Figure 1.

The Expression Patterns of Vitamin K Cycle-Associated Proteins in Rats

(A) qPCR of GGCX, MGP, VKORC1, and VKORC1L1 mRNA in different tissues of adult WT rats.

(B) GGCX and MGP mRNA in the key postnatal stages (days 6–10 and weeks 3–12) of the rat epididymis. Results are means (±SD) of three rats in panels A and B.

(C) Immunoblot of GGCX and MGP proteins in the tissue lysates of the epididymis and kidney from WT rats. Arrows indicate the bands of expected size of GGCX (∼88 kDa) and MGP (∼12 kDa). Actin serves as the loading control. Note the additional band detected at ∼32 kDa by MGP antibody larger than its expected size, a characteristic of MGP-mediated calcium-dependent complex aggregation as described in this study.

(D and E) Immunolabeling of GGCX (D, red) and MGP (E, red) proteins in cryosections of the WT adult rat epididymis. CD, cauda epididymidis; CPS, corpus; CPT, caput; IS, initial segment. Clear cells are labeled for B1-VATPase in green. Nuclei and spermatozoa heads are labeled with DAPI in blue. (L), lumen. Scale bars, 20 μm.

(F) Higher magnification showing GGCX immunolabeling in the granular organelles of principal cells. Arrows: apical stereocilia or principal cells; asterisks: the cytoplasmic droplets of spermatozoa.

(G) Higher magnification showing the MGP-labeled vesicular structures (double arrows) at the head of spermatozoa near the apical domain of principal cells. Scale bars,10 μm in F and G.