Molecular Cloning of Twist Gene and its Expression in Golden Pompano Trachinotus ovatus (Linnaeus 1758) Larvae at Different Water Temperatures

The twist gene in golden pompano Trachinotus ovatus larvae was cloned and analyzed in this study. in the first 18 days the expression of twist during larval fish ontogeny was explored, then on 18 day post hatch (DPH) the expression of twist in fish tissues was evaluated. Subsequently, the response of twist to water temperatures of 23, 26, and 29oC was compared on 12 DPH and 18 DPH. The cDNA sequence length of the twist gene in golden pompano is 880 bp with an open reading frame of 507 bp. The twist gene encodes 168 amino acids and has a calculated molecular weight of 18.93 kDa and a theoretical isoelectric point of 9.14. After hatching, the expression of twist increased with fish age, and peaked at 3 and 4 DPH. The highest expression of twist in fish tissue occurred in the spleen and stomach, followed by the brain and kidney on 18 DPH. On 12 DPH, the highest expression of twist was observed in fish reared at 26oC, and lowest expression was observed in fish reared at 29oC. On 18 DPH, the expression of twist was not significantly affected by the rearing temperatures. This study identified the gene expression of twist at the early developmental stage of golden pompano; the time dependent expression of twist in fish larvae may improve knowledge of bone ontogeny and formation in fish larvae.