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Regulation of motility of myogenic cells in filling limb muscle anlagen by Pitx2.
- Source :
-
PloS one [PLoS One] 2012; Vol. 7 (4), pp. e35822. Date of Electronic Publication: 2012 Apr 27. - Publication Year :
- 2012
-
Abstract
- Cells of the ventrolateral dermomyotome delaminate and migrate into the limb buds where they give rise to all muscles of the limbs. The migratory cells proliferate and form myoblasts, which withdraw from the cell cycle to become terminally differentiated myocytes. The myogenic lineage colonizes pre-patterned regions to form muscle anlagen as muscle fibers are assembled. The regulatory mechanisms that control the later steps of this myogenic program are not well understood. The homeodomain transcription factor Pitx2 is expressed specifically in the muscle lineage from the migration of precursors to adult muscle. Ablation of Pitx2 results in distortion, rather than loss, of limb muscle anlagen, suggesting that its function becomes critical during the colonization of, and/or fiber assembly in, the anlagen. Microarrays were used to identify changes in gene expression in flow-sorted migratory muscle precursors, labeled by Lbx1(EGFP/+), which resulted from the loss of Pitx2. Very few genes showed changes in expression. Many small-fold, yet significant, changes were observed in genes encoding cytoskeletal and adhesion proteins which play a role in cell motility. Myogenic cells from genetically-tagged mice were cultured and subjected to live cell-tracking analysis using time-lapse imaging. Myogenic cells lacking Pitx2 were smaller, more symmetrical, and had more actin bundling. They also migrated about half of the total distance and velocity. Decreased motility may prevent myogenic cells from filling pre-patterned regions of the limb bud in a timely manner. Altered shape may prevent proper assembly of higher-order fibers within anlagen. Pitx2 therefore appears to regulate muscle anlagen development by appropriately balancing expression of cytoskeletal and adhesion molecules.
- Subjects :
- Animals
Cell Differentiation
Cell Movement
Cell Polarity
Cell Size
Embryo, Mammalian
Gene Expression Profiling
Gene Regulatory Networks
Homeodomain Proteins metabolism
Limb Buds cytology
Mice
Mice, Transgenic
Muscle, Skeletal cytology
Time-Lapse Imaging
Transcription Factors metabolism
Homeobox Protein PITX2
Gene Expression Regulation, Developmental
Homeodomain Proteins genetics
Limb Buds metabolism
Muscle Development genetics
Muscle, Skeletal metabolism
Signal Transduction genetics
Transcription Factors genetics
Subjects
Details
- Language :
- English
- ISSN :
- 1932-6203
- Volume :
- 7
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- PloS one
- Publication Type :
- Academic Journal
- Accession number :
- 22558231
- Full Text :
- https://doi.org/10.1371/journal.pone.0035822