PUBLICATION

Lbx2 regulates formation of myofibrils

Authors
Ochi, H., and Westerfield, M.
ID
ZDB-PUB-090217-39
Date
2009
Source
BMC Developmental Biology   9: 13 (Journal)
Registered Authors
Ochi, Haruki, Westerfield, Monte
Keywords
none
MeSH Terms
  • Actin Cytoskeleton/metabolism
  • Animals
  • Embryo, Nonmammalian/metabolism
  • Gene Knockdown Techniques
  • Muscle Development*
  • Muscle Fibers, Fast-Twitch/metabolism
  • Muscle Fibers, Slow-Twitch/metabolism
  • Protein Structure, Tertiary
  • RNA, Messenger/metabolism
  • Repressor Proteins/chemistry
  • Repressor Proteins/genetics
  • Repressor Proteins/metabolism*
  • Zebrafish/embryology*
  • Zebrafish Proteins/chemistry
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism*
PubMed
19216761 Full text @ BMC Dev. Biol.
Abstract
BACKGROUND: Skeletal muscle differentiation requires assembly of contractile proteins into organized myofibrils. The Drosophila ladybird homeobox gene (lad) functions in founder cells of the segmental border muscle to promote myoblast fusion and muscle shaping. Tetrapods have two homologous genes (Lbx). Lbx1 functions in migration and/or proliferation of hypaxial myoblasts, whereas the function of Lbx2 is poorly understood. RESULTS: To elucidate the role of Lbx in vertebrate myogenesis, we examined Lbx function in zebrafish. Zebrafish lbx2 transcripts appear in newly formed paraxial mesoderm and become restricted to adaxial cells, precursors of slow muscle. Slow muscles lose lbx2 expression as they differentiate, while a subset of differentiating fast muscle cells transiently expresses lbx2. Fin and hyoid muscle express lbx2 later. In contrast, lbx1b expression first appears lateral to the somites at late segmentation stages and is later restricted to fin muscle. Morpholino knockdown of Lbx1b and Lbx2 suppresses hypaxial muscle development. Moreover, knockdown of Lbx2 results in malformation of muscle fibers and reduced fusion of fast precursors, although no obvious effects on induction or specification are observed. Expression of myofilament genes, including actin and myosin, requires the engrailed repressor domain of Lbx2. CONCLUSIONS: Our results elucidate a new function of Lbx2 as a regulator of myofibril formation.
Genes / Markers
Figures
Expression
Phenotype
Mutation and Transgenics
Human Disease / Model Data
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping
Errata and Notes