Genetic ablation occurs when a gene is deemed “null” through the homologous genetic recombination of a gene. It is utilized in the selective suppression of a specific cell line or cell type. This genetic engineering technique does not limit growth suppression to just the activity of an individual gene. Specific cell ablation enables the examination of the in vivo activity of cells. An example of this method in action can be seen through the production of a knockout mouse. This is accomplished through the administration of one or more transgenes into a fertilized mouse oocyte’s pronucleus. Afterwards, it is reimplanted into a host mother, who then births a transgenic mouse. The transgenic mouse carries one copy of the transgene3 out of several hundred. From these mice, a homozygous colony can be created through breeding. Historical development In 1990, the gene knockout technique was just developing. There was a lack of information on the initial events that occur throughout the development of the vertebrate embryo. In order to form a better understanding, the instructions for making an entire set of DNA in a person or organism need be dissected, and the genes involved with this process need to be determined. Instructions for embryonic development may have some correlation to the lack of space shown by many genes in their expression patterns. A technique used to evaluate specific gene function is through the inactivation or removal of that gene. By eradicating a specific gene, its role in development of the embryonic expression pattern may be able to be observed. Clinical significance The ability to selectively remove cells by ablation is monumental in the study of the development of eukaryotic biology, contributing greatly to the study of the origin, fate, or function of the cells. Genetic ablation occurs through the delivery of a toxin or death-inducing gene that is directed by a cell-specific enhancer (genetics), or by utilizing the GAL4/UAS system. Due to the array of known enhancers, toxins and death genes are able to be attached to nearly any cell selected, which permits cell-type-specificity. Through genetic ablation, the effects of removing every cell of a specific kind inside of an embryo are able to be observed; additionally, the entire population is able to be studied instead of just the individuals. Advantages Cell-type-specificity is a significant advantage of genetic ablation. The numerous enhancers that exist allow this specificity because toxins and death genes