Tilapia growth hormone binds to a receptor in brush border membrane vesicles from the hepatopancreas of shrimp Litopenaeus vannamei

Abstract

Tilapia growth hormone (GH) was used to determine the presence of a presumed protein with GH receptor-like function in the hepatopancreas of shrimp L. vannamei and to evaluate its effect on growth of L. vannamei postlarvae. The receptor assay was performed using brush border membrane vesicles (BBMV) from the hepatopancreas of L. vannamei and the affinity constant was calculated by the dilution coordinates method. The shrimp postlarvae treated with tilapia GH were 42.4% heavier and 5.2% longer than the control group ( P < 0.05). On the other hand, the water content was lower in the postlarvae treated with GH (75.9%) than in the control group (77.3%) ( P < 0.05). Content of soluble proteins per mg of weight was 1.33 times higher in the GH-treated animals than control animals. No significant differences in survival rates were detected between the experimental groups. Tilapia GH was able to bind to a GH receptor-like protein on BBMV with an affinity constant of 1.30 ⁎ 10 8 M − 1 . In conclusion, a GH receptor-like protein was detected on vesicles from hepatopancreas of the shrimp L. vannamei. Also, it was established that the TiGH was able to enhance the growth of shrimp postlarvae. To our knowledge, this is the first report to demonstrate an interaction between a vertebrate growth hormone and a GH receptor-like protein of a crustacean.