PUBLICATION

Tbx5a and Tbx5b paralogues act in combination to control separate vectors of migration in the fin field of zebrafish

Authors
Anderson, E.B., Mao, Q., Ho, R.K.
ID
ZDB-PUB-211111-6
Date
2021
Source
Developmental Biology   481: 201-214 (Journal)
Registered Authors
Ho, Robert K.
Keywords
Pectoral fin bud, tbx5a, tbx5b
MeSH Terms
  • Animal Fins/embryology*
  • Animals
  • Cell Movement*
  • Fibroblast Growth Factors/genetics
  • Fibroblast Growth Factors/metabolism*
  • Gene Knockdown Techniques
  • Signal Transduction*
  • Transcription Factors/genetics
  • Transcription Factors/metabolism*
  • Zebrafish/embryology*
  • Zebrafish/genetics
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism*
PubMed
34756968 Full text @ Dev. Biol.
Abstract
The T-box containing family member, TBX5, has been shown to play important functional roles in the pectoral appendages of a variety of vertebrate species. While a single TBX5 gene exists in all tetrapods studied to date, the zebrafish genome retains two paralogues, designated as tbx5a and tbx5b, resulting from a whole genome duplication in the teleost lineage. Zebrafish deficient in tbx5a lack pectoral fin buds, whereas zebrafish deficient in tbx5b exhibit misshapen pectoral fins, showing that both paralogues function in fin development. The mesenchymal cells of the limb/fin bud are derived from the Lateral Plate Mesoderm (LPM). Previous fate mapping work in zebrafish has shown that wildtype (wt) fin field cells are initially located adjacent to somites (s)1-4. The wt fin field cells migrate in opposing diagonal directions placing the limb bud between s2-3 and lateral to the main body. To better characterize tbx5 paralogue functions in zebrafish, time-lapse analyses of the migrations of fin bud precursors under conditions of tbx5a knock-down, tbx5b knock-down and double-knock-down were performed. Our data suggest that zebrafish tbx5a and tbx5b have functionally separated migration direction vectors, that when combined recapitulate the migration of the wt fin field. We and others have shown that loss of Tbx5a function abolishes an fgf24 signaling cue resulting in fin field cells failing to converge in an Antero-Posterior (AP) direction and migrating only in a mediolateral (ML) direction. We show here that loss of Tbx5b function affects initial ML directed movements so that fin field cells fail to migrate laterally but continue to converge along the AP axis. Furthermore, fin field cells in the double Tbx5a/Tbx5b knock-down zebrafish do not engage in directed migrations along either the ML or AP axis. Therefore, these two paralogues may be acting to instruct separate vectors of fin field migration in order to direct proper fin bud formation.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping