Human Genome Completed

Researchers have completely sequenced the human genome two decades after genetic research on the human gene code bagan. The work has filled in gaps and corrected errors in previous incomplete versions of the code. A rough draft of the genome was announced by the Human Geonome Project in 2000. Scientistsm have also found around 115 genes previously unknown and some of which code for proteins in addition to a myriad of individual genetic variations. A consortium of 99 scientists have published six papers on-line and now under by peer journals. Sequencing of the entire human genome is a difficult puzzle to solve. There are 3 billion base pairs. Often genes exist in copies that perform different functions and there are "psuedogenes" that get neutralized by mutations. The code contains vast stretches of virus-like DNA that gets copied but whose function is not understood. 

The first reference sequence of the genome came out in 2013, Still, about 8% of the code sequence, about enough to make up an entire chromosome, was undetermined. The latest, complete version complied by the consortium took advantage of computational biology techniques and advanced computers able to read long stretches of code. The increased accuracy they achieved allows them to say with confidence that the human genome is 3.05 billion base pairs long. Altogether, the scientists added or fixed more than 200 million base pairs in the reference genome. They have discovered 2 million places where individual variations can take place. Complete sequencing allows study of alterations in the code that allow diseases to develop in humans and more understanding of chromosome structures such as the centromere where pairs are attched. [human chromosome photo: Science]