Assembly Releases and Versions

Topics


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List of UCSC genome releases

How do UCSC’s release numbers correspond to those of other organizations, such as NCBI?

The first release of an assembly is given a name using the first three characters of the organism’s genus and species classification in the format gggSss#, with subsequent assemblies incrementing the number. Assemblies predating the 2003 introduction of the six-letter naming system were given two-letter names in a similar gs# format and human assemblies are named hg# for human genome.

SPECIES

UCSC VERSION

RELEASE DATE

RELEASE NAME

STATUS

MAMMALS

Human

hg38

Dec. 2013

Genome Reference Consortium GRCh38

Available

hg19

Feb. 2009

Genome Reference Consortium GRCh37

Available

hg18

Mar. 2006

NCBI Build 36.1

Available

hg17

May 2004

NCBI Build 35

Available

hg16

Jul. 2003

NCBI Build 34

Available

hg15

Apr. 2003

NCBI Build 33

Archived

hg13

Nov. 2002

NCBI Build 31

Archived

hg12

Jun. 2002

NCBI Build 30

Archived

hg11

Apr. 2002

NCBI Build 29

Archived (data only)

hg10

Dec. 2001

NCBI Build 28

Archived (data only)

hg8

Aug. 2001

UCSC-assembled

Archived (data only)

hg7

Apr. 2001

UCSC-assembled

Archived (data only)

hg6

Dec. 2000

UCSC-assembled

Archived (data only)

hg5

Oct. 2000

UCSC-assembled

Archived (data only)

hg4

Sep. 2000

UCSC-assembled

Archived (data only)

hg3

Jul. 2000

UCSC-assembled

Archived (data only)

hg2

Jun. 2000

UCSC-assembled

Archived (data only)

hg1

May 2000

UCSC-assembled

Archived (data only)

Alpaca

vicPac2

Mar. 2013

Broad Institute Vicugna_pacos-2.0.1

Available

vicPac1

Jul. 2008

Broad Institute VicPac1.0

Available

Armadillo

dasNov3

Dec. 2011

Broad Institute DasNov3

Available

Baboon

papAnu4

Apr. 2017

Human Genome Sequencing Center

Available

papAnu2

Mar. 2012

Baylor College of Medicine Panu_2.0

Available

papHam1

Nov. 2008

Baylor College of Medicine HGSC Pham_1.0

Available

Bison

bisBis1

Oct. 2014

Univ. of Maryland Bison_UMD1.0

Available

Bonobo

panPan3

May 2020

University of Washington

Available

panPan2

Dec. 2015

Max-Planck Institute for Evolutionary Anthropology panpan1.1

Available

panPan1

May 2012

Max-Planck Institute panpan1

Available

Brown kiwi

aptMan1

Jun. 2015

Max-Planck Institute for Evolutionary Anthropology AptMant0

Available

Bushbaby

otoGar3

Mar. 2011

Broad Institute OtoGar3

Available

Cat

felCat9

Nov. 2017

Genome Sequencing Center (GSC) at Washington University (WashU) School of Medicine Felis_catus_9.0

