TEM images of en face sections from 3-week bovine corneal stroma fibroblasts cultivated in the culture medium supplemented with 1% FBS + 1% ITS (a, b, e) and 10% FBS (c, d). Panels (b) and (d) were taken at higher magnification at the same spot indicated by arrows in (a) and (c), respectively. Asterisks are used to indicate the presence of filopodia aligned in the same direction as surrounding collagen fibrils. Mitochondria (M), Golgi apparatus (G), residual bodies (R), and intracellular fibril bundles that may be actin or procollagen (arrowheads) are indicated in (e). Scale bars are 2 μm in (a–d) and 500 nm in (e).