صدیقه هاشم نیا

Penaeid shrimp constitutes the most important resource in fishery industry and their growth is depend to moltig duration. Molting inhibiting hormone has a crucial function in molting process. Green tiger shrimp, penaeus semisulcatus, belongs to penaeidae family and constitutes large portion of harvests in Persian gulf. In this study, nucleotide and amino acid sequence of MIH are reported. A total RNA was extracted from shrimp X-organ. 5'UTR and ORF of mRNA were isolated and amplified, using 5' and 3' RACE. The results of sequencing showed that isolated mRNA has 399 nucleotides of which 81 nucleotides belong to 5' UTR and 318 to ORF. The mRNA translation by software yielded a polypeptide with 105 amino acid. For mature MIH in other penaeus species, a polypeptide with 75-77 amino acids was reported. These hormones have similar amino acid sequences with six conserved Cysteine residues. Comparison of the sequences obtained in this study with sequences in other reports reveals considerable similarities the level of nucleotides and amino acids. .