Expressing and characterization of mLIN-41 in mouse early embryos and adult muscle tissues.

Heterochronical gene lin-41 plays an important role in regulate the timing of many decelopmental events in Caenorhabditis elegans. Mammalian developmental timing is poorly understood even though many tissues are under temporal control during development. The lin-41 homologues in mouse and chick has been isolated and its expression in developing limb buds and branchial arches has been reported by in situ (Kanamoto et al. in Dev Dyn 235:1142-1149, 2006; Lancman et al. in Dev Dyn 234:948-960, 2005; Schulman et al. in Dev Dyn 234:1046-1054, 2005), but the protein expression pattern in mouse adult tissue and embryo remained to be clarified. To help elucidate the expression of C. elegans lin-41 orthorlogs in mouse adult tissue and developmental embryo, lin-41 cDNA fragment was amplified from the mouse embryonic day 9.5(E9.5) mRNA and expressed in E. coli. The transcripts of mlin-41 and the protein level in mouse adult tissues and embryos from 9.5 to 13 days were detected by RT-PCR and western blot. RT-PCR and western blot showed the expression of mLIN-41 was detected in the mouse adult heart, muscle, and small intestine as well as in the day E9.5 to E12 embryos. Immuno-localization of mLIN-41 in the day E10.5 embryo revealed that mLIN-41 was present in the neuro-epithelium and epithelial tissue covering the first and second branchial arch, somites and mesoderm cells, limb buds as well as the gut epithelium. The expression of mLIN-41 represented the tissue-specific expression pattern. Immuno-precipitation combine with MALDI-TOF mass spectrometry was used to identify the potential proteins interacting with LIN-41. Five potential specific proteins were obtained for future identification in mouse.