Genog

Genog is a term encountered in some genetics and microbiology discussions used as a shorthand for a grouping or cluster of related genomes. It is not an officially defined taxonomic rank, and there is no universally accepted definition. Usage varies by field and author, and the term often carries informal, context-dependent meaning.

In practice, genog can refer to a set of genomes that share a high degree of sequence similarity, a common ancestry, or similar gene content, depending on the criteria chosen for clustering. These criteria may include thresholds based on average nucleotide identity, gene presence or absence, or other genomic features used to delineate groups in comparative genomics and metagenomics.

Genog is typically used to describe an aggregate rather than a single genome, and to discuss evolutionary relationships at a level above genotype but below species or broader lineages in some contexts. Because its definition is not standardized, researchers may apply different technical criteria to define a genog in their work.

Relation to other terms: Genog is related to concepts such as genogroups or genotypes but is not a standardized term. It should not be confused with the more formal usage of genogroup in virology, which follows its own conventions and classifications.

Limitations: As an informal term, genog’s exact meaning depends on the study and authors’ definitions. Readers should consult the specific methods and criteria stated in each work to understand what is meant by genog in that context.

See also: Genogroup, Genotype, Genomics, Metagenomics, Phylogeny.