Diapause induces changes in the composition and biophysical properties of lipids in larvae of the European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae)

• Published in: Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 2013-08, Vol.165 (4), p.219-225
• Main Authors: Vukašinović, Elvira L., Pond, David W., Worland, Michael Roger, Kojić, Danijela, Purać, Jelena, Blagojević, Duško P., Grubor-Lajšić, Gordana
• Format: Article
• Language: English
• Subjects: Analysis of Variance; Animals; body fat; Calorimetry, Differential Scanning; cell membranes; Chromatography, Thin Layer; Cold hardiness; Crambidae; diapause; Diapause, Insect - physiology; fat body; fatty acid composition; Fatty Acids - analysis; Fatty Acids, Monounsaturated - analysis; hemolymph; Insect diapause; instars; Larva - chemistry; larvae; Lepidoptera; linoleic acid; Linoleic Acid - analysis; Lipid classes and fatty acid composition; Lipids - analysis; Moths - metabolism; Moths - physiology; oleic acid; Ostrinia nubilalis; palmitic acid; palmitoleic acid; phase transition; Phase transition temperatures of lipids; Seasons; Temperature; triacylglycerols; Triglycerides - analysis
• ISSN: 1096-4959; 1879-1107
• DOI: 10.1016/j.cbpb.2013.05.001

This study compares the composition and biophysical properties of lipids in non-diapausing and diapausing fifth instar larvae of Ostrinia nubilalis Hubn. (Lepidoptera: Crambidae). The majority of fat body lipids in both of these physiological states were comprised of ~90% triacylglycerols (TAGs), whereas the haemolymph contained a more even distribution of all lipid classes. The fatty acid composition and biophysical properties of the fat body lipids differed markedly between non-diapausing and diapausing larvae. Diapause was associated with a dramatic increase in the proportions of palmitoleic acid (16:1n-7) and oleic acid (18:1n-9), with concurrent reductions in palmitic acid (16:0) and linoleic acid (18:2n-6). The increase in the level of unsaturation of the fat body lipids, which caused a marked shift in their phase transitions to lower temperatures, was triggered by diapause rather than low temperatures. Adjustments of fatty acid compositions are likely to be an important component of winter diapause mechanisms, possibly maintaining the fluidity of cell membranes and the functionality of the organism during lower winter temperatures.