Studia Universitatis Babeş-Bolyai Biologia

Doxorubicin toxicity: Histological and ultrastructural tissue damage

Emilia Anca — 2026-06-25

Doxorubicin (DOX) is an effective chemotherapeutic with known toxic effects over the liver, kidneys and most importantly the heart. DOX effects, such as oxidative stress induction, topoisomerase II poisoning and activation of pro-inflammatory pathways are a double-edged sword. While enhancing the antitumoral activity of this agent, these mechanisms also contribute to tissue damage which limits its use. To build upon previous research that evaluated circulating biomarkers of DOX-induced cardiac toxicity, this study offers additional perspectives on structural effects on tissues along with a short literature review of DOX use.

Article history: Received 3 April 2025; Revised 1 April 2026;
Accepted 2 June 2026; Available online 25 June 2026.

Functional study of PAP3/pTAC10 in the plastid-encoded RNA polymerase during chloroplast biogenesis

Leonard Calistru — 2026-06-25

Chloroplast biogenesis in angiosperms depends on two types of RNA polymerases: the nuclear-encoded RNA polymerase (NEP) and the plastid-encoded RNA polymerase (PEP). PEP, in its active form (PEP-A), is supported by multiple nuclear-encoded proteins called PEP-associated proteins (PAPs). Among these, PAP3 (also known as pTAC10) plays a structural role in the PEP complex. Epifluorescent microscopy was used in order to verify its localization, confirming that PAP3 has a single subcellular localization: the chloroplast. Using the Arabidopsis thaliana pap3-1 mutant and PHYB-GFP (PBG) reporter lines, we demonstrate that PAP3 is not required for PHYB-mediated light signaling pathway nor for photobody formation. Contrary to PAP8, whose loss of function affects red light signaling and photobody formation, pap3 mutants show normal hypocotyl de-etiolation and photobody assembly under red light. These results suggest that in contrast with the nucleo-chloroplastic PAP8, PAP3 is confined to the plastid compartment and that it contributes exclusively to the plastidial transcriptional machinery. The difference in behavior between pap8 and pap3 mutants implements the existence of two distinct albino syndromes in PAPs, depending on their localization: dually localized (nucleus and chloroplasts) or solely localized (chloroplasts).

Article history: Received 30 July 2025; Revised 24 February 2026;
Accepted 30 April 2026; Available online 25 June 2026.

Leveraging the power of computational immunology to develop a novel couplet mRNA vaccine concatenating conserved epitopes of monkeypox virus antigens

Leana Rich Herrera-Ong — 2026-06-25

The monkeypox (Mpox) disease was declared as a Public Health Emergency of International Concern (PHEIC) in 2022 and in 2024. Currently, there are no Mpox-specific vaccines and antiviral drugs for the treatment of Mpox. This study developed a novel couplet mRNA vaccine through immunoinformatics tools and databases. Highly conserved sequences of nine Mpox antigens were identified and utilized for T-cell and B-cell epitope mapping. Using data obtained from experimentally validated epitopes, the potential immunogenicity of predicted T-cell epitopes was evaluated. Peptides that may cause cross-reactivity, toxicity, and allergic reactions were excluded. The population coverage of candidate epitopes was also estimated. Epitopes were arranged and adjoined to form the mRNA constructs, aiming to direct its processing either to exogenous or endogenous pathways, while maximizing cleavage scores to produce the desired peptides. Conservancy analysis revealed that the nine Mpox target antigens A29L, A35R, A42R, B6R, E8L, F13L, H3L, L1R, and M1R are highly conserved. After the exclusion of potentially harmful and non-immunogenic peptides, 559 CD4+ and 104 CD8+ T-cell epitopes remained. The couplet mRNA constructs encode potentially immunogenic T-cell epitopes and accessible B-cell epitopes of multiple Mpox antigens that can be expressed and processed to generate the desired peptide sequences in humans. Estimated population coverage for mTcPox and mBThPox constructs are 77.67% and 81.81%, respectively. This study developed a novel couplet mRNA Mpox vaccine design containing highly conserved, immunogenic epitopes, with acceptable safety profile. Further in vitro, animal, and clinical studies are anticipated for human applications.

Article history: Received 9 August 2025; Revised 2 December 2025;
Accepted 16 March 2026; Available online 25 June 2026.

