The central-marginal model is widely accepted in chromosomally polymorphic species of Drosophila. In fact, geographically and ecologically central populations of Drosophila show higher levels of polymorphism for paracentric inversions, whereas marginal populations tend to be monomorphic. This fact has been variously explained. Chromosomal polymorphisms in grasshoppers have also been attributed to show such geographical structuring, as in the case of the South-American grasshopper Dichroplus pratensis Bruner (Orthoptera: Acrididae). However, in three other cases involving Acrididae – Leptysma argentina Bruner, Trimerotropis pallidipennis (Burmeister) and Cornops aquaticum (Bruner), it is clear that chromosomal polymorphisms (sometimes with a wide extension over the Argentine area) do not conform to this pattern, and show instead clear correlations with environmental variables, especially minimum temperature, showing low or null frequencies of the rearrangements at one extreme of the environmental gradient and with high or fixed frequencies at the other. Furthermore, this correlation with temperature might also be true in the case of D. pratensis. These aforementioned examples emphasise the dangers of over-generalization when discussing chromosomal polymorphisms, and suggests that such polymorphisms should be considered very much in a case-specific manner in terms of the particular genetic system under study., Pablo C. Colombo., and Obsahuje seznam literatury
Cytochrome P450s (P450s) involved in insecticide resistance reduce the efficacy of insecticide-based vector control by rendering vector control ineffective. They are recorded in many species of vectors and have various constitutive and insecticide induction profiles. In this study, the isolation and prediction of the structure of a P450 from a strain of Aedes aegypti originating from Malaysia is reported. Quantitative mRNA expression of this gene and a previously reported P450, CYP4H28v2, in the developmental stages of the mosquito after exposure to sub-lethal concentrations of insecticides is also reported. The isolated P450, CYP4H31v2, is an allelic variant of CYP4H31 and contains several conserved motifs of P450s. The secondary structure of the protein is mostly made up of alpha helices and random coils. The tertiary structure was generated using homology modeling and was of good quality based on structure validation using protein structure assessment tools. CYP4H28v2 and CYP4H31v2 were differentially expressed in the developmental stages of the vector, with a significantly increased expression in adult males. The genes were significantly over-expressed in larvae exposed to deltamethrin and permethrin for 6 h. In the DDT-treated larvae, only CYP4H31v2 was significantly over-expressed after a 6 h exposure. Under-expression of the genes was predominant in larvae treated with the organophosphates malathion and temephos. Though the functions of these P450s are unknown, their response to induction by exposure to insecticides indicates the likely involvement of these genes in insecticide tolerance. and Fatma M. A. El-Garj, Mustafa F.F. Wajidi, Silas W. Avicor.
One of the best documented effects of climate change on biodiversity are shifts in phenology. However, long-term data quantifying and projecting the expected changes in phenology associated with climate warming are limited to a few well-recorded areas in the world. In the absence of temporal recording, an alternative approach is to determine the phenological response of species along marked gradients in climate or along latitudinal or altitudinal transects (space-for-time substitution). We studied the phenology (timing and duration of the flight period) of butterflies in 2006 along an altitudinal gradient (900-1680 m; estimated temperature lapse rate = -6.6°C/km) in the Serranía de Cuenca (central Spain) at the assemblage and individual species levels. Timing of the flight period was later for assemblages at high than at low altitudes. A similar trend of an increasing delay in the flight period with altitude was recorded for some individual species. However, there were also some exceptions to this pattern regardless of the number of sites and the altitudinal ranges of the species, suggesting possible local adaptation to regional climate. The duration of the flight period was shorter at high altitudes for assemblages, but this trend was not mirrored in the response of individual species. The results partly support substituting space-for-time when assessing the potential effect of climate change on phenophases such as the timing of the flight period, but we recommend extreme caution in extrapolating the results in the absence of information on how the responses of populations differ. and Juan Ignacio De Arce Crespo, David Gutiérrez.
