Editing Human genome (section)

== Size of the human genome ==

In 2000, scientists reported the sequencing of 88% of human genome,<ref name="IHSGC2001" /> but as of 2020, at least 8% was still missing.<ref name="Complete" /> In 2021, scientists reported sequencing a complete, female genome (i.e., without the Y chromosome).<ref name=":3" /><ref name="Complete">{{cite journal |vauthors=Nurk S, Koren S, Rhie A, Rautiainen M, Bzikadze AV, Mikheenko A, Vollger MR, Altemose N, Uralsky L, Gershman A, Aganezov S, Hoyt SJ, Diekhans M, Logsdon GA, Alonge M, Antonarakis SE, Borchers M, Bouffard GG, Brooks SY, Caldas GV, Chen NC, Cheng H, Chin CS, Chow W, de Lima LG, Dishuck PC, Durbin R, Dvorkina T, Fiddes IT, Formenti G, Fulton RS, Fungtammasan A, Garrison E, Grady PG, Graves-Lindsay TA, Hall IM, Hansen NF, Hartley GA, Haukness M, Howe K, Hunkapiller MW, Jain C, Jain M, Jarvis ED, Kerpedjiev P, Kirsche M, Kolmogorov M, Korlach J, Kremitzki M, Li H, Maduro VV, Marschall T, McCartney AM, McDaniel J, Miller DE, Mullikin JC, Myers EW, Olson ND, Paten B, Peluso P, Pevzner PA, Porubsky D, Potapova T, Rogaev EI, Rosenfeld JA, Salzberg SL, Schneider VA, Sedlazeck FJ, Shafin K, Shew CJ, Shumate A, Sims Y, Smit AF, Soto DC, Sović I, Storer JM, Streets A, Sullivan BA, Thibaud-Nissen F, Torrance J, Wagner J, Walenz BP, Wenger A, Wood JM, Xiao C, Yan SM, Young AC, Zarate S, Surti U, McCoy RC, Dennis MY, Alexandrov IA, Gerton JL, O'Neill RJ, Timp W, Zook JM, Schatz MC, Eichler EE, Miga KH, Phillippy AM |date=April 2022 |title=The complete sequence of a human genome |journal=Science |volume=376 |issue=6588 |pages=44–53 |bibcode=2022Sci...376...44N |doi=10.1126/science.abj6987 |pmc=9186530 |pmid=35357919 |s2cid=247854936}}</ref> The [[Y chromosome#Human Y chromosome|human Y chromosome]], consisting of 62,460,029 base pairs from a different cell line and found in all males, was sequenced completely in January 2022.<ref name="pmid37612512">{{cite journal | vauthors = Rhie A, Nurk S, Cechova M, Hoyt SJ, Taylor DJ, Altemose N, Hook PW, Koren S, Rautiainen M, Alexandrov IA, Allen J, Asri M, Bzikadze AV, Chen NC, Chin CS, Diekhans M, Flicek P, Formenti G, Fungtammasan A, Garcia Giron C, Garrison E, Gershman A, Gerton JL, Grady PG, Guarracino A, Haggerty L, Halabian R, Hansen NF, Harris R, Hartley GA, Harvey WT, Haukness M, Heinz J, Hourlier T, Hubley RM, Hunt SE, Hwang S, Jain M, Kesharwani RK, Lewis AP, Li H, Logsdon GA, Lucas JK, Makalowski W, Markovic C, Martin FJ, Mc Cartney AM, McCoy RC, McDaniel J, McNulty BM, Medvedev P, Mikheenko A, Munson KM, Murphy TD, Olsen HE, Olson ND, Paulin LF, Porubsky D, Potapova T, Ryabov F, Salzberg SL, Sauria ME, Sedlazeck FJ, Shafin K, Shepelev VA, Shumate A, Storer JM, Surapaneni L, Taravella Oill AM, Thibaud-Nissen F, Timp W, Tomaszkiewicz M, Vollger MR, Walenz BP, Watwood AC, Weissensteiner MH, Wenger AM, Wilson MA, Zarate S, Zhu Y, Zook JM, Eichler EE, O'Neill RJ, Schatz MC, Miga KH, Makova KD, Phillippy AM | title = The complete sequence of a human Y chromosome | journal = Nature | volume = 621 | issue = 7978 | pages = 344–354 | date = September 2023 | pmid = 37612512 | doi = 10.1038/s41586-023-06457-y | bibcode = 2023Natur.621..344R | quote = Received 2 December 2022 | pmc = 10752217 }}</ref>

The current version of the standard reference genome is called GRCh38.p14 (July 2023). It consists of 22 autosomes plus one copy of the X chromosome and one copy of the Y chromosome. It contains approximately 3.1 billion base pairs (3.1 Gb or 3.1 x 10<sup>9</sup> bp).<ref>{{cite web | url= https://useast.ensembl.org/Homo_sapiens/Info/Annotation |title= Human assembly and gene annotation |date= 2022 | website = Ensembl |access-date= 2024-02-28 }}</ref> This represents the size of a composite genome based on data from multiple individuals but it is a good indication of the typical amount of DNA in a haploid set of chromosomes because the Y chromosome is quite small.<ref>{{Cite journal |last1=Hallast |first1=Pille |last2=Ebert |first2=Peter |last3=Loftus |first3=Mark |last4=Yilmaz |first4=Feyza |last5=Audano |first5=Peter A. |last6=Logsdon |first6=Glennis A. |last7=Bonder |first7=Marc Jan |last8=Zhou |first8=Weichen |last9=Höps |first9=Wolfram |last10=Kim |first10=Kwondo |last11=Li |first11=Chong |last12=Hoyt |first12=Savannah J. |last13=Dishuck |first13=Philip C. |last14=Porubsky |first14=David |last15=Tsetsos |first15=Fotios |date=September 2023 |title=Assembly of 43 human Y chromosomes reveals extensive complexity and variation |journal=Nature |volume=621 |issue=7978 |pages=355–364 |doi=10.1038/s41586-023-06425-6 |issn=0028-0836 |pmid=37612510|pmc=10726138 |bibcode=2023Natur.621..355H }}</ref> Most human cells are diploid so they contain twice as much DNA (~6.2 billion base pairs). 

