Gene Drive Genetics Defined

The term “gene drive” began to appear in the scientific literature early in the 21st century although various genetic phenomena that fit under this rubric had been known for almost a century before that.  Today while there are many ongoing conversations and discussions in which the term is used, usages and implied meanings vary.  Researchers have attempted to standardize the definitions of “gene drive” to facilitate discussions by establishing a common vocabulary.

Gene Drive Genetics Explained

Sexually reproducing organisms typically have two forms of each of the genes found in that organisms (their genome).  One form is inherited from the female parent and one form from the male parent.  These forms can be, but often are not, exactly identical.

Transmission of the maternal and paternal forms of genes and chromosomes is typically thought of as being “fair” in that each of the two forms has an equal chance of being transmitted to the next generation in a sperm or egg cell.

The pattern of inheritance shown to the right is familiar and reflects the equal (fair) chance the ‘black’ and ‘blue’ forms of the ‘color’ gene have of being transmitted to the next generation.

For example, the roughly equal number of men and women in the world is a manifestation of this pattern of inheritance with the X and Y chromosomes in males having an equal (fair) chance of being transmitted to the next generation in a sperm cell.

There are forms of some genes that are not ‘fairly’ transmitted to the next generation but instead are preferentially transmitted at the expense of other forms of the gene.  These forms are said to “drive” or to display “gene drive”.

The pattern of inheritance shown on the left reflects the strongly preferential transmission of the ‘black’  form of the ‘color’ gene during sexual reproduction.

The ‘black’ form is said to display strong ‘drive’ or ‘gene drive’.

While the genetic phenomenon of ‘drive’ is largely unfamiliar to non-specialists, it is actually quite common and important in nature and has been known to geneticists for almost 100 years.

Today scientists can assemble transgenes in the laboratory that display ‘drive’ when introduced into plant and animal genomes, including insects.

This is a short 6-minute video that explains the basic genetics involved.  Additional videos that are less basic can be found here.