Life Sciences Commons^™

Rnai-Mediated Gene Silencing In The Exotic Redbay Ambrosia Beetle, Xyleborus Glabratus, And Insect-Fungal Interactions Within The Laurel Wilt Complex, Morgan Christine Knutsen

Theses and Dissertations--Entomology

Laurel wilt disease (LWD) is a lethal vascular disease impacting lauraceous hosts caused by Harringtonia lauricola, the fungal symbiont of the redbay ambrosia beetle (Xyleborus glabratus Eichoff) (RAB) (Coleoptera: Curculionidae). LWD has caused tree mortality throughout the southeastern United States and is continuing to spread into new regions. Current management methods have not been successful in preventing spread, warranting investigation into innovative techniques including RNA interference (RNAi).

Elongation factor-1 alpha (ef1a) and actin (act) were established as stably expressed reference genes after exposing beetles to different photoperiod, temperature, and dsRNA exposure. After RAB oral …

Rna Interference For Emerald Ash Borer Suppression: Ecotoxicological Assessment And Delivery Methods, Flavia Pampolini

Theses and Dissertations--Entomology

The emerald ash borer (EAB), Agrilus planipennis (Coleoptera: Buprestidae), is a highly invasive phloem-feeding insect native to Asia. It has killed millions of ash trees (Fraxinus spp.) since its accidental introduction into North America, causing profound economic and ecological impacts. RNA interference (RNAi) or double-stranded RNA (dsRNA)-mediated gene silencing is an emerging biotechnology that is developing as an innovative tool for pest management. Exogenous dsRNA triggers the RNAi pathway, silences genes, and disrupts protein function, causing insect mortality. RNAi has proven effective in reducing target gene expression and causing mortality in EAB; however, two aspects stand as barriers …

Southern Pine Beetle-Specific Rna Interference Demonstrates No Effects On Nontarget Insects, Hannah Marie Hollowell

Theses and Dissertations--Entomology

The endemic southern pine beetle (SPB), Dendroctonus frontalis Zimmermann, is a highly destructive bark beetle that has devastated coniferous forests of the southern United States for decades. Traditional management strategies have been unable to respond effectively to largescale SPB outbreaks, prompting exploration of novel techniques including RNA interference (RNAi). Double-stranded RNAs (dsRNAs) are effective at triggering gene silencing and inducing mortality in SPB, but determining delivery methods and demonstrating specificity of the treatments is necessary before this technology may progress to deployment.

I evaluated three SPB-specific dsRNAs on model nontarget insects to assess potential lethal effects, sublethal effects such as …

The Mechanism Of Rna Interference In Arthropods, June-Sun Yoon

Theses and Dissertations--Entomology

RNA interference (RNAi) is a useful reverse genetics tool for investigation of gene function as well as for practical applications in many fields including medicine and agriculture. Due to the variability in RNAi efficiency, RNAi-based methods are currently being developed for controlling only coleopteran insects which are known to be amenable to RNAi. The first chapter of my thesis includes findings from research to investigate what are the factors that make coleopteran insects relatively more efficient in RNAi. I used Colorado potato beetle (CPB), Leptinotarsa decemlineata and its cell line (Lepd-SL1) as study models to identify genes that play key …