Available

felCat8

Nov. 2014

ICGSC Felis_catus_8.0

Available

felCat5

Sep. 2011

ICGSC Felis_catus-6.2

Available

felCat4

Dec. 2008

NHGRI catChrV17e

Available

felCat3

Mar. 2006

Broad Institute Release 3

Available

Chimp

panTro6

Jan. 2018

Clint_PTRv2

Available

panTro5

May 2016

CGSC Build 3.0

Available

panTro4

Feb. 2011

CGSC Build 2.1.4

Available

panTro3

Oct. 2010

CGSC Build 2.1.3

Available

panTro2

Mar. 2006

CGSC Build 2.1

Available

panTro1

Nov. 2003

CGSC Build 1.1

Available

Chinese hamster

criGri1

Jul. 2013

Beijing Genomics Institution-Shenzhen C_griseus_v1.0

Available

Chinese hamster ovary cell line

criGriChoV2

Jun. 2017

Eagle Genomics Ltd CHOK1S_HZDv1

Available

criGriChoV1

Aug. 2011

Beijing Genomics Institute CriGri_1.0

Available

Chinese pangolin

manPen1

Aug. 2014

Washington University (WashU) M_pentadactyla-1.1.1

Available

Cow

bosTau9

Apr. 2018

USDA ARS

Available

bosTau8

Jun. 2014

University of Maryland v3.1.1

Available

bosTau7

Oct. 2011

Baylor College of Medicine HGSC Btau_4.6.1

Available

bosTau6

Nov. 2009

University of Maryland v3.1

Available

bosTau4

Oct. 2007

Baylor College of Medicine HGSC Btau_4.0

Available

bosTau3

Aug. 2006

Baylor College of Medicine HGSC Btau_3.1

Available

bosTau2

Mar. 2005

Baylor College of Medicine HGSC Btau_2.0

Available

bosTau1

Sep. 2004

Baylor College of Medicine HGSC Btau_1.0

Archived

Crab-eating macaque

macFas5

Jun. 2013

Washington University Macaca_fascicularis_5.0

Available

Dog

canFam6

Oct. 2020

Dog Genome Sequencing Consortium Dog10K_Boxer_Tasha

Available

canFam5

May 2019

University of Michigan

Available

canFam4

Mar. 2020

Uppsala University

Available

canFam3

Sep. 2011

Broad Institute v3.1

Available

canFam2

May 2005

Broad Institute v2.0

Available

canFam1

Jul. 2004

Broad Institute v1.0

Available

Dolphin

turTru2

Oct. 2011

Baylor College of Medicine Ttru_1.4

Available

Elephant

loxAfr3

Jul. 2009

Broad Institute LoxAfr3

Available

Ferret

musFur1

Apr. 2011

Ferret Genome Sequencing Consortium MusPutFur1.0

Available

Garter snake

thaSir1

Jun. 2015

Washington University Thamnophis_sirtalis-6.0

Available

Gibbon

nomLeu3

Oct. 2012

Gibbon Genome Sequencing Consortium Nleu3.0

Available

nomLeu2

Jun. 2011

Gibbon Genome Sequencing Consortium Nleu1.1

Available

nomLeu1

Jan. 2010

Gibbon Genome Sequencing Consortium Nleu1.0

Available

Golden eagle

aquChr2

Oct. 2014

University of Washington aquChr2-1.0.2

Available

Golden snub-nosed monkey

rhiRox1

Oct. 2014

Novogene Rrox_v1

Available

Gorilla

gorGor6

Aug. 2019

University of Washington

Available

gorGor5

Mar. 2016

University of Washington GSMRT3

Available

gorGor4

Dec. 2014

Wellcome Trust Sanger Institute gorGor4

Available

gorGor3

May 2011

Wellcome Trust Sanger Institute gorGor3.1

Available

Green Monkey

chlSab2

Mar. 2014

Vervet Genomics Consortium 1.1

Available

Guinea pig

cavPor3

Feb. 2008

Broad Institute cavPor3

Available

Hawaiian monk seal

neoSch1

Jun. 2017

Johns Hopkins University ASM220157v1

Available

Hedgehog

eriEur2

May 2012

Broad Institute EriEur2.0

Available

eriEur1

Jun. 2006

Broad Institute Draft_v1

Available

Horse

equCab3

Jan. 2018

University of Louisville

Available

equCab2

Sep. 2007

Broad Institute EquCab2

Available

equCab1

Jan. 2007

Broad Institute EquCab1

Available

Kangaroo rat

dipOrd1

Jul. 2008

Baylor/Broad Institute DipOrd1.0

Available

Little brown bat

myoLuc2

Jul. 2010

Broad Institute MyoLuc2.0

Available

Malayan flying lemur

galVar1

Jul. 2014

WashU G_variegatus-3.0.2

Available

Manatee

triMan1

Oct. 2011

Broad Institute TriManLat1.0

Available

Marmoset

calJac4

May 2020

Washington University Callithrix_jacchus_cj1700_1.1

Available

Marmoset

calJac3

Mar. 2009

WUSTL Callithrix_jacchus-v3.2

Available

calJac1

Jun. 2007

WUSTL Callithrix_jacchus-v2.0.2

Available

Megabat

pteVam1

Jul. 2008

Broad Institute Ptevap1.0

Available

Minke whale

balAcu1

Oct. 2013

KORDI BalAcu1.0

Available

Mouse

mm39

Jun. 2020

Genome Reference Consortium Mouse Build 39

Available

mm10

Dec. 2011

Genome Reference Consortium GRCm38

Available

mm9

Jul. 2007

NCBI Build 37

Available

mm8

Feb. 2006

NCBI Build 36

Available

mm7

Aug. 2005

NCBI Build 35

Available

mm6

Mar. 2005

NCBI Build 34

Archived

mm5

May 2004

NCBI Build 33

Archived

mm4

Oct. 2003

NCBI Build 32

Archived

mm3

Feb. 2003

NCBI Build 30

Archived

mm2

Feb. 2002

MGSCv3

Archived

mm1

Nov. 2001

MGSCv2

Archived (data only)

