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Petrovic T.,Scientific Veterinary Institute Novi Sad | Blazquez A.B.,Instituto Nacional Of Investigacion Y Tecnologia Agraria Y Alimentaria Inia | Lupulovic D.,Scientific Veterinary Institute Novi Sad | Lazic G.,Scientific Veterinary Institute Novi Sad | And 5 more authors.

West Nile virus (WNV), a neurovirulent mosquitotransmissible zoonotic virus, has caused recent outbreaks in Europe, including Serbia from August until October 2012. Although humans can be infected, birds are the main natural WNV reservoir. To assess WNV circulation in northern Serbia, 133 wild birds were investigated. These comprised resident and migratory birds, collected between January and September 2012 in the Vojvodina province. The birds belonged to 45 species within 27 families. Blood sera (n=92) and pooled tissues from respective birds (n=81) were tested by enzyme-linked immunosorbent assay (ELISA), plaque reduction neutralisation test (PRNT) and real-time reverse transcription-polymerase chain reaction (RT-qPCR). WNV antibodies were detected in seven (8%) sera: four from Mute Swans (Cygnus olor), two from White-tailed Eagles (Haliaeetus albicillas), and one from a Common Pheasant (Phasianus colchicus). Five sera neutralised WNV but not Usutu virus. For the first time in Serbia, WNV RNA was detected by RT-qPCR in pooled tissue samples of eight respective birds. WNV RNA was also derived from an additional bird, after a serum sample resulted infective in cell culture. The total nine WNV RNA positive birds included three Northern Goshawks (Accipiter gentilis), two White-tailed Eagles, one Legged Gull (Larus michahelis), one Hooded Crow (Corvus cornix), one Bearded Parrot-bill (Panarus biramicus), and one Common Pheasant. Phylogenetic analysis of partial E region sequences showed the presence of, at least, two lineage 2 Serbian clusters closely related to those responsible for recent human and animal outbreaks in Greece, Hungary and Italy. Full genomic sequence from a goshawk isolate corroborated this data. These results confirm WNV circulation in Serbia and highlight the risk of infection for humans and horses, pointing to the need for implementing WNV surveillance programmes. Source

Smeds L.,Uppsala University | Warmuth V.,Uppsala University | Bolivar P.,Uppsala University | Uebbing S.,Uppsala University | And 14 more authors.
Nature Communications

The typically repetitive nature of the sex-limited chromosome means that it is often excluded from or poorly covered in genome assemblies, hindering studies of evolutionary and population genomic processes in non-recombining chromosomes. Here, we present a draft assembly of the non-recombining region of the collared flycatcher W chromosome, containing 46 genes without evidence of female-specific functional differentiation. Survival of genes during W chromosome degeneration has been highly non-random and expression data suggest that this can be attributed to selection for maintaining gene dose and ancestral expression levels of essential genes. Re-sequencing of large population samples revealed dramatically reduced levels of within-species diversity and elevated rates of between-species differentiation (lineage sorting), consistent with low effective population size. Concordance between W chromosome and mitochondrial DNA phylogenetic trees demonstrates evolutionary stable matrilineal inheritance of this nuclear-cytonuclear pair of chromosomes. Our results show both commonalities and differences between W chromosome and Y chromosome evolution. © 2015 Macmillan Publishers Limited. All rights reserved. Source

Burri R.,Uppsala University | Nater A.,Uppsala University | Kawakami T.,Uppsala University | Mugal C.F.,Uppsala University | And 15 more authors.
Genome Research

Speciation is a continuous process during which genetic changes gradually accumulate in the genomes of diverging species. Recent studies have documented highly heterogeneous differentiation landscapes, with distinct regions of elevated differentiation ("differentiation islands") widespread across genomes. However, it remains unclear which processes drive the evolution of differentiation islands; how the differentiation landscape evolves as speciation advances; and ultimately, how differentiation islands are related to speciation. Here, we addressed these questions based on population genetic analyses of 200 resequenced genomes from 10 populations of four Ficedula flycatcher sister species. We show that a heterogeneous differentiation landscape starts emerging among populations within species, and differentiation islands evolve recurrently in the very same genomic regions among independent lineages. Contrary to expectations from models that interpret differentiation islands as genomic regions involved in reproductive isolation that are shielded from gene flow, patterns of sequence divergence (dxy and relative node depth) do not support a major role of gene flow in the evolution of the differentiation landscape in these species. Instead, as predicted by models of linked selection, genome-wide variation in diversity and differentiation can be explained by variation in recombination rate and the density of targets for selection. We thus conclude that the heterogeneous landscape of differentiation in Ficedula flycatchers evolves mainly as the result of background selection and selective sweeps in genomic regions of low recombination. Our results emphasize the necessity of incorporating linked selection as a null model to identify genome regions involved in adaptation and speciation. © 2015 Burri et al. Source

Sciban M.,Bird Protection and Study Society of Serbia | Markovic A.,Society For Biological Research Sergej D Matvejev | Lukic D.,Society For Biological Research Sergej D Matvejev | Milicic D.,Bird Protection and Study Society of Serbia | Milicic D.,University of Belgrade
North-Western Journal of Zoology

Autumn populations of two large branchiopod species, Branchinecta orientalis and Chirocephalus diaphanus in the area of southern part of Central European Lowlands (Pannonian Plain) are here reported for the first time. During surveys carried out in 2007-2013, autumn populations were observed in November 2009 (C. diaphanus) and in October 2012 (B. orientalis). Autumn specimens were smaller compared to those caught in spring. Although the two species were found in the same area, their habitats were spatially separated: B. orientalis was recorded only in the soda lake Rusanda, while C. diaphanus was found only in small ephemeral ponds placed over the surrounding meadows. Appearance of autumn populations point to the ecologically tolerant character of these species, and suggests they are able to tolerate lower temperatures during growth. © NwjZ, Oradea, Romania, 2014. Source

Fehervari P.,Szent Istvan University | Fehervari P.,Red footed Falcon Conservation Working Group | Solt S.,Red footed Falcon Conservation Working Group | Palatitz P.,Red footed Falcon Conservation Working Group | And 6 more authors.
Animal Conservation

The red-footed falcon Falco vespertinus is an enigmatic colonial raptor of high international conservation concern. One of the identified threatening factors responsible for the recent worldwide population decline is the shortage of suitable colonial nesting sites. In theory, this problem can easily be resolved by establishing artificial colonies. However, the key to a successful large scale nest-box scheme is to provide these artificial colonies in habitats suitable for the species. A Hungarian-Serbian project aimed to establish such nesting facilities in northern Serbia, although the lack of recent full-scale habitat surveys hindered the designation of the locations of these artificial nesting sites. We used five different species distribution models to model the distribution of nest sites on a 10×10km grid in Hungary and in Romania. We then used the ensemble predictions of the best performing models to project the probability of red-footed falcon nest site presence in northern Serbia (predicted area). The models showed that three variables (grasslands, pastures and broad-leaved forests) had the highest importance in describing the spatial pattern of nest sites in the modelling area. The extent of grasslands and pastures had positive effects, while broad-leaved forests had negative impact on the probability of nest site presence. The predictions classified all the currently known colonies in the predicted area correctly. Our results suggest that the potential breeding distribution in Serbia is similar to that of two decades ago, thus large-scale land use changes are presumably not responsible for the reported population decline. We have also reduced the extent of conservation target areas to 11.5%, allowing to pinpoint locations for these future nest box colonies, and also provided a basis for future conservation measures like allocating monitoring efforts and designating future Natura 2000 sites in Serbia. Animal Conservation © 2012 The Zoological Society of London. Source

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