Transgenic Mosquitoes Transferred Their Genes Into a Natural Population

Long-time Slashdot reader cccc828 shares a Nature article "about genetically modified mosquitoes that were supposed to reduce the mosquito population. However, instead of dying, some survived, spreading the new genes."

In an attempt to control the mosquito-borne diseases yellow fever, dengue, chikungunya, and Zika fevers, a strain of transgenically modified Aedes aegypti mosquitoes containing a dominant lethal gene has been developed by a commercial company, Oxitec Ltd... Approximately 450 thousand males of this strain were released each week for 27 months in Jacobina, Bahia, Brazil...

Genetic sampling from the target population six, 12, and 27-30 months after releases commenced provides clear evidence that portions of the transgenic strain genome have been incorporated into the target population. Evidently, rare viable hybrid offspring between the release strain and the Jacobina population are sufficiently robust to be able to reproduce in nature... It is unclear how this may affect disease transmission or affect other efforts to control these dangerous vectors.

These results highlight the importance of having in place a genetic monitoring program during such releases to detect un-anticipated outcomes.