A newly published study in Nature Communications marks a major advance in mosquito genetics, offering powerful new tools to better understand the biology and immune function of Anopheles mosquitoes, the sole vectors of malaria, one of the world’s deadliest infectious diseases.
The research, co-authored by Ryan C. Smith, associate professor in Iowa State University’s Department of Plant Pathology, Entomology and Microbiology (PPEM), introduces the first genome-wide CRISPR screening platform developed specifically for Anopheles mosquito cells. The platform enables scientists to systematically identify genes essential for mosquito survival and immune cell function, opening the door to new strategies for reducing malaria transmission
“Malaria control ultimately depends on understanding the mosquito itself,” Smith said. “This work gives us a way to ask, at a genome-wide level, which genes mosquitoes need to survive and how their immune cells function at a molecular scale.”
Using CRISPR gene-editing technology, the research team conducted a comprehensive “knockout” screen targeting nearly the entire Anopheles gambiae genome. The study identified more than 1,200 genes required for basic cellular fitness, many of which are involved in fundamental biological processes such as protein synthesis, metabolism, and cell division.
“What’s exciting is how conserved many of these genes are,” Smith explained. “We see strong overlap with mosquito genes that are essential in fruit flies and even human cells, which tells us we’re uncovering core biological pathways that play a critical role in global health.”
Because the mosquito cell line used in the study closely resembles immune cells known as hemocytes, the findings also provide new insights into mosquito immunity, an area that has historically lacked robust genetic tools.
In addition to identifying fitness genes, the researchers used the new CRISPR platform to investigate how mosquito immune cells process clodronate liposomes, a widely used tool for selectively depleting immune cells in both vertebrates and invertebrates.
While clodronate liposomes are commonly used in research, the precise mechanisms by which they enter and destroy immune cells were poorly understood. The study revealed that liposome uptake occurs through phagocytosis, followed by processing in the phagolysosome, a specialized cellular compartment involved in immune defense.
“We were able to pinpoint specific genes that control how immune cells take up and process these liposomes,” Smith said. “That gives us not only a better understanding of mosquito immune biology, but also a clearer picture of how this experimental tool actually works.”
Several genes identified in the screen were validated in live mosquitoes, confirming their roles in immune cell depletion and intracellular processing.
By establishing a scalable, genome-wide CRISPR screening system in Anopheles, the research provides a foundation for future studies aimed at mosquito control, including genetic strategies that reduce mosquito survival or interfere with pathogen transmission.
“This platform allows us to move beyond one-gene-at-a-time studies,” Smith said. “It enables unbiased discovery, which is exactly what we need if we want to develop innovative approaches to combat mosquito-borne diseases like malaria.”
The study represents a collaborative effort between Iowa State University and Harvard Medical School and underscores Iowa State’s growing role in cutting-edge vector biology research with global public health relevance.