Functional activity of allatotropin and allatostatin in the pupal stage of a holometablous insect, Tribolium castaneum (Coleoptera, Tenebrionidae)

Involvement of a putative allatostatin in regulation of juvenile hormone titer and the larval development in Leptinotarsa decemlineata (Say)

“…Moreover, the expression levels of LdAS-C were also higher in the midgut and ileum; LdAS-B had higher expression levels in the midgut and rectum. Similarly, TcAS-C and TcAS-B in T. castaneum were also mainly distributed in brain + CC/CA complex and gut (Abdel-latief and Hoffmann, 2014).…”

“…Our data showed that ingestion of dsLdAS-C significantly affected the larval growth and delayed the development in L. decemlineata. Similarly, injection of dsTcAS-C and dsTcAS-B into T. castaneum young pupae (4 hour-old) slightly prolonged pupal duration, and resulted in about 50% of deformed adults (Abdel-latief and Hoffmann, 2014). Topical application of a JH analogue S-71639 also delayed the larval duration in L. decemlineata (Koopmanschap et al, 1989).…”

“…Type A AS (FGLamides, AS-A) peptides have conserved pentapeptide sequence (Y/F)XFG(L/I)amide at the carboxy-terminus (Woodhead et al, 1989). Type B AS peptides contain common W(X 6 )Wamide sequences (Lorenz et al, 1995;Williamson et al, 2001;Amare and Sweedler, 2007;Li et al, 2008;Abdel-latief and Hoffmann, 2014). The third peptide group AS-Cs have two subtypes, pQVRFRQCYFNPISCF (PISCF-AS) (Kramer et al, 1991) and SYWKQCAFNAVSCFamide (AVSCF-AS) (Hummon et al, 2006).…”

“…Moreover, injection of double stranded RNAs (dsRNAs) targeting TcAS-C and TcAS-B into T. castaneum young pupae (4 hour-old) prolongs the pupal duration, and results in the production of about 50% deformed adults. Other 50% of the animals are intact in shape, but have incompletely developed ovaries and lay fewer eggs (Abdel-latief and Hoffmann, 2014). However, the in vivo allatostatic activity of AS-C and AS-B peptides in coleopteran species remains unproven.…”

Emerging strategies for RNA interference (RNAi) applications in insects

“…44,50,51 Similarly, insect metamorphosis can be influenced by different classes and levels of juvenile hormones (JHs); the levels of JHs in turn can be influenced by JH metabolic enzymes (juvenile hormone esterase, JHE; juvenile hormone epoxide hydrolase, JHEH; juvenile hormone acid methyl transferase, JHAMT). Some of the recent studies in Tribolium showed enhanced RNAi effects when the targets were either juvenile hormone 52,53 or juvenile hormone acid methyl transferase. 54 In Bemisia tabaci, RNAi effects were prominent in nymphal stages when the genes in the ecdysone pathway were silenced.…”