The Human Genome Project has been essentially concluded with a complete characterisation of the sequence of human chromosome 1, the final chromosome. Pictured on right, chromosome 1 is the largest of them all, and is estimated to be 237.6 Mbp, including the centromere and a large non-coding region (heterochromatin) in the centre of the chromosome.
The Sanger Institute comments on this monumental international achievement, results of which were published in the latest Nature:
The finished sequence of chromosome 1 enabled the team to bring together chromosome-wide information associated with genetic variation from projects such as the HapMap – a leading international study of human genetic variation. Our chromosome pairs ‘recombine’ with each other, so that regions inherited from our two parents are shuffled when passed on to our children.
Shuffling the deck tends not to disrupt genes. Most of the recombination found on chromosome 1 occurs at a few hotspots and more than 80% of hotspots are in only 15% of the sequence. Fine scale analyses have shown that recombination tends to be near to genes but outside the actual gene structures themselves…
Chromosome 1 is particularly susceptible to rearrangement and it is thought that disruption to genes within these rearrangements play a role in several cancers and in mental retardation. The high-quality sequence has already helped researchers around the world to home in on genes that affect a range of cancers.
Rearrangements, deletions and duplications can tell us about our evolution and our diseases. More than 5% of the chromosome is duplicated and can provide material for the evolution of new functions. In one example, the partial duplication of a gene called NOTCH2 has resulted in a novel protein that is known to be functional in humans and has been implicated in disease. Meanwhile, deletion of regions of chromosome 1p is found in 1/5000 to 1/10,000 live births and may contribute to mental retardation syndromes…
“The Human Genome Project has provided us with a wealth of information about our genes and their many variations,” said Dr Mark Walport, Director of the Wellcome Trust. “It is a vital resource for answering important questions about health and disease. We have been a committed partner in the project since 1992 both in supporting the research and ensuring the results are freely accessible to all”.
The press release…
