title: Modulation of gene expression during early stages of reconnection of the turtle spinal cord.
abstract: The spinal cord of the freshwater turtle Trachemys dorbignyi regenerates after complete transection (Rehermann et al. J. Comp. Neurol. 515, 2009, 197-214). This remarkable ability may be related to the persistence around the central canal (CC) of progenitors functionally clustered via connexin 43 (Cx43) that express brain lipid binding protein (BLBP) and the transcription factor Pax6 (Russo et al. J. Neurosci. 28, 2008, 8510-8516). Indeed, because BLBP+ cells appear in the bridge joining the rostral and caudal stumps, we speculated that progenitors contacting the central canal may play a key part in spinal cord regeneration. To test this hypothesis, we designed degenerated primers pairing conserved regions for key proteins synthesized in progenitors (BLBP, Cx43, and Pax6) and the neuronal protein HuB. Fragments of these proteins were amplified, cloned, and sequenced. Based on these sequences, we analyzed the changes in the expression levels using quantitative real-time RT-PCR with specific primers, comparing the injured spinal cord at different times after injury (4, 12, 20, and 60 days) with uninjured spinal cords. We found a transient, early increase of BLBP, Cx43 and HuB mRNA, with Pax6 remaining unchanged. These results suggest that the selected genes--active in progenitor cells--play an important part in early mechanisms of spinal cord regeneration.
authors.affiliation: Neurofisiología Celular y Molecular. Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay.
authors.forename: Gabriela
authors.initials: G
authors.lastname: García
authors.forename: Gabriela
authors.initials: G
authors.lastname: Libisch
authors.forename: Omar
authors.initials: O
authors.lastname: Trujillo-Cenóz
authors.forename: Carlos
authors.initials: C
authors.lastname: Robello
authors.forename: Raúl E
authors.initials: RE
authors.lastname: Russo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005136:Eye Proteins; D020869:Gene Expression Profiling; D018398:Homeodomain Proteins; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D058953:Neural Stem Cells; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D060888:Real-Time Polymerase Chain Reaction; D012097:Repressor Proteins; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013116:Spinal Cord / Q000473:pathology; D013119:Spinal Cord Injuries / Q000235:genetics*; D058630:Spinal Cord Regeneration / Q000235:genetics*; D014426:Turtles / Q000235:genetics*
chemical_list: D005136:Eye Proteins; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins