IDENTIFICATION OF GROWTH HORMONE GENE OF Pangasionodon hypophthalmus

Abstract

Identification of growth hormone (GH) gene in a target fish is the first step in the construction of “all fish genes transfer vector” to generate transgenic fish. The research was done to identify and characterize the GH gene of Pangasionodon hypophthalmus. There were several activities performed in identifying the GH gene: RNA extraction, cDNA synthesis, PCR amplification, and DNA fragment isolation. The characterizations were done using the nucleotide sequencing engine ABIPRISM 3100. The results were then analyzed using BLASTN/P and GENETYX version 7 program. The full-length GH gene of P. hypophthalmus was 1151 bp in length, coding for an open reading frame (ORF) of 603 bp. The 5’ and 3’ untranslated regions of the GH gene were 22 bp and 526 bp long, respectively. The GH gene of P. hypophthalmus had some common characteristics that are owned by GH genes, such as single tryptophan residue (W) on the 104th amino acid, 5 cysteine residues (C) on the amino acid 71, 135, 173, 190, and 198 and a motif of Asn-Xaa-Thr on C terminus which is the potential location for N-linked glycosilation. Polyadenylation signal (aataaa) was on the 14 bp at the upstream of polyadenylation location. Growth hormone of P. hypophthalmus consisted of over 200 amino acids from GH cDNA deduction. The highest proportion of amino acid composition was leusin (14%) while the lowest was tryptophan (0.5%).

ISOLATION AND IDENTIFICATION OF PARTIAL GROWTH HORMONE (GH) mRNA OF TIGER SHOVELNOSE CATFISH Pseudoplatystoma fasciatum (LINNAEUS, 1766)

“…The amplification of cDNA from tiger shovelnose catfish samples using b-actin primers indicates that the gene was successfully isolated from the pituitary gland and producing a single band. This is in line with Dewi et al (2009), using the b-actin gene as an internal control to confirm GH gene isolation in catfish (P. hypophthalmus).…”

“…GH grouper duck (Cromileptes altivelis) has 618 bp of GH gene sequence translated into amino acids into 205 amino acid codes consisting of 20 types of amino acids (Syarifudin et al, 2007). The composition of amino acids in Tiger shovelnose catfish was than giant grouper and striped catfish with 20 types of amino acids (Dewi et al, 2009;Syarifudin et al, 2007).…”

“…The characteristics of the GH gene from various species have different amino acid compositions produced. The growth hormone peptide of P. hypophthalamus has about 200 amino acid residues with 20 types contained therein (Dewi et al, 2009).…”

“…Although 234 nucleotides were initially supposed to be translated into 78 aa residues, three of them could not be translated into aa because they were TAG sequences. The TAG sequence was a stop codon (end), so it was not translated into amino acids but served as a signal sequence for the last translational activity (Dewi et al, 2009). GH genes between fish species have different lengths.…”

“…GH genes between fish species have different lengths. The length of the GH gene in P. gigas was 1.176 bp (Lemaire et al, 1994); while in P. hypophthalmus, it was 1.151 bp (Dewi et al, 2009). The GH gene in yellow catfish (Pelteobagrus fulvidraco) has 615 bp ORF translated into a polypeptide amino acid code to 204 (Tang et al, 2021).…”