Due to unavoidable maintenance, the HGNC and VGNC online resources may be unavailable from 6th - 8th December

HCOP help

The HGNC Comparison of Orthology Predictions (HCOP) search is a tool that integrates and displays the orthology assertions predicted for a specified human gene, or set of human genes, by eggNOG, Ensembl Compara, HGNC, HomoloGene, Inparanoid, NCBI Gene Orthology, OMA, OrthoDB, OrthoMCL, Panther, PhylomeDB, PomBase, TreeFam and ZFIN. An indication of the reliability of a prediction is provided by the number of databases which concur. HCOP was originally designed to show orthology predictions between human and mouse, but has been expanded to include data from chimp, macaque, rat, dog*, horse, cattle, pig, opossum, platypus, chicken, anole lizard, xenopus, zebrafish, C. elegans, Drosophila, S. cerevisiae, and S. pombe meaning that there are currently 19 genomes available for comparison in HCOP.

*In release 105 of Ensembl the default dog assembly was changed from CanFam3.1 (a boxer) to ROS_Cfam_1.0 (a labrador retriever). As HCOP aims to be as comprehensive as possible it will include orthology data predicted using sequences from both dog genome assemblies until all the orthology sources have updated to use the Ros_Cfam_1.0 assembly data, at which point orthology predictions from CanFam3.1 will be retired. HCOP results use two different dog icons to allow users to easily distinguish which assembly the orthology prediction comes from.

Using the search

Orthology assertions can be obtained for a gene by searching with its Ensembl gene identifier or its NCBI Gene identifier. For species with either a model organism or nomenclature database you can also search with an approved gene symbol, an approved gene name or the gene identifier from that database. The species of the query gene must be selected using the drop down menu in the “Search for ortholog(s) between;” section of the form, and one or more species for which you wish to see orthology data should be selected using the species check boxes just below this. If your query is not a human gene you will only be able to identify orthologs beween the species you have provided gene information for and human. In the latest version of HCOP you can now specify which orthology sources you wish to see represented in the results. To include or exclude particular sources use the checkboxes in the ‘include orthologs from’ section of the form. If you choose to exclude a certain source then orthologs assignments made based only on evidence from that source will be excluded from the result set. You will still see assignments made by the excluded source appearing in results where the orthology assignment is supported by one or more of the other ortholog sources you have selected to use for the search. Not all sources have data for every species see the section on ‘origins of the data’ to find out what data are available. The results provide basic data about the query and its predicted homologs as well as a list of databases that support the assertion and links to further information.

The consensus orthology assertions for multiple genes can be viewed simultaneously by searching with a list of query terms, separated by commas, newlines or spaces. This list may either be pasted into the ‘enter identifier(s)’ box or uploaded as a file using the ‘upload file’ option on the form. If you have entered information into the ‘enter identifiers’ text box but then decide you would rather upload a file containing your data you must either delete the data in the text box or clear the form using the ‘reset’ button before uploading your file of data.

If provided with a list of terms (either comma, space or newline delimited), HCOP searches with each term in turn e.g. ABCA1 ABCA2 ABCA3. A separate result panel will appear for each query term that produces a result. If more than one query term was supplied the results sections may be scrollable.

HCOP supports wild cards. Use _ to substitute for a single character and * or % to substitute for 1 or more characters. For example ABCA* fetches all genes beginning ABCA, while ABCA_ fetches only ABCA1 to ABCA9. It is not advisable to start a query with a wildcard as the database will not be able to use its indexes and the search will be slow.

Searches are case insensitive. The ‘HGNC:’, ‘VGNC:’, ‘MGI:’, ‘RGD:’, ‘ZFIN’, ‘SGD:’, ‘XENBASE’, ‘BGD:’ or ‘CGNC:’ database identifier prefixes are not required, but the search will work whether they are included or not.

Search results

The latest version of HCOP has changed the way in which the results are displayed to make it more user friendly. Each query term that has an ortholog assignment in one or more of the ortholog species selected will have a results panel like this:

Example HCOP result

At the top of the results panel in the blue section you will see data relating to the query term you supplied. Below this you will see a section for each ortholog that has been returned. For the both the query and orthologs you should see:

Gene symbol

This will either be prefixed with ‘Approved symbol’ to indicate that the symbol was assigned by a nomenclature committee or with ‘Gene symbol’ to indicate that it is not an approved symbola non-approved symbol may in some cases be listed as ‘Unknown’. If you hover your mouse over the information icon to the left of the symbol a popup will tell you where we got the symbol data from.

Gene name

Again this will be prefixed with ‘Approved name’ to indicate that the name was assigned by a nomenclature committee or with ‘Gene name’ to indicate that this is not an approved name. If you hover your mouse over the information icon to the left of the name a popup will tell you where we got the name data from.

Locus type

This is the locus type of the gene; if you hover your mouse over the information icon to the left of the name a popup will tell you where we got the locus type information from.

Chromosomal location

Indicates the cytogenetic location of the gene or region on the chromsome. In the absence of that information one of the following may be listed:

Gene resources

Links to the gene in its model organism or nomenclature database, Ensembl and NCBI Gene where applicable.

For each ortholog gene you will also see a section labelled ‘Assertion derived from:’ that contains a series of icons. These icons represent the ortholog sources that support this orthology assignement. Clicking on the icon will take you to the entry for that gene in the orthology database, while hovering over the icon will give you the full name of the ortholog data source.

