duplication that led to

Germline low-methylated regions are more prone for structural mutation than methylated regions

The human genome contains many loci with high incidence of structural mutations, including insertions and deletions of chromosomal segments. This excessive mutability has accelerated evolution and contributed to human disease but has yet to be explained. 


Segments of DNA repeated in low-copy numbers (LCRs) have been previously implicated in promoting structural mutability in specific disease-associated loci. Lack of methylation (hypo-methylation) of genomic DNA has been previously associated with high structural mutability in gibbons and in human cancer cells, but the association with structural mutability in the human germline has not been explored. 


A recent study carried out by Scientists from

Million Genomes by 2014

Without a doubt the hottest company in the genomics sector right now is gene sequencing powerhouse Complete Genomics. In just the last four years the company has come out of nowhere to dominate the market for low cost sequencing of human genomes in large quantities. Although Complete Genomics is now slated to sequence an incredible 5,000 human genomes in 2010, this is nothing compared to what the company has in store for the years ahead.  Just days ago, in a Singularity Hub exclusive interview with Complete Genomics CEO Dr. Cliff Reid, we have learned that the company is now hoping to sequence 50,000 genomes in 2011 and a whopping 1 million genomes by 2014.