Use of the dart apparatus by the hermaphroditic land snail Polymita muscarum (Lea, 1834).

Many species of pulmonate land snails are equipped with one or more so-called "love darts". Even though the number and shape of these calcareous darts vary considerably between species, dart use has only been investigated in very few species. Here, we redescribe the mating behaviour of Polymita muscarum because previous reports did not include the use of the dart apparatus. Mating in this hermaphroditic land snail can be divided into three stages: courtship, copulation and post-copulatory activity. During courtship, full eversion of the genital atrium is reached, thus exposing the sensitive zone, genital lobes and dart apparatus. We observed that P. muscarum pushes the everted dart apparatus repeatedly onto different parts of the partner's body and does not lose its dart after stabbing. Dissected specimens had a single, slender dart with a round base, a broad corona and a circular cross-section. We propose that the morphology of P. muscarum's dart is consistent with the idea of simple darts needing to be stabbed more often in order to increase the transfer of mucus, which contains a biologically active substance (i.e. allohormone) that enhances the chances of paternity. Besides adding to the growing diversity in the use of love darts in land snails, these findings contribute to the understanding of the evolution of this peculiar reproductive act. © Koninklijke Brill NV 2007

Tales of two snails: sexual selection and sexual conflict in Lymnaea stagnalis and Helix aspersa.

Sexual selection and sexual conflict have been shown to play key roles in the evolution of species with separate sexes. Experimental evidence is accumulating that this is also true for simultaneous hermaphrodites. For example, many species of land snails forcefully stab their mating partners with love darts. In the brown garden snail (Helix aspersa, now called Cantareus asperses), this dart increases sperm storage and paternity, probably via the transfer of an allohormone that inhibits sperm digestion. A recent interspecies comparison of dart-possessing land snails revealed coevolution between darts and spermatophore-receiving organs that is consistent with counteradaptation against an allohormonal manipulation. The great pond snail (Lymnaea stagnalis) seems to use a seminal product to manipulate its partner and mates in the male role when enough seminal fluid is available in the prostate gland. Receipt of semen not only initiates egg laying in virgin animals, but also feminizes the mating partner later in life. These increases in the female function have been shown to go at the expense of growth and seminal fluid production of the sperm recipient. Although in Helix, and probably also Lymnaea, the sperm donor benefits from the induced changes through increased fertilization success, the sperm recipient may experience injury, imposed reallocation of resources, and altered sperm storage. These findings support the existence of sexual conflict in simultaneously hermaphroditic snails, and its importance for the evolution of mating behaviors and reproductive morphologies is discussed. © The Author 2006. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved

Ongerief bij konijnen, kalkoenen, eenden, schapen en geiten; inventarisatie en prioritering = Discomfort among rabbit, turkey, duck, sheep and goat; inventory and priorization

Discomfort among rabbit, turkeys, duck, sheep and goat is surveyed and prioritized based on an expert view from animal scientists. Possible solutions for the most serious items of discomfort are mentione

Membranous glomerulonephritis in the mouse

Membranous glomerulonephritis in the mouse. Glomerulonephritis was induced in C57.B110 mice by a single injection of rabbit IgG against homologous, pronase-digested, renal tubular antigens. The heterologous phase was characterized by a transient increase of glomerular permeability with fixation of rabbit IgG to the capillary walls, in a linear or fine-granular pattern, and to the brush borders of the proximal tubuli. The autologous phase was marked by the immune response to the injected protein, during which subepithelial immune deposits, consisting of mouse IgG1, rabbit IgG, and mouse C3 developed. Small amounts were still present at 1 year after the injection of antiserum. The antibody response of the mice correlated with the development and resolution of the deposits. None of the mice developed a nephrotic syndrome. Control mice treated with normal rabbit IgG did not show immune deposits in their kidneys at any stage despite a comparable antibody response to rabbit IgG. Immunoelectronmicroscopy showed that the rabbit antibodies fixed directly to an antigen in the cell membrane of the glomerular visceral epithelium. It seems, therefore, likely that in situ formation of subepithelial immune complexes occurred in the autologous phase by fixation of mouse immunoglobulins to rabbit IgG already present in the glomerular wall.Glomérulonéphrite extra-membraneuse chez la souris. Une glomérulonéphrite a été induite chez des souris C57.B110 par une injection unique d'IgG de lapin contre des antigènes tubulaires rénaux homologues, digérés par de la pronase. La phase hétérologue était caractérisée par une augmentation transitoire de la perméabilité glomérulaire avec fixation d'IgG de lapin aux parois capillaires, d'une façon linéaire ou finement granuleuse, et aux bordures en brosse des tubules proximaux. La phase autologue était marquée par la réponse immune à la protéine injectée, pendant laquelle des dépôts immuns sous-épithéliaux, consistant en de l'IgG1 de souris, de l'IgG de lapin et du C3 de souris, se sont développés. Il en restait encore de faibles quantités 1 an après l'injection de l'antisérum. La réponse anticorps des souris était corrélée avec le développement et la disparition des dépôts. Aucune des souris n'a développé de syndrome néphrotique. Les souris contrôles traitées avec de l'IgG de lapin normal n'ont pas eu de dépôts immuns dans le rein à aucun stade, malgré une réponse anticorps aux IgG de lapin comparable. La microscopie immuno-électronique a montré que les anticorps de lapin se fixaient directement à un antigène situé sur la membrane des cellules de l'épithélium viscéral glomérulaire. Il semble donc probable que la formation in situ de complexes immuns sous-épithéliaux est survenue à la phase autologue par fixation d'immunoglobulines de souris à de l'IgG de lapin déjà présente dans la paroi glomérulaire

