CLOSELY COMPLETE HUMAN GENOME SEQUENCED

 

The Human Genome Project, announcing the draft genome sequence in 2000, was a great achievement for science, it was announced that most of the genome had already been read. The results surprise scientists, some of the results were far from what they expected. Although this was not really complete, there were some parts, which due to their location within the genome was difficult to access, such as the sequences in the vicinity of the centrioles. In total, about 8 percent of the human genome of more than 3 billion base pairs—mostly repeats that are computationally difficult to assemble—has remained unsealed in the two decades since that first sequence brador.

These un sequenced spaces were not abandoned   because the unknown asides werevery difficult to sequence. But an international group of scientists published last month (May 27) a preprint that begins to do just that, adding nearly 200 million DNA bases to the known sequence of the human genome and discovering some 115 potentially protein-coding genes in the process.

This excited the scientists: they now had sequenced the problem areas.

Scientists used long-reading sequencing technologies to sequence DNA extracted from a cell line derived from a uterine growth called a hydatidiform to altered egg. This structure is formed through the fertilization of a nucleusles egg, meaning that the altered egg only carries DNA from the sperm and none from the person in whose uterus it was growing, a genetic anomaly that made it easier to decipher more of the genome because it did not involve classifying the genetic contributions of two parents.

Researchers years ago had generated cell lines from this hydatidiform altered ovilo, and therefore it is possible that mutations arose in the genome before it was sequenced for this latest project, so that the new genetic information may be largely the detritus that accumulates as a cell line spreads for many years in culture.

Because the cells were frozen for years and didn't spend all that time in series, she thinks the new sequences are biologically relevant. However, he points out to Nature that there are some regions that need more confirmation. Because the sperm that fertilized the egg to form the altered ovile carried an X chromosome, the team hasn't dug into the genomic holes that exist in the human Y chromosome sequence, something researchers are working on now.