The genes, proteins and structure of cilia, flagella and their parent organelles, centrioles and basal bodies, have been highly conserved from protists and lower plants to humans (but lost in fungi and higher plants) [Cavalier-Smith, 2002]. Pathologies involving cilia (and flagella) present an astonishing diversity of human diseases and developmental disorders affecting virtually every organ in the embryo and adult body [Fliegauf et al., 2007], including anosmia (loss of olfactory sensation), brain development & disease (hydrocephaly, myoclonic epilepsy), neurological abnormalities, obesity (in Bardet-Biedl Syndrome), respiratory diseases, polycystic kidney disease, retinitis pigmentosis (retinal disease), situs inversus (reversal of left-right body axis, heart on the right side), and male infertility (asthenozoospermia being the leading cause, world-wide). The importance of cilia stems from their dual, motile and sensory functions. Some cell types possess entirely sensory but non-motile cilia, whereas in other cell types the sensory functions are coupled to motile cilia. The universal feature of cilia is their 9-fold arrangement of doublet MTs, whose complexity revolves around the A-tubule. The nature of this complexity is not understood but it involves a specialized region of 3-protofilaments that contain a filament composed of the proteins tektins, which my laboratory discovered and characterized [Linck & Stephens, 2007; Setter et al., 2006]. The hypothesis concerning tektin function includes several concepts: (i) That tektin filaments stabilize doublet MTs, even during tubulin-turnover and motility; (ii) that they act as molecular rulers, determining the periodic binding sites of the effector molecules; and (iii) that they interact functionally with the effector molecules, forming load-bearing cables in A-tubules, critical for ciliary/flagellar propulsion. Moreover, the evidence strongly suggests that a tektin filament forms one of the 13 protofilaments of the A-tubule, contrary to the long-held dogma that all protofilaments of cilia are composed solely of tubulin. (iv) Finally, tektin sequences have been found to be powerful evolutionary markers: “Partitioned Bremer analysis, with mitochondrial cytochrome oxidase I and II, and nuclear wingless and elongation factor 1-a sequences, revealed Tektin to have the greatest utility for inferring relationships at the genus, tribe, and subfamily levels across the studied taxa . . . Tektin is arguably the most accurate single marker for inferring relationships among all taxa studied” [Whinnett et al., 2005; and Mallarino et al., 2005].

Students working in this lab can learn a variety of valuable skills, including protein biochemistry, immunochemistry, molecular biology, and light & electron microscopy.

Cavalier-Smith, T. (2002) Int J Syst Evol Microbiol 52, 297-354.
Fliegauf, M., Benzing, T., and Omran, H. (2007) Nat Rev Mol Cell Biol. 8, 880-893.
Linck, R.W., and Stephens, R.E. (2007) Cell Motil. Cytoskeleton 64, 489-495..
Setter, P.W., Malvey-Dorn, E., Steffen, W., Stephens, R.E., and Linck, R.W. (2006) Exp. Cell Res. 312, 2880-96.
Mallarino, R., Bermingham, E., Willmott, K.R., Whinnett, A., and Jiggins, C.D. (2005). Mol. Phylogenet. Evol. 34, 625-644.
Whinnett, A., Brower, A.V.Z., Lee, M.-M., Willmott, K.R., and Mallet, J. (2005). Ann. Ent. Soc. Am. 98, 873-886.