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bioRxiv · 10.1101/2024.11.22.624848

A reference genome for Trichogramma kaykai: A tiny desert-dwelling parasitoid wasp with competing sex-ratio distorters

Culotta, J.·Lindsey, A. R. I.
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Abstract

The tiny parasitoid wasp Trichogramma kaykai inhabits the Mojave Desert of the southwest United States. Populations of this tiny insect variably host up to two different sex-distorting genetic elements: (1) the endosymbiotic bacterium Wolbachia which induces the parthenogenetic reproduction of females, and (2) a B-chromosome, "Paternal Sex Ratio" (PSR), which converts would-be female offspring to PSR-transmitting males. We report here the genome of a Wolbachia-infected Trichogramma kaykai isofemale colony KSX58. Using Oxford Nanopore sequencing we produced a final genome assembly of 203 Mbp with 45x coverage, consisting of 213 contigs with an N50 of 1.9 Mbp. The assembly is quite complete, with 91.41% complete BUSCOs recovered: a very high score for Trichogrammatids that have been previously characterized for having high levels of core gene losses. We also report a complete mitochondrial genome for T. kaykai, and an assembly of the associated Wolbachia, strain wTkk. We identified copies of the parthenogenesis-inducing genes pifA and pifB in a remnant prophage region of the wTkk genome. The Trichogramma kaykai assembly is the highest quality genome assembly for the genus to-date and will serve as a great resource for understanding the evolution of sex and selfish genetic elements.

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Culotta, J., Lindsey, A. R. I.. 2024-11-22. A reference genome for Trichogramma kaykai: A tiny desert-dwelling parasitoid wasp with competing sex-ratio distorters. https://doi.org/10.1101/2024.11.22.624848

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