Mouse lemur

micMur2

May 2015

Baylor/Broad Institute Mmur_2.0

Available

micMur1

Jul. 2007

Broad Institute MicMur1.0

Available

Naked mole-rat

hetGla2

Jan. 2012

Broad Institute HetGla_female_1.0

Available

hetGla1

Jul. 2011

Beijing Genomics Institute HetGla_1.0

Available

Opossum

monDom5

Oct. 2006

Broad Institute release MonDom5

Available

monDom4

Jan. 2006

Broad Institute release MonDom4

Available

monDom1

Oct. 2004

Broad Institute release MonDom1

Available

Orangutan

ponAbe2

Jul. 2007

WUSTL Pongo_albelii-2.0.2

Available

ponAbe3

Jan. 2018

Susie_PABv2/ponAbe3

Available

Panda

ailMel1

Dec. 2009

BGI-Shenzhen AilMel 1.0

Available

Pig

susScr11

Feb. 2017

Swine Genome Sequencing Consortium Sscrofa11.1

Available

susScr3

Aug. 2011

Swine Genome Sequencing Consortium Sscrofa10.2

Available

susScr2

Nov. 2009

Swine Genome Sequencing Consortium Sscrofa9.2

Available

Pika

ochPri3

May 2012

Broad Institute OchPri3.0

Available

ochPri2

Jul. 2008

Broad Institute OchPri2

Available

Platypus

ornAna2

Feb. 2007

WUSTL v5.0.1

Available

ornAna1

Mar. 2007

WUSTL v5.0.1

Available

Proboscis Monkey

nasLar1

Nov. 2014

Proboscis Monkey Functional Genome Consortium Charlie1.0

Available

Rabbit

oryCun2

Apr. 2009

Broad Institute release OryCun2

Available

Rat

rn7

Nov. 2020

Wellcome Sanger Institute mRatBN7.2

Available

rn6

Jul. 2014

RGSC Rnor_6.0

Available

rn5

Mar. 2012

RGSC Rnor_5.0

Available

rn4

Nov. 2004

Baylor College of Medicine HGSC v3.4

Available

rn3

Jun. 2003

Baylor College of Medicine HGSC v3.1

Available

rn2

Jan. 2003

Baylor College of Medicine HGSC v2.1

Archived

rn1

Nov. 2002

Baylor College of Medicine HGSC v1.0

Archived

Rhesus

rheMac10

Feb. 2019

The Genome Institute at Washington University School of Medicine Mmul_10

Available

rheMac8

Nov. 2015

Baylor College of Medicine HGSC Mmul_8.0.1

Available

rheMac3

Oct. 2010

Beijing Genomics Institute CR_1.0

Available

rheMac2

Jan. 2006

Baylor College of Medicine HGSC v1.0 Mmul_051212

Available

rheMac1

Jan. 2005

Baylor College of Medicine HGSC Mmul_0.1

Archived

Rock hyrax

proCap1

Jul. 2008

Baylor College of Medicine HGSC Procap1.0

Available

Sheep

oviAri4

Dec. 2015

ISGC Oar_v4.0

Available

oviAri3

Aug. 2012

ISGC Oar_v3.1

Available

oviAri1

Feb. 2010

ISGC Ovis aries 1.0

Available

Shrew

sorAra2

Aug. 2008

Broad Institute SorAra2.0

Available

sorAra1

Jun. 2006

Broad Institute SorAra1.0

Available

Sloth

choHof1

Jul. 2008

Broad Institute ChoHof1.0

Available

Squirrel

speTri2

Nov. 2011

Broad Institute SpeTri2.0

Available

Squirrel monkey

saiBol1

Oct. 2011

Broad Institute SaiBol1.0

Available

Tarsier

tarSyr2

Sep. 2013

WashU Tarsius_syrichta-2.0.1

Available

tarSyr1

Aug. 2008

WUSTL/Broad Institute Tarsyr1.0

Available

Tasmanian devil

sarHar1

Feb. 2011

Wellcome Trust Sanger Institute Devil_refv7.0

Available

Tenrec

echTel2

Nov. 2012

Broad Institute EchTel2.0

Available

echTel1

Jul. 2005

Broad Institute echTel1

Available

