Differences in Culturable Microbial Communities in Bird Nestboxes According to Orientation and Influences on Offspring Quality in Great Tits (Parus major)

Although bird-microbial interactions have become a topic of increasing research, the influence of nest-site characteristics, such as cavity orientation, on nest microbial communities in free-living passerines has not, to our knowledge, been investigated. This is despite the possibility of microbial differences explaining non-random patterns in nest-site selection and offspring quality, such as those exhibited by great tits (Parus major). We swabbed great tit nestboxes that faced either south-southwest (180-269°) or north-northeast (0-89°). Overall, 28 bacterial species and 11 fungal species were isolated, but the culturable microbial community differed substantially between different orientations-indeed nestboxes could be classified to their orientation group with high accuracy using microbial data. Nestboxes facing south-southwest had a significantly higher fungal load (typically double) than those facing north-northeast due to a higher abundance of two species, Epicoccum purpurascens and Cladosporium cladosporioides. There was no relationship between total bacterial load and orientation, although the abundance of one species, Pseudomonas veronii, was significantly lower in south-southwest boxes. The abundance of the allergen E. purpurascens explained almost 20% of the variation in offspring quality, being significantly and inversely related to chick size (high loads associated with small, poor quality, chicks). Our results provide empirical evidence for a correlation between nestbox orientation and culturable microbial load and a further correlation between abundance of one species, E. purpurascens, and offspring quality. Thus, microbial load, which is itself influenced by nest cavity parameters, could be the proximate factor that influences nest-site choice through its effect on offspring quality (and thus, overall fecundity).     

Managing calcareous grassland for the declining Duke of Burgundy <Emphasis Type="Italic">Hamearis lucina</Emphasis> butterfly: effects of grazing management on <Emphasis Type="Italic">Primula</Emphasis> host plants

Many butterfly species are declining in range and abundance, sometimes to the point of becoming vulnerable to extinction. Several traits increase a species’ vulnerability to population decline through stochastic processes, including high larval specificity and poor dispersal rate. The Duke of Burgundy Hamearis lucina relies on Primula as its sole larval host plant. This monophagus dependency, coupled with susceptibility to environmental stochasticity, low dispersal and poor recolonization potential, means it is vital that sites supporting this rapidly-declining species are managed optimally. Here, we use two calcareous grassland sites in the UK with different grazing systems to identify optimal grazing management for Primula abundance and, for the first time, Primula characteristics linked previously to Duke oviposting preference and success: size, condition, succulence and surrounding sward height. We find that autumn and winter grazing intensity are both positively associated with Primula abundance, but there is a trade-off for winter grazing with negative effects on plant size, condition and succulence. Winter grazing also decreased the sward height below the optimum. Plants were bigger and better at the site managed using continuous (free-roaming) grazing versus the site managed using rotational (paddock-based) grazing. We recommend moderately high grazing intensity during autumn using a free-roaming system where possible to attain abundant Primula, with a reduction in grazing intensity or grazing removal during winter to ensure suitability of individual plants. This management would also benefit other host plants, such as bird’s foot trefoil Lotus corniculatus, which are vital for other declining butterflies that frequently co-occur with Dukes.     

Development and characterization of microsatellite loci from Olea europaea

This study reports 19 simple sequence repeat loci developed from a genomic library of the olive tree (Olea europaea L.), of which 12 revealed to be polymorphic and informative, ranging from two to 14 alleles.     

Connexin37 protects against atherosclerosis by regulating monocyte adhesion

A genetic polymorphism in the human gene encoding connexin37 (CX37, encoded by GJA4, also known as CX37) has been reported as a potential prognostic marker for atherosclerosis. The expression of this gap-junction protein is altered in mouse and human atherosclerotic lesions: it disappears from the endothelium of advanced plaques but is detected in macrophages recruited to the lesions. The role of CX37 in atherogenesis, however, remains unknown. Here we have investigated the effect of deleting the mouse connexin37 (Cx37) gene (Gja4, also known as Cx37) on atherosclerosis in apolipoprotein E-deficient (Apoe(-/-)) mice, an animal model of this disease. We find that Gja4(-/-)Apoe(-/-) mice develop more aortic lesions than Gja4(+/+)Apoe(-/-) mice that express Cx37. Using in vivo adoptive transfer, we show that monocyte and macrophage recruitment is enhanced by eliminating expression of Cx37 in these leukocytes but not by eliminating its expression in the endothelium. We further show that Cx37 hemichannel activity in primary monocytes, macrophages and a macrophage cell line (H36.12j) inhibits leukocyte adhesion. This antiadhesive effect is mediated by release of ATP into the extracellular space. Thus, Cx37 hemichannels may control initiation of the development of atherosclerotic plaques by regulating monocyte adhesion. H36.12j macrophages expressing either of the two CX37 proteins encoded by a polymorphism in the human GJA4 gene show differential ATP-dependent adhesion. These results provide a potential mechanism by which a polymorphism in CX37 protects against atherosclerosis.     

