Institute of Molecular Life Sciences, University of Zürich, Zürich, 8057, Switzerland.
Department of Biology, University of Naples Federico II, 80126, Napoli, Italy.
Sci Rep. 2017 Jul 4;7(1):4582. doi: 10.1038/s41598-017-04686-6.
The classic brown body (bwb) mutation in the housefly Musca domestica impairs normal melanization of the adult cuticle. In Drosophila melanogaster, a reminiscent pigmentation defect results from mutations in the yellow gene encoding dopachrome conversion enzyme (DCE). Here, we demonstrate that the bwb locus structurally and functionally represents the yellow ortholog of Musca domestica, MdY. In bwb Musca strains, we identified two mutant MdY alleles that contain lesions predicted to result in premature truncation of the MdY open reading frame. We targeted wildtype MdY by CRISPR-Cas9 RNPs and generated new mutant alleles that fail to complement existing MdY alleles, genetically confirming that MdY is the bwb locus. We further found evidence for Cas9-mediated interchromosomal recombination between wildtype and mutant bwb alleles. Our work resolves the molecular identity of the classic bwb mutation in Musca domestica and establishes the feasibility of Cas9-mediated genome editing in the Musca model.
家蝇（Musca domestica）中的经典棕色体（bwb）突变会损害成虫表皮的正常黑化。在果蝇（Drosophila melanogaster）中，黄色基因（编码多巴色素转化酶（DCE））的突变会导致类似的色素沉着缺陷。在这里，我们证明 bwb 基因座在结构和功能上代表了家蝇的黄色直系同源物 MdY。在家蝇 bwb 品系中，我们鉴定了两个含突变的 MdY 等位基因，这些突变预计会导致 MdY 开放阅读框过早截短。我们使用 CRISPR-Cas9 RNPs 靶向野生型 MdY，并产生了新的突变等位基因，这些突变等位基因不能互补现有的 MdY 等位基因，从遗传学上证实了 MdY 就是 bwb 基因座。我们进一步发现了 Cas9 介导的野生型和突变型 bwb 等位基因之间的染色体间重组的证据。我们的工作解决了家蝇中经典 bwb 突变的分子身份问题，并确立了 Cas9 介导的家蝇模型基因组编辑的可行性。
