short stop (shot) is required for sensory and motor axons to reach their targets in the Drosophila embryo. Growth cones in shot mutants initiate at the normal times, and they appear normal with respect to overall morphology and their abilities to orient and fasciculate. However, sensory axons are unable to extend beyond a short distance from the cell body, and motor axons are unable to reach target muscles. The shot gene encodes novel actin binding proteins that are related to plakins and dystrophin and expressed in axons during development. The longer isoforms identified are predicted to contain an N-terminal actin binding domain, a long central triple helical coiled-coil domain, and a C-terminal domain that contains two EF-hand Ca(2+) binding motifs and a short stretch of homology to the growth arrest-specific 2 protein. Other isoforms lack all or part of the actin binding domains or are truncated and contain a different C-terminal domain. Only the isoforms containing full-length actin binding domains are detectably expressed in the nervous system. shot is allelic to kakapo, a gene that may function in integrin-mediated adhesion in the wing and embryo. We propose that Shot's interactions with the actin cytoskeleton allow sensory and motor axons to extend.

This study examined relationships between important aspects of a university education and the assessment and development of generic skills. A sample of 323 students enrolled in single or double arts, engineering and/or science degrees from a researchintensive university in Australia were administered the Graduate Skills Assessment to measure four generic skills-critical thinking, interpersonal understandings, problem solving and written communication. As expected, students' grade point average was generally found to be significantly related to scores for all four skill scales both within each discipline area and across the total sample. Reporting of academic achievement through the GPA therefore provides some measure of students' generic skill levels. However, since relationships were modest, GPA should be considered an imperfect indicator of levels of generic skills attainment. In addition, we found only limited evidence that students' skill levels increased with progression through their studies, with study length being consistently related only to Problem Solving. Finally, our analyses revealed significant, interdisciplinary variations in students' skill scores. Results are discussed with respect to theoretical, practical and methodological implications.

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roundabout (robo) family genes play key roles in axon guidance in a wide variety of animals. We have investigated the roles of the robo family members, robo, robo2, and robo3, in the guidance of sensory axons in the Drosophila embryo. In robo(-/-), slit(-/-), and robo(-/+) slit(-/+) mutants, lateral cluster sensory neurons misproject to cells and axons in the nearby ventral' (v') cluster. These phenotypes, together with the normal expression pattern of Slit and Robo, suggest that Slit ligand secreted from the epidermis interacts with Robo receptors on lateral cluster sensory growth cones to limit their exploration of nearby attractive substrates. The most common sensory axon phenotype seen in robo2(-/-) mutants was misprojection of dorsal cluster sensory axons away from their normal growth substrate, the transverse connective of the trachea. slit appears to play no role in this aspect of sensory axon growth. Robo2 is expressed, not on the dorsal sensory axons, but on the transverse connective. These results suggest a novel, non-cell-autonomous mechanism for axon guidance by robo family genes: Robo2 expressed on the trachea acts as an attractant for the dorsal sensory growth cones.

The pattern of axon growth from the population of neurons that pioneers the major axon pathways in the central nervous system is highly conserved in winged insects. This study sought to determine whether the same pattern of axon growth is shared by an apterygotic insect, the silverfish. We have found that homologues to at least nine early differentiating winged insect neurons are present in the silverfish. The axon trajectories and the sequence of axon outgrowth from these neurons are very similar in silverfish and winged insects, suggesting that the pterygotic and apterygotic insects share a common developmental Bauplan for the construction of the central nervous system. Some of these neurons do show differences in several aspects of axon growth, including the relative timing of axonogenesis, the polarity of axon growth and the pattern of axon fasciculation. In addition, a major, early-appearing fascicle in the posterior commissure of the silverfish is pioneered by a neuron which does not appear to have an equivalent in the winged insects. These differences are similar in character to, albeit more pronounced than, differences previously reported between two winged insects, the fruitfly Drosophila and the grasshopper. Some of the features of early central axon growth, that set the silverfish embryo apart from the winged insects, are shared by crustacean embryos, providing support for the claim that insects and crustaceans share a common developmental Bauplan for the construction of central axonal pathways.