Molecular cloning, sequence analysis and expression detection of β-actin gene in the oriental armyworm, Mythimna separata

Key Words： Mythimna separata, β-actin gene, cloning

Abstract：     β-actin, a member of the actin family, is often used as an internal standard in quantitative gene analysis. In this study, a full-length cDNA of the β-actin gene from Mythimna separata (Walker) was cloned using RT-PCR and the RACE technique. The results show that this cDNA is 1　472 base pairs (bp) long and contains a 5′-untranslated region (5′ -UTR) of 68 bp and a 3′-untranslated region (3′ -UTR) of 273 bp. The open reading frame (ORF) of 1 131 bp encodes a 376 amino acid protein with a predicted molecular weight of 41.7497 ku and PI value of 5.29. This predicted protein contains 6 functional sites, shares the typical actin family signature and 97.9 %～99.7 % identity with actin from other animals. Quantitative assays indicate that there was no significant difference (P>0.05) between 6 different tissues, suggesting that β-actin is a reliable internal control in M. separata. The cloned cDNA has been submitted to GenBank (Accession number: GQ856238).