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Aphidius ervi Haliday (Hymenoptera, Braconidae) is an endophagous parasitoid of the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera, Aphididae). This parasitoid strongly redirects host reproduction and metabolism to favour nutrition and development of its juvenile stages. Parasite-regulated biosynthesis and mobilization of nitrogen metabolites determine a significant increase of host nutritional suitability. The aim of the present study was mainly to investigate the temporal changes of A. pisum amino acid pools, as affected by A. ervi parasitism, and to assess the role of the aphid bacterial endosymbiont Buchnera in determining the observed changes. In parasitized aphids, we observed a very significant increase in total free amino acids, compared with synchronous non-parasitized controls, starting from day 4 after parasitization (+51%). This trend culminated with more than doubling the control value (+152%) on day 6 after parasitization. However, a significant “parasitism” effect was observed only for 10 of the 28 amino acids detected. Tyrosine accumulation was the most prominent parasitoid-induced alteration, with a fourfold increase over control levels registered on day 6. In parasitized hosts, the amino acid biosynthetic capacity of Buchnera was unaltered, or even enhanced for the phenolic pool, and contributed greatly to the definition and maintainance of host free amino acid pools. The hypertyrosinemic syndrome was not dependent on food supply of the aromatic nucleus but was induced by parasitism, which likely enhanced the aromatic shuttle mediating phenylalanine transfer from bacteria to the host tissues, where tyrosine conversion occurs. This process is likely associated with a selective disruption of the host’s functions requiring tyrosine, leading to the remarkable accumulation of this amino acid. The possible mechanisms determining these parasitism-induced host alterations, and their nutritional significance for the developing parasitoid larva, are discussed. [ABSTRACT FROM AUTHOR]

Abstract: Aminograms of tubal and follicular fluids were obtained using fluids collected by aspiratory puncture from six cats. The amino acids were separated and quantified by high-performance liquid chromatography analysis. The serum of the cats was used as control. The three most prevalent amino acids quantified in cat tubal fluid were glycine, glutamic acid, and taurine. Their mean concentrations were 840 μmol/l (μm), 808 μm and 596 μm, respectively. The three most prevalent amino acids quantified in cat follicular fluid were alanine, glutamine, and taurine. Their mean concentrations were 359 μm, 351 μm, and 258 μm, respectively. This result is consistent with aminograms of tubal fluid previously determined in other mammals. As previously observed in other species and humans, glycine was quantitatively the most abundant and most prevalent free amino acid in cat tubal fluid. The total quantity of amino acids in tubal fluid was similar in cats and other species. However, in contrast with other species studied, hypotaurine was not detected in tubal and follicular fluids of female cats. [Copyright &y& Elsevier]