Dominant lethal mutations

Definition

Mutations that cause death or developmental failure when present in a single copy (heterozygous state), typically due to disruption of essential gene functions. In arthropod genetics, these mutations are exploited in pest control strategies and laboratory studies to suppress populations or map essential genes.

Etymology

From Latin 'dominari' (to rule) and 'lethalis' (deadly), describing mutations whose deleterious effects mask the wild-type allele.

Example

In the sterile insect technique, male mosquitoes or fruit flies are irradiated to induce dominant lethal mutations in their sperm; when these males mate with wild females, the resulting embryos die early in development, reducing the pest population without environmental pesticide use.

Synonyms

• dominant lethals

Related Terms

• recessive lethal mutations
• conditional lethal mutations
• balanced lethal system
• sterile insect technique
• haploinsufficiency
• essential genes
• genetic load

Usage Notes

Distinguished from recessive lethal mutations, which only cause death when homozygous. The term 'dominant' here refers to genetic dominance, not ecological dominance. In practice, many induced dominant lethals are actually chromosomal rearrangements (deletions, inversions, translocations) rather than point mutations. Strictly complete dominant lethals cannot be maintained as stocks; laboratory stocks rely on conditional lethals or balanced chromosome systems.