Heterologe

Heterologe, or heterologous, is an adjective used in biology and related disciplines to describe something that arises from a different origin or is not homologous to a reference. The term combines Greek heteros “other” and logos “relation” or “study.” It is contrasted with homologous, meaning sharing common origin or structure.

In molecular biology and biotechnology, heterologous expression refers to producing a gene product in a host organism that is different from the source of the gene. This approach enables production of proteins in bacteria, yeast, or mammalian cells, and is widely used in research and industry.

Heterologous recombination denotes genetic exchange between dissimilar DNA sequences, enabling targeted insertion, deletion, or modification when sequences are not mutually identical.

In immunology, heterologous immunity describes cross-reactive immune responses where prior exposure to one pathogen influences responses to a different, related pathogen, sometimes altering disease outcome or vaccine efficacy.

In clinical and translational contexts, heterologous materials or tissues are derived from a donor or source different from the recipient, as in xenotransplantation or the use of heterologous antibodies, with associated compatibility and immune considerations.

See also: homologous, xenograft, cross-species. Additional terms: heterologous expression, heterologous immunity.