A novel marker for terminal Schwann cells, homocysteine-responsive ER-resident protein, as isolated by a single cell PCR-differential display

Single molecule transcription profiling with AFM

Established techniques for global gene expression profiling, such as microarrays, face fundamental sensitivity constraints. Due to greatly increasing interest in examining minute samples from micro-dissected tissues, including single cells, unorthodox approaches, including molecular nanotechnologies, are being explored in this application. Here, we examine the use of single molecule, ordered restriction mapping, combined with AFM, to measure gene transcription levels from very low abundance samples. We frame the problem mathematically, using coding theory, and present an analysis of the critical error sources that may serve as a guide to designing future studies. We follow with experiments detailing the construction of high density, single molecule, ordered restriction maps from plasmids and from cDNA molecules, using two different enzymes, a result not previously reported. We discuss these results in the context of our calculations.

Lysophospholipid receptors are differentially expressed in rat terminal Schwann cells, as revealed by a single cell rt-PCR and in situ hybridization

Terminal Schwann cells (TSCs) that cover motor neuron terminals, are known to play an important role in maintaining neuromuscular junctions, as well as in the repair process after nerve injury. However, the molecular characteristics of TSCs remain unknown, because of the difficulties in analyzing them due to their paucity. By using our previously reported method of selectively and efficiently collecting TSCs, we have analyzed the difference in expression patterns of lysophospholipid (LPL) receptor genes (LPA1, LPA2, LPA3, S1P1, S1P2, S1P3, S1P4, and S1P5) between TSCs and myelinating Schwann cells (MSCs). LPL, which includes lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P), is the bioactive lipid that induces a myriad of cellular responses through specific members of G-protein coupled receptors for LPA. It turned out that LPA3 was expressed only in TSCs, whereas S1P1 was expressed in TSCs and skeletal muscle, but not in MSCs. Other types of LPL receptor genes, including LPA1, S1P2, S1P3, S1P4, were expressed in both types of Schwann cells. None of the LPL receptor gene family showed MSCs-specific expression.

Spatiotemporal patterns of Musashi1 expression during inner ear development

Musashi1 (Msi 1) is an RNA binding protein associated with asymmetric cell divisions in neural progenitor cells. To investigate the involvement of Msi1 in the inner ear development, we studied the expression of Msi1 in mouse inner ears with RT-PCR and immunohistochemistry. Immunohistochemistry revealed that Msi1 was expressed in all otocyst cells at embryonic day (E) 10 and 12. Msi1 immunoreactivity became lost in hair cells after E14 in vestibule and after E16 in cochlea, whereas it persisted in supporting cells until adulthood. The subcellular localization of Msi1 changed from "cytoplasmic predominance" to "nuclear predominance" during the first 2 weeks after birth. The present data suggested that Msi may play a role in inner ear development.