Functional characterization of the S. cerevisiae genome by gene deletion and parallel analysis.

The functions of many open reading frames (ORFs) identified in genome-sequencing projects are unknown. New, whole-genome approaches are required to systematically determine their function. A total of 6925 Saccharomyces cerevisiae strains were constructed, by a high-throughput strategy, each with a precise deletion of one of 2026 ORFs (more than one-third of the ORFs in the genome). Of the deleted ORFs, 17 percent were essential for viability in rich medium. The phenotypes of more than 500 deletion strains were assayed in parallel. Of the deletion strains, 40 percent showed quantitative growth defects in either rich or minimal medium.

[Cerebral glucose metabolism in schizophrenia. Studies using positron-emission tomography]. / Métabolisme cérébral du glucose dans la schizophrénie. Etudes par la tomographie à émission de positons.

Several studies using positron emission tomography with 18F-fluorodeoxyglucose (18F-FDG) have revealed functional hypofrontality in schizophrenia. However, frontal hypometabolism is not consistently found and is not specific to schizophrenia. Basal ganglia glucose hypermetabolism related to neuroleptic treatment has been demonstrated. Methodological and clinical differences between studies are discussed in this paper.