Exogenous DNA

Definition

DNA originating from outside an organism, as opposed to endogenous DNA inherited or naturally produced within that organism. In arthropod research, exogenous DNA enters cells through natural mechanisms (such as horizontal gene transfer via transposable elements or viral integration) or artificial methods including microinjection, electroporation, and transfection. The term distinguishes foreign genetic material from the host genome regardless of whether integration occurs.

Etymology

From Greek exō- (outside, external) + -genēs (born, produced) + DNA (deoxyribonucleic acid)

Example

In CRISPR-based gene drive research, exogenous DNA encoding Cas9 and guide RNAs is microinjected into mosquito embryos, creating heritable modifications that spread through wild populations to suppress malaria transmission.

Synonyms

• foreign DNA
• heterologous DNA

Related Terms

• transfection
• Transformation
• transgenesis
• Horizontal gene transfer
• endogenous DNA
• gene drive
• microinjection

Usage Notes

Contrast with endogenous DNA (native to the organism). The distinction matters experimentally: detection of exogenous DNA in field-collected arthropods may indicate laboratory escape, natural horizontal transfer, or contamination. In applied entomology, 'exogenous' typically refers to intentionally introduced sequences; in evolutionary studies, it may describe viral or bacterial DNA integrated into arthropod genomes over evolutionary time. The term does not imply functional status—exogenous DNA may be transient, episomal, or chromosomally integrated.