Yale: Genes from a common bacterium can be harnessed to sterilize male
insects, a tool that can potentially control populations of both
disease-bearing mosquitoes and agricultural pests, researchers at Yale
University and Vanderbilt University report in related studies published
Feb. 27 in two Nature journals. The studies highlight the
peculiar reproductive role of Wolbachia bacteria, which are found in the
testes and ovaries of most insect species. Eggs fail to develop when
fertilized by infected males, a process called cytoplasmic
incompatibility. However, when females are also infected with Wolbachia,
healthy embryos can develop.
In research published in the
journals Nature and Nature Microbiology, Yale and Vanderbilt researchers
report finding two genes encoded by Wolbachia that when introduced into
fruit flies can completely sterilize male insects. The sterility is
triggered by a specific enzyme mechanism operating in the sperm and
embryo, Yale researchers report in the journal Nature Microbiology. The
discovery may allow public health officials to control the size of
insect populations by introducing sterile males into the wild.
“Females
inseminated by these males only lay dead eggs,” said Yale’s John
Beckmann, a postdoctoral researcher in the Department of Molecular
Biophysics and Biochemistry, lead author of the paper in Nature
Microbiology, and contributing author of a related paper published in
the journal Nature. “If the sterilized males are released into problem
areas we can eliminate insect populations.”
Wolbachia, however, is
not found in some insects — most notably Aedes aegypti mosquitoes,
which are the primary transmitters of diseases such as Zika and dengue
fever. Understanding the molecular mechanisms of Wolbachia’s effect on
reproduction may help researchers produce sterile male Aedes by direct
insertion of the genes. When released into the wild, these males could
help control mosquito populations, said Mark Hochstrasser, the Eugene
Higgins Professor of Molecular Biophysics and Biochemistry and professor
of molecular, cellular, and developmental biology and senior author of
the Nature Microbiology paper.
Yale’s Judith Ronau is co-lead
author of the Nature Microbiology paper. Vanderbilt’s Seth Bordenstein
is senior author of the Nature research.
The work was funded by the National Institute of Food and Agriculture and the National Institutes of Health.