یافته های نوین در علوم زیستی

چکیده Objective: Plants, as sessile organisms, are subjected to diverse abiotic stresses, including salinity, metal toxicity, thermal fluctuations, and hypoxia at different phases of plant growth. Plants can activate messenger molecules to initiate a signaling cascade in response to environmental stresses, resulting in either cell death or plant acclimation. Nitric oxide (NO) is a small, , gaseous, redox-active molecule that plays a plethora of physiological roles in plants and has emerged as a key regulator of plant growth, development, flowering, senescence, stomatal closure, dormancy, photosynthesis, geotropism, and responses to abiotic and biotic stressors. It can also facilitate alteration in protein function and reprogram the gene profiling by direct or indirect interaction with different target molecules. As a key redox molecule, nitric oxide is an important signaling molecule with diverse physiological functions in plants was classified as a phytohormone that might regulate plant growth. NO had physiological effects in plants, such as growth and development, dormancy, regulation of metabolism, aging, cell death, stomata, photosynthesis, geotropism, flowering, and response to abiotic and biotic stressors.

Conclusions: This review discusses some aspects related to NO in plants, such as chemical properties, synthesis pathways, and physiological and biochemical changes that occur in plants under stress conditions.

چکیده Phylogenetic analyses of Avicennia species have been carried out using diverse molecular datasets, including chloroplast genome sequences and multilocus nuclear gene markers. These studies have contributed valuable insights into evolutionary relationships within the genus and clarified its placement in the Acanthaceae family. Concatenated sequence datasets provide broader genomic information and can enhance the resolution and reliability of phylogenetic trees. In parallel, the multispecies coalescent (MSC) model offers a robust framework for addressing evolutionary questions such as estimating species divergence times, population sizes, species tree topologies despite gene tree discordance, interspecific gene flow, and species delimitation.The genus Avicennia L., comprising approximately eight species, represents a key group of mangrove plants, some of which occur along the southern coasts of Iran. However, considerable uncertainty remains regarding the molecular phylogeny of these species. Therefore, this study applies both MSC-based and concatenation-based phylogenetic approaches to investigate species relationships within Avicennia, using molecular data from nuclear ITS and chloroplast psbA sequences. We constructed species trees using BEAST (StarBEAST), performed gene-based analyses in Mesquite, and generated maximum likelihood trees. The results revealed two major divergent clades, with evidence of deep coalescence, interspecific introgression, and structural DNA variations, suggesting a complex evolutionary history within the genus.

چکیده Introduction: Hypertrophic cardiomyopathy (HCM) is defined as the most common genetic myocardial disease with significant genotypic and phenotypic heterogeneity. A dozen of sarcomeric and non-sarcomeric genes have been reported associated with HCM. In this study, we present a family with Hypertrophic cardiomyopathy with the same genotype and different phenotypes in affected members.

Methods: Physical examination and echocardiography followed by Whole-exome sequencing (WES) and co-segregation analysis were performed in the family and first relatives.

Results: Genetic analysis of the proband using WES identified the p.R286H variant in the TNNT2 gene and co-segregation analysis revealed the proband’s sister and son carrying the variant. The proband had a reverse curvature type of HCM in echocardiography evaluation and her sister was affected by the apical type of HCM with aneurysm formation and small thrombus inside confirmed by CMR. Proband’s son had no evidence of disease in the Imaging study and will be under follow-up.

Conclusions: Genetic testing can be an efficient risk indicator for proband relatives and those who carry the detected mutation, further imaging evaluation should be considered. As our results showed, genetic counseling, genetic testing, and multimodality imaging are crucial in the screening and also management of a family affected by HCM.

چکیده Objective: Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among reproductive-age women, with a prevalence of 6–13%. The precise molecular network structure and central driver genes in PCOS pathogenesis remain incompletely understood.

Method: A total of 200 differentially expressed genes linked to PCOS were retrieved from multiple transcriptomic studies. Protein-protein interaction (PPI) networks were constructed using the STRING database (confidence score >0.40) and further analyzed in Cytoscape version 3.10.2. Hub genes were identified by CytoHubba plugin based on degree, betweenness, and closeness centrality measures. Pathway enrichment analysis was conducted using KEGG, Gene Ontology, Reactome, and WikiPathways databases; only terms with FDR <0.05 were considered significant.

