Table I

Intracellular Distribution of DLP1 in Rat Liver Hepatocytes In Situ*

Compartments examined (n)Labeling density‡
No. gold/profile areaNo. gold/profile perimeter
Golgi stacks§ (87)3.32
ER tubular networks‖ (381)8.31
Mitochondria/Peroxisomes (159)1.89
Golgi cisternae¶ (27)0.19
ER cisternae¶ (29)0.51
Bile Canalicular/Lateral0.20
 Plasma Membranes¶ (45)
Mitochondrial/Perixisomal0.06
 Membranes¶ (14)
  • n, no. of micrograph.  

  • *  Rat liver cryosections were imunolabeled with rabbit anti-DLP1 (DLP-N) followed by goat anti–rabbit IgG–gold (10 nm). 35 micrographs of hepatocyte sections (final magnification, 36000×) were evaluated for gold particle labeling density in the indicated compartments.  

  •  Labeling density was evaluated by dividing the total number of gold particles over a particular compartment (e.g., Golgi stacks) by the total profile area of that compartment (in μm2) or total profile membrane perimeter length (μm). Only gold particles within 20 nm of membranous profiles (for Golgi and ER profiles) were scored.  

  • §  This compartment consists of stacks of Golgi apparatus.  

  •  Consists of long continuous cisternae, 30–50 nm in thickness (rough ER) and membranous tubular reticular profiles in the cytoplasm (smooth ER) and at the periphery of Golgi stacks.  

  •  In a second quantitative analysis, gold particle labeling was determined per membrane length of compartments whose delimiting membrane is clearly visualized on cryosections (i.e., individual Golgi and ER cisternae, the bile canalicalicular and lateral plasma membranes, mitochondrial outer membrane, and peroxisomal membrane). DLP1 is predominantly found along rough ER cisternae and vesicular tubular membranes of smooth ER around the Golgi apparatus.