Dr Alan Bowman

Research Overview

Varroa Mite Research

 A short video of the bee health crisis and our work is available here

The varroa mite (Varroa destructor) is the biggest global killer of honey bees.  The mite is an ectoparasite that sucks the blood from developing and adult bees whilst spitting viruses into the bee as well as immunosuppressants that render the bee more susceptible to normally benign bacteria and fungi.  Our lab works with DEFRA's National Bee Unit on several aspects of varroa research: (1) we have developed a method of gene knockdown in varroa that has potential as a control measure; (2) we have dissected out the "brain" of mites (not an easy task!!) and studied the genes expressed in that vital tissue by transcriptomics; (3) we have developed a method of collecting saliva from these tiny beasts and studied the effect of the saliva on insect immune cell function.

For full report on our gene knockdown see publicly available paper and as a pdf version.

Dietary Protection against Sea Lice

Sea lice remain major economic burden to the salmon aquaculture industry and have been implicated in wild salmon and sea trout stock declines. Various components in some salmon diets are reported to confer protection against sea louse infestation.  In a project funded by BioMar Ld, we aim to elucidate the underlying mechanism of this dietary protection employing next-generation sequencing and proteomics to assess changes in the transcriptome and proteome.

Employing semio-chemicals for sea louse control

Sea lice use semiochemicals ("smells") emanating from their preferred host for host location.  Conversely, the lice use semiochemicals from non-host fish species to avoid locating and settling on inappropriate hosts.  Funded by three industrial partners, our lab investigates the feasibility of moving semiochemical control approaches from the lab to the field.

Acaricide Targets:

Increased emergence of resistance to currently used acarcides ("tickicides"), together with the withdrawal of other aracicides, has necessitated the development of new acaricides.  We investigate the presence of new targets at the protein and gene level and the development of protocols for assessing their potential as targets for acaricides.  Transcriptome analysis of both salivary gland and synganglion ("brain") is performed to identify potential acaricide targets and these targets are then functionally characterised in hrterologous expression systems. Gene knockdown by double-stranded RNA-interference to "genetically validate" our putative targets is a useful approach in our studies

Water channels or Aquaporins: 

Cell membranes are, by default, impermeable to water.  Cells are rendered water-permeable by aquaporins or water-channels embedded in the membrane. Unsurprisingly, cells involved in the movement of large volumes of water have high levels of aquaporins.  Relatively little is known about aquaporins in invertebrates.  Our lab investigates aquaporins in ticks, earthworms and silkworms. We study the transport properties and regulation by the expression of aquaporins in frogs eggs and site-directed mutagenesis.   By depleting isolated tissues or whole animals of these aquaporins using RNA-interference "knock-down" we can study the functional role and importance of these aquaporins and, hence, genetically validate whether such aquaporins might be appropriate for drug development.

Fatty Acid Binding Proteins in Tick Salivary Glands: 

Tick salivary glands contain an intracellular fatty acid binding protein (FABP) postulated to play a role in arachidonate and eicosanoid metabolism. This project assesses the ligand binding characteristics of the recombinant tick FABP and investigates the regulation and localization of its expression.

Programmed Cell Death in Tick Salivary Glands: 

After adult ticks have fed on the host, the salivary glands are no longer needed and degenerate over the next few days. This project investigates the mechanisms of this deliberate and non-pathological process and studies the genes and proteins involved.

Immunomodulators in Tick Saliva: 

Ticks remain attached to the host for many days without eliciting an immune or inflammatory response capable of rejecting the tick. Compounds in the saliva suppress the host's inflammatory and immune response. This project investigates what these factors are and how they function.  

Collaborations

Sam Martin, University of Aberdeen

Stefan Hoppler, University of Aberdeen

Lucy Gilbert, Macaulay Institute

Ken Forbes, University of Aberdeen

David Sattelle, University of Oxford

Giles Budge, National Bee Unit, FERA

Elaine Richards, FERA, Sand Hutton, York

Funding and Grants

2014-2019: Veterinary Medicine Directive: Establishing off-host culturing methods for Varroa destructor as a tool to evaluate new veterinary medicines

2014-2018: EU-FP7 Sustainable Management of Resilient Bee Populations (SMARTBEES)

2014-2018: BBSRC EASTBIO with EARS2 PhD Studentship: How does deformed wing virus change as it passes between honey bees and Varroa?

2013-2017: Biosciences KTN BBSRC-CASE PhD Studentship with Pfizer Animal Health (now Zoetis) Drug target identification in the cat flea by transcriptomics and gene knockdown

2013-2017: Norwegian Research Council and Skretting Aquaculture Research, Norway PhD Studentship: Developing dietary protection against sea lice in the Atlantic salmon.

2012-2014: BBSRC-LINK (Industrial Partner: Vita Europe) : The potential of gene-knockdown for controlling varroa mites.

2012 – 2013: Meriden Animal Health: Assessing the potential and mode of action of essential plant oils on the sea louse, Lepeoptheirus salmonis

2011-2015: Raigmore Hospital, NHS PhD Studentship: Improving discriminatory specificity of patient diagnosis testing for early-, mid- and late-Lyme borreliosis

2011 Marine Harvest; Scottish Salmon Producers Organisation; Sainsbury's Supermarkets "Feasibility study of semiochemicals  for sea louse control"

2010/2014 BioMar Ltd "Understanding the molecular basis of dietary protection against sealice in Atlantic salmon: application of transcriptomics and proteomics"

2009 National Bee Unit, FERA "The Varroa mite: feasibilbity study of synganglion transcriptome analysis and gene knockdown"

2009 Genesis Faraday "The Varroa mite: feasibilbity study of synganglion transcriptome analysis and gene knockdown"

2009 CLSM Pump Priming Initiative "Gene knockdown in sea lice"

2008 Pfizer Animal Health "Functional characterisation of a nicotinic acetlycholine receptor from the dog tick, Rhipicephalus sanguineus"

2007 Evolutec plc "EST analysis of a Ixodes ricinus salivary gland"

2006/2007 Evolutec plc "Generation of a cDNA library from the salivary glands of Ixodes ricinus and its validation"

2006/2009 BBSRC, "Tick salivary gland aquaporins"

2006/2010 BBSRC-DTG CASE studentship with the Macaulay Institute "Lyme borreliosis in Scotland"

2006/2009 Evolutec plc / College of Life Sciences and Medicine studentship "Bioactive factors in the sheep tick, Ixodes ricinus"

2004/2007 BBSRC Committee studentship "Earthworm aquaporins"

2004/2007 BBSRC Industrial-CASE studentship (with Pfizer) "Drug targets in the tick synganglia"

2003/2006 NERC studentship (with CEH Banchory) "Ticks & pathogens in the Scottish Uplands)

2002/2005: BBSRC-CASE (with Pfizer) studentship, "Drug targets in tick salivary glands"

2002/2005: BBSRC, "Tick Fatty Acid Binding Proteins"

2001/2004: Leverhulme Trust, "Programmed Cell Death in Ticks"

2001/2003: Cunningham Trust, "Tick Salivary Immunomodulators"