Selenoprotein N is dynamically expressed during mouse development and detected early in muscle precursors

Abstract

<p>Abstract</p> <p>Background</p> <p>In humans, mutations in the <it>SEPN1 </it>gene, encoding selenoprotein N (SelN), are involved in early onset recessive neuromuscular disorders, referred to as <it>SEPN1</it>-related-myopathies. The mechanisms behind these pathologies are poorly understood since the function of SelN remains elusive. However, previous results obtained in humans and more recently in zebrafish pointed to a potential role for SelN during embryogenesis. Using qRT-PCR, Western blot and whole mount <it>in situ </it>hybridization, we characterized in detail the spatio-temporal expression pattern of the murine <it>Sepn1 </it>gene during development, focusing particularly on skeletal muscles.</p> <p>Results</p> <p>In whole embryos, <it>Sepn1 </it>transcripts were detected as early as E5.5, with expression levels peaking at E12.5, and then strongly decreasing until birth. In isolated tissues, only mild transcriptional variations were observed during development, whereas a striking reduction of the protein expression was detected during the perinatal period. Furthermore, we demonstrated that <it>Sepn1 </it>is expressed early in somites and restricted to the myotome, the sub-ectodermal mesenchyme and the dorsal root ganglia at mid-gestation stages. Interestingly, <it>Sepn1 </it>deficiency did not alter somitogenesis in embryos, suggesting that SelN is dispensable for these processes in mouse.</p> <p>Conclusion</p> <p>We characterized for the first time the expression pattern of <it>Sepn1 </it>during mammalian embryogenesis and we demonstrated that its differential expression is most likely dependent on major post-transcriptional regulations. Overall, our data strongly suggest a potential role for selenoprotein N from mid-gestation stages to the perinatal period. Interestingly, its specific expression pattern could be related to the current hypothesis that selenoprotein N may regulate the activity of the ryanodine receptors.</p