Specific detection of Plesiomonas shigelloides isolated from aquatic environments, animals and human diarrhoeal cases by PCR based on 23S rRNA gene

Twenty-five strains of Plesiomonas shigelloides isolated from aquatic environment, 10 strains from human cases of diarrhoea and five strains from animals were identified by the polymerase chain reaction technique based on 23S rRNA gene. For this purpose, two primers targeted against part of the 5' half of the 23S rRNA gene of P. shigelloides (Escherichia coli number C-912, G-1195; Plesiomonas number C-906, G-1189) were designed. Results from our study indicated that this method might serve as a tool for a rapid and sensitive identification of P. shigelloides from different environmental and clinical sources.     

Annual routines of non-migratory birds: optimal moult strategies

In a periodically changing environment it is important for animals to properly time the major events of their life in order to maximise their lifetime fitness. For a non-migratory bird the timing of breeding and moult are thought to be the most crucial. We develop a state-dependent optimal annual routine model that incorporates explicit density dependence in the food supply. In the model the birds' decisions depend on the time of year, their energy reserves, breeding status, experience, and the quality of two types of feathers (outer and inner primaries). Our model predicts that, under a seasonal environment, feathers with large effects on flight ability, higher abrasion rate and lower energetic cost of moult should be moulted closer to the winter (i.e. later) than those with the opposite attributes. Therefore, we argue that the sequence of moult may be an adaptive response to the problem of optimal timing of moult of differing feathers within the same feather tract. The model also predicts that environmental seasonality greatly affects optimal annual routines. Under high seasonality birds breed first then immediately moult, whereas under low seasonality an alternation occurs between breeding and moulting some of the feathers in one year and having a complete moult but no breeding in the other year. Increasing food abundance has a similar effect.     

Engineering a Monomeric Fc Domain Modality by N-Glycosylation for the Half-life Extension of Biotherapeutics

Human IgG is a bivalent molecule that has two identical Fab domains connected by a dimeric Fc domain. For therapeutic purposes, however, the bivalency of IgG and Fc fusion proteins could cause undesired properties. We therefore engineered the conversion of the natural dimeric Fc domain to a highly soluble monomer by introducing two Asn-linked glycans onto the hydrophobic C_H3-C_H3 dimer interface. The monomeric Fc (monoFc) maintained the binding affinity for neonatal Fc receptor (FcRn) in a pH-dependent manner. We solved the crystal structure of monoFc, which explains how the carbohydrates can stabilize the protein surface and provides the rationale for molecular recognition between monoFc and FcRn. The monoFc prolonged the in vivo half-life of an antibody Fab domain, and a tandem repeat of the monoFc further prolonged the half-life. This monoFc modality can be used to improve the pharmacokinetics of monomeric therapeutic proteins with an option to modulate the degree of half-life extension.     

Mycobacterium tuberculosis Strains Are Differentially Recognized by TLRs with an Impact on the Immune Response

Tuberculosis associates with a wide spectrum of disease outcomes. The Beijing (Bj) lineage of Mycobacterium tuberculosis (Mtb) is suggested to be more virulent than other Mtb lineages and prone to elicit non-protective immune responses. However, highly heterogeneous immune responses were reported upon infection of innate immune cells with Bj strains or stimulation with their glycolipids. Using both in vitro and in vivo mouse models of infection, we here report that the molecular mechanism for this heterogeneity may be related to distinct TLR activations. Among this Mtb lineage, we found strains that preferentially activate TLR2, and others that also activate TLR4. Recognition of Mtb strains by TLR4 resulted in a distinct cytokine profile in vitro and in vivo, with specific production of type I IFN. We also uncover a novel protective role for TLR4 activation in vivo. Thus, our findings contribute to the knowledge of the molecular basis underlying how host innate immune cells handle different Mtb strains, in particular the intricate host-pathogen interaction with strains of the Mtb Bj lineage.     

