No biological Data available (ND) evidence code

From GO Wiki
Jump to: navigation, search

Overview

  • The ND evidence code is used for annotations when information about the molecular function, biological process, or cellular component of the gene or gene product being annotated is not available.
  • Use of the ND evidence code specifically indicates that a curator has looked but not been able to find information that supports making an annotation to any term from the Molecular Function, Biological Process, or Cellular Component as of the annotation date indicated.
  • ND should be used only for annotations to the root terms, Molecular Function (GO:0003674), Biological Process (GO:0008150), or Cellular Component (GO:0005575), which, when used in annotations, indicates that no knowledge is available about a gene product in that aspect of GO.
  • Annotations made with the ND evidence code are required to use the GO_REF:0000015 reference that explains that curators looked but found no information.
  • Note that some groups check only published literature while other groups also make sequence comparisons to see if an annotation can be made on the basis of a sequence comparison. The GO Reference collection includes a reference that can be used with ND when both literature and sequence have been checked; to use it, put it in the reference column of a gene association file.
  • Note that use of the ND evidence code with an annotation to one of the root nodes to indicate lack of knowledge in that aspect makes a statement about the lack of knowledge only with respect to that particular aspect of the ontology. Use of the ND evidence code to indicate lack of knowledge in one particular aspect does not make any statement about the availability of knowledge or evidence in the other GO aspects.
  • Even if an author states in a paper that there is no data available or nothing is known about the gene product in a particular GO aspect, annotation to the corresponding root node should be made with ND evidence code citing either the annotating group's internal reference or the GOC's reference on use of the ND evidence code, not a specific paper.
  • Note: The ND evidence code, unlike other evidence codes, should be considered as a code that indicates curation status/progress than as method used to derive an annotation.
  • When a gene product is annotated to a GO term using the NOT qualifier, this is a statement that it is not appropriate to associate that specific GO term with that particular gene product. However, such a negative annotation does not make any positive statements about the role of that gene product. Thus, there should always be a positive annotation, in addition to the NOT annotation. If nothing is known about the role of the gene product in a given aspect (molecular function, biological process, or cellular component) of GO, then the positive annotation should be made to the root node for that aspect using the ND evidence code.

Examples of ND Usage

DB Object ID DB Object Symbol GO ID DB:Reference Evidence Code With (or) From
PomBase:SPBC31F10.17c na GO:0008150 (biological_process) GO_REF:0000015 ND na
PomBase:SPBC31F10.17c na GO:0003674 (molecular_function) GO_REF:0000015 ND na
PomBase:SPCC594.01 na GO:0005575 (cellular_component) GO_REF:0000015 ND na

Usage of the With/From Column for ND

  • The With/From column is not used with the ND evidence code.

When NOT to use ND

Quality Control Checks

ND annotations to root nodes only

Evidence and Conclusion Ontology

ECO:0000307 no biological data found used in manual assertion

Links

Curator Guide to GO Evidence Codes

Gene Ontology website GO Evidence Codes list

Review Status

Last reviewed: April 12, 2018