In 2023, a draft human [[pan-genome|pangenome]] reference was published.<ref name="2023-human-pangenome-47">{{cite journal | vauthors = Liao WW, Asri M, Ebler J, Doerr D, Haukness M, Hickey G, Lu S, Lucas JK, Monlong J, Abel HJ, Buonaiuto S, Chang XH, Cheng H, Chu J, Colonna V, Eizenga JM, Feng X, Fischer C, Fulton RS, Garg S, Groza C, Guarracino A, Harvey WT, Heumos S, Howe K, Jain M, Lu TY, Markello C, Martin FJ, Mitchell MW, Munson KM, Mwaniki MN, Novak AM, Olsen HE, Pesout T, Porubsky D, Prins P, Sibbesen JA, Sirén J, Tomlinson C, Villani F, Vollger MR, Antonacci-Fulton LL, Baid G, Baker CA, Belyaeva A, Billis K, Carroll A, Chang PC, Cody S, Cook DE, Cook-Deegan RM, Cornejo OE, Diekhans M, Ebert P, Fairley S, Fedrigo O, Felsenfeld AL, Formenti G, Frankish A, Gao Y, Garrison NA, Giron CG, Green RE, Haggerty L, Hoekzema K, Hourlier T, Ji HP, Kenny EE, Koenig BA, Kolesnikov A, Korbel JO, Kordosky J, Koren S, Lee H, Lewis AP, Magalhães H, Marco-Sola S, Marijon P, McCartney A, McDaniel J, Mountcastle J, Nattestad M, Nurk S, Olson ND, Popejoy AB, Puiu D, Rautiainen M, Regier AA, Rhie A, Sacco S, Sanders AD, Schneider VA, Schultz BI, Shafin K, Smith MW, Sofia HJ, Abou Tayoun AN, Thibaud-Nissen F, Tricomi FF, Wagner J, Walenz B, Wood JM, Zimin AV, Bourque G, Chaisson MJ, Flicek P, Phillippy AM, Zook JM, Eichler EE, Haussler D, Wang T, Jarvis ED, Miga KH, Garrison E, Marschall T, Hall IM, Li H, Paten B | title = A draft human pangenome reference | journal = Nature | volume = 617 | issue = 7960 | pages = 312–324 | date = May 2023 | pmid = 37165242 | doi = 10.1038/s41586-023-05896-x | pmc = 10172123 | bibcode = 2023Natur.617..312L }}</ref> It is based on 47 genomes from persons of varied ethnicity.<ref name="2023-human-pangenome-47"/> Plans are underway for an improved reference capturing still more biodiversity from a still wider sample.<ref name="2023-human-pangenome-47"/>

While there are significant differences among the genomes of human individuals (on the order of 0.1% due to [[single-nucleotide variant]]s<ref name="nature.com">{{cite journal | vauthors = Abecasis GR, Auton A, Brooks LD, DePristo MA, Durbin RM, Handsaker RE, Kang HM, Marth GT, McVean GA | title = An integrated map of genetic variation from 1,092 human genomes | journal = Nature | volume = 491 | issue = 7422 | pages = 56–65 | date = November 2012 | pmid = 23128226 | pmc = 3498066 | doi = 10.1038/nature11632 | bibcode = 2012Natur.491...56T }}</ref> and 0.6% when considering [[indel]]s),<ref>{{cite journal | vauthors = Auton A, Brooks LD, Durbin RM, Garrison EP, Kang HM, Korbel JO, Marchini JL, McCarthy S, McVean GA, Abecasis GR | title = A global reference for human genetic variation | journal = Nature | volume = 526 | issue = 7571 | pages = 68–74 | date = October 2015 | pmid = 26432245 | pmc = 4750478 | doi = 10.1038/nature15393 | bibcode = 2015Natur.526...68T }}</ref> these are considerably smaller than the differences between humans and their closest living relatives, the [[bonobo]]s and [[Common chimpanzee|chimpanzee]]s (~1.1% [[Fixation (population genetics)|fixed]] single-nucleotide variants<ref>{{cite journal | author = Chimpanzee Sequencing Analysis Consortium | title = Initial sequence of the chimpanzee genome and comparison with the human genome | journal = Nature | volume = 437 | issue = 7055 | pages = 69–87 | date = September 2005 | pmid = 16136131 | doi = 10.1038/nature04072 | s2cid = 2638825 | doi-access = free | bibcode = 2005Natur.437...69. }}</ref> and 4% when including indels).<ref>{{cite journal | vauthors = Varki A, Altheide TK | title = Comparing the human and chimpanzee genomes: searching for needles in a haystack | journal = Genome Research | volume = 15 | issue = 12 | pages = 1746–1758 | date = December 2005 | pmid = 16339373 | doi = 10.1101/gr.3737405 | doi-access = free }}</ref>