Frontiers in Bioengineering and Biotechnology (Dec 2021)

The Potential for a Released Autosomal X-Shredder Becoming a Driving-Y Chromosome and Invasively Suppressing Wild Populations of Malaria Mosquitoes

  • Yehonatan Alcalay,
  • Silke Fuchs,
  • Roberto Galizi,
  • Federica Bernardini,
  • Roya Elaine Haghighat-Khah,
  • Douglas B. Rusch,
  • Jeffrey R. Adrion,
  • Matthew W. Hahn,
  • Matthew W. Hahn,
  • Pablo Tortosa,
  • Rachel Rotenberry,
  • Philippos Aris Papathanos

DOI
https://doi.org/10.3389/fbioe.2021.752253
Journal volume & issue
Vol. 9

Abstract

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Sex-ratio distorters based on X-chromosome shredding are more efficient than sterile male releases for population suppression. X-shredding is a form of sex distortion that skews spermatogenesis of XY males towards the preferential transmission of Y-bearing gametes, resulting in a higher fraction of sons than daughters. Strains harboring X-shredders on autosomes were first developed in the malaria mosquito Anopheles gambiae, resulting in strong sex-ratio distortion. Since autosomal X-shredders are transmitted in a Mendelian fashion and can be selected against, their frequency in the population declines once releases are halted. However, unintended transfer of X-shredders to the Y-chromosome could produce an invasive meiotic drive element, that benefits from its biased transmission to the predominant male-biased offspring and its effective shielding from female negative selection. Indeed, linkage to the Y-chromosome of an active X-shredder instigated the development of the nuclease-based X-shredding system. Here, we analyze mechanisms whereby an autosomal X-shredder could become unintentionally Y-linked after release by evaluating the stability of an established X-shredder strain that is being considered for release, exploring its potential for remobilization in laboratory and wild-type genomes of An. gambiae and provide data regarding expression on the mosquito Y-chromosome. Our data suggest that an invasive X-shredder resulting from a post-release movement of such autosomal transgenes onto the Y-chromosome is unlikely.

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