Fig. 8

Subcellular localization of the mouse PRAMEX1 in spermatogenic cells by IEM. Heavy PRAMEX1 labeling (red arrows) was observed in the cement region of intermitochondrial cement (IMC) in spermatocytes (A). A low density of gold particles was seen in the nucleus (N) of spermatocytes (A) and round spermatids (B, C). In contrast, a high density of clustered labeling was seen in elongated spermatids (D, E). No labeling was observed in the acrosome granule (AG) and acrosome vesicle (AV) (B) and acrosome matrix (AM) (E), though a low to moderate density of PRAMEX1 labeling was clearly seen in the Golgi apparatus and acroplaxome (B). The heaviest labeling of PRAMEX1 was seen in the electron-dense materials surround mitochondria (M) of midpiece (MP) in lateral (F) and cross sections (G). Clusters of gold particles were also seen in the microtubules of axoneme (Axo) in the MP (F, arrowhead) and principal piece (PP) (H) and the end piece (EP) (H) of the flagellum. Gold particles were hardly detected in the negative control (I). Inserts enlarge the boxed regions (A–D, F, H). Scale bar = 1 µm