Telomere-to-Telomere Consortium, an international team of researchers is claiming to have at last sequenced the entire human genome. They have written a paper describing their efforts and have uploaded it to the bioRxiv preprint server.In 2000 a team from the Human Genome Project working with biotech firm Celera Genomics announced that they had completed the first draft of sequencing of the human genome. That first draft was missing 15% of the genome. Work since that time has brought the percentage down to just 8%.
The Telomere-to-Telomere Consortium is claiming to have reduced it to zero though there are still some caveats. The team admits that they had some trouble with 0.3% of the genome, and there might be a few errors here. But there are no gaps, which is why the group have called themselves the Telomere-to-Telomere Consortium. As part of their work, the team discovered 115 new genes that code for proteins, giving a new total of 19,969.
Oxford Nanopore and Pacific Biosciences developed a new technology that allowed for sequencing without cutting the DNA into pieces. This technology helped the researchers. Researchers ran the DNA through a nanoscopic hole with lasers reading the sequences frequently to decrease errors. They also claim that the number of known bases has now grown from 2.92 billion to 3.05 billion and the number of known genes has increased by 0.4%.
The researchers also note that the genome they sequenced did not come from a person but a hydatidiform, which is a growth that on rare occasions forms on the inside of a woman’s uterus. Such growths occur when a sperm manages to fertilize an egg that has no nucleus; thus, it has just 23 chromosomes rather than the normal 46 found in most human cells. The researchers chose to sequence the hydatidiform because it made their computations easier.