The first fully complete human genome with no gaps is now available to view for scientists and the public , marking a immense bit for human genetics . Announced in a preprintin June 2021 , six papers have now been publish in the journalScience . They describe the painstaking work that goes into sequence an over 6 billion base pair genome , with 200 million added in this new enquiry . The newfangled genome now sum 99 genes likely to code for proteins and 2,000 candidate genes that were previously strange .
Many will be ask : " waitress , did n’t we already sequence the human genome ? " In part , yes – in 2000 , the Human Genome Sequencing Consortium release their first drafts of the human genome , lead that afterward paved the way for almost every aspect of human genetics available today .
The most recent order of payment of the human genome has been used as a reference since 2013 . But weighed down by impractical sequencing techniques , these drafts leave out the most complex region of our DNA , which make up around 8 percent of the total genome . This is because these sequence are highly repetitive and contain many duplicated regions – attempting to put them together in the ripe place is like trying to dispatch a scroll saw teaser where all the while are the same shape and have no prototype on the front . Long gap and underrepresentation of prominent , repeating sequences made it so that this genetic material has been exclude for the past 20 old age . Scientists had to come up with more precise methods of sequence to illuminate the dour corners of the genome .
“ These component part of the human genome that we have n’t been able to study for 20 - plus years are important to our understanding of how the genome works , genetic disease , and human diversity and evolution , ” pronounce Karen Miga , assistant prof of biomolecular engineering at UC Santa Cruz , in astatement .
Much like the Human Genome Sequencing Consortium , the new reference genome ( call T2T - CHM13 ) was produced by the Telomere-2 - Telomere Consortium , a group of research worker dedicated to finally mapping each chromosome from one telomere to the other . T2T - CHM13 will now be uncommitted onUCSC Genome Browserfor everyone to enjoy , complimenting the standard human reference genome , GRCh38 .
The young character reference genome was create using two modern sequencing techniques , calledOxford NanoporeandPacBio HiFiultra - long read sequencing , which massively increase the length of DNA that can be read while also meliorate the accuracy . Through this , they could sequence strings of DNA antecedently undecipherable by more fundamental technique , alongside correcting some structural errors that existed in the late reference genome .
Looking to the future , the pool hopes to add even more reference genome as part of the Human Pangenome Reference Consortium to improve diversity in human genetic science , something sorely lack at present .
“ We ’re adding a 2nd complete genome , and then there will be more , ” said David Haussler , director of the UC Santa Cruz Genomics Institute , in astatement .
“ The next phase is to think about the character reference for manhood ’s genome as not being a single genome sequence . This is a unsounded passage , the forerunner of a new era in which we will eventually capture human diverseness in an unbiased style . ”