Whole genome analysis of a schistosomiasis-transmitting freshwater snail

Biomphalaria snails are instrumental in transmission of the human blood fluke Schistosoma mansoni. With the World Health Organization's goal to eliminate schistosomiasis as a global health problem by 2025, there is now renewed emphasis on snail control. Here, we characterize the genome of Biomphalaria glabrata, a lophotrochozoan protostome, and provide timely and important information on snail biology. We describe aspects of phero-perception, stress responses, immune function and regulation of gene expression that support the persistence of B. glabrata in the field and may define this species as a suitable snail host for S. mansoni. We identify several potential targets for developing novel control measures aimed at reducing snail-mediated transmission of schistosomiasis

Proteomic markers with prognostic impact on outcome of chronic lymphocytic leukemia patients under chemo-immunotherapy: results from the HOVON 109 study

Despite recent identification of several prognostic markers, there is still a need for new prognostic parameters able to predict clinical outcome in chronic lymphocytic leukemia (CLL) patients. Here, we aimed to validate the prognostic ability of known (proteomic) markers measured pretreatment and to search for new proteomic markers that might be related to treatment response in CLL. To this end, baseline serum samples of 51 CLL patients treated with chemo-immunotherapy were analyzed for 360 proteomic markers, using Olink technology. Median event-free survival (EFS) was 23 months (range: 1.25–60.9). Patients with high levels of sCD23 (>11.27, p = 0.026), sCD27 (>11.03, p = 0.04), SPINT1 (>1.6, p = 0.001), and LY9 (>8.22, p = 0.0003) had a shorter EFS than those with marker levels below the median. The effect of sCD23 on EFS differed between immunoglobulin heavy chain variable gene-mutated and unmutated patients, with the shortest EFS for unmutated CLL patients with sCD23 levels above the median. Taken together, our results validate the prognostic impact of sCD23 and highlight SPINT1 and LY9 as possible promising markers for treatment response in CLL patients

Updated precision measurement of the average lifetime of B hadrons

The measurement of the average lifetime of B hadrons using inclusively reconstructed secondary vertices has been updated using both an improved processing of previous data and additional statistics from new data. This has reduced the statistical and systematic uncertainties and gives \tau_{\mathrm{B}} = 1.582 \pm 0.011\ \mathrm{(stat.)} \pm 0.027\ \mathrm{(syst.)}\ \mathrm{ps.} Combining this result with the previous result based on charged particle impact parameter distributions yields \tau_{\mathrm{B}} = 1.575 \pm 0.010\ \mathrm{(stat.)} \pm 0.026\ \mathrm{(syst.)}\ \mathrm{ps.

Limits on the production of scalar leptoquarks from Z (0) decays at LEP

A search has been made for pairs and for single production of scalar leptoquarks of the first and second generations using a data sample of 392000 Z0 decays from the DELPHI detector at LEP 1. No signal was found and limits on the leptoquark mass, production cross section and branching ratio were set. A mass limit at 95% confidence level of 45.5 GeV/c2 was obtained for leptoquark pair production. The search for the production of a single leptoquark probed the mass region above this limit and its results exclude first and second generation leptoquarks D0 with masses below 65 GeV/c2 and 73 GeV/c2 respectively, at 95% confidence level, assuming that the D0lq Yukawa coupling alpha(lambda) is equal to the electromagnetic one. An upper limit is also given on the coupling alpha(lambda) as a function of the leptoquark mass m(D0)