Genesis of the project
I retired to Saltspring Island, BC, in July 2012. Since then, through the kind courtesy of Dr. Justene Tedder, I have been given space to set up a small laboratory at the Gulf Islands Veterinary Clinic. The Department of Biology at the University of Alberta have most kindly allowed me to have, on extended loan, some of my former laboratory equipment and sundry supplies. I placed an announcement in the local newspaper and on the island's e-mail exchange list that I am willing to remove ticks from the pets of island residents, and thus have access to experimental ticks. The response so far has been very good indeed!
A little bit about ticks
Ticks as a group are able to transmit a number of diseases, Lyme disease (LD) being the one best known in North America. The most common tick species on Salt Spring (Ixodes pacificus) is a potential transmitter of LD (most tick species are not). A non-technical consideration of the relationship between ticks and Lyme disease is presented here: http://canlyme.com/lyme-basics/. Those interested in pursuing aspects of Lyme Disease in greater depth should navigate the website of the Canadian Lyme Disease Foundation: http://canlyme.com/
My research focus on ticks
The main project we are pursuing involves measuring the mechanical properties of the cuticle ("outer skin"). The tick's cuticle faces a challenge: it is the supportive skeleton of the tick, but it also must expand enormously to enable the female to increase 100-fold in size during her blood meal! We think that the tick softens its cuticle to enable expansion, and then restores its original strength. We are exploring the mechanism by which it does this: we are thinking along the lines that the nerve supply to the cuticle controls the softening that makes the stretching process easier. If so, such information could lead to the discovery of drugs that might inhibit the process. Such a drug might inhibit feeding, which in turn would likely inhibit transmission of tick-borne disease agents.
I began this project on an African tick during a sabbatical leave at the University of Bath (2007-08), and continued it since then at the U of A, collaborating with Prof. emeritus, Peter Flynn, a colleague from the Mechanical Engineering Department. For a more technical understanding of what we've discovered about the tick cuticle in recent years, refer to this publication on the synthesis of cuticle during the feeding period, and to this publication on the changes in mechanical properties during the feeding period and the effects of some drugs on those mechanical properties. Here on Salt Spring we are able to continue our research using a tick species that is known to transmit LD (Ixodes pacificus).
The following paper extends our knowledge of the mechanical properties of the cuticle reported originally in 2010, using much improved experimental methods (Flynn & Kaufman, 2015). And this one demonstrates that the tick is able to create the incredibly high internal hydrostatic pressure needed to expand the cuticle during the last day of engorgement (Kaufman, Kaufman & Flynn, 2016). Until now, the highest systolic blood pressure recorded in any animal was ~350 mm Hg (the giraffe). Now the record for the highest internal pressure recorded on the planet is held by the African tick, Amblyomma hebraeum, (~ 500 mm Hg)!!
And now, finally in 2018, we have published our first paper from the work carried out since 2012 at the Gulf Islands Veterinary Clinic (Kaufman & Flynn, 2018). The paper basically compares the mechanical properties of Ixodes pacificus cuticle with those described earlier for Amblyomma hebraeum. It's interesting that the differences observed between the two species were largely predicted from the huge difference in body size: I. pacificus is only one-tenth the weight of A. hebraeum.
Saltspringers have been supplying us with more ticks than we are able to use for our cuticle experiments (after all, I am supposed to have retired!). But not a single tick I collect goes to waste. Janet Sperling is pursuing her doctorate in the Department of Biological Sciences on some major tick-borne diseases, including LD. Janet is hoping to produce a detailed inventory of the bacteria and viruses associated with these ticks, and hopes to learn how they interact with each other. All ticks in excess of what we are able to use are sent to Janet for her tick project. So far, Janet has found that ticks have about 100 distinct types of bacteria associated with them. Probably only a minority of these bacteria are nasty (!), but some of them may be able to prevent other disease-causing bacteria from making us ill.
If you would like further information on any of the foregoing, please contact me at: firstname.lastname@example.org
Last Modified:2016-06-27 |