Origins of the data

The data behind HCOP is stored in a MySQL database to allow for rapid querying. Each orthology assignment is stored as a pair of genes, with mapped database identifiers and basic gene data as well as a list of associated databases that support that assertion. The data in HCOP is updated weekly by running a pipeline that first works out if we have new data from any of our orthology sources and then updates the data as required. We currently import gene data from:

These data are used to ensure that we have the current approved gene symbols, names, locus types and location information from the appropriate nomenclature or model organism database. For those species without a nomenclature committee (currently this applies to chimp, macaque, dog, horse, cattle, pig, opossum and platypus) or where a nomenclature resource exists but gene data are not available (anole lizard) in a form we can use in our pipeline we take this information from the NCBI Gene database or from Ensembl if the gene in question can not be mapped to an NCBI Gene identifier.

Orthology data are imported from various sources, the table below details the sources we use, the current version of the data and the species this applies to:

Orthology Source Version Species data applies to
eggNOG Version 5.0 All species except horse
Ensembl Release 109 All species
HGNC N/A Human and mouse
HomoloGene Release 68 Human, chimp, macaque, mouse, rat, dog, cattle, chicken, xenopus, zebrafish, C. elegans, fruitfly, S. cerevisiae & S. pombe
Inparanoid Version 8.0 All species
OMA Release November 2022 All species
OrthoDB Version 11 Human, chimp, macaque, mouse, rat, dog, cat, horse, cattle, pig, opossum, platypus, chicken, anole lizard, xenopus, zebrafish, C. elegans & fruitfly
OrthoMCL Version 6.15 Human, mouse, dog, chicken, xenopus, zebrafish, C. elegans, fruitfly, S. cerevisiae & S. pombe
NCBI gene orthology N/A All species except C. elegans, fruitfly, S. cervisiae & S. pombe
Panther Version 17.0 All species
PhylomeDB Version 4, data are taken from phylome 514 Human, chimp, macaque, mouse, rat, dog, cattle, opossum, platypus, chicken, xenopus, zebrafish, C. elegans, fruitfly, S. cerevisiae & S. pombe
PomBase N/A Human & S. pombe
TreeFam Release 9.0 All species except cat & S. pombe
ZFIN N/A Human & zebrafish

For versioned orthology sources the pipeline used for updating HCOP will detect that the version of the data has changed and update the data accordingly. For those ortholog sources where no data version is specified the data will be updated each time the HCOP pipeline is run (currently weekly), so that HCOP will never be more than one week out of sync with the data source.

If there is an orthology source that you would like to see in HCOP please contact us via our feedback form and we will see if it is possible for it to be incorporated.

Linking to a HCOP result

It is now possible to go directly to an HCOP result using a URL with set parameters; this enables you to add links to our HCOP results within your own web applications. Use the following URL template:

https://www.genenames.org/tools/hcop/#!/?q=<query>&qtype=<query type>&qtax_id=<query NCBI taxon ID>&ttax_id=<target species NCBI taxon ID>&submit=true

e.g. Probable chimp and macaque orthologs of a human gene with the approved symbol of BRCA2.


Probable human orthologs of the chimp gene with the Ensembl gene ID of ENSPTRG00000005766.

Below is a table that will help you to fill in the ‘query type’ and taxon IDs. If the qtax_id is not human (9606) then only one ttax_id can be used and must be 9606.

Species NCBI taxon ID Allowed query types for species
Human 9606 symbol, name, ensembl (i.e Ensembl gene ID), egene (i.e NCBI gene ID), hgnc (i.e HGNC ID)
Chimp 9598 symbol, name, ensembl, egene, vgnc (i.e VGNC ID)
Macaque 9544 symbol, name, ensembl, egene, vgnc (i.e VGNC ID)
Mouse 10090 symbol, name, ensembl, egene, mgi (i.e MGI ID)
Rat 10116 symbol, name, ensembl, egene, rgd (i.e RGD ID)
Dog 9615 symbol, name, ensembl, egene, vgnc (i.e VGNC ID)
Cat 9685 symbol, name, ensembl, egene, vgnc (i.e VGNC ID)
Horse 9796 symbol, name, ensembl, egene, vgnc (i.e VGNC ID)
Cattle 9913 symbol, name, ensembl, egene, vgnc (i.e VGNC ID)
Pig 9823 symbol, name, ensembl, egene, vgnc (i.e VGNC ID)
Opossum 13616 ensembl, egene
Platypus 9258 ensembl, egene
Chicken 9031 symbol, name, ensembl, egene
Anole lizard 28377 ensembl, egene
Xenopus 8364 symbol, name, ensembl, egene, xenbase (i.e XENBASE ID)
Zebrafish 7955 symbol, name, ensembl, egene, zfin (i.e ZFIN ID)
C.elegans 6239 symbol, name, ensembl, egene, wormbase (i.e WormBase ID)
Fruitfly 7227 symbol, name, ensembl, egene, flybase (i.e FlyBase ID)
S.cerevisiae 4932 symbol, name, ensembl, egene, sgd (i.e SGD ID)
S.pombe 284812 ensembl, pombase (i.e PomBase ID)

Using the Bulk downloads tool

For your convenience we have pre-calculated some files of HCOP data that you can download from our FTP site. You have the option of getting a file containing human and ortholog data from a single species, or human and ortholog data from all HCOP species in a single file. For the human - single ortholog species files the ‘6 Column’ output returns the raw assertions, Ensembl gene IDs and Entrez Gene IDs for human and one other species, while the ‘15 Column’ output includes additional information such as the chromosomal location, accession numbers and where possible references the approved gene nomenclature.

The files containing all species ortholog data have an additional column at the start giving the taxon id for each ortholog species.

Referencing the HGNC Comparison of Orthology Predictions search tool

If you use this tool or the ‘Bulk Downloads’ in published work please reference:

Image credits

Images used in HCOP are either used with permission from the image owner, or are in the public domain.