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2. Out of Liguria : how polyploidy affected diversification of the sweet spurge (Euphorbia dulcis, Euphorbiaceae), European widespread forest speciesMarija Kravanja, Jasna Dolenc Koce, Božo Frajman, 2025, izvirni znanstveni članek Povzetek: Polyploidy is an important evolutionary mechanism in flowering plants that can strongly affect their morphological and distributional traits. In this study, we investigated the differences in these traits among di-, tri-, and tetraploid populations of sweet spurge (Euphorbia dulcis), a common understory species in deciduous and mixed forests across Europe. We inferred the ploidy of 188 populations of E. dulcis by estimating relative genome size and chromosome counting. The data indicate that tri- and tetraploids are more widespread compared to the ancestral diploid populations, which are restricted to Liguria (north-western Italy) and adjacent regions. We suggest that polyploidisation was crucial for range expansion and the colonisation of higher latitudes, but not for the colonisation of higher elevations, where diploids appear to be more successful. Similarly, morphological differentiation after polyploidisation is only partly consistent with the classical hypothesis that polyploids are larger and have larger organs. Using nuclear ITS and plastid ndhF–trnL sequences, we inferred the spatio-temporal diversification of E. dulcis. It diverged from its diploid sister species E. duvalii, an endemic of southwestern France and adjacent Spain, in the mid-Pliocene. This divergence was likely due to vicariant speciation accompanied by adaptation to forest and grassland environments in E. dulcis and E. duvallii, respectively. Whereas the diploid populations of both taxa have restricted ranges today, polyploidisation within E. dulcis likely triggered by the Pleistocene climatic oscillations contributed to its significant range expansion and diversification. The species exhibits the highest genetic diversity in the south-western Alps, where all three ploidies co-occur. Based on the ploidy differentiation and the less pronounced genetic and morphological differentiation, we propose treating di- and triploids as well as two geographically and genetically divergent groups of tetraploids (eastern and western) as four subspecies. This challenges various taxonomic treatments previously proposed for this species. Our study highlights the importance of polyploidisation for diversification and range expansion, and indicates the necessity of further research to test hypotheses related to the morphological and distributional characteristics of polyploid organisms.
Ključne besede: forest understory species, morphometry, phylogeography, polyploidisation, taxonomy
Objavljeno v DiRROS: 18.04.2025; Ogledov: 128; Prenosov: 53
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3. Comprehensive insights into Pseudo-nitzschia research in the Adriatic Sea : diverse perspectives and emerging discoveriesTimotej Turk Dermastia, Janja Francé, Jasna Arapov, Francesca Neri, Stefano Accoroni, Cecilia Totti, Federica Cerino, Maria Immacolata Ferrante, Fabrizio Bernardi Aubry, Stefania Finotto, Jelena Godrijan, Dragana Drakulović, Patricija Mozetič, 2025, pregledni znanstveni članek Povzetek: Pseudo-nitzschia, a globally distributed diatom genus, dominates phytoplankton communities in biomass and abundance, with some species producing domoic acid (DA), the neurotoxin responsible for Amnesic Shellfish Poisoning (ASP). The Adriatic Sea has become a hub of Pseudo-nitzschia research over the past 15 years. This review synthesizes multidisciplinary research across Adriatic sub-basins, integrating morphological, genetic, and ecological data. While ASP has never been documented in the Adriatic, DA was occasionally detected in shellfish. The production was linked to toxic species such as P. multistriata, P. calliantha, and P. galaxiae, which were found to produce DA in cultures from Adriatic isolates. Despite progress, LM-based monitoring remains prevalent, underestimating species complexity and toxigenic potential. Electron microscopy and genetic barcoding have nonetheless revealed new insights into the species composition of this genus in Adriatic. A total of 14 species have been reported so far with prominent regional disparity: the northern and middle Adriatic host higher diversity, contrasting with the southern Adriatic, where only five species were confirmed, and research remains sparse. Seasonal dynamics show summer-autumn peaks in abundance, though interannual and regional variability is notable. We present recent advances from the Adriatic including the discovery of Pseudo-nitzschia-infecting viruses, population genomic insights in P. multistriata, and metabarcoding-driven revelations of cryptic diversity. Finally, we highlight critical knowledge gaps, including the ecological drivers of toxicity and the impacts of oligotrophication on community shifts. Collaborative, high-resolution methodologies (e.g., omics, automated imaging) are urged to address emerging challenges under climate change and anthropogenic pressures.
Ključne besede: Adriatic, Pseudo-nitzschia, diversity, ecology
Objavljeno v DiRROS: 14.04.2025; Ogledov: 182; Prenosov: 75
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4. Coumaphos affects food transfer between workers of honeybee Apis melliferaDanilo Bevk, Jasna Kralj, Andrej Čokl, 2012, izvirni znanstveni članek Povzetek: We investigated whether coumaphos, an organophosphate used to control the parasitic mite Varroa destructor, affects trophallaxis in honeybees. Donors were treated with coumaphos 1 h before experiments. In this, uncontaminated food was transferred from donors to recipients. The amount of food transferred was measured (a) directly by weighing food or (b) indirectly by the number of recipients that died due to insufficient trophallaxis. A large reduction in the amount of transferred food was observed when the donors received 5 μg of coumaphos 1 h prior to the experiment. High mortality was observed among the recipients that were fed by donors treated with 2 or 5 μg of coumaphos indicating insufficient food transfer. Demonstrated side effects of coumaphos on trophallaxis could reduce distribution of this systemic agent in the colony and decreases its efficacy. The described assays are feasible and could be a useful tool to test the effects of pesticides on trophallaxis.