Results: The resulting network consisted of 200 nodes and 4,979 edges. Four core genes—PIK3CA, PIK3CD, AKT1, and PIK3CB—were present in all eight highly dysregulated pathways (PI3K-Akt, AMPK, longevity regulating, AGE-RAGE, FoxO, insulin resistance, HIF-1, and TNF signaling), with PI3K-Akt showing the strongest enrichment (29 genes, FDR=3.28×10⁻¹â°). Three additional biomarkers (INSR, INS, IL6) overlapped in six pathways.

Conclusions: PIK3CA, PIK3CD, AKT1, and PIK3CB emerge as central molecular hubs and promising therapeutic targets in PCOS. Extensive pathway convergence on these nodes highlights the systemic metabolic-inflammatory basis of the disorder.

چکیده Objective: The genus Datura (Solanaceae), comprising two species in Iran, includes toxic yet medicinal plants found in temperate and tropical regions. Despite their wide distribution, morphological and anatomical studies of these species remain scarce, with most research focused on phytochemical composition. This study aims to comprehensively evaluate the morphological and anatomical features of leaves and stems of D. stramonium and D. innoxia to identify reliable diagnostic characters for species discrimination.

Method: Quantitative and qualitative traits of vegetative and reproductive organs were assessed for 3–6 individuals from each of 37 populations across Iran. Leaf and stem cross-sections were manually prepared and stained with Toluidine blue O. Multivariate statistical methods, including PCA, UPGMA clustering, and PCoA, were employed to evaluate the observed variation.

Results: D. innoxia and D. stramonium differed significantly in several morphological traits. Leaf margin shape, leaf type, fruit type, hair presence/absence, petiole length, leaf dimensions, and fruit dimensions showed diagnostic value. Anatomically, midrib dimensions, phloem and xylem thickness, palisade and spongy parenchyma thickness, and adaxial epidermal thickness were important leaf characters. Stem anatomical features—including phloem thickness, parenchyma thickness, trichome size and presence/absence, collenchyma thickness, and xylem thickness—also provided valuable diagnostic criteria. Notably, Iranian D. stramonium populations were consistently glabrous, contrasting with previous reports from other regions.

Conclusions: The two species formed distinct, well-separated clusters in all multivariate analyses. Inter- and intra-specific variations, including population-level differentiation, are discussed. The diagnostic characters identified provide a robust framework for species identification and contribute to the systematic understanding of Datura in Southwest Asia

چکیده Objective: This study assessed total aflatoxin concentrations in Iranian fish and meat powders by product type, season, and year.

Methods: We analyzed 166 samples collected during 2014–2024 (fish powder, n = 85; meat powder, n = 81) using the AgraQuant® Total Aflatoxin 1/20 competitive ELISA (Romer Labs; catalog no. 10002100). Product types were compared using Mann–Whitney U tests; seasonal and annual distributions were analyzed using Kruskal–Wallis tests with Dunn’s comparisons. Results below the kit-reported LOD of 1 µg/kg were assigned zero by lower-bound substitution; samples ≥1 µg/kg were classified as positive. This operational threshold was not a validated matrix-specific LOD or LOQ. Chi-square tests and Spearman correlation assessed prevalence and temporal associations, respectively.

Results: Overall, 117/166 samples (70.5%) met the positivity threshold. Concentrations ranged from 0 to 10.0 µg/kg (mean, 1.92 ± 2.23; median, 1; IQR, 0–3). No significant differences occurred by product type (U = 3206, p = 0.4298) or season (H(3) = 3.865, p = 0.2764). Annual distributions differed (H(10) = 26.09, p = 0.0036), with a significant difference only between 2015 and 2021 (adjusted p = 0.0042). Sample-level correlation between year and concentration was weakly negative (ρ = −0.195, p = 0.0120), whereas annual median correlation was not significant (ρ = −0.258, p = 0.4441).

Conclusions: Total aflatoxin concentrations were generally low. Concentrations did not differ significantly by product type or season. Annual distributions varied, but annual medians showed no significant monotonic trend. Continued monitoring is warranted, although contamination sources cannot be inferred.