Maciej Szewczyk

University of Gdańsk | UG · Department of Vertebrate Ecology and Zoology

The GC skew in vertebrate mitochondrial genomes results in synthesis of RNAs that are prone to form G-quadruplexes (G4s). Such RNAs, although mostly non-coding, are transcribed at high rates and are degraded by an unknown mechanism. Here we describe a dedicated mechanism of degradation of G4-containing RNAs, which is based on cooperation between mi...

Local extinction and recolonization events can shape genetic structure of subdivided animal populations. The gray wolf (Canis lupus) was extirpated from most of Europe, but recently recolonized big part of its historical range. An exceptionally dynamic expansion of wolf population is observed in the western part of the Great European Plain. Nonethe...

RNA decay is a key element of mitochondrial RNA metabolism. To date, the only well-documented machinery that plays a role in mtRNA decay in humans is the complex of polynucleotide phosphorylase (PNPase) and SUV3 helicase, forming the degradosome. REXO2, a homolog of prokaryotic oligoribonucleases present in humans both in mitochondria and the cytop...

The gray wolf Canis lupus range in central Europe is dynamically expanding, reconnecting previously isolated populations. Thus, a recent paper has proposed to merge the current Baltic and Central European (CE) wolf management units, which are no longer isolated by distance. However, recent genetic findings indicate that these two populations are no...

Aim The aim of the study was to assess the effect of changes in population size and migration on variation in functional immunity genes in the previously bottlenecked population of the grey wolf, Canis lupus. Location Eastern/Central Europe: Poland, Czechia, Slovakia. Methods We genotyped 7 immunity genes: three MHC-DLA genes (dog leukocyte antig...

Molecular methods are routinely used to estimate the effective size of populations (Ne). However, underlying model assumptions are frequently violated to an unknown extent. Although simulations can detect sources of bias and help to adjust sampling strategies and analyses methods, additional information from empirical data can also be used to calib...

After a long period of persecution, wolves are recolonizing Europe's human-dominated landscapes. Previous studies from areas with low human presence or ongoing human risk find wolves to avoid humans. However, close human-wolf encounters are increasingly reported in areas where wolves are strictly protected and raise concerns about the potential hab...

We assessed changes in the population size, density, and diet composition of wolves inhabiting the Romincka Forest (RF), an area of 480 km² situated along the state border between Poland, Russian Federation (Kaliningrad), and Lithuania. We compared the results of our research in 2020–2021 with data from other projects conducted since 1999. We found...

The wolf (Canis lupus) is arguably the most successful species at recolonizing its now human‐dominated former ranges in Europe and North America. Over the centuries while the wolf was absent, humans have transformed ecosystems to a large extent. In this paper, we highlight key aspects of these human‐modified ecosystems that include changes to (meso...

In Central and Eastern Europe, wolf populations have been increasing over the last two decades, recolonizing areas from which the species had been previously exterminated. As wolves are still recovering after years of persecution by humans, recognizing pathogens infecting this species, including tick-borne infections, is crucial for its conservatio...

Wilk szary jest w Polsce gatunkiem coraz liczniejszym dzięki objęciu ochroną ścisłą. Poznanie przyczyn jego śmiertelności pozwala na skuteczniejszą ochronę gatunku. Na UG w latach 2019-23, w celach potwierdzenia przyczyny śmierci i edukacyjnych, przeprowadzono sekcje 25, a sumarycznie zebrano dane na temat 30 osobników. Wśród nich dominowały samice...

The European grey wolf (Canis lupus) and the domestic dog (Canis lupus familiaris) share not only a common origin but also many similarities in their behavior. Due to the implementation of protection wolves repopulated large parts of Europe. The increase of wolves in human-dominated landscapes also leads to a growing potential for interactions betw...

The gray wolf Canis lupus was extirpated from western Poland, but since enforcement of strict protection in 1998 recolonized most of the suitable habitats. One of such recently recolonized areas is Tuchola Forest, a large forest complex in northwestern Poland, where an alien medium-sized ungulate species, fallow deer Dama dama, was introduced for h...

The gray wolf (Canis lupus) is dynamically recolonizing western Poland. One of such recently recolonized areas is Tuchola Forest, a large forest characterized by high density of an artificially introduced, medium-sized ungulate species, fallow deer (Dama dama). We investigated how fallow deer density affects diet composition and prey preference pat...

Humans drastically reduced and changed natural habitats, therefore nowadays many wild species have to adapt to human-dominated landscapes. An understanding of how wild animals function in a mosaic of natural and modified by humans areas as well as how they adapt to human-caused disturbance and how they take advantage of the opportunities created by...

Wolves are currently recolonizing parts of their former Holarctic range. The western part of Central Europe is a striking example of rapid range expansion after long-term absence of territorial wolves. We present the genetic reconstruction of wolf recolonization in the area since the year 2000, with several hundreds of wolf packs that inhabit the a...

