کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2840317 1570990 2015 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Expressional and functional analysis of CYP15A1, a juvenile hormone epoxidase, in the red flour beetle Tribolium castaneum
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک دانش حشره شناسی
پیش نمایش صفحه اول مقاله
Expressional and functional analysis of CYP15A1, a juvenile hormone epoxidase, in the red flour beetle Tribolium castaneum
چکیده انگلیسی


• We identified a homolog of CYP15 from the red flour beetle Tribolium castaneum.
• The CYP15 mRNA was abundant in the embryonic stage and in the final larval instar.
• The recombinant CYP15 protein epoxidized both farnesoic acid and methyl farnesoate.
• Epoxidation by the recombinant CYP15 protein was highly stereo-specific.
• Knockdown of CYP15 did not result in precocious larva–pupa metamorphosis.

Juvenile hormone (JH) is synthesized and secreted by the corpora allata. In the final two steps of JH biosynthesis, farnesoic acid (FA) is converted to JH through methylation by JH acid O-methyltransferase (JHAMT) and epoxidation by the cytochrome P450 enzyme CYP15. In the present study, we identified a homolog of CYP15 from the red flour beetle Tribolium castaneum (TcCYP15A1), and analyzed its expression as well as its role in JH biosynthesis. Quantitative RT-PCR analysis showed that the level of TcCYP15A1 mRNA was high in the embryonic stage as well as in the middle of the final larval instar. In the embryonic stage, the transcript level of TcCYP15A1 started to increase 30 h after egg laying (AEL), peaked 54–60 h AEL, and was followed by an increase of TcJHAMT mRNA, suggesting that JH biosynthesis started at this time point. TcCYP15A1 mRNA was present, but not exclusively so in the larval corpora allata. The recombinant TcCYP15A1 protein epoxidized both FA and methyl farnesoate (MF) in highly stereo-specific manners. These results confirmed that TcCYP15A1 is involved in JH biosynthesis. The RNAi-mediated knockdown of TcCYP15A1 in the pre-final larval instar did not result in precocious metamorphosis to pupa, indicating that MF may exhibit JH-like activity in order to maintain the larval status. The double knockdown of TcJHAMT and TcCYP15A1 resulted in pupae and adults with shorter wings, suggesting that the precursors of JH, JH acid and MF, may be essential for wing expansion.

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ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Insect Physiology - Volume 80, September 2015, Pages 61–70
نویسندگان
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