Tree shrew

tupBel1

Dec. 2006

Broad Institute Tupbel1.0

Available

Wallaby

macEug2

Sep. 2009

Tammar Wallaby Genome Sequencing Consortium Meug_1.1

Available

White rhinoceros

cerSim1

May 2012

Broad Institute CerSimSim1.0

Available

VERTEBRATES

African clawed frog

xenLae2

Aug. 2016

Int. Xenopus Sequencing Consortium

Available

American alligator

allMis1

Aug. 2012

Int. Crocodilian Genomes Working Group allMis0.2

Available

Atlantic cod

gadMor1

May 2010

Genofisk GadMor_May2010

Available

Budgerigar

melUnd1

Sep. 2011

WUSTL v6.3

Available

Chicken

galGal6

Mar. 2018

GRCg6 Gallus-gallus-6.0

Available

galGal5

Dec. 2015

ICGC Gallus-gallus-5.0

Available

galGal4

Nov. 2011

ICGC Gallus-gallus-4.0

Available

galGal3

May 2006

WUSTL Gallus-gallus-2.1

Available

galGal2

Feb. 2004

WUSTL Gallus-gallus-1.0

Available

Coelacanth

latCha1

Aug. 2011

Broad Institute LatCha1

Available

Elephant shark

calMil1

Dec. 2013

IMCB Callorhinchus_milli_6.1.3

Available

Fugu

fr3

Oct. 2011

JGI v5.0

Available

fr2

Oct. 2004

JGI v4.0

Available

fr1

Aug. 2002

JGI v3.0

Available

Lamprey

petMar3

Dec. 2017

University of Kentucky Pmar_germline 1.0

Available

petMar2

Sep. 2010

WUGSC 7.0

Available

petMar1

Mar. 2007

WUSTL v3.0

Available

Lizard

anoCar2

May 2010

Broad Institute AnoCar2

Available

anoCar1

Feb. 2007

Broad Institute AnoCar1

Available

Medaka

oryLat2

Oct. 2005

NIG v1.0

Available

Medium ground finch

geoFor1

Apr. 2012

BGI GeoFor_1.0 / NCBI 13302

Available

Nile tilapia

oreNil2

Jan. 2011

Broad Institute Release OreNil1.1

Available

Painted turtle

chrPic1

Dec. 2011

IPTGSC Chrysemys_picta_bellii-3.0.1

Available

Stickleback

gasAcu1

Feb. 2006

Broad Institute Release 1.0

Available

Tetraodon

tetNig2

Mar. 2007

Genoscope v7

Available

tetNig1

Feb. 2004

Genoscope v7

Available

Tibetan frog

nanPar1

Mar. 2015

Beijing Genomics Institute BGI_ZX_20015

Available

Turkey

melGal5

Nov. 2014

Turkey Genome Consortium v5.0

Available

melGal1

Dec. 2009

Turkey Genome Consortium v2.01

Available

X. tropicalis

xenTro10

Nov. 2019

University of California, Berkeley UCB_Xtro_10.0

Available

xenTro9

Jul. 2016

JGI v.9.1

Available

xenTro7

Sep. 2012

JGI v.7.0

Available

xenTro3

Nov. 2009

JGI v.4.2

Available

xenTro2

Aug. 2005

JGI v.4.1

Available

xenTro1

Oct. 2004

JGI v.3.0

Available

Zebra finch

taeGut2

Feb. 2013

WashU taeGut324

Available

taeGut1

Jul. 2008

WUSTL v3.2.4

Available

Zebrafish

danRer11

May 2017

Genome Reference Consortium GRCz11

Available

danRer10

Sep. 2014

Genome Reference Consortium GRCz10

Available

danRer7

Jul. 2010

Sanger Institute Zv9

Available

danRer6

Dec. 2008

Sanger Institute Zv8

Available

danRer5

Jul. 2007

Sanger Institute Zv7

Available

danRer4

Mar. 2006

Sanger Institute Zv6

Available

danRer3

May 2005

Sanger Institute Zv5

Available

danRer2

Jun. 2004

Sanger Institute Zv4

Archived

danRer1

Nov. 2003

Sanger Institute Zv3

Archived

DEUTEROSTOMES

C. intestinalis

ci3

