Graduate Student Bios
Title: PhD student, Integrative Biosciences
Office: ASEC E512
In general, I am interested in evolutionary ecology of terrestrial invertebrates, but with a biophysics twist (biomechanics, color ecology, etc.) Currently, my research focuses on two aspects of spider silk:
1) Silk plasticity: The properties of spider silk (e.g. strength, extensibility) vary both between species and within species. Even within one individual, silk exhibits daily variation. I am interested in this variation: What triggers it? What mechanisms are responsible for it?
2) Supercontraction: Unlike most natural material, spider silk "shrinks" greatly (by up to 50%) when exposed to water. This ability is termed "supercontraction". Supercontracted silk is also more elastic than non-supercontracted silk. I am interested in the mechanisms and functions of supercontraction. Is it due to the unique chemical composition of silk? Why has it been selected for? What are the consequences of supercontraction for whole-web function?
2005: M.S. Biology. Université François Rabelais, Tours, France. Thesis: "Imperfect mimicry of crab spiders (Araneae: Thomisidae): observations in the lab and biochemical basis of mimicry". Advisor: Pr. Jérôme Casas.
2004: B.S. Biology. Université des Sciences et Technologies de Lille, Lille, France.
Spider silk has gathered much attention because of its exceptional combination of strength and extensibility. However, there is still a lack of research on the evolutionary and ecological aspects of silk. I am interested in the evolution of silk. There are two main axis to my research:
1) Silk plasticity
The properties (e.g. strength, extensibility) of one type of silk can vary from day to day within one individual. However, the mechanisms, causes, role of this variation are unknown. I thought this variation may be somewhat adaptive, and studied silk plasticity within cobwebs of the common house spider. I found that silk changes depending on spider feeding regime, although I am unsure whether it is an adaptation to the prey (stronger silk for stronger prey) or a response to spider condition (hungry spiders do not have the energy to make strong silk) (Boutry & Blackledge, 2008). I also found that silk vary within the web itself, in ways that may improve web function (Boutry & Blackledge, 2009). Finally, I investigated one potential mechanism of variation: the presence of a valve within the spider's spinning duct. Comparison of silk plasticity between spiders with and without this valve, shows that this valve is probably involved in control of silk property (Boutry, Řezáč and Blackledge, submitted).
"Supercontraction" is the large shrinking (up to half its length) of silk fibers exposed to water. This unique ability has important consequences both for exploitation of spider silk by the industry, but also, probably, for spiders themselves. Moreover, supercontracted silk's properties differ from non-supercontracted silk's. Several hypotheses have been proposed for supercontraction's mechanisms and functions, but these hypotheses have not been tested. I tested them through a large phylogenetic survey, suggesting that supercontraction is due to the presence of a certain amino acid motif in silk, and serves a "tailoring" function (Boutry & Blackledge, in press). Further research involves the consequences of supercontraction for whole-web function.
Boutry & Blackledge, 2008. The common house spider alters the material and mechanical properties of cobweb silk in response to different prey. Journal of Experimental Zoology. 309A: 542-552
Boutry & Blackledge, 2009. Biomechanical variation of silk links spinning plasticity to spider web function. Zoology. 112: 451-460
Boutry & Blackledge, in press. Evolution of supercontraction in spider silk: structure-function relationship from tarantulas to orb-weavers. Journal of Experimental Biology.