Department of Genetics and Biochemistry and Center for Human Genetics, Clemson University, 114 Gregor Mendel Circle, Greenwood, SC 29646, USA.
Department of Biological Sciences, Program in Genetics, North Carolina State University, Raleigh, NC 27695, USA.
G3 (Bethesda). 2023 Feb 9;13(2). doi: 10.1093/g3journal/jkac307.
Insect odorant-binding proteins (OBPs) are members of a rapidly evolving multigene family traditionally thought to facilitate chemosensation. However, studies on Drosophila have shown that members of this family have evolved functions beyond chemosensation, as evident from their expression in reproductive tissues and the brain. Previous studies implicated diverse functions of Obp56h, a member of the largest gene cluster of the D. melanogaster Obp repertoire. Here, we examined the effect of CRISPR/Cas9-mediated deletion of Obp56h on 2 fitness phenotypes, on resistance to starvation stress and heat stress, and on locomotion and sleep phenotypes. Obp56h-/- mutants show a strong sexually dimorphic effect on starvation stress survival, with females being more resistant to starvation stress than the control. In contrast, Obp56h-/- females, but not males, are highly sensitive to heat stress. Both sexes show changes in locomotion and sleep patterns. Transcriptional profiling of RNA from heads of Obp56h-/- flies and the wildtype control reveals differentially expressed genes, including gene products associated with antimicrobial immune responses and members of the Turandot family of stress-induced secreted peptides. In addition, differentially expressed genes of unknown function were identified in both sexes. Genes encoding components of the mitochondrial electron transport chain, cuticular proteins, gene products associated with regulation of feeding behavior (Lst and CCHa2), ribosomal proteins, lncRNAs, snoRNAs, tRNAs, and snRNAs show changes in transcript abundances in Obp56h-/- females. These differentially expressed genes are likely to contribute to Obp56h-mediated effects on the diverse phenotypes that arise upon deletion of this OBP.
昆虫气味结合蛋白 (OBP) 是一个快速进化的多基因家族的成员，传统上被认为有助于化学感觉。然而，对果蝇的研究表明，该家族的成员已经进化出了超越化学感觉的功能，这从它们在生殖组织和大脑中的表达中可以明显看出。以前的研究表明，Obp56h 具有多种功能，Obp56h 是 D. melanogaster Obp 库中最大基因簇的成员之一。在这里，我们研究了 CRISPR/Cas9 介导的 Obp56h 缺失对 2 种适应度表型的影响，即对饥饿应激和热应激的抵抗力，以及对运动和睡眠表型的影响。Obp56h-/- 突变体对饥饿应激存活率表现出强烈的性别二态效应，雌性比对照更能抵抗饥饿应激。相比之下，Obp56h-/- 雌性而非雄性对热应激高度敏感。两性都表现出运动和睡眠模式的变化。Obp56h-/- 果蝇和野生型对照头部的 RNA 转录谱分析显示差异表达基因，包括与抗菌免疫反应相关的基因产物和应激诱导分泌肽 Turandot 家族的成员。此外，两性都鉴定出了功能未知的差异表达基因。编码线粒体电子传递链组件、角质蛋白、与调节摄食行为相关的基因产物 (Lst 和 CCHa2)、核糖体蛋白、lncRNA、snoRNA、tRNA 和 snRNA 的基因在 Obp56h-/- 雌性中显示出转录丰度的变化。这些差异表达基因可能有助于 Obp56h 介导的这种 OBP 缺失对多种表型的影响。
