A Critical Component of Meiotic Drive in Neurospora Is Located Near a Chromosome Rearrangement |
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Authors: | Austin M Harvey David G Rehard Katie M Groskreutz Danielle R Kuntz Kevin J Sharp Patrick K T Shiu Thomas M Hammond |
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Institution: | *School of Biological Sciences, Illinois State University, Normal, Illinois 61790;†Division of Biological Sciences, University of Missouri, Columbia, Missouri 65211 |
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Abstract: | Neurospora fungi harbor a group of meiotic drive elements known as Spore killers (Sk). Spore killer-2 (Sk-2) and Spore killer-3 (Sk-3) are two Sk elements that map to a region of suppressed recombination. Although this recombination block is limited to crosses between Sk and Sk-sensitive (SkS) strains, its existence has hindered Sk characterization. Here we report the circumvention of this obstacle by combining a classical genetic screen with next-generation sequencing technology and three-point crossing assays. This approach has allowed us to identify a novel locus called rfk-1, mutation of which disrupts spore killing by Sk-2. We have mapped rfk-1 to a 45-kb region near the right border of the Sk-2 element, a location that also harbors an 11-kb insertion (Sk-2INS1) and part of a >220-kb inversion (Sk-2INV1). These are the first two chromosome rearrangements to be formally identified in a Neurospora Sk element, providing evidence that they are at least partially responsible for Sk-based recombination suppression. Additionally, the proximity of these chromosome rearrangements to rfk-1 (a critical component of the spore-killing mechanism) suggests that they have played a key role in the evolution of meiotic drive in Neurospora. |
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Keywords: | meiosis meiotic drive genome sequencing and mapping selfish elements Spore killer |
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