Peroxisomes in human and mouse testis: differential expression of peroxisomal proteins in germ cells and distinct somatic cell types of the testis

The vital importance of peroxisomal metabolism for regular function of the testis is stressed by the severe spermatogenesis defects induced by peroxisomal dysfunction. However, only sparse information is available on the role and enzyme composition of this organelle in distinct cell types of the testis. In the present study, we characterized the peroxisomal compartment in human and mouse testis in primary cultures of murine somatic cells (Sertoli, peritubular myoid, and Leydig cells) and in GFP-PTS1 transgenic mice with a variety of morphological and biochemical techniques. Formerly, peroxisomes were thought to be absent in late stages of spermatogenesis. However, our results obtained by detection of different peroxisomal marker proteins show the presence of these organelles in most cell types in the testis, except for mature spermatozoa. Furthermore, we demonstrate a strong heterogeneity of peroxisomal protein content in various cell types of the human and mouse testis and show marked differences in structure, abundance, and localization of these organelles in spermatids, depending on their maturation. Highest and selective enrichment of the peroxisomal lipid transporters (ABCD1 and ABCD3) as well as ACOX2, the key regulatory enzyme of the beta-oxidation pathway 2 for side chain oxidation of cholesterol, were found in Sertoli cells, whereas Leydig cells were enriched in catalase and ABCD2. Our results suggest a cell type-specific metabolic function of peroxisomes in the testis and point to an important role for peroxisomes in spermiogenesis and in the lipid metabolism of Sertoli cells.     

Revision of the Neotropical bark mantis genus Liturgusa Saussure, 1869 (Insecta,Mantodea, Liturgusini)

The praying mantis genus Liturgusa Saussure, 1869 occurs only in Central and South America and represents the most diverse genus of Neotropical Liturgusini (Ehrmann 2002). The genus includes bark dwelling species, which live entirely on the trunks and branches of trees and run extremely fast. All species included within the genus Liturgusa are comprehensively revised with a distribution stretching from central Mexico, the island of Dominica to the southeastern regions of Brazil and southern Bolivia. All known species are redescribed to meet the standards of the new treatment of the genus (11 species). Three new genera are described including Fuga gen. n., Velox gen. n., and Corticomantis gen. n. for species previously included in Liturgusa as well as Hagiomantis. Liturgusa mesopoda Westwood, 1889 is moved to within the previously described genus Hagiomantis Audinet Serville, 1838. A total of 19 species are newly described within Liturgusa, Fuga, and Velox including L. algorei sp. n., L. bororum sp. n., L. cameroni sp. n., L. cura sp. n., L. dominica sp. n., L. fossetti sp. n., L. kirtlandi sp. n., L. krattorum sp. n., L. manausensis sp. n., L. maroni sp. n., L. milleri sp. n., L. neblina sp. n., L. purus sp. n., L. stiewei sp. n., L. tessae sp. n., L. trinidadensis sp. n., L. zoae sp. n., F. grimaldii sp. n., and V. wielandi sp. n. Four species names are synonymized: Liturgusa peruviana Giglio-Tos, 1914, syn. n. = Liturgusa nubeculosa Gerstaecker, 1889 and Hagiomantis parva Piza, 1966, syn. n., Liturgusa sinvalnetoi Piza, 1982, syn. n., and Liturgusa parva Giglio-Tos, 1914, syn. n. = Mantis annulipes Audinet Serville, 1838. Lectotypes are designated for the following two species: Liturgusa maya Saussure & Zehntner, 1894 and Fuga annulipes (Audinet Serville, 1838). A male neotype is designated for Liturgusa guyanensis La Greca, 1939. Males for eight species are described for the first time including Liturgusa cayennensis Saussure, 1869, Liturgusa lichenalis Gerstaecker, 1889, Liturgusa guyanensis La Greca, 1939, Liturgusa maya Saussure & Zehntner, 1894, Liturgusa nubeculosa Gerstaecker, 1889, Fuga annulipes (Audinet Serville, 1838), Corticomantis atricoxata (Beier, 1931), and Hagiomantis mesopoda (Westwood, 1889). The female of Fuga fluminensis (Piza, 1965) is described for the first time. Complete bibliographic histories are provided for previously described species. The spelling confusion surrounding Liturgusa/Liturgousa is resolved. Full habitus images for males and females are provided for nearly all species. Habitus and label images of type specimens are provided when possible. Diagnostic illustrations of the head and pronotum for males and females are provided for all species when possible. Illustrations of male genital structures are provided for all species for which males are known. Measurement data, including ranges and averages, are provided for males and females of all species. Combined male and female genus and species level dichotomous keys are provided with a Spanish translation. A complete table of all examined specimens lists label data, museum codes, repositories, and other specimen specific information. A KML file with all georeferenced locality records is downloadable from mantodearesearch.com for viewing in Google Earth. Natural history information is provided for species observed by the author.     