Forticulcita platana sp. n. and Forticulcita apiensis sp. n. are described from Mugil liza Valenciennes in Argentina, and from Mugil cephalus Linnaeus in Salt Springs, Florida, USA, respectively. Supplemental material relating to the hermaphroditic sac of Forticulcita gibsoni Blasco-Costa, Montero, Balbuena, Raga et Kostadinova, 2009 is provided from a specimen isolated from M. cephalus off Crete, Greece.Forticulcita platana can be distinguished from all species of Forticulcita Overstreet, 1982 except F. gibsoni, based on possessing small pads or gland cells along the hermaphroditic duct. It can be differentiated from that species in possessing a hermaphroditic sac that is one and a half to two times longer than wide rather than one that is approximately three times longer than wide, longer eggs (44-52μm rather than 34-44 μm long) and a shorter post-testicular space (<45% of the body length). Forticulcita apiensis can be differentiated from the other species of Forticulcita in possessing a testis that is shorter than or equal to the pharynx rather than one that is longer than the pharynx. Xiha gen. n. is erected for Dicrogaster fastigatus Thatcher et Sparks, 1958 as Xiha fastigata (Thatcher et Sparks,1958) comb. n., and we tentatively consider Dicrogaster fragilis Fernández Bargiela, 1987 to be Xiha fragilis (Fernández Bargiela, 1987) comb.n. The new genus fits within the concept of Forticulcitinae Blasco-Costa, Balbuena, Kostadinova et Olson, 2009 in having a vitellarium comprised of a single elongate to subspherical mass. Xiha can be differentiated from Forticulcita in having spines lining the hermaphroditic duct, or intromittent organ. A Bayesian inference analysis of partial 28S rDNA sequences of the two New World species of Forticulcita, Xiha fastigata and previously published haploporids places Xiha fastigata within the Forticulcitinae and sister to Forticulcita. Amended diagnos for the subfamily and for Dicrogaster Looss, 1902 are provided., Michael J. Andres, Stephen S. Curran, Thomas J. Fayton, Eric E. Pulis, Robin M. Overstreet., and Obsahuje bibliografii
Three adult nematode specimens, all ovigerous females belonging to the family Cystidicolidae Skryabin, 1946, were found for the first time in the subcutaneous tissue around the eye of the captive porcupinefish Diodon nichthemerus Cuvier at a public aquarium in Osaka, Japan. Because no male was available, these could not be identified to the genus and species. This case highlights the risk of parasitism in aquaculture puffer fish, as these may ingest small shrimp, which probably act as intermediate hosts for the nematode., Kozue Sasaki, Yoshimi Miyagawa, Itsuki Kiyatake, Kiyoko Onda, Takaomi Ito, Mitsuhiko Asakawa., and Obsahuje bibliografii
Classical biological control is an important means of managing the increasing threat of invasive plants. It constitutes the introduction of natural enemies from the native range of the target plant into the invaded area. This method may be the only cost-effective solution to control the rapidly expanding common ragweed, Ambrosia artemisiifolia, in non-crop habitats in Europe. Therefore, candidate biocontrol agents urgently need to be assessed for their suitability for ragweed control in Europe. A previous literature review prioritized the host-specific leaf beetle Ophraella slobodkini as a candidate agent for ragweed control in Europe, whereas it rejected its oligophagous congener O. communa. Meanwhile, O. communa was accidentally introduced and became established south of the European Alps, and we show here that it is expanding its European range. We then present a short version of the traditional pre-release risk-benefit assessment for these two candidate agents to facilitate fast decision-making about further research efforts. We selected two complementary tests that can be conducted relatively rapidly and inform about essential risks and benefits. We conducted a comparative no-choice juvenile performance assay using leaves of ragweed and sunflower, the most important non-target plant, in Petri dishes in climatic conditions similar to that in the current European range of O. communa. This informs on the fundamental host range and potential for increasing abundance on these host plants. The results confirm that O. slobodkini does not survive on, and is hence unlikely to cause severe damage to sunflower, while O. communa can survive but develops more slowly on sunflower than on ragweed. In parallel, our species distribution models predict no suitable area for the establishment of O. slobodkini in Europe, while O. communa is likely to expand its current range to include a maximum of 18% of the European ragweed distribution. Based on this early assessment, the prioritization and further assessment of O. slobodkini seem unwarranted whereas the results urgently advocate further risk-benefit analysis of O. communa. Having revealed that most of the European area colonized by ragweed is unlikely to be suitable for these species of Ophraella we suggest the use of such relatively short and cheap preliminary assessment to prioritise other candidate agents or strains for these areas., Suzanne T. E. Lommen, Emilien F. Jolidon, Yan Sun, José I. Bustamante Eduardo, Heinz Müller-Schärer., and Obsahuje bibliografii
