@article {545,
	title = {Oleic acid is elevated in cell membranes during rapid cold-hardening and pupal diapause in the flesh fly, Sarcophaga crassipalpis},
	volume = {52},
	year = {Submitted},
	note = {08-10-200906-02-2012NormalDepartment of Entomology, Ohio State University, Columbus, OH 43210-1242, USA. michaud.11@osu.eduenghttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=pubmed\&dopt=Abstract\&list_uids=16997319},
	pages = {1073 - 1082},
	abstract = {The integrity of cellular membranes is critical to the survival of insects at low temperatures, thus an advantage is conferred to insects that can adjust their composition of membrane fatty acids (FAs). Such changes contribute to homeoviscous adaption, a process that allows cellular membranes to maintain a liquid-crystalline state at temperatures that are potentially low enough to cause the membrane to enter the gel state and thereby lose its ability to maintain homeostasis. Flesh flies (Sarcophaga crassipalpis) were subjected to two experimental conditions that elicit low temperature tolerance: rapid cold-hardening and diapause. FAs were isolated and analyzed using gas chromatography-mass spectrometry. FAs changed in response to both rapid cold-hardening and diapause. In response to rapid cold-hardening (8 h at 4 degrees C), the proportion of oleic acid (18:1n-9) in pharate adults increased from 30\% to 47\% of the total FA pool. The proportion of almost every other FA was reduced. By entering diapause, pupae experienced an even greater increase in oleic acid proportion, to 58\% of the total FA pool. Oleic acid not only promotes membrane fluidity at low temperature but also allows the cell membrane to maintain a liquid crystalline state if temperatures increase.},
	keywords = {*Cold Temperature, Acclimatization/*physiology, Analysis of Variance, Animals, Cell Membrane/*metabolism, Chromatography, Thin Layer, Diptera/metabolism/*physiology, Gas Chromatography-Mass Spectrometry, Hibernation/*physiology, Oleic Acid/*metabolism, Pupa/metabolism/physiology},
	author = {Michaud, M. R. and Denlinger, D. L.}
}
@article {467,
	title = {Shifts in the carbohydrate, polyol, and amino acid pools during rapid cold-hardening and diapause-associated cold-hardening in flesh flies (Sarcophaga crassipalpis): a metabolomic comparison},
	volume = {177},
	year = {Submitted},
	note = {08-10-200906-02-2012NormalDepartment of Entomology, Ohio State University, 318 W. 12th Avenue, Columbus, OH 43210-1242, USA. michaud.11@osu.eduenghttp://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=pubmed\&dopt=Abstract\&list_uids=17576567},
	pages = {753 - 763},
	abstract = {Flesh flies can enhance their cold hardiness by entering a photoperiod-induced pupal diapause or by a temperature-induced rapid cold-hardening process. To determine whether the same or different metabolites are involved in these two responses, derivatized polar extracts from flesh flies subjected to these treatments were examined using gas chromatography-mass spectrophotometry (GC-MS). This metabolomic approach demonstrated that levels of metabolites involved in glycolysis (glycerol, glucose, alanine, pyruvate) were elevated by both treatments. Metabolites elevated uniquely in response to rapid cold-hardening include glutamine, cystathionine, sorbitol, and urea while levels of beta-alanine, ornithine, trehalose, and mannose levels were reduced. Rapid cold-hardening also uniquely perturbed the urea cycle. In addition to the elevated metabolites shared with rapid cold-hardening, leucine concentrations were uniquely elevated during diapause while levels of a number of other amino acids were reduced. Pools of two aerobic metabolic intermediates, fumarate and citrate, were reduced during diapause, indicating a reduction of Krebs cycle activity. Principal component analysis demonstrated that rapid cold-hardening and diapause are metabolically distinct from their untreated, non-diapausing counterparts. We discuss the possible contribution of each altered metabolite in enhancing the overall cold hardiness of the organism, as well as the efficacy of GC-MS metabolomics for investigating insect physiological systems.},
	keywords = {*Carbohydrate Metabolism, *Cold Temperature, Amino Acids/*metabolism, Animals, Diptera/metabolism/*physiology, Gas Chromatography-Mass Spectrometry, Models, Biological, Polymers/*metabolism, Principal Component Analysis, Time Factors},
	author = {Michaud, M. R. and Denlinger, D. L.}
}
