Figure 2.

Ultrastructure of posterior intestinal cells of hybrid yellow catfish fed with different glycinin levels under electron microscope. Intestinal villi from fish of control group showing neat arrangement (a). Posterior intestine from fish of 2% glycinin group have clear tight junctions between enterocytes, with abundant organelles (b). However, posterior intestine from fish of 4% glycinin group showing mild microvesicular vacuolation and intestinal villous striated margin shedding, as well as mitochondria damage (triangle) and broken tight junction (arrow) (c). Enterocytes from fish of 6% glycinin group displaying moderate vacuolation, with cytoplasmic transparency, as well as loose intestinal villi and broken tight junction (arrow) (d). Intestinal villi from fish of 8% glycinin group disorganized and enterocytes appearing serious vacuolation (e). Five-pointed star indicating fusion morphology of secondary lysosome and phagocytic vesicles. Vi, intestinal villi; Ti, tight junction; Nu, nucleus; Mi, mitochondria; Pe, peroxisome; Au, autolysosome; Va, vacuolation; Ly, lysosome. The scale represents 2 μm.