Molecular Characterization of Gregarines from Sand Flies (Diptera: Psychodidae) and Description of Psychodiella n. g. (Apicomplexa: Gregarinida)

ABSTRACT. Sand fly and mosquito gregarines have been lumped for a long time in the single genus Ascogregarina and on the basis of their morphological characters and the lack of merogony been placed into the eugregarine family Lecudinidae. Phylogenetic analyses performed in this study clearly demonstrated paraphyly of the current genus Ascogregarina and revealed disparate phylogenetic positions of gregarines parasitizing mosquitoes and gregarines retrieved from sand flies. Therefore, we reclassified the genus Ascogregarina and created a new genus Psychodiella to accommodate gregarines from sand flies. The genus Psychodiella is distinguished from all other related gregarine genera by the characteristic localization of oocysts in accessory glands of female hosts, distinctive nucleotide sequences of the small subunit rDNA, and host specificity to flies belonging to the subfamily Phlebotominae. The genus comprises three described species: the type species for the new genus— Psychodiella chagasi ( Adler and Mayrink 1961 ) n. comb., Psychodiella mackiei ( Shortt and Swaminath 1927 ) n. comb., and Psychodiella saraviae ( Ostrovska, Warburg, and Montoya-Lerma 1990 ) n. comb. Its creation is additionally supported by sequencing data from other gregarine species originating from the sand fly Phlebotomus sergenti . In the evolutionary context, both genera of gregarines from mosquitoes ( Ascogregarina ) and sand flies ( Psychodiella ) have a close relationship to neogregarines; the genera represent clades distinct from the other previously sequenced gregarines.     

Population trends of European common birds are predicted by characteristics of their climatic niche

Temperate species are projected to experience the greatest temperature increases across a range of modelled climate change scenarios, and climate warming has been linked to geographical range and population changes of individual species at such latitudes. However, beyond the multiple modelling approaches, we lack empirical evidence of contemporary climate change impacts on populations in broad taxonomic groups and at continental scales. Identifying reliable predictors of species resilience or susceptibility to climate warming is of critical importance in assessing potential risks to species, ecosystems and ecosystem services. Here we analysed long‐term trends of 110 common breeding birds across Europe (20 countries), to identify climate niche characteristics, adjusted to other environmental and life history traits, that predict large‐scale population changes accounting for phylogenetic relatedness among species. Beyond the now well‐documented decline of farmland specialists, we found that species with the lowest thermal maxima (as the mean spring and summer temperature of the hottest part of the breeding distribution in Europe) showed the sharpest declines between 1980 and 2005. Thermal maximum predicted the recent trends independently of other potential predictors. This study emphasizes the need to account for both land‐use and climate changes to assess the fate of species. Moreover, we highlight that thermal maximum appears as a reliable and simple predictor of the long‐term trends of such endothermic species facing climate change.     

Sandfly midgut lectin: effect of galactosamine on Leishmania major infections

Galactosamine, which has been shown in vitro to specifically inhibit sandfly midgut lectin activity, was fed to Phlebotomus duboscqi females with blood containing promastigotes of Leishmania major . Non-inhibitory sugar, galactose, was added in controls. For two strains of L. major (LV 561 and Neal-P), galactosamine substantially enhanced the establishment of infection in the sandfly posterior midgut and significantly increased parasite loads after defaecation, but did not affect anterior migration of Leishmania . On day 3 post-infection, most infections in galactosamine-fed sandfly groups (92% of LV 561 and 100% of Neal-P) were found in the ectoperitrophic space of the posterior midgut, whereas most infections in the galactose-fed groups of sandflies (85% in LV 561 and 96% in Neal-P) were restricted to the peritrophic sac. On day 9, however, the proportion of infections colonizing the stomodeal valve was similar in both dietary groups of sandflies for both strains of L. major . The addition of galactosamine prevented the decrease of parasite loads which occurred in controls between days 3 and 6 post-infection. On days 6 and 9, heavy infections were observed almost exclusively in galactosamine-fed females. Differences between groups were more pronounced for the Neal-P strain, which normally developed poorly in sandflies. Morphology of L. major LV 561 was not affected by galactosamine supplement: the lengths of parasite body and flagellum were similar in both sandfly groups. Two hypotheses are considered for the role of sandfly midgut lectin in Leishmania development in the vector midgut. One proposes that sandfly lectin kills Leishmania promastigotes, the other assumes that lectin blocks LPG-mediated binding of promastigotes to sandfly midgut microvilli.     

