image: Male Aedes aegypti. view more
Credit: Image credit: Jieyan Chen and Craig Montell.
Researchers used CRISPR/Cas9 to produce sterile male Aedes aegypti mosquitoes, thereby reducing female fertility. The sterile insect technique aims to reduce female insect fertility by inundating wild populations with sterile males. However, the technique has had limited success with Ae. aegypti mosquitoes, which spread dengue and other diseases, partly due to the use of sterility-inducing radiation, which mutates genes randomly and impairs the health of male mosquitoes. Craig Montell and colleagues used CRISPR/Cas9 to generate a mutation that targets the testes and fertility of male Ae. aegypti. Examining a collection of genes that were previously identified in Drosophila melanogaster and are expressed in the testes of Ae. aegypti and implicated in male fertility, the authors homed in on the candidate gene B2t. The authors knocked out B2t using CRISPR/Cas9 and established gene-edited male mosquito lines. Single-pair matings between gene-edited males and virgin wild-type females yielded no progeny, and the seminal vesicles of the gene-edited males were devoid of sperm. Results from cage assays suggested that exposure to 15 gene-edited males reduced female fertility to 2.6 ± 1.6%, even if the females later copulated with wild-type males. Pre-exposure to an average of 5.6 gene-edited males reduced female fertility by 50%. According to the authors, the introduced mutation allows the mutant males to compete with wild-type males and reduce female fertility.
Article #2021-05075: "Suppression of female fertility in Aedes aegypti with a CRISPR-targeted male-sterile mutation," by Jieyan Chen, Junjie Luo, et al.
MEDIA CONTACT: Craig Montell, University of California, Santa Barbara, CA; tel: 443-570-4705; email: craig.montell@lifesci.ucsb.edu
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Journal
Proceedings of the National Academy of Sciences