Ključne besede: trophallaxis, social behaviour, food
Objavljeno v DiRROS: 12.03.2025; Ogledov: 166; Prenosov: 120
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5. A new perspective on the molecular dating of the brown trout complex with an extended phylogeographic information on the species in SerbiaTijana Veličković, Aleš Snoj, Vladica Simić, Radek Šanda, Jasna Vukić, Dovilė Barcytė, David Stanković, Saša Marić, 2023, izvirni znanstveni članek Povzetek: To elucidate the historical biogeography of a species, the patterns of population divergence must be understood, and the evolutionary history of the species must be accurately known. For brown trout (Salmo trutta complex), estimating divergence times remains a challenge due to the lack of well-defined time calibration points and insufficient phylogeographic coverage in previous studies. The present work aims to improve molecular dating of mitochondrial control region sequences by using a multicalibration framework based on the latest paleogeological evidence for dating the origin of Lake Ohrid and two available Salmo fossils, including the overlooked Salmo immigratus. Our results clearly show that, contrary to common belief, the major divisions within the brown trout occurred in the Late Pliocene, not the Pleistocene. The Pliocene origin suggests that the brown trout lineages did not form because of geo(hydro)morphological changes during glaciation cycles but may be the result of orogeny and drainage evolution. In addition, increased sampling, particularly in Serbia, led to the identification of a new haplogroup (da-int) occupying an intermediate position with respect to da-es and da-bs haplogroups. While the control region can delineate brown trout lineages, its phylogenetic resolution is limited, so even extensive sampling could not further resolve the lineage level polytomies.
Ključne besede: brown trout, phylogeography, Pleistocene, Pliocene, calibrated phylogenetic analysis
Objavljeno v DiRROS: 04.03.2025; Ogledov: 170; Prenosov: 4582
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6. Clinical and structural features of sperm head vacuoles in men included in the in vitro fertilization programmeNina Fekonja, Jasna Štrus, Magda Tušek-Žnidarič, Katja Knez, Eda Vrtačnik-Bokal, Ivan Verdenik, Irma Virant-Klun, 2014, izvirni znanstveni članek Povzetek: The human sperm head vacuoles and their role in male infertility are still poorly understood. The aim of this study was to identify the clinical and ultrastructural features of human sperm head vacuoles in men included in the in vitro fertilization programme: men with normal (normozoospermia) and impaired sperm morphology (teratozoospermia). The sperm samples were observed under 6000-time magnification using motile sperm organelle morphology examination (MSOME). The proportion of sperm with head vacuoles was evaluated and related to the outcome of in vitro fertilization. The sperm of men with impaired sperm morphology was characterized by a higher proportion of sperm head vacuoles. The sperm head vacuoles were related to impaired semen quality (sperm concentration, motility, and morphology) but were not influenced by male factors (semen volume, height, age, weight, or body mass index). Moreover, sperm head vacuoles were related to impaired fertilization rate merely after classical in vitro fertilization (IVF), while there was no relation to pregnancy. In a subgroup of men, the sperm was fixed and observed by transmission electron microscopy (TEM). The ultrastructural study revealed that sperm head vacuoles are large nuclear indentations of various sizes and positions, packed with membranous material organized in membrane whorls (MW).
Ključne besede: human sperm head vacuoles, male infertility
Objavljeno v DiRROS: 04.03.2025; Ogledov: 153; Prenosov: 129
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7. Quaternionic Cartan coverings and applicationsJasna Prezelj, Fabio Vlacci, 2025, izvirni znanstveni članek Povzetek: We present the topological foundations for solvability of multiplicative Cousin problems formulated on an axially symmetric domain $\Omega \subset {\mathbb H}$. In particular, we provide a geometric construction of quaternionic Cartan coverings, which are generalizations of (complex) Cartan coverings as presented in Section 4 of Forstnerič and Prezelj (Math. Ann. 322(4), 633-666 (2002)). Because of the requirements of symmetry inherent to the domains of definition of quaternionic regular functions, the existence of quaternionic Cartan coverings of $\Omega$ is not a consequence of the existence of complex Cartan coverings; for the latter, there are no requirements for the symmetries with respect to the real axis. Due to the real axis’s special role, also the covering restricted to $\Omega \cap {\mathbb R}$ must have additional properties. All these required properties were achieved by starting from a particular symmetric tiling of the symmetric set $\Omega \cap ({\mathbb R}+ i{\mathbb R})$. Finally, we apply these results to prove the vanishing of ’antisymmetric’ cohomology groups of planar symmetric domains for $n \ge 2$.
Ključne besede: quaternionic Cartan coverings, antisymmetric cohomology groups
Objavljeno v DiRROS: 10.02.2025; Ogledov: 198; Prenosov: 96
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