Characterization of Plant Alcohol Dehydrogenase

The final activity of the alcohol dehydrogenase (E.C.1.1.1.1, abbreviated ADH) from germinating pea, isolated by fractionating with ammonium sulphate, chromatography on DEAE cellulose and gel filtration, was 80,000, from bean 25,000 and from lentil 13,500 units per mg protein. Molecular weights of the ADHs are close to each other: pea and bean ADH 60,000, lentil ADH 70,000. The K_m values are mutually similar with three enzymes, i.e. of the order of 10⁻⁴M for NAD and 10⁻²M for ethanol. The pH optima lie in the alkaline region. These enzymes catalyse oxidation of a number of monovalent alcohols. At temperatures above 60°C the enzymes are thermally unstable. Stability is enhanced slowly by ethanol but not by NAD. Pyrazol, imidazol and pyridine inhibit plant ADH similarly to the enzyme from horse liver. There is a similarity between plant alcohol dehydrogenases and animal and yeast enzymes.     

Low population differentiation and high genetic diversity in the invasive species Carduus acanthoides L. (Asteraceae) within its native range in the Czech Republic

Colonizing species are predicted to suffer from reductions in genetic diversity during founding events. Although there is no unique mode of reproduction that is characteristic of successful plant colonizers, many of them are predominantly self-fertilizing or apomictic species, and almost all outcrossing colonizers are self-compatible. Carduus acanthoides comprises a species of disturbed habitats with wind-dispersed seeds that colonizes open spaces of various sizes. Population genetic diversity was expressed by assessing patterns of variation at nine putatively neutral allozyme loci within and among 20 natural populations in its native distribution range in the Czech Republic. Overall, C. acanthoides displayed high levels of genetic diversity compared to other herbaceous plants. The percentage of polymorphic loci was 84.5, with values of 2.37, 0.330, and 0.364 for the mean number of alleles per polymorphic locus ( A ), observed heterozygosity ( H _o), and expected heterozygosity ( H _e), respectively. There was only weak evidence of inbreeding within populations ( f  = 0.097) and very low genetic differentiation among populations ( θ  = 0.085). Analyses of the data provide strong evidence for isolation-by-distance for the whole study area. Even the colonizing species, C. acanthoides , currently supports a substantial amount of allozyme variation at both the species and population levels.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 98 , 596–607.     

Hybridization between diploid Centaurea pseudophrygia and tetraploid C. jacea (Asteraceae): the role of mixed pollination,unreduced gametes,and mentor effects

We studied hybridization between the diploid Centaurea pseudophrygia and the tetraploid C. jacea by performing crossing experiments and screening natural populations using flow cytometry. The experiments confirm that the studied species exhibit strong reproductive isolation. Interspecific hybrids were formed at a low frequency, including triploids (originating from reduced gametes) and tetraploids (involving unreduced gametes of the diploids). In contrast, hybrids were almost absent among seeds and adult plants of natural mixed populations and among the offspring from experimental pollinations with a mixture of pollen of both ploidy levels. We found that mixed pollination is an important mechanism for preventing hybridization between plants of different ploidy levels and sustaining the reproduction of the tetraploids. A mentor effect (induced selfing in the presence of pollen of different ploidy levels) was observed in both diploids and tetraploids, reinforcing the reproductive isolation between cytotypes. Higher ploidy levels (pentaploid, hexaploid) involving unreduced gametes of the tetraploid species were identified. Notably, pentaploids were discovered for the first time in Centaurea sect. Jacea. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 93–106.     