While hybridization between wolves (Canis lupus) and domestic dogs (C. l. familiaris) is considered a threat to the genomic integrity of wolf populations worldwide, this phenomenon appears to occur particularly often in areas currently recolonised by wolves. Despite its importance assessments of optimal management strategies for wolf-dog hybrids as...

The European grey wolf (Canis lupus) and the domestic dog (Canis lupus familiaris) share not only a common origin, but also many similarities in their behavior. Because of their improved protection, wolf populations have increased in Poland and across Europe. The increasing presence of wolves in human-dominated landscapes brings them increasingly i...

Motives: Unlike nature monitoring, recreational activities in forests are not monitored regularly or over wide areas. Therefore, research studies involving various methodologies are needed to generate valuable data for forest management. Aim: The aim of the present study was to identify different types of forest recreational activities in Wdecki L...

African swine fever (ASF), caused by a DNA virus (ASFV) belonging to genus Asfivirus of the Asfarviridae family, is one of the most threatening diseases of suids. During last few years, it has spread among populations of wild boars and pigs in countries of Eastern and Central Europe, causing huge economical losses. While local ASF occurrence is pos...

Abstract: As a result of species protection in Poland, wolves now appear in places that are attractive for human recreation, increasing their exposure to dogs. This creates a risk of spontaneous direct interactions between these two canine species. Aggressive interactions between the gray wolf and the domestic dog lead to human-large predator confl...

Understanding factors and mechanisms causing large carnivore aggression towards people is crucial for their conservation in modern human-dominated landscapes. We present detailed descriptions of wolf attacks on people in early summer 2018 in two areas of Poland, analysis of behaviour, fitness and origin of individuals responsible for the attacks an...

In wolves Canis lupus, scent marking plays an important role in territory defence. In Europe, studies on patterns of scent marking in wolves have mostly been conducted in mountains or primeval forests, but since these areas are characterised by low human activity, the impact of people on this behaviour has been neglected. We conducted a study that...

Grey wolves C. lupus as apex predators have impact on ecology of smaller predators, e.g. red foxes V. vulpes. Coexistence with wolves entrails both with danger, because they often kill foxes, and availability of rich source of food – carrion. We compared sympatric canids’ diet in Tuchola Forest (TF), one of the biggest forests in Poland (ca. 3000 k...

Grey wolves C. lupus as apex predators have impact on ecology of smaller predators, e.g. red foxes V. vulpes. Coexistence with wolves entrails both with danger, because they often kill foxes, and availability of rich source of food – carrion. We compared sympatric canids’ diet in Tuchola Forest (TF), one of the biggest forests in Poland (ca. 3000 k...

We used 13 autosomal microsatellite loci to evaluate the genetic diversity in the wolf (Canis lupus) population inhabiting Tatra Mountains along Polish-Slovak border. From samples of biological material collected in 2017- 2018, we identifi ed genotypes of 42 wolves. All studied loci were polymorphic, with mean number of alleles being Na = 5.077 and...

Tracking, camera trapping and – in case of wolves – non-invasive genetic sampling based on 13 microsatellite loci, were used to determine the number of wolves and lynx in Roztocze National Park (south-eastern Poland). There were two wolf family groups breeding in the national park, which size accounted for 4-7 individuals. There were also four lynx...

Transcription of the human mitochondrial genome produces a vast amount of non-coding antisense RNAs. These RNA species can form G-quadraplexes (G4), which affect their decay. We found that the mitochondrial degradosome, a complex of RNA helicase SUPV3L1 (best known as SUV3) and the ribonuclease PNPT1 (also known as PNPase), together with G4-melting...

The wolf population has flourished across the whole of Poland since its strict protection in 1998. Wolves are also protected within the national parks and Natura 2000 sites that secure their habitats. Precise data on the status of local populations are required to plan conservation actions. For this reason, we applied camera trapping and non-invasi...

Aim Population fragmentation represents a leitmotif of conservation biology, but the impact of population reconnection is less well studied. The recent recolonization of large carnivores in Europe is a good model for studying this phenomenon. We aim to show novel data regarding distribution and population genetic structure of the grey wolf in Centr...

Monitoring of the wolf Canis lupus is a demanding task as it lives in low densities, utilizes vast home ranges and disperses over large areas. These factors make obtaining accurate data about population parameters over the whole distribution area of the species impossible. Thus detailed local studies on socio-spatial organization are essential to c...

Nanostructures as color-tunable luminescent markers have become major, promising tools for bioimaging and biosensing. The separated molybdate/Gd2O3 doped rare earth ions (erbium, Er(3+) and ytterbium, Yb(3+)) core-shell nanoparticles (NPs), were fabricated by a one step homogeneous precipitation process. Emission properties were studied by cathodo-...

The HtrA proteins due to their proteolytic, and in many cases chaperone activity, efficiently counteract consequences of stressful conditions. In the environmental bacterium and nosocomial pathogen Stenotrophomonas maltophilia HtrA (HtrASm) is induced as a part of adaptive response to host temperature (37 °C). We examined the biochemical properties...

