利用 CRISPR/Cas9 系统定向编辑黑腹果蝇Osiris24基因

Osiris基因在几丁质沉积过程中表达,可能参与昆虫表皮的发育。本研究利用CRISPR/Cas9 基因编辑系统对Osiris24基因进行编辑,进而观察Osiris24突变体果蝇的性状并且检测Osiris24的表达特征。在Osiris24第1外显子设计2个sgRNA靶位点,插入到pCFD4敲除载体骨架中,同时构建酵母Gal4蛋白序列的供体(donor)载体,将2个载体同时注射到nos-Cas9胚胎中获得G0代转基因果蝇。结果显示,G0代基因编辑阳性率为92.8%,Osiris24纯合突变体在胚胎或1龄幼虫期致死,杂合突变体未观察到可见表型。将阳性G0代雄虫与UAS-GFP雌虫杂交,检测不同龄期和不同组织GFP信号表达情况。结果发现,Osiris24在不同龄期幼虫中均有表达,幼虫期主要在体壁、气管、前肠和后肠高表达,蛹期主要在体壁和翅上表达,推测其在果蝇发育中发挥重要作用,本研究为深入探究Osiris基因功能提供了研究模型。

CRISPR/Cas9 Targeted Editing of Osiris24 in Drosophlia melanogaster

The gene expression of Osiris is coincident with the timing of chitin deposition. Osiris gene may be involved in the developmental regulation of insect cuticle. The objective of this study is to generate the gene-edited flies with Osiris24 by CRISPR/Cas9-mediated editing system to understand the traits of Osiris24 mutant flies and the expression pattern of Osiris24. Two sgRNA targeted sequences were designed according to the sequence of exon 1 of Osiris24 and inserted into pCFD4 vector backbone. A donor vector with Gal4 protein sequence was constructed. Above two plasmids were mixed and injected into nos-Cas9 fly embryos to generate G0 generation. The results showed that 92.8% G0 flies have Gal4 protein insert in genome. Homozygous mutants of Osiris24 were lethal at the embryonic stage or first-instar stage, and no visible phenotype was observed in heterozygous mutants. Osiris24 is expressed throughout larval and pupal stages. At the larval stage, Osiris24 is mainly expressed in the integument, foregut and hindgut, while Osiris24 is expressed in the integument and wings at the pupal stage. These results indicated that Osiris24 plays an important role in the development of Drosophila. This study provides a research model for in-depth exploration of Osiris gene function.