Project description:The conserved Mef2 transcription factor is a major regulator of gene expression and differentiation. Recent genomic studies have identified a large number of mef2-regulated target genes with distinct temporal expression profiles during Drosophila myogenesis. However, the question remains as to how a single transcription factor can control such diverse patterns of gene expression. The aim of this project was to investigate whether there are genes with different mef2-requirements for their expression during muscle differentiation in vivo during the development of Drosophila melanogaster. Experiment Overall Design: We used microarrays in conjunction with a mef2 allelic series to determine the gene expression profile in developing embryos at five different levels of mef2 activity. The allelic series extends from a null mutation, mef222.21, through to the control, via three hypomorphic alleles, mef2113, mef2424, and mef265. The series corresponds to different levels of Mef2 in the following order: control > 65 > 424 > 113 > 22.21. The control stock for the microarray analysis was dp cn a px sp, the stock used for the mutagenesis that produced mef265, mef2424 and mef2113. For the microarrays, 30 minute collections of control and mutant embryos for each mef2 allele were individually staged and pools of 150 embryos were then processed at mid stage 13. This corresponds to the early differentiation phase of muscle development and the expression of multiple muscle sarcomeric protein genes. Quadruplicate samples were assayed using Affymetrix® Genechips by the Flychip Drosophila microarray resource.
Project description:The conserved Mef2 transcription factor is a major regulator of gene expression and differentiation. Recent genomic studies have identified a large number of mef2-regulated target genes with distinct temporal expression profiles during Drosophila myogenesis. However, the question remains as to how a single transcription factor can control such diverse patterns of gene expression. The aim of this project was to investigate whether there are genes with different mef2-requirements for their expression during muscle differentiation in vivo during the development of Drosophila melanogaster. Keywords: allelic series comparison
Project description:In order to understand the chronic hypoxia (CH) effect upon the absence of dystrophin, Drosophila melanogaster wild type and the model for DMD (dmDys), in which all dystrophins expression was knocked out by iRNA, were exposed to high altitude hypoxia (hypobaric hypoxia) during a 16-day climbing period reaching the summit of Mount McKinley (6194 meters above sea level). Furthermore, dmDys and Drosophila wild type were exposed to normobaric hypoxia (hypoxic chamber) following the same oxygen levels observed during the climbing expedition and to normoxic conditions for comparison. Affymetrix GeneChip® profiling was performed for individual flies from each experimental group. CH-dmDys differentially expressed 1281 genes, whereas control group differentially expressed 57 genes. Eight heat shock protein genes detected in the CH-dmDys microarray study were down-regulated, instead of up-regulated as seen in wild type hypoxic flies. This result suggests a differential gene expression response to CH, which could affect muscle performance.These results suggest that dmDys is more sensitive to CH due to reduced muscle function and hypoxic stress response.
Project description:Genomewide mapping of D. melanogaster the muscle differentiation factor Mef2 protein binding during embryonic development. Five consecutive timepoints (2-4, 4-6, 6-8, 8-10, 10-12 hrs after egg-laying) were assayed in two independent repeats each. Two different antibodies were used to precipitate the Mef2 protein. Additionally the respective preimmune-serum was used as a control for every precipitation. The enriched DNA was hybridized to high density Affymetrix GeneChip Drosophila Tiling 1.0R array.
Project description:In order to understand the chronic hypoxia (CH) effect upon the absence of dystrophin, Drosophila melanogaster wild type and the model for DMD (dmDys), in which all dystrophins expression was knocked out by iRNA, were exposed to high altitude hypoxia (hypobaric hypoxia) during a 16-day climbing period reaching the summit of Mount McKinley (6194 meters above sea level). Furthermore, dmDys and Drosophila wild type were exposed to normobaric hypoxia (hypoxic chamber) following the same oxygen levels observed during the climbing expedition and to normoxic conditions for comparison. Affymetrix GeneChip® profiling was performed for individual flies from each experimental group. CH-dmDys differentially expressed 1281 genes, whereas control group differentially expressed 57 genes. Eight heat shock protein genes detected in the CH-dmDys microarray study were down-regulated, instead of up-regulated as seen in wild type hypoxic flies. This result suggests a differential gene expression response to CH, which could affect muscle performance.These results suggest that dmDys is more sensitive to CH due to reduced muscle function and hypoxic stress response. In order to understand the chronic hypoxia (CH) effect upon the absence of dystrophin, Drosophila melanogaster wild type and the model for DMD (dmDys), in which all dystrophins expression was knocked out by iRNA, were exposed to high altitude hypoxia (hypobaric hypoxia) during a 16-day climbing period reaching the summit of Mount McKinley (6194 meters above sea level). Furthermore, dmDys and Drosophila wild type were exposed to normobaric hypoxia (hypoxic chamber) following the same oxygen levels observed during the climbing expedition and to normoxic conditions for comparison. Affymetrix GeneChip® profiling was performed for individual flies from each experimental group. CH-dmDys differentially expressed 1281 genes, whereas control group differentially expressed 57 genes. Eight heat shock protein genes detected in the CH-dmDys microarray study were down-regulated, instead of up-regulated as seen in wild type hypoxic flies. This result suggests a differential gene expression response to CH, which could affect muscle performance.These results suggest that dmDys is more sensitive to CH due to reduced muscle function and hypoxic stress response. Overall design: Adults wild type and dystrophic flies (3-5 days old) were exposed to hypobaric hypoxia for two weeks during the summer expedition to Mount McKinley, Alaska (6194 MASL). Another set of wild types and dystrophic flies were exposed to normobaric hypoxia according to the table I obtained during the climbing expedition. During the expedition, the flies were maintained in vials with regular molasses and covered by thermo isolation to avoid low temperature, keeping the temperature at 25C. The experiment performed in the laboratory also used vials with regular molasses and at 25C. Table I. Expedition log book for mount McKinley ascent. Information obtained during the ascent and summit of Mount McKinley, June 1st to June 16th of 2007. The oxygen pressure (PO2) was calculated from the barometric pressure. GNB means go and back from the mentioned point. DAY In order to understand the chronic hypoxia (CH) effect upon the absence of dystrophin, Drosophila melanogaster wild type and the model for DMD (dmDys), in which all dystrophins expression was knocked out by iRNA, were exposed to high altitude hypoxia (hypobaric hypoxia) during a 16-day climbing period reaching the summit of Mount McKinley (6194 meters above sea level). Furthermore, dmDys and Drosophila wild type were exposed to normobaric hypoxia (hypoxic chamber) following the same oxygen levels observed during the climbing expedition and to normoxic conditions for comparison. Affymetrix GeneChip® profiling was performed for individual flies from each experimental group. CH-dmDys differentially expressed 1281 genes, whereas control group differentially expressed 57 genes. Eight heat shock protein genes detected in the CH-dmDys microarray study were down-regulated, instead of up-regulated as seen in wild type hypoxic flies. This result suggests a differential gene expression response to CH, which could affect muscle performance.These results suggest that dmDys is more sensitive to CH due to reduced muscle function and hypoxic stress response. In order to understand the chronic hypoxia (CH) effect upon the absence of dystrophin, Drosophila melanogaster wild type and the model for DMD (dmDys), in which all dystrophins expression was knocked out by iRNA, were exposed to high altitude hypoxia (hypobaric hypoxia) during a 16-day climbing period reaching the summit of Mount McKinley (6194 meters above sea level). Furthermore, dmDys and Drosophila wild type were exposed to normobaric hypoxia (hypoxic chamber) following the same oxygen levels observed during the climbing expedition and to normoxic conditions for comparison. Affymetrix GeneChip® profiling was performed for individual flies from each experimental group. CH-dmDys differentially expressed 1281 genes, whereas control group differentially expressed 57 genes. Eight heat shock protein genes detected in the CH-dmDys microarray study were down-regulated, instead of up-regulated as seen in wild type hypoxic flies. This result suggests a differential gene expression response to CH, which could affect muscle performance.These results suggest that dmDys is more sensitive to CH due to reduced muscle function and hypoxic stress response. Overall design: Adults wild type and dystrophic flies (3-5 days old) were exposed to hypobaric hypoxia for two weeks during the summer expedition to Mount McKinley, Alaska (6194 MASL). Another set of wild types and dystrophic flies were exposed to normobaric hypoxia according to the table I obtained during the climbing expedition. During the expedition, the flies were maintained in vials with regular molasses and covered by thermo isolation to avoid low temperature, keeping the temperature at 25C. The experiment performed in the laboratory also used vials with regular molasses and at 25C. Table I. Expedition log book for mount McKinley ascent. Information obtained during the ascent and summit of Mount McKinley, June 1st to June 16th of 2007. The oxygen pressure (PO2) was calculated from the barometric pressure. GNB means go and back from the mentioned point. DAY LOCATION ALTITUDE m PO2 mmHg (%) 1 Base Camp 2200 123.6 (16.3%) 2 Base Camp 2200 123.6 (16.3%) 3 Base Camp 2200 123.6 (16.3%) 4 Ski Hill 2400 120.7 (15.9%) 5 Kahiltna Pass 2950 113.0 (14.9%) 6 Motorcycle Hill 3350 107.7 (14.2%) 7 Motorcycle Hill 3350 107.7 (14.2%) 8 GNB from Motorcycle 4150 (5 hours) 97.7 (12.9%) 9 Medical Camp 4350 95.3 (12.5%) 10 GNB from Medical Camp 4150 (5 hours) 97.7 (12.9%) 11 Medical Camp 4350 95.3 (12.5%) 12 GNB from Medical Camp 4900 89.0 (11.7%) 13 Medical Camp 4350 95.3 (12.5%) 14 High Camp 5250 85.1 (11.2%) 15 Summit 6194 (0.3 hours) 75.4 (9.9%) 16 High Camp 5250 85.1 (11.2%)