If protected areas are to remain relevant in our dynamic world they must be adapted to changes in species ranges. In the EU one of the most notable such changes is the recent recovery of large carnivores, which are protected by Natura 2000 at the national and population levels. However, the Natura 2000 network was designed prior to their recent rec...

List and details of all SACs in Poland with ≥ 1 km2 of wolf habitat. Sites are sorted by population, and then by the amount of wolf habitat they protect. (DOCX)

Statistical significance of the Mann-Whitney U-tests for the pairwise comparisons of protected habitat area sizes between wolf populations in Poland. (DOCX)

Water-soluble upconversion nanoparticles (UCNPs), based on polyvinylpyrrolidone (PVP)-coated NaYF4:Er3+,Yb3+,Gd3+, with various concentrations of Gd3+ ions and relatively high upconversion efficiencies, were synthesized. Internalization and cytotoxicity of the thus obtained UCNPs was evaluated in three cell lines (HeLa, HEK293 and astrocytes). No c...

Aim To compare predictions of the habitat suitability model (HSM) for wolves Canis lupus in Poland with actual wolf distribution in western Poland after 15 years of recolonization. Location Western Poland (WPL, ca. 136,000 km2), west of the 18°48′E meridian. Methods Data on wolf occurrence (8,057 records) were gathered in 2001–2016. Wolf presenc...

Wolves live in family groups occupying vast territories. To avoid conflicts between individuals from neighbouring groups wolves apply territory marking using olfactory, visual and vocal signs. Marking with scats, urine and ground scratching play a particularly important role in maintaining territories, however human caused alteration of the environ...

At the turn of the 21st century, restriction of hunting and legal protection paved the way for natural recovery of the wolf Canis lupus in Europe. Wolves recolonizing central Europe – mainly western Poland and eastern Germany – originate from north-eastern Poland, where they inhabit forests sparsely populated by humans. In contrast, the areas being...

Inorganic nanomaterials able to generate reactive oxygen species (ROS) are promising components for modern medical applications. Activated by near-infrared light, up-converting β-NaYF4 doped with Er³⁺–Yb³⁺ and Tm³⁺–Yb³⁺ pair ions nanoparticles (UCNPs), have a wide range of applications in biological imaging as compared to traditional reagents excit...

The human SUV3 helicase (SUV3, hSUV3, SUPV3L1) is a DNA/RNA unwinding enzyme belonging to the class of DexH-box helicases. It localizes predominantly in the mitochondria, where it forms an RNA-degrading complex called mitochondrial degradosome with exonuclease PNP (polynucleotide phosphorylase). Association of this complex with the polyA polymerase...

Lesser horseshoe bat Rhinolophus hipposideros (Bechstein, 1800) have undergone a severe decline in Europe. The same dramatic population decrease was recorded in Poland, where the species is still critically endangered according to the Polish Red Data Book. Network of Natura 2000 sites is the most important conservation effort being implemented in E...

Mitochondria are not only ATP producing organelles, but they play pivotal roles in apoptosis, neurodegeneration, cancer and aging. Mammalian mitochondrial genome is a small DNA molecule of about 16.5 kb, encoding less than 20 polypeptides and a set of ribosomal RNAs and tRNAs. In order to ensure proper cell functioning a continous communication bet...

Following protection measures implemented since the 1970s, large carnivores are currently increasing in number and returning to areas from which they were absent for decades or even centuries. Monitoring programmes for these species rely extensively on non‐invasive sampling and genotyping. However, attempts to connect results of such studies at lar...

p>Following protection measures implemented since the 1970s, large carnivores are currently increasing in number and returning to areas from which they were absent for decades or even centuries. Monitoring programmes for these species rely extensively on non-invasive sampling and genotyping. However, attempts to connect results of such studies at l...

Upconverting Gd2O3 nanoparticles (NPs) doped 1% Er3+ and 18% Yb3+ permits one to perform optical imaging. Because of the presence of Gd3+ they are useful in MRI. The main challenge is to enhance the NPs upconversion efficiency. As a result of co-doping the NPs with Zn2+ ions, achieved using microwave-induced solution combustion synthesis, we obtain...

In this work, we present optical and structural properties of fluoride nanocrystals doped with lanthanide ions (β-NaGdF4:Eu3+, ß-NaGdF4:Yb3+,Er3+ and ß-NaGdF4:Yb3+,Tm3+) obtained in modified co-thermolysis method. We discuss some aspects of their functionalization with ligand exchange and silanization approaches and present some potential applicati...

Introducing to medicine and biology concept of optical markers in tremendous way has changed the recent status of these two important disciplines. This was mainly due to strong development in imaging techniques which recently allow us to investigate both static as well dynamic properties of living cells, their components and their interactions with...

Mitochondria are semiautonomous organelles which contain their own genome. Both maintenance and expression of mitochondrial DNA require activity of RNA and DNA helicases. In Saccharomyces cerevisiae the nuclear genome encodes four DExH/D supefamily members (MSS116, SUV3, MRH4, IRC3) that act as helicases and/or RNA chaperones. Their activity is nec...