Problems with parasitic infections and their interspecies transmissions are common in zoological gardens and could pose serious health damage to captive animals. This study presents results of eight-year monitoring of intestinal parasites in animals from Zoo Ljubljana, Slovenia. A total of 741 faecal samples from 40 animal species were collected two to four times per year and examined microscopically. Intestinal parasites were detected in 45% of samples, with detection of helminths (Cestoda, Nematoda - Ascaridida, Enoplida, Strongylida, Oxyurida, Rhabditida and Trichurida) and protists (Apicomplexa and Ciliophora) in 25% and 13% of samples, respectively; mixed infection was found in 7% of samples. The mostly infected were ungulates (61%), followed by reptiles (44%), ratites (29%), primates (22%) and carnivores (7%). During the observation period, the number of infected animal species increased from 8 to 25. This is the first long-term monitoring study of intestinal parasites in zoo animals from Slovenia. Routine monitoring of parasitic infection and regular deworming and hygienic measures are necessary to prevent gastrointestinal infections in captive animals., Pavel Kvapil, Marjan Kastelic, Alenka Dovč, Eva Bártová, Petr Čížek, Natacha Lima, Špela Štrus., and Obsahuje bibliografii
About 30-50% of the world human population are infected with the protozoan parasite Toxoplasma gondii (Nicolle et Manceaux, 1908). Latent toxoplasmosis has many specific behavioural and physiological effects on the human body and influences the course of pregnancy, including secondary sex ratio of children of infected mothers. It was suggested that an increased concentration of glucose could be the proximate cause of increased sex ratio. There are some indirect indications of possible association between toxoplasmosis and certain forms of diabetes. Here we searched for a possible link between latent toxoplasmosis and the level of glucose in the blood. In a cross-sectional study, we found that pregnant women with latent toxoplasmosis had significantly higher blood glucose levels during the oral glucose tolerance test (n = 191, p = 0.010; the level of fasting plasma glucose: mean = 5.04 mmol/l vs mean = 4.88 mmol/l; blood glucose level at 1 hour mean = 7.73 mmol/l vs mean = 6.89 mmol/l and blood glucose level at two hours mean = 6.43 mmol/l vs mean = 5.74 mmol/l) and higher prevalence (19.5 %) of gestational diabetes mellitus (n = 532, p = 0.033, odds ratio = 1.78) in the 24-28th gestational weeks than T. gondii-free women (12.0 %). Increased level of glucose and increased incidence of gestational diabetes mellitus could have considerable clinical impact as contributors to the development of the metabolic syndrome and type 2 diabetes in T. gondii-infected women. Our results also brought the first empirical support for the hypothesis that the glucose concentration may play a role in T. gondii-associated offspring sex ratio shifts., Šárka Kaňková, Jaroslav Flegr, Pavel Calda., and Obsahuje bibliografii
The pine bark beetle, Dendroctonus armandi, is a native pest restricted to forests in the Qinling Mountains in China. There was an outbreak of this species there that affected over 0.36 million hectares of pine forest. We hypothesized that there are differences between the numbers of beetles captured by traps baited with various combinations of candidate semiochemicals extracted from the hindguts of D. armandi. In order to determine whether a better operational lure could be developed for D. armandi, we analyzed the volatiles in extracts of the hindgut of D. armandi and tested various combinations of candidate semiochemicals. The GC-MS and GC-FID analyses of volatiles in the extracts of the hindguts of D. armandi collected at different stages of the attack revealed that they are mainly a-pinene, b-caryophyllene and (+)-3-carene with minor amounts of myrcene, limonene, verbenol and verbenone. We tested various combinations of these candidate semiochemicals in order to determine an optimal blend. Our results suggest that the addition of b-caryophyllene to either a-pinene, or blends of a-pinene and other candidate semiochemicals, significantly enhanced the attractiveness of the lures for D. armandi. Field trapping experiments indicated that the blends that included b-caryophyllene, myrcene and other candidate semiochemicals resulted in significantly higher trap catches (161–243% higher) than a-pinene alone. Therefore, a simple lure consisting of a-pinene and b-caryophyllene would be an optimal blend for D. armandi. We conclude that this blend of semiochemicals may provide a better method of reducing the numbers of D. armandi in forest ecosystem., Shou-An Xie, Shu-Jie LV., and Obsahuje seznam literatury
Toxoplasma gondii (Nicolle et Manceaux, 1908) is an obligate intracellular apicomplexan parasite and can infect warmblooded animals and humans all over the world. Development of effective vaccines is considered the only ideal way to control infection with T. gondii. However, only one live vaccine is commercially available for use in sheep and goats. Thus more effective antigenic proteins are searched for. In the present study we report a novel protein by secreted T. gondii termed Myc regulation 1 (MYR1). The physical and chemical characteristics, epitopes, hydrophilicity and functional sites of MYR1 were analysed by multiple bioinformatic approaches. The 3D models of MYR1 proteins were constructed and analysed. Furthermore, liner B-cell epitopes and T-cell epitopes of MYR1 protein and SAG1 were predicted. Compared to SAG1, MYR1 with good B-cell epitopes and T-cell epitopes had a potentiality to become a more successful vaccine against T. gondii. The bioinformatics analysis of MYR1 proteins could laid the foundation for further studies of its biological function experimentally and provide valuable information necessary for a better prevention and treatment of toxoplasmosis., Jian Zhou, Gang Lu, Shenyi He., and Obsahuje bibliografii