Conserved form and function of the germinal epithelium through 500 million years of vertebrate evolution.

The germinal epithelium, i.e., the site of germ cell production in males and females, has maintained a constant form and function throughout 500 million years of vertebrate evolution.

Alterations of digestive enzyme activities, intestinal morphology and microbiota in juvenile paddlefish, Polyodon spathula, fed dietary probiotics.

The effects of dietary supplementation of probiotics on digestive enzymes activities, intestinal morphology and microbiota in juvenile paddlefish (Polyodon spathula) were studied. A total of 400 fish were reared in two cages and fed with a basal diet (control group, CG) or diet supplemented with commercial probiotics (treatment group, TG) for 80 days. Enzymes activities analysis indicated that protease and α-amylase activities increased (P < 0.