A central process in connective tissue homeostasis is cell migration, which involves dynamic interactions between focal adhesions, the actin cytoskeleton and mitochondria, but the role of focal adhesion proteins in cell migration is not wholly defined. We examined focal adhesion-associated proteins from mouse fibroblasts and identified Flightless I (FliI) as a potential focal adhesion protein. We determined that FliI is distributed in the cytosol and co-localizes with actin monomers and mitochondria, but partially with paxillin. Biochemical assays showed that FliI associates with both actin monomers and short oligomers/filaments. Migration assay determined that cells with reduced FliI expression migrated more quickly and that FliI knockdown inhibited activation of β1 integrins. Consistent with these data, cell adhesion assay demonstrated that FliI knockdown cells were less adherent than wildtype cells. Our findings indicate that FliI may regulate cell migration by interacting with the actin monomers and the mitochondria to affect cell adhesion.

Most living eukaryotes are currently classified into one of five or six ‘supergroups’, which are in turn often divided between two assemblages: ‘unikonts’ and ‘bikonts’. This thesis explores the cytoskeletal morphology and phylogeny of three lineages that do not belong to any supergroup: ancyromonads, apusomonads, and breviates, likely relatives of supergroups Opisthokonta and Amoebozoa. It also investigates the phylogeny of malawimonads (basal members of supergroup Excavata) and collodictyonids (another unaffiliated lineage). Serial-section transmission electron microscopy was used to model the flagellar apparatus cytoskeletons of the ancyromonad Ancyromonas sigmoides, the breviate Breviata anathema, and the apusomonad Thecamonas trahens. Each has two main posterior microtubular roots and at least one anterior root (two in Ancyromonas). All three possess splitting posterior right microtubular roots and supernumerary singlets, features also characteristic of basal members of the supergroup Excavata (‘typical excavates’). One peripheral microtubule system in Ancyromonas, and the ‘right ribbon’ in Thecamonas, are likely homologous to dorsal fans in Breviata and ‘typical excavates’, and to the ‘r2’ root of myxogastrid Amoebozoa. One of the branches of the splitting root in Breviata and Thecamonas joins the right and intermediate roots, similarly to some myxogastrids. This implies that myxogastrids, and not the simpler pelobionts, represent the ancestral state for Amoebozoa. A phylogenomic analysis was performed focussing on apusomonads breviates, ancyromonads, and the problematic ‘typical excavate’ malawimonads, based on new transcriptomic data from Ancyromonas and an undescribed malawimonad. Rapid-site- removal analyses recover the ‘unikont’/‘bikont’ partition, and do not support the previously demonstrated affiliation between breviates and the ‘unikont’ supergroup Amoebozoa. Specifically, they group apusomonads with the ‘unikont’ supergroup Opisthokonta, and ancyromonads with breviates. Taxon-removal analyses group ancyromonads, breviates, and apusomonads together. Most analyses group malawimonads (perhaps with collodictyonids, another problematic group) between ‘unikonts’ and (other) ‘bikonts’, while other excavates are in a basal position amongst other ‘bikonts’. Combining these morphological and phylogenetic results suggests that splitting right roots, supernumerary intermediate singlets, and dorsal fans are found in multiple ‘basal’ lineages in both ‘unikont’ and ‘bikont’ portions of the eukaryotic tree, are likely characters of the last common ancestor of most or all living eukaryotes.

Pinus radiata is by far the dominant species grown in New Zealand plantations as a renewable source of wood. Several wood quality issues have been identified in the material produced, including the high incidence of compression wood, which is undesirable for end users. At present our understanding of the complex array of developmental processes involved in wood formation (which has a direct bearing on wood quality) is limited. Hence, the forest industry is interested in attaining a better understanding of the processes involved. Towards this goal, and for reasons of biological curiosity, the experiments described in this thesis were carried out to investigate several aspects of xylem cell development. In an in arbor study, changes in the orientation of cortical microtubules and cellulose microfibrils were observed in developing tracheids. Results obtained provide evidence that cortical microtubules act to guide cellulose synthase complexes during secondary wall formation in tracheids. The mechanisms involved in controlling cell wall deposition in wood cells are poorly understood, and are difficult to study, especially in arbor. A major part of this thesis involved the development of an in vitro method for culturing radiata pine wood in which hormone levels, nutrients, sugars and other factors, could be controlled without confounding influences from other parts of the tree. The method developed was used in subsequent parts of this thesis to study compression wood development, and the influence of the hormone gibberellin on cellulose microfibril organisation in the cell wall. Results from the in vitro compression wood experiments suggested that: 1. when a tree is growing at a lean, the developing cell wall was able to perceive compressive forces generated by the weight of the rest of the tree, rather than perceive the lean per se. 2. ethylene, rather than auxin, was involved in the induction of compression wood. Culture of stem explants with gibberellin resulted in wider cells, with steeper cortical microtubules, and correspondingly steeper cellulose microfibrils in the S2 layer of developing wood cells. This observation provides further evidence that the orientation of microtubules guides the orientation of cellulose microfibrils. Overall, the work described in this thesis furthers our knowledge in the field of xylem cell development. The stem culture protocol developed will undoubtedly provide a valuable tool for future studies to be carried out.

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 4 uppsatser.

Thesis (doctoral)--Karolinska Institutet, Stockholm, 1982. / Extra t.p. with thesis statement inserted. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph.D.)--University of Alberta, 2009. / Title from pdf file main screen (viewed on August 13, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy, Medical Sciences - Biomedical Engineering, University of Alberta." Includes bibliographical references.

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2010. / Härtill 3 uppsatser.

Thesis (Ph.D.)--University of Alabama at Birmingham, 2008. / Title from PDF title page (viewed on July 14, 2010). Includes bibliographical references

Thesis (doctoral)--Karolinska Institutet, Stockholm, 1982. / Extra t.p. with thesis statement inserted. Includes bibliographical references.