Leaf morphological variation in common yew (Taxus baccata L.) at the species’ southern range margin in North Africa

Chafiaa Hamidouche-Si Mohammed — 2026-06-25

The main aim of this study was to provide the first morphometric characterization of Taxus baccata L. leaves in North Africa. Phenotypic variability was investigated in nine natural populations from Algeria and Morocco using 11 quantitative and qualitative traits. analysis of variance (ANOVA) followed by Fisher’s post hoc test revealed significant differences at multiple hierarchical levels, including trees within populations, among populations, regions and mountain ranges for all quantitative variables. In parallel chi-square analysis indicated significant variation in qualitative traits. Hierarchical clustering classified the studied populations into two major clusters for both types of morphological traits. The Chrea population displayed the largest leaves, whereas the Saharan Atlas populations showed the smallest. Principal component analysis (PCA) clearly separated populations and geographic groups in relation to both ecological and leaf morphological factors. Overall, the observed morphological differentiation suggested that phenotypic plasticity together with possible genetic differentiation, is driven more by local ecological conditions than by latitude alone. North African yews are characterized by relatively narow leaves and region specific variation in petiole and apex morphology, reflecting high degree of ecological adaptability to various ecological and geographical conditions. These findings have important implications for conservation of southern marginal population of this relic threatened conifer.

Article history: Received 8 January 2026; Revised 29 April 2026;
Accepted 16 June 2026; Available online 25 June 2026.

Phylogenetic structuring of intrinsic disorder and charge patterning in vertebrate Ermin

Ilka Koszorus — 2026-06-25

Ermin (ERMN) is an oligodendrocyte-enriched cytoskeletal protein implicated in myelin sheath formation and stability. Although previously described as intrinsically disordered, its evolutionary diversification across vertebrates has not been systematically examined. Here, we performed a comprehensive phylogenetic and comparative analysis of 159 vertebrate Ermin orthologs to characterize the evolution of intrinsic disorder and physicochemical sequence properties. Across all major vertebrate clades, Ermin consistently fulfilled criteria for highly intrinsically disordered proteins based on Average Disorder Score (ADS) and Percent of Predicted Disordered Residues (PPDR), demonstrating that extensive disorder represents a deeply conserved structural feature. Despite this conserved disorder abundance, the architectural organization of intrinsically disordered regions (IDRs) varied among lineages. Mammalian Ermin proteins exhibited increased fragmentation of long IDRs compared to birds, which retained largely continuous long-IDR segments, indicating that IDR partitioning evolves independently of total disorder content. Amino-acid composition analyses revealed conserved depletion of aromatic and bulky hydrophobic residues across vertebrates, combined with clade-structured variation in charged and disorder-promoting residues.

Phylogenetic generalized least squares (PGLS) analyses detected strong phylogenetic signal across disorder and electrostatic traits. Root-to-tip regressions revealed a significant directional decrease in mean hydrophobicity across vertebrate divergence, whereas disorder propensity and sequence charge decoration (SCD) did not exhibit consistent monotonic Fraction of charged residues (FCR) showed more modest evolutionary variation. Multivariate models further demonstrated that hydrophobicity, global charge density, and sequence charge decoration independently contribute to evolutionary variation in Ermin sequence architecture.

Together, these results indicate that Ermin evolution is characterized by architectural remodeling and compositional retuning of an already disordered scaffold rather than by progressive increases in intrinsic disorder. This study highlights IDR fragmentation and electrostatic organization as key evolutionary dimensions shaping the diversification of intrinsically disordered proteins across vertebrate lineages.

Article history: Received 27 February 2026; Revised 17 June 2026;
Accepted 17 June 2026; Available online 25 June 2026.

Evaluating soil microbial metabolic activity in response to two plant biostimulants using the Biolog Ecoplate™ method

Katya Dimitrova — 2026-06-25

Biostimulants are emerging as viable alternatives to chemical fertilizers, offering a pathway toward more sustainable and environmentally friendly agricultural practices. Their effectiveness, however, is influenced by a range of environmental and biological conditions, making outcomes variable. Evidence suggests that biostimulants may exert their influence by modifying the metabolic activity and composition of soil microbial communities – key drivers of nutrient cycling. This study aimed to assess microbial activity in untreated soil and soil treated with two distinct biostimulants: a seaweed-derived product (PStim) and a microbial-based formulation (MbPB), under greenhouse conditions. Microbial dynamics were evaluated using the Biolog EcoPlate™ method, focusing on substrate utilization pattern. Soil respiration rate was also estimated. No significant changes in soil chemical properties were observed following biostimulant application. Nonetheless, all variants demonstrated high metabolic activity, as indicated by average well-color development (AWCD), with notable differences in substrate preferences. Functional indices pointed to increased metabolic diversity and evenness in biostimulant-treated soils, potentially linked to the targeted stimulation of specific microbial taxa.

Article history: Received 16 February 2026; Revised 17 June 2026;
Accepted 19 June 2026; Available online 25 June 2026.

