title: Temporal expression pattern of Fkbp8 in rodent cochlea.
abstract: BACKGROUND
  FKBP8 is a multifunctional protein involved in many distinct processes like formation of central nervous system, viral RNA replication and inhibition of apoptosis. Fkbp8 expression was reported in different tissues, various cell lines and malignancies, in the latter displaying changes during carcinogenesis. Loss of Fkbp8 leads to substantial neurodegenerations during regular mouse development, thus hearing onset in mice could also potentially depend on Fkbp8 expression. Since Fkbp8 is crucial for patterning of neuronal function, we studied its expression during maturation of the rodent auditory function.
  
  
  METHODS
  Fkbp8 gene expression in rodent cochlear samples was studied by RT-PCR, qPCR, and western blot. Localization of Fkbp8 transcripts and protein was analyzed by in-situ hybridization and immunohistochemistry.
  
  
  RESULTS
  Studies of auditory organ demonstrate that Fkbp8 gene activity is increasing just before hearing onset and gradually decreasing after onset of hearing. Western blot analysis suggests substantial levels of Fkbp8 protein before hearing onset, and slow degradation after onset of hearing. The Fkbp8 mRNA is localized in spiral ganglion of cochlea but its distribution changes over time to the stria vascularis, a finding supported by immunohistochemistry staining. Additionally, in pre-hearing time Fkbp8-specific signal was also observed in the tectorial membrane, whose α- and β-Tectorin components show similar time-dependent expression of mRNA as Fkbp8.
  
  
  CONCLUSIONS
  These results indicate a temporal shift in expression of Fkbp8 which correlates with cochlear maturation, strongly suggesting a contribution of Fkbp8 to the onset of the rodent hearing processes.
authors.affiliation: University of Tübingen, Institute of Human Genetics, Tübingen, Germany. magdalena.zak1@gmail.com
authors.forename: Magdalena
authors.initials: M
authors.lastname: Zak
authors.forename: Andreas
authors.initials: A
authors.lastname: Bress
authors.forename: Markus
authors.initials: M
authors.lastname: Pfister
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Blin
mesh_terms: D000818:Animals; D003051:Cochlea / Q000378:metabolism* / Q000473:pathology; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D058851:GPI-Linked Proteins / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D006309:Hearing / Q000502:physiology; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D009925:Organ of Corti / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D013136:Spiral Ganglion / Q000378:metabolism / Q000473:pathology; D013316:Stria Vascularis / Q000378:metabolism / Q000473:pathology; D022021:Tacrolimus Binding Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors
chemical_list: D016326:Extracellular Matrix Proteins; C119437:Fkbp8 protein, mouse; D058851:GPI-Linked Proteins; D008565:Membrane Proteins; D012333:RNA, Messenger; C105350:Tecta protein, mouse; C512625:beta-tectorin, mouse; D022021:Tacrolimus Binding Proteins