Table 2.
Summary of included studies. Main characteristics and outcome.
| Study | Gene | Knockout or Overexpression | Fibre Type Analysis Procedure | Output Measure | Outcome (Relative to Wildtype) |
|---|---|---|---|---|---|
| [43] | Akirin1 | Knockout | MHC immunofluorescence MHC analysis |
Quadriceps Type 1 | ↓ |
| Quadriceps Type 2A | ↑ | ||||
| Quadriceps Myh7 1 | ↓ | ||||
| Quadriceps Myh2 2A | ↑ | ||||
| [44] | Bdkrb2 | Knockout | ATPase staining | Soleus % type 1 | ↑ |
| Soleus % type 2A | ↓ | ||||
| Soleus % type Intermediary | ↑ | ||||
| [45] | Bdnf | Knockout | MHC immunohistochemistry | TA % type 2X | ↑ |
| TA % type 2B | ↓ | ||||
| EDL % type 2X | ↑ | ||||
| EDL % type 2B | ↓ | ||||
| [46] | CamK4 | Knockout | MHC immunofluorescence | Soleus % type 1 | ↑ |
| Soleus % type 2A | ↓ | ||||
| Soleus % type other | ↓ | ||||
| [47] | Ccnd3 | Knockout | MHC immunostaining | TA % myofiber type 2A | ↑ |
| TA % myofiber type 2B | ↓ | ||||
| [48] | Cpt1a | Conditional knockout | MHC immunostaining | TA % type 2A | ↑ |
| [49] | FoxJ3 | Knockout | ATPase staining | EDL % type 1 | ↓ |
| Soleus % type 1 | ↓ | ||||
| [50] | Foxo1 | Overexpression | ATPase staining | Soleus number type 1 | ↓ |
| Soleus number type 2 | ↑ | ||||
| [51] | Mapk12 | Knockout | MHC immunostaining | Soleus % type 1 | ↑ |
| Soleus % type 2A | ↓ | ||||
| [52] | Mstn | Knockout | MHC immunostaining | Biceps femoris % type 1 | ↓ |
| Biceps femoris % type 2A | ↓ | ||||
| Biceps femoris % type 2B/X | ↑ | ||||
| TA % type 2A | ↓ | ||||
| TA % type 2B/X | ↑ | ||||
| [53] | MyoD1 | Knockout | MHC immunohistochemistry | EDL % Type 1 | ↑ |
| [54] | Nfatc1 | Conditional knockout | ATPase staining | Soleus number Type 1 | ↓ |
| [55] | Nol3 | Knockout | Immunofluorescence MHC | Soleus % type 1 | ↓ |
| Soleus % Type 2A | ↑ | ||||
| Plantaris % Type 2A | ↓ | ||||
| Plantaris % Type 2B | ↑ | ||||
| [32] | Ppargc1a | Overexpression | ATPase staining | Plantaris number Type 1 | ↑ |
| Plantaris number Type 2A | ↑ | ||||
| Plantaris number Type 2B | ↓ | ||||
| [56] | Thra | Knockout | ATPase staining | Soleus % Type 1 | ↑ |
| Soleus % Type 2A | ↓ | ||||
| Thrb | Soleus % Type 1 | ↓ | |||
| Soleus % Type 2A | ↑ | ||||
| [57] | Epas1 | Conditional Knockout | MHC analysis | Soleus number type 1 | ↓ |
| Soleus number type 2B | ↑ | ||||
| Soleus MHC 1 | ↓ | ||||
| Soleus MHC 2B | ↑ | ||||
| [58] | Esrrg | Conditional overexpression | MHC gene expression analysis | Gastrocnemius MHC 2A | ↑ |
| Gastrocnemius MHC 2B | ↓ | ||||
| [59] | Il15 | Conditional overexpression | MHC gene expression analysis | Soleus MHC 1 | ↑ |
| Soleus MHC 2A | ↓ | ||||
| Soleus a MHC 2X | ↓ | ||||
| EDL MHC 1 | ↑ | ||||
| EDL MHC 2X | ↑ | ||||
| Gastrocnemius MHC 1 | ↑ | ||||
| [60] | Ncor1 | Conditional knockout | MHC gene expression analysis | Gastrocnemius MHC 2A | ↑ |
| Gastrocnemius MHC 2X | ↑ | ||||
| Quadriceps MHC 1 | ↑ | ||||
| Quadriceps MHC 2A | ↑ | ||||
| Quadriceps MHC 2X | ↑ | ||||
| [61] | Ppargc1b | Conditional overexpression | MHC gene expression analysis | Gastrocnemius MHC 1 | ↓ |
| Gastrocnemius MHC 2X | ↑ | ||||
| Gastrocnemius MHC 2B | ↓ | ||||
| EDL MHC 1 | ↓ | ||||
| EDL MHC 2A | ↓ | ||||
| EDL MHC 2X | ↑ | ||||
| EDL MHC 2B | ↓ | ||||
| TA MHC 2A | ↓ | ||||
| TA MHC 2X | ↑ | ||||
| TA MHC 2B | ↓ | ||||
| [62] | Sirt3 | Conditional overexpression | Western blot | Quadriceps MHC 1 | ↑ |
| Quadriceps MHC 2B | ↓ | ||||
| [63] | Trib3 | Conditional overexpression | Electrophorese of MHC | Soleus MHC 1 | ↑ |
| Soleus MHC 2B | ↓ | ||||
| TA MHC 2B | ↓ | ||||
| [64] | Vgll2 | Knockout | qPCR MHC analysis | Soleus number type 2A | ↓ |
| Soleus number type 2B | ↑ | ||||
| Soleus Myh7 1 | ↓ | ||||
| Soleus Myh2 2A | ↓ | ||||
| Soleus Myh1 2X | ↑ | ||||
| Soleus Myh4 2B | ↑ | ||||
| [65] | Sirt1 | Conditional overexpression | ATPase staining and PCR MHC analysis | Gastrocnemius % Type 1 | ↑ |
| Gastrocnemius % Type 2 | ↓ | ||||
| Gastrocnemius MHC 2A | ↑ | ||||
| Gastrocnemius MHC 2X | ↑ | ||||
| Gastrocnemius MHC 2B | ↓ |
Legend ↑ Significantly increased proportion, concentration, or expression when compared to control. ↓ Significantly decreased proportion, concentration, or expression when compared to control. For more detail, see also Table S2 in the supplemental data.