QIMR Berghofer Medical Research Institute, Infectious Diseases Department, 300 Herston Road, Herston, Brisbane, 4006, Australia.
School of Veterinary Sciences, University of Queensland, Gatton, QLD, 4343, Australia.
Parasit Vectors. 2017 Jun 10;10(1):289. doi: 10.1186/s13071-017-2226-1.
Scabies is one of the most common and widespread parasitic skin infections globally, affecting a large range of mammals including humans, yet the molecular biology of Sarcoptes scabiei is astonishingly understudied. Research has been hampered primarily due to the difficulty of sampling or culturing these obligatory parasitic mites. A further and major impediment to identify and functionally analyse potential therapeutic targets from the recently emerging molecular databases is the lack of appropriate molecular tools.
We performed standard BLAST based searches of the existing S. scabiei genome databases using sequences of genes described to be involved in RNA interference in Drosophila and the mite model organism Tetranychus urticae. Experimenting with the S. scabiei mu-class glutathione S-transferase (SsGST-mu1) as a candidate gene we explored the feasibility of gene knockdown in S. scabiei by double-stranded RNA-interference (dsRNAi).
We provide here an analysis of the existing S. scabiei draft genomes, confirming the presence of a double stranded RNA (dsRNA) - mediated silencing machinery. We report for the first time experimental gene silencing by RNA interference (RNAi) in S. scabiei. Non-invasive immersion of S. scabiei in dsRNA encoding an S. scabiei glutathione S-transferase mu-class 1 enzyme (SsGST-mu1) resulted in a 35% reduction in the transcription of the target gene compared to controls.
A series of experiments identified the optimal conditions allowing systemic experimental RNAi without detrimental side effects on mite viability. This technique can now be used to address the key questions on the fundamental aspects of mite biology and pathogenesis, and to assess the potential therapeutic benefits of silencing S. scabiei target genes.
疥疮是全球最常见和广泛传播的寄生虫性皮肤感染之一，影响范围广泛，包括人类在内的多种哺乳动物都可能感染，但疥螨的分子生物学却惊人地研究不足。由于这些专性寄生螨难以采样或培养，研究主要受到阻碍。另一个主要障碍是，缺乏适当的分子工具，使得从最近出现的分子数据库中识别和分析潜在治疗靶点变得更加困难。
我们使用已描述的参与果蝇和螨类模式生物四纹豆芫菁 RNA 干扰的基因序列，对现有的疥螨基因组数据库进行标准 BLAST 搜索。我们以 S. scabiei mu 类谷胱甘肽 S-转移酶（SsGST-mu1）作为候选基因进行实验，探索双链 RNA 干扰（dsRNAi）在 S. scabiei 中进行基因敲低的可行性。
我们在此提供了对现有 S. scabiei 草图基因组的分析，证实了双链 RNA（dsRNA）介导的沉默机制的存在。我们首次报道了 S. scabiei 中的实验基因沉默通过 RNA 干扰（RNAi）。非侵入性地将 S. scabiei 浸入双链 RNA 编码 S. scabiei 谷胱甘肽 S-转移酶 mu 类 1 酶（SsGST-mu1）中，与对照相比，靶基因的转录减少了 35%。
一系列实验确定了允许系统实验 RNAi 的最佳条件，而不会对螨的活力产生不利的副作用。该技术现在可用于解决螨生物学和发病机制的基本方面的关键问题，并评估沉默 S. scabiei 靶基因的潜在治疗益处。
