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Biology subjects

McGann, E.

Publications and source records attributed to McGann, E..

2 recordsLinked to original sources

The longevity effects of reduced IGF-1 signaling depend on the stability of the mitochondrial genome

Suppression of insulin-like growth factor-1 (IGF-1) signaling extends mammalian lifespan and protects against a range of age-related diseases. Surprisingly though, we found that reduced IGF-1 signaling fails to extend the lifespan of mitochondrial mutator mice. Accordingly, most of the longevity pathways that are normally initiated by IGF-1 suppression were either blocked or blunted in the mutator mice. These observations suggest that the pro-longevity effects of IGF-1 suppression critically depend on the integrity of the mitochondrial genome and that mitochondrial mutations may impose a hard limit on mammalian lifespan. Together, these findings deepen our understanding of the interactions between the hallmarks of aging and underscore the need for interventions that preserve the integrity of the mitochondrial genome.

molecular biology↗

The fidelity of transcription in human cells

Accurate transcription is required for the faithful expression of genetic information. To provide insight into the molecular mechanisms that control the fidelity of transcription, we analyzed the landscape of transcription errors in human embryonic stem cells. These measurements provide the first reasonable estimate of the fidelity of transcription in human cells and identify multiple genetic and epigenetic factors that control its accuracy. In addition, we developed a new reporter mouse to identify cell types and tissues that commit these errors the most. These experiments revealed that CA1 and dentate gyrus neurons are highly sensitive to transcriptional mutagenesis, lending new support to the hypothesis that transcription errors play a role in the progression of Alzheimers disease. Taken together, these experiments provide unprecedented insight into the fidelity of gene expression in human cells and the molecular mechanisms that govern the central dogma of life.

genetics↗