Brood size: a major factor influencing male dimorphism in the non‐pollinating fig wasp Sycobia sp.

• 1 Male polymorphisms have been described in some non‐pollinating fig wasps, as well as in other animals. The proximal basis and the maintenance of alternative male reproductive strategies are either genetic or environmental.
• 2 Here we studied male dimorphism in the non‐pollinating fig wasp Sycobia sp. We conducted experimental manipulations to study the factors influencing offspring male morph allocations and explore a possible basis for the determination and maintenance of male dimorphism in Sycobia sp.
• 3 The results showed that brood size was the major and underlying factor influencing the male morph ratio. When the brood size increases, the wingless male ratio also increases.
• 4 Also, our results indicated that there was no direct maternal control on offspring male morph allocation.
• 5 Male dimorphism in Sycobia sp. probably represents an environmentally determined conditional strategy, which responded to offspring population density at the level of the individual fig.

     

Acanthamoeba Interaction with Extracellular Matrix Glycoproteins: Biological and Biochemical Characterization and Role in Cytotoxicity and Invasiveness

ABSTRACT. Acanthamoeba are free-living amoebae that are dispersed in most environments. Occasionally, Acanthamoeba cause serious human infections, such as keratitis and encephalitis. During the infection process, amoebic adhesion to, and degradation of, host cells and their extracellular matrix (ECM) appear to be important requirements. We examined the interaction of Acanthamoeba with the ECM, and related this event to host cell destruction and tissue invasion. Pathogenic Acanthamoeba culbertsoni differentially attached on the ECM glycoproteins laminin-1, collagen-I, and fibronectin, as compared with non-pathogenic Acanthamoeba astronyxis . Binding to collagen-I and laminin-1 induced A. culbertsoni to become flattened and elongated. Because attachment on laminin-1 was higher in A. culbertsoni , laminin-1 was chosen for further analysis. A 55-kDa laminin-binding protein was identified in pathogenic amoebae, but it was not found in non-pathogenic amoebae. No differential cytotoxicity against distinct cell types was observed between A. culbertsoni incubated with or without ECM. On the other hand, binding on collagen-I or matrigel scaffolds induced a differential effect where A. culbertsoni invaded collagen-I matrices more rapidly. These results indicate that ECM recognition, as an antecedent to tissue invasion, may be a trait characteristic of pathogenic Acanthamoeba .     

First Record of the Peritrich Trichodina diaptomiBasson and Van As, 1991 (Protozoa: Ciliophora) on a South American Calanoid Notodiaptomus deitersi (Poppe, 1890) (Crustacea: Copepoda)

ABSTRACT. The ciliate Trichodina was recorded on the calanoid Notodiaptomus deitersi in a shallow, eutrophic reservoir, located in the centre‐west of Brazil. The species was confirmed as Trichodina diaptomi, a species widely distributed in Europe, Africa, Asia and Australia. It was observed moving freely over the carapace of the copepod, and using its adhesive disc. This is the first record for the species in the Americas.     

Paravahlkampfia francinae n. sp. Masquerading as an Agent of Primary Amoebic Meningoencephalitis

ABSTRACT. Paravahlkampfia francinae n. sp., a new species of the free-living amoeba genus Paravahlkampfia , designated as CDC:V595, was isolated from the cerebrospinal fluid of a patient with headache, sore throat, and vomiting, typical symptoms of primary amoebic meningoencephalitis (PAM) caused by Naegleria fowleri . The isolate grew at 33 °C, 37 °C, 40 °C, and 42 °C and destroyed mammalian cell cultures. However, it did not kill young mice upon intranasal inoculation. P. francinae does not produce flagellates and does not grow on agar plates coated with Gram-negative bacteria such as Escherichia coli , the usual food source of Paravahlkampfia ustiana , the type species of the genus. The trophozoite at light microscopy exhibited eruptive locomotion and possessed a single vesicular nucleus. Ultrastructurally, the trophozoites had numerous mitochondria with discoidal cristae but did not have a Golgi apparatus. The trophozoites differentiated into cysts after consuming most of the monolayer. The cyst had an inner well-differentiated endocyst and an outer thin, wrinkled, and wavy ectocyst with no pores. During excystation trophozoites ruptured the cyst wall and emerged from the cysts. A unique feature seen in the cysts was the presence of bacterial endosymbionts, both in the endoplasm and within the cyst wall. Full-length sequencing analysis of the 18S and 5.8S RNA genes of P. francinae showed that they were distinct from those of other Paravahlkampfia species. The patient recovered within a few days indicating that some of the previously reported cases of PAM that survived may have been due to P. francinae .