title: Analysis of connexin expression during mouse Schwann cell development identifies connexin29 as a novel marker for the transition of neural crest to precursor cells.
abstract: Connexins are transmembrane proteins forming gap junction channels for direct intercellular and, for example in myelinating glia cells, intracellular communication. In mature myelin-forming Schwann cells, expression of multiple connexins, i.e. connexin (Cx) 43, Cx29, Cx32, and Cx46 (after nerve injury) has been detected. However, little is known about connexin protein expression during Schwann cell development. Here we use histochemical methods on wildtype and Cx29lacZ transgenic mice to investigate the developmental expression of connexins in the Schwann cell lineage. Our data demonstrate that in the mouse Cx43, Cx29, and Cx32 protein expression is activated in a developmental sequence that is clearly correlated with major developmental steps in the lineage. Only Cx43 was expressed from neural crest cells onwards. Cx29 protein expression was absent from neural crest cells but appeared as neural crest cells generated precursors (embryonic day 12) both in vivo and in vitro. This identifies Cx29 as a novel marker for cells of the defined Schwann cell lineage. The only exception to this were dorsal roots, where the expression of Cx29 was delayed four days relative to ventral roots and spinal nerves. Expression of Cx32 commenced postnatally, coinciding with the onset of myelination. Thus, the coordinated expression of connexin proteins in cells of the embryonic and postnatal Schwann cell lineage might point to a potential role in peripheral nerve development and maturation.
authors.affiliation: Department of Neuroanatomy and Molecular Brain Research, Ruhr-University Bochum, D-44801 Bochum, Germany.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Hans-Werner
authors.initials: HW
authors.lastname: Habbes
authors.forename: Jürgen
authors.initials: J
authors.lastname: Eiberger
authors.forename: Klaus
authors.initials: K
authors.lastname: Willecke
authors.forename: Rolf
authors.initials: R
authors.lastname: Dermietzel
authors.forename: Carola
authors.initials: C
authors.lastname: Meier
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D015415:Biomarkers; D002454:Cell Differentiation / Q000502:physiology*; D019070:Cell Lineage / Q000502:physiology; D002478:Cells, Cultured; D018031:Connexin 43; D017630:Connexins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D017629:Gap Junctions / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009432:Neural Crest / Q000166:cytology / Q000378:metabolism*; D017933:Peripheral Nervous System / Q000166:cytology / Q000196:embryology* / Q000254:growth & development*; D012583:Schwann Cells / Q000166:cytology / Q000378:metabolism*; D013126:Spinal Nerve Roots / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D000097002:Gap Junction beta-1 Protein
chemical_list: D015415:Biomarkers; D018031:Connexin 43; D017630:Connexins; D009419:Nerve Tissue Proteins; D000097002:Gap Junction beta-1 Protein; C464673:Gje1 protein, mouse; C471698:connexin 43alpha1, mouse