Expression of the Growth Hormone Gene during Early Development of Tiger Shovelnose Catfish (Pseudoplatystoma Fasciatum Linnaeus, 1766)

Abstract

The early development stage of fish is crucial in fish farming, especially catfish species with cannibal characteristics, such as the Tiger Shovelnose Catfish (Pseudoplatystoma fasciatum Linnaeus 1766). Growth plays an essential role in fish’s life, which is influenced by the mechanism of growth hormone (GH). This study analyzed the level of growth hormone (GH) gene expression at several early developmental stages of Tiger Shovelnose Catfish. Samples were taken from an embryo, three days post hatched (dph) larvae to 60 dph juvenile. Isolation of mRNA was carried from the pituitary gland located at the head of the fish. Gene expression analysis was performed using RT-PCR method that compared GH/b-actin genes from band thickness. The results of the analysis showed the highest expression at 60 dph juvenile. The most significant increase in GH gene expression occurred from the egg to three dph larvae (P < 0.05), then decreased to 20 dph juvenile. The increased phenotypic growth was seen from the increased length and weight at 45 dph juveniles. This indicates the amount of growth hormone released at the juvenile stage of 20 dph, thus triggering rapid growth in the next stage at 45 dph juvenile. Growth hormones can act as growth biomarkers in Tiger Shovelnose Catfish. The novelty of this study was to determine the level of GH gene expression in Pseudoplatystoma fasciatum ornamental fish as the object of research. Suggestions for further research to explore genes related to growth mechanisms through transcriptomic and proteomic technologies.