Growth cone motility.

Neurons obtain their stereotyped morphologies and connections as a result of growth cone migration. In the past year, studies on growth cone migration and pathfinding have helped to define certain properties of cytoskeletal filaments and cell membranes that may be important in growth cone function. Antisense mRNAs have proved to be particularly useful for examining the roles of specific neurite proteins.

Reactivation of newt lung cilia: evidence for a possible temperature- and MgATP-induced activation mechanism.

Optimal conditions have been developed for the isolation and reactivation of highly coupled, demembranated ciliary axonemes from newt lungs [Hard, Cypher, and Schabtach, 1988, Cell Motil. Cytoskeleton 10:271-284]. In the present study, the motility of these cilia was further characterized by examining the effects of nucleotides, divalent cations, and temperature on beat frequency.

Identification of cytoskeletal, focal adhesion, and cell adhesion proteins in growth cone particles isolated from developing chick brain.

Growth cones are intimately involved in determining the direction and extent of neurite elongation during development. They are able to monitor their environment and respond to it by undergoing directed motility. We have isolated a fraction enriched in growth cone particles from embryonic chick brain.

Nerve growth cone motility.

Although many issues remain unresolved, the past year has witnessed a number of advances in our understanding of the inter-relationships between extracellular influences, cell phenotype, growth associated proteins, second messengers, and cytoskeletal components in the control of neurite outgrowth and growth cone behavior. Some of the early events associated with process initiation have been tentatively identified, and more is known about the assembly and stabilization of the microtubular framework of growing neurites. The mechanical forces involved in neurite extension have begun to be quantified, and interactions between the actin and microtubule systems are being further characterized.

Isolation and reactivation of highly-coupled newt lung cilia.

The paired lungs of the newt, Taricha granulosa, are simple, unbranched sacs, 3.5-5.0 cm in length.

Taxol-induced anaphase reversal: evidence that elongating microtubules can exert a pushing force in living cells.

The effects of taxol on mitosis in Haemanthus endosperm were studied. Immuno-gold staining was used to visualize microtubules; observations on microtubule arrangements were correlated with studies in vivo. Mitosis is slowed down, but not arrested, by taxol over a wide range of concentrations.