E,F) Representative electron microscopy images of cross sections of femoral quadriceps nerves. (E) Nerves from Ttll1-/- and Ccp1-/-Ttll1-/- mice show no abnormalities of myelinated axons (green asterisks), indicating that loss of TTLL1 prevents axonal degeneration caused by the absence of CCP1. (F) Ccp1-/- and Ccp1-/-Ttll7-/- mice both show the presence of foamy macrophages (magenta arrowheads), which are signs for myelin phagocytosis during axon degeneration. This indicates that loss of TTLL7 cannot prevent the CCP1-induced degeneration of femoral quadriceps nerves. 