Food quality affects the expression of antimicrobial peptide genes upon simulated parasite attack in the larvae of greater wax moth

Predator‐prey interactions are an important evolutionary force affecting the immunity of the prey. Parasitoids and mites pierce the cuticle of their prey, which respond by activating their immune system against predatory attacks. Immunity is a costly function for the organism, as it often competes with other life‐history traits for limited nutrients. We tested whether the expression of antimicrobial peptides (AMP) of the larvae of the greater wax moth Galleria mellonella (L.) (Lepidoptera: Pyralidae) changes as a consequence of insertion of a nylon monofilament, which acts like a synthetic parasite. The treatment was done for larvae grown on a high‐quality vs. a low‐quality diet. The expression of Gloverin and 6‐tox were upregulated in response to the insertion of the nylon monofilament. The expression of 6‐tox, Cecropin‐D, and Gallerimycin were significantly higher in the ‘low‐quality diet’ group than in the ‘high‐quality diet’ group. As food quality seems to affect AMP gene expression in G. mellonella larvae, it should always be controlled for in studies on bacterial and fungal infections in G. mellonella.     

Effects of Varied Housing Density on a Hybrid Mouse Strain Followed for 20 Months

To evaluate the effect of increased housing density in a hybrid mouse strain, we evaluated a panel of physiological and behavioral traits in animals that were housed in groups of 3, 5, 8, or 12, using cages that provide 78.1 in² of floor space. Such groupings resulted in cage densities that ranged from half to almost twice the density recommended by the Guide for the Care and Use of Laboratory Animals. While previous studies have investigated physiological effects of increased housing density using inbred mouse strains, including C57BL/6J and 129S1/SvImJ, this study tested an F1 hybrid population of C57BL/6J x 129S1/SvImJ for changes resulting from either decreased or increased housing density. Mice were followed until they were 20 months old, a substantially longer duration than has been used in previous density studies. We evaluated mortality, growth, home cage behavior, blood pressure, body composition, clinical plasma chemistries, immune function, and organ weights (heart, kidney, adrenal glands, and testes) as endpoints of chronic stress that may arise from sub-optimal housing conditions. Few statistically different parameters were observed in this study, none of which describe chronic stress and all within normal physiological ranges for research mice, suggesting that this hybrid strain was not adversely affected by housing at twice the density currently recommended.     

Oligomer formation of staphylococcal α-toxin analyzed by electron microscopy and image processing

Abstract The 12S oligomeric form of Staphylococcus aureus α-toxin has been studied with electron microscopy after incubation of the toxin with membrane preparations or liposomes. The target material originated from human platelet. Different electron microscopic preparation techniques were used including negative staining, freeze-fracture and vitrification in liquid ethane. Analysis of micrographs with image processing methods revealed two groups of ring-like structures corresponding to α-toxin oligomers. One form measured 75 Å in diameter and had a high stain density in the central protein deficient part while the other was larger with a diameter of 100 Å and less stain accumulation in the center. The conditions under which the latter were formed suggest that this corresponds to an inactive loosely-bound form of the toxin. The high stain density in the smaller particle is consistent with the presence of a penetrating pore in this structure.     

Phylogeny of Mantodea based on molecular data: evolution of a charismatic predator

Abstract. The previously unknown phylogenetic relationships among Mantodea (praying mantids) were inferred from DNA sequence data. Five genes (16S rDNA, 18S rDNA, 28S rDNA, cytochrome oxidase II and histone 3) were sequenced for sixty‐three taxa representing major mantid lineages and outgroups. The monophyly of mantid families and subfamilies was tested under varying parameter settings using parsimony and Bayesian analyses. The analyses revealed the paraphyly of Hymenopodidae, Iridopterygidae, Mantidae, and Thespidae and the monophyly of the Amorphoscelidae subfamily Paraoxypilinae. All represented subfamilies of Iridopterygidae and Mantidae appear paraphyletic. Mantoididae is sister group to the rest of the sampled mantid taxa. Lineages congruent with current subfamilial taxonomy include Paraoxypilinae, Hoplocoryphinae, Hymenopodinae, Acromantinae and Oligonicinae. The mantid hunting strategy is defined as either generalist, cursorial or ambush predators. By mapping hunting strategy onto our phylogeny, we reconstructed the ancestral predatory condition as generalist hunting, with three independent shifts to cursorial hunting and one shift to ambush hunting, associated with the largest radiation of mantid species.