Title: | Neofunctionalization in an ancestral insect desaturase lineage led to rare Delta6 pheromone signals in the Chinese tussah silkworm |
Author(s): | Wang HL; Lienard MA; Zhao CH; Wang CZ; Lofstedt C; |
Address: | "Chemical Ecology and Ecotoxicology, Department of Biology, Lund University, SE-223 62 Lund, Sweden" |
DOI: | 10.1016/j.ibmb.2010.07.009 |
ISSN/ISBN: | 1879-0240 (Electronic) 0965-1748 (Linking) |
Abstract: | "The Chinese tussah silkworm, Antheraea pernyi (Lepidoptera: Saturniidae) produces a rare dienoic sex pheromone composed of (E,Z)-6,11-hexadecadienal, (E,Z)-6,11-hexadecadienyl acetate and (E,Z)-4,9-tetradecadienyl acetate, and for which the biosynthetic routes are yet unresolved. By means of gland composition analyses and in vivo labeling we evidenced that pheromone biosynthesis towards the immediate dienoic gland precursor, the (E,Z)-6,11-hexadecadienoic acid, involves desaturation steps with Delta(6) and Delta(11) regioselectivity. cDNA cloning of pheromone gland desaturases and heterologous expression in yeast demonstrated that the 6,11-dienoic pheromone is generated from two biosynthetic routes implicating a Delta(6) and Delta(11) desaturase duo albeit with an inverted reaction order. The two desaturases first catalyze the formation of the (E)-6-hexadecenoic acid or (Z)-11-hexadecenoic acid, key mono-unsaturated biosynthetic intermediates. Subsequently, each enzyme is able to produce the (E,Z)-6,11-hexadecadienoic acid by accommodating its non-respective mono-unsaturated product. Besides elucidating an unusually flexible pheromone biosynthetic pathway, our data provide the first identification of a biosynthetic Delta(6) desaturase involved in insect mate communication. The occurrence of this novel Delta(6) desaturase function is consistent with an evolutionary scenario involving neo-functionalization of an ancestral desaturase belonging to a gene lineage different from the Delta(11) desaturases commonly involved in moth pheromone biosynthesis" |
Keywords: | "Animals Bombyx/chemistry/*enzymology/genetics/metabolism *Evolution, Molecular Fatty Acid Desaturases/chemistry/genetics/*metabolism Insect Proteins/chemistry/genetics/*metabolism Insecta/chemistry/classification/*enzymology/genetics Molecular Sequence Da;" |
Notes: | "MedlineWang, Hong-Lei Lienard, Marjorie A Zhao, Cheng-Hua Wang, Chen-Zhu Lofstedt, Christer eng Research Support, Non-U.S. Gov't England 2010/08/10 Insect Biochem Mol Biol. 2010 Oct; 40(10):742-51. doi: 10.1016/j.ibmb.2010.07.009. Epub 2010 Aug 5" |