Apr. 2011

Kyoto KH

Available

C. intestinalis

ci2

Mar. 2005

JGI v2.0

Available

ci1

Dec. 2002

JGI v1.0

Available

Lancelet

braFlo1

Mar. 2006

JGI v1.0

Available

S. purpuratus

strPur2

Sep. 2006

Baylor College of Medicine HGSC v. Spur 2.1

Available

strPur1

Apr. 2005

Baylor College of Medicine HGSC v. Spur_0.5

Available

INSECTS

A. mellifera

apiMel2

Jan. 2005

Baylor College of Medicine HGSC v.Amel_2.0

Available

apiMel1

Jul. 2004

Baylor College of Medicine HGSC v.Amel_1.2

Available

A. gambiae

anoGam3

Oct. 2006

International Consortium for the Sequencing of Anopheles Genome AgamP3

Available

anoGam1

Feb. 2003

IAGP v.MOZ2

Available

D. ananassae

droAna2

Aug. 2005

Agencourt Arachne release

Available

droAna1

Jul. 2004

TIGR Celera release

Available

D. erecta

droEre1

Aug. 2005

Agencourt Arachne release

Available

D. grimshawi

droGri1

Aug. 2005

Agencourt Arachne release

Available

D. melanogaster

dm6

Aug. 2014

BDGP Release 6 + ISO1 MT

Available

dm3

Apr. 2006

BDGP Release 5

Available

dm2

Apr. 2004

BDGP Release 4

Available

dm1

Jan. 2003

BDGP Release 3

Available

D. mojavensis

droMoj2

Aug. 2005

Agencourt Arachne release

Available

droMoj1

Aug. 2004

Agencourt Arachne release

Available

D. persimilis

droPer1

Oct. 2005

Broad Institute release

Available

D. pseudoobscura

dp3

Nov. 2004

FlyBase Release 1.0

Available

dp2

Aug. 2003

Baylor College of Medicine HGSC Freeze 1

Available

D. sechellia

droSec1

Oct. 2005

Broad Institute Release 1.0

Available

D. simulans

droSim1

Apr. 2005

WUSTL Release 1.0

Available

D. virilis

droVir2

Aug. 2005

Agencourt Arachne release

Available

droVir1

Jul. 2004

Agencourt Arachne release

Available

D. yakuba

droYak2

Nov. 2005

WUSTL Release 2.0

Available

droYak1

Apr. 2004

WUSTL Release 1.0

Available

NEMATODES

C. brenneri

caePb2

Feb. 2008

WUSTL 6.0.1

Available

caePb1

Jan. 2007

WUSTL 4.0

Available

C. briggsae

cb3

Jan. 2007

WUSTL Cb3

Available

cb1

Jul. 2002

WormBase v. cb25.agp8

Available

C. elegans

ce11

Feb. 2013

  1. elegans Sequencing Consortium WBcel235

Available

ce10

Oct. 2010

WormBase v. WS220

Available

ce6

May 2008

WormBase v. WS190

Available

ce4

Jan. 2007

WormBase v. WS170

Available

ce2

Mar. 2004

WormBase v. WS120

Available

ce1

May 2003

WormBase v. WS100

Archived

C. japonica

caeJap1

Mar. 2008

WUSTL 3.0.2

Available

C. remanei

caeRem3

May 2007

WUSTL 15.0.1

Available

caeRem2

Mar. 2006

WUSTL 1.0

Available

P. pacificus

priPac1

Feb. 2007

WUSTL 5.0

Available

OTHER

Sea Hare

aplCal1

Sep. 2008

Broad Release Aplcal2.0

Available

Yeast

sacCer3

April 2011

SGD April 2011 sequence

Available

sacCer2

June 2008

SGD June 2008 sequence

Available

sacCer1

Oct. 2003

SGD 1 Oct 2003 sequence

Available

VIRUSES

Ebola Virus

eboVir3

June 2014

Sierra Leone 2014 (G3683/KM034562.1)

Available

SARS-CoV-2

wuhCor1

Jan. 2020

SARS-CoV-2 ASM985889v3

Available

Initial assembly release dates

When will the next assembly be out?

