Technical terms

  • CRISPR-Cas9: A DNA cutting enzyme from bacteria that can be engineered to cut particular DNA sequences with a high degree of specificity.   It has found a number of applications in bio-technology, including as a component of gene drives.

  • Gene drive: We use this term to refer to [1] a technological system designed to force novel genes into a wild population to purposefully modify, replace, ‘suppress’, or eliminate such populations (also referred to as a gene drive system) or [2] the modified genetic material that forms the molecular basis of such technology (also referred to as a gene drive element(s)). Gene drives are almost always based on engineered selfish genetic elements.

  • Gene drive modified population : A population of a target species that has been modified by the action of a gene drive, i.e. a population carrying gene drive elements.

  • Gene drive organism: A genetically modified organism carrying a gene drive element or elements

  • Homing gene drive: A common form of gene drive employing CRISPR-Cas9. For more see here.

  • Selfish genetic element: Any natural or engineered genetic sequence that shows biassed inheritance – i.e. it is inherited by more than 50% of the next generation.

  • Target species : The species that a particular gene drive aims to modify, ‘suppress’ or eliminate

  • Target organism : An individual member of a target species

  • Target sequence : The specific DNA sequence in the genome of a target species where a gene drive element is inserted.

  • Unmodified population: A population of a target species that has not been modified by the action of a gene drive. Such populations could also be referred to as a wild type population.