Diatom communities in freshwater springs with contrasting geology in the Apuseni Mountains

Anca-Mihaela Șuteu — 2026-06-25

Freshwater springs are unique and fragile aquatic ecosystems characterized by a mosaic of microhabitats, hydrochemical properties influenced by geological substrate, and specialized biological communities. Springs from the Romanian Carpathian Mountains are poorly explored and the role of geological substrate in structuring diatom assemblages remains unclear. This study aims to characterize diatom communities and their dynamics in ten springs developed on contrasting geological substrates. Epibryon and epilithon samples were collected from at least three points of available microhabitats within the spring area. Standard methods were applied to obtain cleaned diatom material and the resulting assemblages were analyzed using multivariate ordination techniques, alongside ecological indicator values and functional guild structure. A total of 126 diatom taxa were identified and three of the investigated springs are reported here for the first time with respect to their diatom flora. Community composition differed significantly between the two contrasting groups of springs. Crystalline–metamorphic springs were associated with assemblages dominated by taxa typical of acidic and weakly mineralized waters, whereas carbonate springs supported communities characteristic of more alkaline conditions. Low-profile guilds dominated carbonate springs, whereas one crystalline–metamorphic spring showed a distinct high-profile-dominated structure. The results indicate that geological substrate shapes diatom community dynamics primarily through its control of physicochemical water properties. Indicator species analysis (IndVal) identified Pinnularia subcapitata W. Gregory as associated with crystalline–metamorphic springs, whereas Cocconeis euglypta Ehrenberg, Cocconeis placentula Ehrenberg and Meridion circulare C.Agardh were linked to carbonate-dominated springs. This study provides one of the first integrative multivariate assessments of crenic diatom communities in the Apuseni Mountains and highlights contrasting ecological patterns associated with different geological settings.

Article history: Received 13 March 2026; Revised 20 May 2026;
Accepted 20 May 2026; Available online 25 June 2026.

First record of Parasyrphus malinellus (Collin, 1952) (Diptera: Syrphidae) in Romania at low altitude in the Danube Gorge

Amalia-Raluca Dumbravă — 2026-06-25

Hoverflies (Diptera: Syrphidae) represent an ecologically important group of pollinating insects. Of these, Parasyrphus malinellus (Collin, 1952) is a Palaearctic species, mainly distributed in northern Europe. In southern Europe, particularly on the Balkan Peninsula, its distribution is scattered and has been recorded only recently at high altitudes. Although Romania lies north of the Balkans, P. malinellus has not previously been recorded in the country. In April 2025, we recorded a female in the Mraconia Valley Basin (Danube Gorge, southwestern Romania). This is the first record of P. malinellus for the Romanian Carpathians and the country. This record partially fills the distribution gap between the species’ known distribution in northern and western Europe and its southern Balkan occurrences (Serbia and Greece). Unlike other records from the Balkan Peninsula, where P. malinellus is present at high elevations, we recorded it at an unexpectedly low altitude, at only approximately 400 m a.s.l. Moreover, although P. malinellus is typically associated with coniferous forests, it was found in a humid valley surrounded by steep slopes dominated by beech and oak forests, in a region where conifers are not naturally present. Thus, P. malinellus is another mountain species, probably relict, present in the Danube Gorge close to its southern distribution limit, at a low altitude and in atypical habitats. This finding further supports the role of the Danube Gorge as a refugium, increasing its conservation value. At the same time, it highlights the limited knowledge of hoverfly diversity in the Carpathian Mountains, even within well-studied protected areas.

Article history: Received 3 February 2026; Revised 26 March 2026;
Accepted 4 April 2027; Available online 25 June 2026.

Advances in molecular sexing of monomorphic birds in Indonesia: A scoping-review with potential application on the Bali starling (Leucopsar rothschildi) breeding

I Dewa Agung Panji Dwipayana — 2026-06-25

Accurate sex determination is essential for ecological research, captive breeding, and conservation of sexually monomorphic birds. In Indonesia, despite exceptional avian diversity and urgent conservation needs, the application of molecular sexing remains uneven across taxa. This scoping review synthesizes evidence from 35 studies published between 2015 and 2025, drawn from 176 records, that employed PCR amplification of chromo-helicase-DNA-binding (CHD) genes using various primer sets and sample types. Blood and feathers were the most commonly used materials (≈80% of records), while swabs, eggshell membranes, and casque tissue were reported infrequently. Primer performance varied markedly among avian families and sample types. CHD1LF/CHD1LR and NP + P2 + MP consistently showed high amplification reliability, whereas P2/P8 and 1237L/1272H yielded inconsistent results. To enable objective comparison, we propose the Primer Performance Index (PPI), a composite metric integrating amplification success with taxonomic breadth. PPI analysis demonstrated that primers with broad family coverage maintained high reliability after normalization, while taxa-restricted primers showed reduced performance. These findings support improved primer selection for conservation breeding, particularly for the critically endangered Bali Starling (Leucopsar rothschildi), and promote more standardized integration of molecular sexing into avian conservation practice in Indonesia.

Article history: Received 20 March 2026; Revised 18 May 2026;
Accepted 18 May 2026; Available online 25 June 2026.