The yeast Saccharomyces cerevisiae is a valuable model for unveiling the mechanisms of cellular aging in multicellular eukaryotes. Yeast aging can be slowed down by calorie restriction (CR), a low‐calorie dietary regimen that extends life span and delays age‐related disorders in a wide spectrum of organisms. To establish the mechanisms underlying the anti‐aging effect of CR, we assessed the effect of a CR diet and numerous mutations extending life span on the metabolic history and age‐dependent organelle dynamics of chronologically aging yeast. We found that yeast merge a number of cellular processes, which we call modules, into a metabolic longevity network. Our findings imply that 1) yeast establish a diet‐ and genotype‐specific configuration of the network by setting up the rates of the processes taking place within each of its modules; 2) the establishment of a network's configuration occurs before yeast enter a non‐proliferative state; and 3) different network's configurations established prior to entry into a non‐proliferative state define different rates of survival following such entry. Thus, by designing a specific configuration of the longevity network prior to reproductive maturation, yeast define their life span. We concluded that the chronological aging of yeast is an ontogenetic program. Implementing our knowledge, we identified five groups of novel anti‐aging small molecules that greatly extend yeast longevity by remodelling two key modules of the network.

We define the dynamics of spatial and temporal reorganization of the team of proteins and lipids serving peroxisome division in yeast. Overloading the peroxisome with soluble matrix proteins promotes the relocation of acyl‐CoA oxidase (Aox), an enzyme of fatty acid oxidation, from the matrix to the membrane. The binding of Aox to the membrane‐associated peroxin Pex16p greatly decreases the affinity between Pex16p and lysophosphatidic acid (LPA). This allows LPA to enter a two‐step biosynthetic pathway leading to the formation of phosphatidic acid (PA) and diacylglycerol (DAG). The accumulation of PA and DAG in the lumenal leaflet of the peroxisomal membrane is followed by the spontaneous movement of DAG from the lumenal to the cytosolic leaflet of the membrane bilayer and by the simultaneous translocation of phosphatidylserine in the opposite direction. The resulting bending of the membrane initiates the docking of a distinct protein complex to the surface of the peroxisome. This pre‐assembled in the cytosol protein complex consists of: 1) Vps1p, a dynamin‐like GTPase; 2) Sla1p, a protein that regulates actin cytoskeleton organization and dynamics; and 3) Abp1p, a protein that promotes F‐actin assembly. After its binding to the membrane‐associated peroxin Pex19p, the Vps1p‐Sla1p‐Abp1p complex interacts with Act1p, thereby recruiting this structural constituent of actin cytoskeleton to the surface of the peroxisome and promoting peroxisome division.

The CSLSR is a nationally registered non-profit organization created by life science students for fellow student researchers. We are dedicated to bringing together young student researchers at the undergraduate, graduate, postgraduate and professional levels to share upcoming scientific/health research and discoveries, and allow for furthering the knowledge amongst these future academics, clinicians, clinician-scientists and industry professionals in the life science fields. During the conference, we were honoured to welcome renowned scientist keynote speakers from both academia and industry. For a synopsis of the conference, and for more information on our upcoming events and student opportunities, please visit our website at www.cslsr.ca. On behalf of the executive and chapter representatives of the CSLSR, I would like to thank the Canadian Institutes of Health Research (CIHR)'s Institute of Infection and Immunity and Merck-Frosst for their support of this year's conference. We gratefully acknowledge McGill University for their support in our hosting of this year's conference at their institution. I would also like to personally congratulate the student oral and poster presentation award winners: Finally, we would like to thank all attendees, speakers, affiliates and sponsors from across the country for making this conference a great success. We look forward to seeing you in 2008. Heats shock cognate protein 70 accumulates in the nucleolus of HeLa cells during heat stress recovery. Influence of oral and subcutaneous bisphenol-A on intrauterine implantation of fertilized ova in inseminated female mice Lipid metabolism in peroxisomes, endoplasmic reticulum and lipid bodies controls chronological aging in yeast Breast cancer cells inhibit osteoblast differentiation. potlights on the DNA repair system in late spermatogenesis: stage-specific DNA fragmentation and activation of H2AX Characterization of CD11d leukocyte integrin surface expression I. Moheshwarnath and M. Bisaillon Probing into the GTP specificity of an mRNA capping enzyme Interleukin 33 (IL-33) in severe asthma and modulation of its expression in airway smooth muscle cell (ASMC) Biological activity of cross-linked intravenous immunoglobulins (IVIg) on human B cells Apoptosis in epithelial fetal lung cells exposed to stretching as a result of positive ventilation Caspase substrates screening by diagonal gel approach and study on caspase-1 substrates on glycolytic pathway Megakaryocytic cells expressing a peptide derived from a protein regulating the actin cytoskeleton, MTPG-24, exhibit an increased cell size ADAM12 effects on Dupuytren's Disease cell morphology and cytoplasmic beta catenin accumulation require Type I IGF receptor tyrosine kinase activity