UCSC does not produce its own genome assemblies, but instead obtains them from standard sources. Because of this, you can expect us to release a new version of a genome soon after the assembling organization has released the version. A new assembly release initially consists of the genome sequence and a small set of aligned annotation tracks. Additional annotation tracks are added as they are obtained or generated. Bulk downloads of the data are typically available in the first week after the assembly is released in the browser.

Data sources - UCSC assemblies

Where does UCSC obtain the assembly and annotation data displayed in the Genome Browser?

All the assembly data displayed in the UCSC Genome Browser are obtained from external sequencing centers. To determine the data source and version for a given assembly, see the assembly’s description on the Genome Browser Gateway page or the List of UCSC Genome Releases.

The annotations accompanying an assembly are obtained from a variety of sources. The UCSC Genome Bioinformatics Group generates several of the tracks; the remainder are contributed by collaborators at other sites. Each track has an associated description page that credits the authors of the annotation.

For detailed information about the individuals and organizations who contributed to a specific assembly, see the Credits page.

Which UCSC assemblies are equivalent to Ensembl or NCBI assemblies?

The asmEquivalent table on the hgFixed database is available on the public MySQL server to show which assemblies versions are identical (or almost identical) to each other between UCSC, Ensembl, Genbank, and RefSeq assemblies.

mysql --user=genome --host=genome-mysql.soe.ucsc.edu -A -e 'desc asmEquivalent;' hgFixed
+----------------------+-------------------------------------------+
| Field                | Type                                      |
+----------------------+-------------------------------------------+
| source               | varchar(255)                              |
| destination          | varchar(255)                              |
| sourceAuthority      | enum('ensembl','ucsc','genbank','refseq') |
| destinationAuthority | enum('ensembl','ucsc','genbank','refseq') |
| matchCount           | bigint(20)                                |
| sourceCount          | bigint(20)                                |
| destinationCount     | bigint(20)                                |
+----------------------+-------------------------------------------+

The “Count” indications are the count of individual sequences in the assembly. When all three counts are identical, matchCount == sourceCount == destinationCount, then the match between genome assemblies is perfectly identical.

Non-perfect matches can be due to a number of factors:

  1. different or not included chrMT genome sequences in an assembly

  2. identical duplicated sequences present or absent from an assembly

  3. some smaller contigs not included in an assembly

  4. slight differences in versions of assemblies where some contain sequences not in the other assembly

Comparison of UCSC and NCBI human assemblies

How do the human assemblies displayed in the UCSC Genome Browser differ from the NCBI human assemblies?

Human assemblies displayed in the Genome Browser (hg10 and higher) are near identical to the NCBI assemblies when it comes to primary sequence. Minor differences may be present, however. Sources include:

  • NCBI genomes are repeat masked with RepeatMasker, however, UCSC genomes are independently masked with both RepeatMasker (with different flags) and WindowMasker, ultimately using the program output with the highest percentage masked for the base sequence

  • In genome download files, UCSC uses the ‘chr1’ nomenclature for sequence identifiers, whereas the primary NCBI sequence identifiers are RefSeq accessions

  • The original mitochondrion (chrM) for hg19 differs from the one in NCBI (GRCh37)

  • The mitochondrion released by NCBI after the hg19 browser was built has been added to the assemby as chrMT. See our documentation for details.

Looking for a genome assembly not shown in the tree?

When looking for a specific assembly, the best place to start is the Gateway page. If you begin to type the common name, species name, or NCBI RefSeq accession number in the search box on the left side of the screen, suggestions will appear if any matches are found. This search will also match any assembly hubs that are listed in UCSC’s Public Hubs. Nearly every NCBI RefSeq assembly and Vertebrate Genomes Project assembly is included here within the GenArk hubs. NCBI RefSeq assemblies can be loaded with direct links such as http://genome.ucsc.edu/h/GCF_001984765.1 with the GCF accession. These assembly hubs are automatically updated, but not reviewed by UCSC. The species tree shows all genomes reviewed by UCSC.

