Maternal effect dominant embryonic arrest
Maternal effect dominant embryonic arrest is a flour beetle selfish gene composed of a toxin and an antidote. A mother carrying Medea will express the toxin in her germline, killing her progeny. If the children also carry Medea, they produce copies of the antidote, saving their lives. Therefore, if a mother has one Medea allele and one non-Medea allele, half of her children will inherit Medea and survive while the other half will inherit the non-Medea allele and die.
Medeas selfish behavior gives it a selective advantage over normal genes. If introduced into a population at sufficiently high levels, the Medea gene will spread, replacing entire populations of normal beetles with beetles carrying Medea. Because of this, Medea has been proposed as a way of genetically modifying insect populations. By linking the Medea construct to a gene of interest – for instance, a gene conferring resistance to malaria – Medeas unique dynamics could be exploited to drive both genes into a population. These findings have dramatic implications for the control of insect-borne diseases such as malaria and dengue fever.