Project description:Investigation of whole genome gene expression level changes in C. elegans genes kin-1 and crh-1 mutant, compared to the wild-type strain. NimbleScan softwareM-bM-^@M-^Ys implementation of RMA offers quantile normalization and background correction. There are three steps of RMA: Firstly, background subtraction was performed using a local background estimator. Secondly, quantile normalization (Bioinformatics 2003; 19:185) at probe level was done to make the expression distributions the same for all arrays. Last, probe set summarization was performed using Robust Multichip Average (RMA) algorithm as described by Irizarry, et al. (Nucleic Acids Res. 2003; 31:e15 and Biostatistics 2003; 4:249). A nine chip study using total RNA recovered from three separate wild-type cultures of C. elegans and three separate cultures of kin-1 mutant, and three separate cultures of crh-1 mutant. The C. elegans 12 x 135K Gene Expression Array was manufactured by Roche NimbleGen. This array enables you to conveniently and simultaneously hybridize 12 samples on each slide. About 13,187 genes are collected from the authoritative data source including Wormbase.
Project description:Investigation of whole genome gene expression level changes in C. elegans genes kin-1 and crh-1 mutant, compared to the wild-type strain. NimbleScan software’s implementation of RMA offers quantile normalization and background correction. There are three steps of RMA: Firstly, background subtraction was performed using a local background estimator. Secondly, quantile normalization (Bioinformatics 2003; 19:185) at probe level was done to make the expression distributions the same for all arrays. Last, probe set summarization was performed using Robust Multichip Average (RMA) algorithm as described by Irizarry, et al. (Nucleic Acids Res. 2003; 31:e15 and Biostatistics 2003; 4:249).
Project description:Temperature is a prominent environmental stimulus that influences life span. Previous studies indicate that in Caenorhabditis elegans, thermosensory perception in the AFD neuron maintains life span at warm temperatures. How thermosensation is translated into neuronal signals that shape aging remains elusive. We found that the Caenorhabditis elegans CREB crh-1, as well as several key genes in AFD thermosensory transduction, were specifically required for normal life span at warm temperatures. crh-1 acted in the AFD to increase transcription of the CRE-containing neuropeptide gene flp-6 in a temperature-dependent manner. Both crh-1 and flp-6 were necessary and sufficient for longevity at warm temperatures, and their effects depended on the AIY interneuron. Moreover, flp-6 signaling downregulated ins-7/insulin and several insulin pathway genes, whose activity compromised life span. We postulate that temperature experience is integrated in the thermosensory neurons to generate CREB-dependent neuropeptide signals that antagonize insulin signaling and promote temperature-specific longevity.