Bioinformatics. 2009 Jun 1; 25: 1466-1467
pySolo: a complete suite for sleep analysis in Drosophila
Giorgio F. Gilestro, Chiara Cirelli
pySolo is a multi-platform software for analysis of sleep and locomotor activity in Drosophila melanogaster. pySolo provides a user-friendly graphic interface and it has been developed with the specific aim of being accessible, portable, fast and easily expandable through an intuitive plug-in structure. Support for development of additional plug-ins is provided through a community website.
Availability: Software and documentation are located at http://www.pysolo.net. pySolo is a free software and the entire project is leased under the GNU General Public License.
Science. 2009 Apr 3;324(5923):109-12
Widespread Changes in Synaptic Markers as a Function of Sleep and Wakefulness in Drosophila
Gilestro GF, Tononi G, Cirelli C
Sleep is universal, strictly regulated, and necessary for cognition. Why this is so remains a mystery, though recent work suggests a link between sleep, memory, and plasticity. However, little is known about how wakefulness and sleep affect synapses. Using Western blots and confocal microscopy in Drosophila, we found that protein levels of key components of central synapses were high after waking and low after sleep. These changes were related to behavioral state rather than time of day and occurred in all major areas of the Drosophila brain. The decrease of synaptic markers during sleep was progressive and sleep was necessary for their decline. Thus, sleep may be involved in maintaining synaptic homeostasis altered by waking activities.
PLoS ONE. 2008;3(11):e3798. Epub 2008 Nov 24.
Redundant mechanisms for regulation of midline crossing in Drosophila.
During development, all neurons have to decide on whether to cross the longitudinal midline to project on the contralateral side of the body. In vertebrates and invertebrates regulation of crossing is achieved by interfering with Robo signalling either through sorting and degradation of the receptor, in flies, or through silencing of its repulsive activity, in vertebrates. Here I show that in Drosophila a second mechanism of regulation exists that is independent of sorting. Using in vitro and in vivo assays, I mapped the region of Robo that is sufficient and required for its interaction with Comm, its sorting receptor. By modifying that region, I generated new forms of Robo that are insensitive to Comm sorting in vitro and in vivo, yet still able to normally translate repulsive activity in vivo. Using gene targeting by homologous recombination I created new conditional alleles of robo that are sorting defective (robo(SD)). Surprisingly, expression of these modified proteins results in phenotypically normal flies, unveiling a sorting independent mechanism of regulation.
Annu Rev Cell Dev Biol. 2006;22:651-75.
Regulation of commissural axon pathfinding by slit and its Robo receptors.
Barry J. Dickson, Giorgio F. Gilestro
Commissural axons grow along complex pathways toward, across, and beyond the midline of the central nervous system. Taking commissural axons in the vertebrate spinal cord and the Drosophila ventral nerve cord as examples, we examine how commissural axon pathfinding is regulated by the Slit family of guidance cues and their Robo family receptors. We extract several principles that seem likely to apply to other axons and other contexts, such as the reiterative use of the same guidance molecules in distinct pathfinding decisions, the transcriptional specification of a pathway, the posttranscriptional regulation of growth along the pathway, and the possible role of feedback mechanisms to ensure the fidelity of pathfinding choices. Such mechanisms may help explain how a relatively small number of guidance molecules can generate complex and stereotyped wiring patterns. We also highlight the many gaps in our understanding of commissural axon pathfinding and question some widely accepted views. We hope that this review encourages further efforts to tackle these questions, in the expectation that this system will continue to reveal the general principles of axon pathfinding.