Agricultural intensification and farmland birds: new insights from a central European country

The relationship between agricultural intensification and a decline in farmland bird populations is well documented in Europe, but the results are mostly based on data from the western part of the continent. In the former socialist eastern and central European countries, political changes around 1990 resulted in a steep decline in the intensity of agriculture. Therefore, one would expect populations of farmland birds to have recovered under these conditions of lower agricultural intensity. We explored population trends of 19 farmland bird species in the Czech Republic between 1982 and 2003 using data from a large‐scale monitoring scheme, and, additionally, we looked for relationships between such population changes and a number of variables describing the temporal development of Czech agriculture. Most farmland species declined during the focal period, and this decline was steepest in farmland specialists (Northern Lapwing Vanellus vanellus, Skylark Alauda arvensis, Linnet Carduelis cannabina and Yellowhammer Emberiza citrinella). Although the intensity of agriculture was lower after than before 1990, the overall decline continued in most farmland bird species, albeit at a slower rate. The correlations between agricultural intensity and farmland bird decline showed opposite patterns to that found in other European studies, because bird populations were highest in years with the most intensive agriculture. We speculate that this pattern could have resulted from the impact of different driving forces causing farmland bird decline in different periods. The high intensity of agriculture could have caused the decline of the originally abundant populations before 1990. After 1990, the decreasing area of arable land could be the most important factor resulting in the continued decline of farmland bird populations. Our results demonstrate that the drivers of farmland bird population changes could differ across Europe, and thus investigations into the effect of farmland management in different parts of the continent are urgently required.     

Population changes in Czech passerines are predicted by their life‐history and ecological traits

A species’ susceptibility to environmental change might be predicted by its ecological and life‐history traits. However, the effects of such traits on long‐term bird population trends have not yet been assessed using a comprehensive set of explanatory variables. Moreover, the extent to which phylogeny affects patterns in the interspecific variability of population changes is unclear. Our study focuses on the interspecific variability in long‐term population trends and annual population fluctuations of 68 passerine species in the Czech Republic, assessing the effects of eight life‐history and five ecological traits. Ordination of life‐history traits of 68 species revealed a life‐history gradient, from ‘r‐selected’ (e.g. small body mass, short lifespan, high fecundity, large clutch size) to ‘K‐selected’ species. r‐selected species had more negative population trends than K‐selected species, and seed‐eaters declined compared with insectivores. We suggest that the r‐selected species probably suffer from widespread environmental changes, and the seed‐eaters from current changes in agriculture and land use. Populations of residents fluctuated more than populations of short‐distance migrants, probably due to the effect of winter climatic variability. Variance partitioning at three taxonomic levels showed that whereas population trends, population fluctuations and habitat specialization expressed the highest variability at the species level, most life‐history traits were more variable at higher taxonomic levels. These results explain the loss of statistical power in the relationship between life histories and population trends after controlling for phylogeny. However, we argue that a lack of significance after controlling for phylogeny should not reduce the value of such results for conservation purposes.     

A New Entodiniomorphid Ciliate,Troglocorys cava n. g., n. sp., from the Wild Eastern Chimpanzee (Pan troglodytes schweinfurthii) from Uganda

ABSTRACT. Troglocorys cava n. g., n. sp. is described from the feces of wild eastern chimpanzee, Pan troglodytes schweinfurthii, in Uganda. This new species has a spherical body with a frontal lobe, a long vestibulum, a cytoproct located at the posterior dorsal side of the body, an ovoid macronucleus, a contractile vacuole near the cytoproct, and a large concavity on the left surface of the body. Buccal ciliature is non‐retractable and consists of three ciliary zones: an adoral zone surrounding the vestibular opening, a dorso‐adoral zone extending transversely at the basis of the frontal lobe, and a vestibular zone longitudinally extending in a gently spiral curve to line the surface of the vestibulum. Two non‐retractable somatic ciliary zones comprise arches over the body surface: a short dorsal ciliary arch extending transversely at the basis of the frontal lobe and a wide C‐shaped left ciliary arch in the left concavity. Because of the presence of three ciliary zones in the non‐retractable buccal ciliature, the present genus might be a member of the family Blepharocorythidae, but the large left concavity and the C‐shaped left ciliary arch are unique, such structures have never been described from other blepharocorythids.