ʻIʻiwi in Waikīkī: The vision and work of the Reed Lab
Floyd Reed, PhD, Professor of Biology, feels a deep sense of urgency. Hawaiʻi’s native and endemic birds are at risk of being infected with avian malaria from invasive mosquitoes, and time is running out to find a solution.
“Non-native mosquitoes were introduced to Hawaiʻi over a century ago and, in addition to spreading human disease, they are also primarily responsible for the ongoing extinction of many native Hawaiian bird species by Plasmodium, or avian malaria,” says Reed.
“This threat is real,” he says. “We are losing them.”
Seeing the danger and recognizing the value of these birds to Hawaiʻi, Dr. Reed and his lab, along with Asst. Prof. Jolene Sutton at UH Hilo, are genetically modifying mosquitoes to use evolutionary forces to protect the birds. “We are developing a safe and reversible form of gene drive in these mosquitoes, termed underdominance, in which we insert a small sequence of DNA into their genome that modifies the function of one of the mosquitoes own genes. As a result, mosquitoes with one copy of the modification (heterozygotes) are less fit than either homozygote (with zero or two copies). This creates an unstable equilibrium where genetic modifications (constructs that block Plasmodium replication in mosquitoes) can be stably established at 100% frequency in wild populations.” It is important to note that this form of gene drive is geographically contained, it is not predicted to spread between islands or to the mainland, and reversible; all copies of the modification can be removed from the wild.
The genetic transformation work has been successful and is proceeding quickly. Both the Reed Lab and the Sutton Lab have produced Culex mosquito larvae, the species that vectors avian malaria, with a construct that expresses a red fluorescent protein and has a self-docking site for further genetic constructs to be added. The next step is to verify that the self-docking site is functioning as expected and then add the underdominant construct.
Reed is excited about this research, not only for the impact he hopes to have on the native bird populations, but for the capacity Hawaiʻi can build for itself.
“At this time our lab and the Sutton Lab are the only labs in the world that have genetically modified Culex mosquitoes," he says. “It’s exciting to show that Hawaiʻi can create its own technology and solve its own problems in state. Hawaiʻi has a history of things being done to the islands from elsewhere, and this is an example of how Hawaiʻi can harness what it already has to create its own solutions.”
But the pressure mounts as the days tick by and Honeycreeper species like the ʻIʻiwi continue to perish as a result of invasive mosquitoes.
“If we can buy them enough time,” says Reed, “they may eventually adapt to tolerate avian malaria like other birds and then we can remove the genetically modified mosquitoes.”
He hopes through this work, the birds, which have fled the lower, warmer elevations where mosquitoes live, will move lower and begin to reintegrate even down to the coastal environments.
“I don’t know about you,” he says, “but I’m ready to see ʻIʻiwi in Waikīkī.”