37 research outputs found
An Integrated Strategy to Study Muscle Development and Myofilament Structure in Caenorhabditis elegans
A crucial step in the development of muscle cells in all metazoan animals is the assembly and anchorage of the sarcomere, the essential repeat unit responsible for muscle contraction. In Caenorhabditis elegans, many of the critical proteins involved in this process have been uncovered through mutational screens focusing on uncoordinated movement and embryonic arrest phenotypes. We propose that additional sarcomeric proteins exist for which there is a less severe, or entirely different, mutant phenotype produced in their absence. We have used Serial Analysis of Gene Expression (SAGE) to generate a comprehensive profile of late embryonic muscle gene expression. We generated two replicate long SAGE libraries for sorted embryonic muscle cells, identifying 7,974 protein-coding genes. A refined list of 3,577 genes expressed in muscle cells was compiled from the overlap between our SAGE data and available microarray data. Using the genes in our refined list, we have performed two separate RNA interference (RNAi) screens to identify novel genes that play a role in sarcomere assembly and/or maintenance in either embryonic or adult muscle. To identify muscle defects in embryos, we screened specifically for the Pat embryonic arrest phenotype. To visualize muscle defects in adult animals, we fed dsRNA to worms producing a GFP-tagged myosin protein, thus allowing us to analyze their myofilament organization under gene knockdown conditions using fluorescence microscopy. By eliminating or severely reducing the expression of 3,300 genes using RNAi, we identified 122 genes necessary for proper myofilament organization, 108 of which are genes without a previously characterized role in muscle. Many of the genes affecting sarcomere integrity have human homologs for which little or nothing is known
Recommended from our members
Failure of fluosol to influence the incidence of cerebral infarction or mortality in gerbils subjected to temporary carotid occlusion
Three hundred two gerbils were subjected to 2, 4, or 6 hours of temporary occlusion of the right common carotid artery. The animals were divided into four groups. The first two groups were given an infusion of Fluosol DA 20% (20 ml/kg) before arterial occlusion. One of these groups was kept in an environment of 100% oxygen during the time of occlusion and the other group was kept in room air. The two other groups of animals did not receive Fluosol. One of these groups was kept in 100% oxygen and the other group in room air during the time of arterial occlusion. The surviving animals were sacrificed 7 days later, and their brains were examined grossly and microscopically for evidence of cerebral infarction. There was a lesser incidence of early hemiparesis in the two groups treated with Fluosol, as well as in the untreated group that was kept in 100% oxygen. However, the incidence of infarction and the mortality were not significantly different in any of the groups