Cell Size |
small |
large |
small |
GATA4/6 |
185, 210 |
Cell Shape |
In situ: rod-shaped (4:1::L:W); cultured: stellate |
In situ and dissociated: rod-shaped (7:1::L:W) |
irregular/round |
ECM composition and patterning, mechanical load, ERK1/2 signaling |
184, 186, 190, 224 |
Sarcomere Alignment |
organized |
superbly organized |
disorganized |
cell shape, mechanical load, substrate stiffness |
190, 216, 217 |
Sarcomere Components |
TNNI1, MYH7, TTN-N2BA, EH-MYOM1,TNNT2 exon 5 inclusion |
TNNI3, MYH6, TTN-N2B, TNNT2 exon 5 exclusion |
variable |
Thyroid hormone; maturation related transcriptional programs are currently not well understood |
191–195, 221 |
Metabolism |
glycolysis |
oxidative phosphorylation |
Glycolysis |
PPAR signaling, greater oxygen availability after birth |
200, 205, 208 |
Mitochondria |
low number, small and round |
high number, large and ovoid, close proximity to myofibers |
ovoid, clustered around nucleus and cell periphery |
AMPK, PPAR signaling, Mitofusins 1 and 2 |
201–203 |
Proliferative Capacity |
high |
very low |
can proliferate for ~1month after contraction begins |
NRG1/ERBB2/4, YAP/TEAD, IGF2/IGF1R/PI3K/ERK, BMP10, WNT/β-catenin, NOTCH |
101, 103, 110, 115, 116, 159 |
Nucleus |
mononucleated |
multinucleated or polyploid |
mononucleated |
Proliferation regulators above |
101, 103, 110, 115, 116, 159 |
T-Tubules |
none |
extensive network |
none |
JPH2, BIN1 |
198, 199 |