Melanocortin-4 receptor in swamp eel (Monopterus albus): Cloning, tissue distribution, and pharmacology.

Melanocortin-4 receptor (MC4R) plays critical roles in the regulation of various physiological processes, such as energy homeostasis, reproduction and sexual function, cardiovascular function, and other functions in mammals. Although the functions of the MC4R in fish have not been extensively studied, the importance of MC4R in regulation of piscine energy expenditure and sexual functions is emerging. Swamp eel (Monopterus albus) is an economically and evolutionarily important fish widely distributed in tropics and subtropics.

Molecular characterization of trypsinogens and development of trypsinogen gene expression and tryptic activities in grass carp (Ctenopharyngodon idellus) and topmouth culter (Culter alburnus).

This study examined the gene structures and expression of trypsinogens, as well as the trypsin activities of the grass carp Ctenopharyngodon idellus (herbivorous) and the topmouth culter Culter alburnus (carnivorous), which are commercially important freshwater species of the family Cyprinidae in China. Isolated full-length trypsinogen cDNA clones were 869 bp and 857 bp. The deduced amino acid sequences were 242aa and 247aa long, both containing the highly conserved residues essential for serine protease catalytic and conformational maintenance.

[Effects of starvation on digestive enzyme activities of Monopterus albus].

Starvation is a major environmental stress, which has a broad effect on the physiology and ecology of aquatic animals. In this study, Monopterus albus was starved for 30 days at (20 +/- 0.5) degrees C, and the activities of protease, trypsin, amylase and lipase in its digestive organs were measured on the 0, 3rd, 5th, 10th, 15th, 20th, and 30th day of starvation.