This web page was produced as an assignment for Genetics 677, an undergraduate course at UW-Madison
Gene Expression and Microarrays
GEO is an online resource for gene expression data. I used GEO to search find information about the expression of SMN1 in different situations. I was able to find thousands of experiments that related to spinal muscular atrophy and SMN1 when searched separately, however only one study investigated the gene expression of SMN1 in a way that related to spinal muscular atrophy. In the words of Corti et al. the experiment was an “analysis of neuromuscular degeneration mutant (nmd) spinal cords transplanted with ALDHhiSSClo neural stem cells. nmd is a model for spinal muscular atrophy with respiratory distress type 1. Results provide insight into the mechanisms underlying neuromuscular improvements in stem cell recipients.”1 Although the study did not examine spinal muscular atrophy in particular, it gave insight into the expression of SMN1 in neuromuscular degeneration mutants. There is no need to study the expression of SMN1 in a spinal muscular atrophy patient because it should be non-functioning and thus not expressed.
The experiment was performed on mice and shows that SMN1 was much more active in mice with nmd and even higher overall for stem cell recipients. This indicates that SMN1 is very important for those with neuromuscular impairments. This only helps to confirm what we already know and have been able to learn by linking a mutant SMN1 gene to spinal muscular atrophy.
Figure 1
Title.
This study used RNAi in human cells to study the effect on the SMN Complex(A complex formed by SMN with other proteins that functions in sm-protein binding and snRNP assembly). All of the proteins listed are involved in this complex and the bar in red indicates the protein that was inactivated by RNAi. The expression of the other proteins can then be noted.
References:
1. Corti S, Locatelli F, Papadimitriou D, Donadoni C et al. Transplanted ALDHhiSSClo neural stem cells generate motor neurons and delay disease progression of nmd mice, an animal model of SMARD1. Hum Mol Genet 2006 Jan 15;15(2):167-87. PMID
2. (Figure 1) NCBI. GEO retrieved April 26 2009 from http://www.ncbi.nlm.nih.gov/geo/gds/profileGraph.cgi?&dataset=VXAwQitzr&dataset=772c6abca$&gmin=65.500000&gmax=139.200000&absc=67523p1&gds=1468&idref=1426596_a_at&annot=Smn1
3. (Figure 2) Feng et al. Gemins modulate the expression and activity of the SMN Complex (2005) Human Molecular Genetics 14: 1605-1611
William Baader
[email protected]
Apr 26 2009
www.gen677.weebly.com