If the assembly of interest is not found, you may write in to our mailing list (genome@soe.ucsc.edu) including the NCBI Genbank assembly accession for the requested assembly in the message. These will start with either GCA_ or GCF_. Our agreement with the genomics community is that we wait until the assembly has been deposited into Genbank at NCBI before we process it. See the Assembly Submission Guidelines page at NCBI for directions on their submission process.

Another option available to all users is to create an assembly hub. These are assemblies created and hosted by users and displayed on the Genome Browser. This requires no intervention by the UCSC Genome Browser and can be done for any assembly. See our Quick Start Guide to Assembly Hubs page for additional information and resources. If you create an assembly hub, consider sharing it with others as a Public Hub.

Differences between UCSC and NCBI mouse assemblies

Is the mouse genome assembly displayed in the UCSC Genome Browser the same as the one on the NCBI website?

The mouse genome assemblies featured in the UCSC Genome Browser are the same as those on the NCBI web site with one difference: the UCSC versions contain only the reference strain data (C57BL/6J). NCBI provides data for several additional strains in their builds.

Accessing older assembly versions

I need to access an older version of a genome assembly that’s no longer listed in the Genome Browser menu. What should I do?

In addition to the assembly versions currently available in the Genome Browser, you can access the data for older assemblies of the browser through our Downloads page.

Frequency of GenBank data updates

How frequently does UCSC update its databases with new data from GenBank?

GenBank updates for mRNA, RefSeq, and EST data occur on a semi-quarterly basis, following major NCBI releases. These updates are in place for most Genome Browser assemblies. Assemblies that are not on an incremental update schedule are updated whenever we load a new assembly or make a major revision to a table.

Coordinate changes between assemblies

I noticed that the chromosomal coordinates for a particular gene that I’m looking at have changed since the last time I used your browser. What happened?

A common source of confusion for users arises from mixing up different assemblies. It is very important to be aware of which assembly you are looking at. Within the Genome Browser display, assemblies are labeled by organism and date. To look up the corresponding UCSC database name or NCBI build number, use the release table.

UCSC database labels are of the form hg#, panTro#, etc. The letters designate the organism, e.g. hg for human genome or panTro for Pan troglodytes. The number denotes the UCSC assembly version for that organism. For example, ce1 refers to the first UCSC assembly of the C. elegans genome.

The coordinates of your favorite gene in one assembly may not be the same as those in the next release of the assembly unless the gene happens to lie on a completely sequenced and unrevised chromosome. For information on integrating data from one assembly into another, see the Converting positions between assembly versions section.

Converting positions between assembly versions

I’ve been researching a specific area of the human genome on the current assembly, and now you’ve just released a new version. Is there an easy way to locate my area of interest on the new assembly?

See the section on converting coordinates for information on assembly migration tools.

Missing annotation tracks

Why is my favorite annotation track missing from your latest release?

The initial release of a new genome assembly typically contains a small subset of core annotation tracks. New tracks are added as they are generated. In many cases, our annotation tracks are contributed by scientists not affiliated with UCSC who must first obtain the sequence, repeatmasked data, etc. before they can produce their tracks. If you have need of an annotation that has not appeared on an assembly within a month or so of its release, feel free to send an inquiry to genome@soe.ucsc.edu. **Messages sent to this address will be posted to the moderated genome mailing list, which is archived on a SEARCHABLE, PUBLIC**Google Groups forum.

What next with the human genome?

Now that the human genome is “finished”, will there be any more releases?

Rest assured that work will continue. There will be updates to the assembly over the next several years. This has been the case for all other finished (i.e. essentially complete) genome assemblies as gaps are closed. For example, the C. elegans genome has been “finished” for several years, but small bits of sequence are still being added and corrections are being made. NCBI will continue to coordinate the human genome assemblies in collaboration with the individual chromosome coordinators, and UCSC will continue to QC the assembly in conjunction with NCBI (and, to a lesser extent, Ensembl). UCSC, NCBI, Ensembl, and others will display the new releases on their sites as they become available.

Mouse strain used for mouse genome sequence

What strain of mouse was used for the Mus musculus genome?

C57BL/6J.