title: Life stage-related differences in fatty acid composition of an obligate ectoparasite, the deer ked (Lipoptena cervi)-influence of blood meals and gender.
abstract: Metamorphosis and diet often influence fatty acid (FA) signatures (FAS) of insects. We investigated FAS in a hematophagous ectoparasite, the deer ked (Lipoptena cervi). Deer keds shed their wings upon attachment on the host and, thus, the FAS of an individual blood-fed imago/pupa in the fur of its host can be traced back to the blood FA profile of a single moose (Alces alces). Host blood and different life stages of deer keds were investigated for FA by gas chromatography. The FAS of life stages resembled each other more closely than the diet. Blood meals modified the FAS of both sexes but the FAS of the blood-fed females were closer to those of the prepupae/pupae. The parasitizing males had higher proportions of major saturated FA (SFA) and polyunsaturated FA (PUFA) than the females, which contained more monounsaturated FA (MUFA) with higher ratios of n-3/n-6 PUFA and unsaturated FA (UFA)/SFA. The proportions of 16:1n-7 were <1% in the blood but 18% (males) and 29% (females) in the blood-fed keds. Allocation of lipids to offspring by the females and possible accumulation of PUFA in male reproductive organs may have induced these sex-related differences. MUFA percentages and UFA/SFA ratios increased while SFA and many PUFA decreased from the reproducing females to the pupae. The diapausing pupae displayed lowered n-3/n-6 PUFA ratios and could have mobilized 16:0 and 18:3n-3 for the most fundamental metabolic processes. In conclusion, FAS are modified through the life stages of the deer ked possibly due to their different FA requirements.
authors.affiliation: University of Eastern Finland, Faculty of Science and Forestry, Department of Biology, P.O. Box 111, FI-80101 Joensuu, Finland; University of Eastern Finland, Faculty of Health Sciences, School of Medicine, Institute of Biomedicine/Anatomy, P.O. Box 1627, FI-70211 Kuopio, Finland. Electronic address: Anne-Mari.Mustonen@uef.fi.
authors.forename: Anne-Mari
authors.initials: AM
authors.lastname: Mustonen
authors.affiliation: University of Helsinki, Faculty of Biological and Environmental Sciences, Department of Biosciences, P.O. Box 65, FI-00014 University of Helsinki, Finland.
authors.forename: Reijo
authors.initials: R
authors.lastname: Käkelä
authors.affiliation: University of Eastern Finland, Faculty of Science and Forestry, Department of Biology, P.O. Box 111, FI-80101 Joensuu, Finland; University of Eastern Finland, Faculty of Health Sciences, School of Medicine, Institute of Biomedicine/Anatomy, P.O. Box 1627, FI-70211 Kuopio, Finland.
authors.forename: Tommi
authors.initials: T
authors.lastname: Paakkonen
authors.affiliation: University of Eastern Finland, Faculty of Science and Forestry, Department of Biology, P.O. Box 111, FI-80101 Joensuu, Finland; University of Eastern Finland, Faculty of Health Sciences, School of Medicine, Institute of Biomedicine/Anatomy, P.O. Box 1627, FI-70211 Kuopio, Finland.
authors.forename: Petteri
authors.initials: P
authors.lastname: Nieminen
mesh_terms: D000818:Animals; D003670:Deer / Q000469:parasitology*; D004175:Diptera / Q000254:growth & development*; D005227:Fatty Acids / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D005247:Feeding Behavior; D005260:Female; D008018:Life Cycle Stages; D008297:Male; D010271:Parasites / Q000254:growth & development*; D025341:Principal Component Analysis; D012727:Sex Characteristics
chemical_list: D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated
keywords: Deer ked; Ectoparasite; Fatty acid signature; Life stage; Lipoptena cervi; Metamorphosis