THE REGULATION OF PHYSIOLOGY AND IMMUNOLOGY BY TYROSINE HYDROXYLASE ON Litopenaeus vannamei

Tyrosine hydroxylase (TH) belongs to the biopterin-dependent aromatic amino acid hydroxylase enzyme family, and it represents the first and rate-limiting step in the synthesis of catecholamines that are required for physiological and immune process in invertebrates and vertebrates. A short alpha helix domain, a catalytic core, a regulatory domain, a phosphorylation site and two potential N-linked glycosylation sites included the cloned Litopenaeus vannamei TH (LvTH). LvTH expression was abundant in gill and haemocytes by quantitative real-time PCR. The TH mRNA expression and activity in both haemocytes and brain, and glucose level in haemolymph significantly increased in pathogen challenged and in hypothermal stressed shrimp. In addition, the immune responses and resistance were observed in TH silenced shrimp. In conclusion, the cloned LvTH in our current study is a neural TH appears to be involved in the physiological and immune responses of whiteleg shrimp, L. vannamei suffering stressful and infective stimulation.

Keywords: Tyrosine hydroxylase, Catecholamine, Litopenaeus vannamei, Hypothermal stress, Vibrio alginolyticus ,Gene silencing.