The vesicular monoamine transporter 2 (VMAT2) is localized primarily within the CNS and is responsible for transporting monoamines from the cytoplasm into secretory vesicles. Because reserpine (a VMAT inhibitor) can precipitate depressive-like symptoms in humans, we investigated whether Vmat2 heterozygous (HET) mice present with depressive-like behaviors. The mutants showed locomotor and rearing retardation in the open field and appeared anhedonic to 1 and 1.5% sucrose solutions. Immobility times for Vmat2 heterozygotes were prolonged in forced swim and imipramine normalized this behavior. HET animals also showed enhanced immobility in tail suspension and this response was alleviated by fluoxetine, reboxetine, and bupropion. Stimulated GTP␥S binding indicated that ␣ 2 -adrenergic receptors in HET hippocampus were more sensitive to UK 14,304 (5-bromo-N-(4,5-dihydro-1-H-imidazol-2-yl)-6-quinoxalinamine) stimulation than in wild type (WT) mice. In learned helplessness, mice were exposed to a shuttle box for 4 d or were given inescapable foot-shocks for the same time period. On day 5, all animals were tested in shock escape. Failure rates and the latency to escape were similar for WT and HET mice that were only pre-exposed to the test apparatus. In foot-shock groups, learned helplessness was more robust in heterozygotes than in WT controls. Basal secretion of serum corticosterone was not distinguished by genotype; however, corticosterone levels in mutants were more responsive to stress. Anxiety-like responses of WT and HET animals in the open field, light-dark exploration, zero maze, and novelty-suppressed feeding tests were indistinguishable. Collectively, these findings suggest that Vmat2 heterozygotes display a depressive-like phenotype that is devoid of anxiety-like behavior.

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Fatty acid amides (FAAs) are known elicitors that induce plants to release volatile compounds that, in turn, attract foraging parasitoids. Since the discovery of volicitin [N-(17-hydroxylinolenoyl)-L-glutamine] in the regurgitant of larval Spodoptera exigua, a series of related FAAs have been identified in several other species of lepidopteran caterpillars. We screened 13 non-lepidopteran insects for the presence of FAAs and found that these compounds were present in adults of two closely related cricket species, Teleogryllus taiwanemma and T. emma (Orthoptera: Gryllidae), and larvae of the fruit fly, Drosophila melanogaster (Diptera: Drosophilidae). When analyzed by liquid chromatography/mass spectrometry-ion trap-time-of-flight (LCMS-IT-TOF), the gut contents of both crickets had nearly identical FAA composition, the major FAAs comprising N-linolenoyl-L-glutamic acid and N-linoleoyl-L-glutamic acid. There were also two previously uncharacterized FAAs that were thought to be hydroxylated derivatives of these glutamic acid conjugates, based on their observed fragmentation patterns. In addition to these four FAAs containing glutamic acid, N-linolenoyl-L-glutamine and a small amount of volicitin were detected. In D. melanogaster, N-linolenoyl-L-glutamic acid and N-linoleoyl-L-glutamic acid were the major FAAs found in larval extracts, while hydroxylated glutamic acid conjugates, volicitin and N-linolenoyl-L-glutamine, were detected as trace components. Although these FAAs were not found in ten of the insects studied here, their identification in two additional orders of insects suggests that FAAs are more common than previously reported and may have physiological roles in a wide range of insects besides caterpillars.

Monoclonal antibodies (mAbs) against not only human, mouse, and rat but also rabbit, dog, cat, bovine, pig, and horse podoplanins (PDPNs) have been established in our previous studies. PDPN is used as a lymphatic endothelial cell marker in pathological diagnoses. However, mAbs against Tasmanian devil PDPN (tasPDPN), which are useful for immunohistochemical analysis, remain to be developed. Herein, mice were immunized with tasPDPN-overexpressing Chinese hamster ovary (CHO)-K1 (CHO/tasPDPN) cells, and hybridomas producing mAbs against tasPDPN were screened using flow cytometry. One of the mAbs, PMab-233 (IgG 1 , kappa), specifically detected CHO/tasPDPN cells by flow cytometry and recognized tasPDPN protein by western blotting. Furthermore, PMab-233 strongly detected CHO/tasPDPN cells by immunohistochemistry. These findings suggest that PMab-233 may be useful as a lymphatic endothelial cell marker of the Tasmanian devil.

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