Developmental expression of neuromodulators in the central complex of the grasshopper Schistocerca gregaria

The central complex is a major integrative region within the insect brain with demonstrated roles in spatial orientation, the regulation of locomotor behavior, and sound production. In the hemimetabolous grasshopper, the central complex comprises the protocerebral bridge, central body (CB), ellipsoid body, noduli, and accessory lobes, and this modular organization develops entirely during embryogenesis. From a biochemical perspective, a range of neuroactive substances has been demonstrated in these modules of the adult central complex, but little is known about their developmental expression. In this study, we use matrix‐assisted laser desorption/ionization‐imaging mass spectrometry on single brain slices to confirm the presence of several peptide families (tachykinin, allatostatin, periviscerokinin/pyrokinin, FLRFamide, and neuropeptide F) in the adult central complex and then use immunohistochemistry and histology to examine their developmental expression, together with that of the indolamin serotonin, and the endogenous messenger nitric oxide (NO; via its synthesizing enzyme). We find that each neuromodulator is expressed according to a unique, stereotypic, pattern within the various modules making up the central complex. Neuropeptides such as tachykinin (55%) and allatostatin (65%), and the NO‐synthesizing enzyme diaphorase (70%), are expressed earlier during embryonic development than the biogenic amine serotonin (80%), whereas periviscerokinin‐like peptides and FLRFamide‐like peptides begin to be expressed only postembryonically. Within the CB, these neuroactive substances are present in tangential projection neurons before they appear in columnar neurons. There is also no colocalization of serotonin‐positive and peptide‐positive projections up to the third larval instar during development, consistent with the clear dorsoventral layering of the neuropil we observe. Our results provide the first neurochemical fingerprint of the developing central complex in an hemimetabolous insect. J. Morphol., 2010. © 2010 Wiley‐Liss, Inc.     

Wanda: a database of duplicated fish genes

Comparative genomics has shown that ray-finned fish (Actinopterygii) contain more copies of many genes than other vertebrates. A large number of these additional genes appear to have been produced during a genome duplication event that occurred early during the evolution of Actinopterygii (i.e. before the teleost radiation). In addition to this ancient genome duplication event, many lineages within Actinopterygii have experienced more recent genome duplications. Here we introduce a curated database named Wanda that lists groups of orthologous genes with one copy from man, mouse and chicken, one or two from tetraploid Xenopus and two or more ancient copies (i.e. paralogs) from ray-finned fish. The database also contains the sequence alignments and phylogenetic trees that were necessary for determining the correct orthologous and paralogous relationships among genes. Where available, map positions and functional data are also reported. The Wanda database should be of particular use to evolutionary and developmental biologists who are interested in the evolutionary and functional divergence of genes after duplication. Wanda is available at http://www.evolutionsbiologie.uni-konstanz.de/Wanda/.     

Mid-gestation pregnancy termination by the progesterone antagonist aglepristone in queens

The efficacy of aglepristone, a progesterone receptor antagonist, to induce abortion on days 25 and 26 after first mating was investigated in queens. The cats were divided into two groups: aglepristone (10 mg/kg, subcutaneously) was injected twice, 24 h apart, on days 25 and 26 after first mating, into group I queens (n = 23). Group II queens (n = 6) were not treated and served as controls. Termination of pregnancy and expulsion of the fetuses were successful in 20 (87%) queens in group I. The mean interval between the first administration of aglepristone and the beginning of vaginal discharge was 5+/-1 days (range 4-7 days) and the mean duration of abortion, defined as time span from first occurrence of vaginal discharge to expulsion of all fetuses observed by ultrasonography was 1 day in nine cats, 2 days in five cats and in five cats, less than 1 day. Treatment failed in three queens. In one queen treatment resulted in birth (66 days after mating) of two vital kittens. In another case, three macerated fetuses were found intrauterine without vaginal discharge. In one cat, two fetuses were expulsed and two remained intrauterine and were born 66 days after last mating. All group II queens gave birth to vital kittens after a normal pregnancy length. The mean serum P4 concentrations were similar in treated and control animals. The results indicate that aglepristone treatment at day 25 of pregnancy could induce abortion in 87% of the treated queens. Itching at the site of injection right after injection was the only side effect noticed and only in one queen.     

