ZFIN ID: ZDB-PUB-170604-1
Cx43 suppresses evx1 expression to regulate joint initiation in the regenerating fin
Dardis, G., Tryon, R., Ton, Q., Johnson, S.L., Iovine, M.K.
Date: 2017
Source: Developmental dynamics : an official publication of the American Association of Anatomists   246(9): 691-699 (Journal)
Registered Authors: Iovine, M. Kathryn, Johnson, Stephen L.
Keywords: gap junction, interzone, skeletal regeneration, zebrafish
MeSH Terms:
  • Animal Fins/embryology
  • Animal Fins/metabolism
  • Animals
  • Connexin 43/genetics
  • Connexin 43/metabolism*
  • Gene Expression Regulation, Developmental/drug effects
  • Gene Expression Regulation, Developmental/genetics
  • Homeodomain Proteins/genetics
  • Homeodomain Proteins/metabolism*
  • In Situ Hybridization
  • Morphogenesis/genetics
  • Morphogenesis/physiology
  • Tacrolimus/pharmacology
  • Zebrafish
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism*
PubMed: 28577298 Full text @ Dev. Dyn.
How joints are correctly positioned in the vertebrate skeleton remains poorly understood. From our studies on the regenerating fin, we have evidence that the gap junction protein Cx43 suppresses joint formation by suppressing the expression of the evx1 transcription factor. Joint morphogenesis proceeds through at least two discrete stages. First, cells that will produce the joint condense in a single row on the bone matrix ("initiation"). Second, these cells separate coincident with articulation of the bone matrix. We propose that Cx43 activity is transiently reduced prior to joint initiation.
We first define the timing of joint initiation with respect to regeneration. We next correlate reduced cx43 expression and increased evx1 expression with initiation. Through manipulation of cx43 expression, we demonstrate that Cx43 negatively influences evx1 expression and joint formation. We further demonstrate that Cx43 activity in the dermal fibroblasts is required to rescue joint formation in the cx43 mutant, short finb123 .
We conclude that Cx43 activity in the dermal fibroblasts influences the expression of evx1, and therefore the differentiation of the precursor cells that give rise to the joint-forming osteoblasts. Developmental Dynamics 246:691-699, 2017. © 2017 Wiley Periodicals, Inc.