Dendritic cell-derived IL-12p40 homodimer contributes to susceptibility in cutaneous leishmaniasis in BALB/c mice

Protection against Leishmania major in resistant C57BL/6 mice is mediated by Th1 cells, whereas susceptibility in BALB/c mice is the result of Th2 development. IL-12 release by L. major-infected dendritic cells (DC) is critically involved in differentiation of Th1 cells. Previously, we reported that strain differences in the production of DC-derived factors, e.g., IL-1alphabeta, are in part responsible for disparate disease outcome. In the present study, we analyzed the release of IL-12 from DC in more detail. Stimulated DC from C57BL/6 and BALB/c mice released comparable amounts of IL-12p40 and p70. In the absence of IL-4, BALB/c DC produced significantly more IL-12p40 than C57BL/6 DC. Detailed analyses by Western blot and ELISA revealed that one-tenth of IL-12p40 detected in DC supernatants was released as the IL-12 antagonist IL-12p40 homodimer (IL-12p80). BALB/c DC released approximately 2-fold more IL-12p80 than C57BL/6 DC both in vitro and in vivo. Local injection of IL-12p80 during the first 3 days after infection resulted in increased lesion volumes for several weeks in both L. major-infected BALB/c or C57BL/6 mice, in higher lesional parasite burdens, and decreased Th1-cytokine production. Finally, IL-12p40-transgenic C57BL/6 mice characterized by overexpression of p40 showed increased levels of serum IL-12p80 and enhanced disease susceptibility. Thus, in addition to IL-1alphabeta, strain-dependent differences in the release of other DC-derived factors such as IL-12p80 may influence genetically determined disease outcome.     

Chemistry of the uropygial gland secretion of Hume’s ground jay Pseudopodoces humilis and its taxonomic implications

Humes ground jay (Pseudopodoces humilis), a species living in the high altitude steppes of the Qinghai-Tibet-Plateau (China), was traditionally thought to be a ground jay related to the genus Podoces (Corvidae). Recently, however, based on three independent datasets (comparative osteology, nuclear and mitochondrial DNA sequences), this species was discovered to be a member of the Paridae. Here, we reinvestigate the systematic position of Pseudopodoces humilis using the chemical composition of uropygial gland secretions, which have previously been shown to be phylogenetically informative in birds, including Corvidae and Paridae. We found strong similarities in the fatty acid composition of uropygial gland secretions between Pseudopodoces humilis and parids, but clear differences from corvids. This result supports the parid affinites of Pseudopodoces, but stands in contrast to behavioural and vocal characteristics which are clearly more similar to corvids than to parids.Communicated by A.J. Helbig     

The gut microbiota of the pine weevil is similar across Europe and resembles that of other conifer‐feeding beetles

The pine weevil (Hylobius abietis, Coleoptera: Curculionidae) is an important pest of conifer seedlings in Europe. Despite its economic importance, little is known about the composition of its gut microbial community and the role it plays in mediating the weevil's ability to utilize conifers as a food source. Here, we characterized the gut bacterial communities of different populations of H. abietis across Europe and compared them to those of other beetles that occupy similar ecological niches. We demonstrate that the microbial community of H. abietis is similar at higher taxonomic levels (family and genus) across locations in Europe, with Wolbachia as the dominant microbe, followed by Enterobacteria and Firmicutes. Despite this similarity, we observed consistent differences between countries and locations, but not sexes. Our meta‐analysis demonstrates that the gut bacterial community of the pine weevil is very similar to that of bark beetles that also exploit conifers as a food source. The Enterobacteriaceae symbionts of both host taxa are especially closely related phylogenetically. Conversely, the microbiota of H. abietis is distinct from that of closely related weevils feeding on nonconifer food sources, suggesting that the microbial community of the pine weevil is determined by the environment and may be relevant to host ecology. Furthermore, several H. abietis‐associated members of the Enterobacteriaceae family are known to contain genes involved in terpenoid degradation. As such, we hypothesize that the gut microbial community is important for the utilization of conifer seedlings as a food source, either through the detoxification of plant secondary metabolites or through the supplementation of essential nutrients.