Interspecies Variation Research Articles

Humanlike manual activities in Australopithecus

The evolution of the human hand is a topic of great interest in paleoanthropology. As the hand can be involved in a vast array of activities, knowledge regarding how it was used by early hominins can yield crucial information on the factors driving biocultural evolution. Previous research on early hominin hands focused on the overall bone shape. However, while such approaches can inform on mechanical abilities and the evolved efficiency of manipulation, they cannot be used as a definite proxy for individual habitual activity. Accordingly, it is crucial to examine bone structures more responsive to lifetime biomechanical loading, such as muscle attachment sites or internal bone architecture. In this study, we investigate the manual entheseal patterns of Australopithecus afarensis, Australopithecus africanus, and Australopithecus sediba through the application of the validated entheses-based reconstruction of activity method. Using a comparative sample of later Homo and three great ape genera, we analyze the muscle attachment site proportions on the thumb, fifth ray, and third intermediate phalanx to gain insight into the habitual hand use of Australopithecus. We use a novel statistical procedure to account for the effects of interspecies variation in overall size and ray proportions. Our results highlight the importance of certain muscles of the first and fifth digits for humanlike hand use. In humans, these muscles are required for variable in-hand manipulation and are activated during stone-tool production. The entheses of A. sediba suggest muscle activation patterns consistent with a similar suite of habitual manual activities as in later Homo. In contrast, A. africanus and A. afarensis display a mosaic entheseal pattern that combines indications of both humanlike and apelike manipulation. Overall, these findings provide new evidence that some australopith species were already habitually engaging in humanlike manipulation, even if their manual dexterity was likely not as high as in later Homo.

Establishment of an evaluation method of a chemical-susceptibility for wildlife using counter-QSAR and machine learning

Certain environmental chemicals are harmful to lifeforms. Determining the extent to which they are damaging to animals is challenging as it is ethically reprehensible to expose animals to lethal doses of chemicals in the lab and, besides, not every species of animal can be housed in a laboratory. So, how can experiments involving animals in their natural habitat, and without causing harm, be conducted? A team of researchers at the Laboratory of Toxicology in the School of Veterinary Medicine at Kitasato University in Japan, which includes Junior Associate Professor Kazuki Takeda, is working to develop a way to determine the susceptibility of animal species to given environmental chemicals. Takeda is applying his background in environmental toxicology to the research. The focus for the team is on wild animals and using non-invasive methods. As there is such great interspecies variability in chemical sensitivity, it is difficult to extrapolate toxicity test results obtained from laboratory animals to wild animals. Therefore, the researchers are using genetic information and protein-chemical binding simulations to evaluate interspecies differences in chemical sensitivity. The goal is to develop a model that can predict chemical sensitivity differences between species using simulation methods and machine learning using DNA information obtained from hair.

Multi-scale hierarchical brain regions detect individual and interspecies variations of structural connectivity in macaque monkeys and humans

Macaques are representative animal models in translational research. However, the distinct shape and location of the brain regions between macaques and humans prevents us from comparing the brain structure directly. Here, we calculated structural connectivity (SC) with multi-scale hierarchical regions of interest (ROIs) to parcel out human and macaque brain into 8 (level 1 ROIs), 28 (level 2 ROIs), or 46 (level 3 ROIs) regions, which consist of anatomically and functionally defined level 4 ROIs (around 100 parcellation of the brain). The SC with the level 1 ROIs showed lower individual and interspecies variation in macaques and humans. SC with level 2 and 3 ROIs shows that the several regions in frontal, temporal and parietal lobe show distinct connectivity between macaques and humans. Lateral frontal cortex, motor cortex and auditory cortex were shown to be important areas for interspecies differences. These results provide insights to use macaques as animal models for translational study.

Comparative analysis of rhesus macaque and human placental organoids highlights evolutionary differences in placentation.

Throughout evolution, the placenta has diversified in both structure and cellular composition while maintaining its fundamental function. Trophoblasts are fetal-derived cells responsible for nourishing and protecting the developing fetus and are a universal component of all placentas. While primate placentas exhibit many shared morphological features, species-specific differences in gene expression remain largely unexplored, primarily due to the lack of suitable in vitro models. To address this gap, we developed organoids from rhesus macaque placentas, including trophoblast and maternal-derived decidua types, and compared them with organoids derived from human placentas. We performed comparative single-cell RNA sequencing to delineate shared and distinct transcriptional signatures between rhesus macaque and human trophoblasts. We further defined the differentiation trajectories leading to the multinucleated syncytiotrophoblast, highlighting both shared and unique transcriptional signatures between rhesus macaque and human placentas. This work establishes novel in vitro models of the non-human primate placenta and characterizes distinct trophoblast gene profiles in rhesus macaques and humans, providing insights into interspecies variations in placental biology.

Discovery of a new gall-inducing species, Aciurinaluminaria (Insecta, Diptera, Tephritidae) via multi-trait integrative taxonomy.

Integrative taxonomic practices that combine multiple lines of evidence for species delimitation greatly improve our understanding of intra- and inter-species variation and biodiversity. However, extended phenotypes remain underutilized despite their potential as a species-specific set of extracorporeal morphological and life history traits. Primarily relying on variations in wing patterns has caused taxonomic confusion in the genus Aciurina, which are gall-inducing flies on Asteraceae plants in western North America. However, species display distinct gall morphologies that can be crucial for species identification. Here we investigate a unique gall morphotype in New Mexico and Colorado that was previously described as a variant of that induced by Aciurinabigeloviae (Cockerell, 1890). Our analysis has discovered several consistent features that distinguish it from galls of A.bigeloviae. A comprehensive description of Aciurinaluminaria Baine, sp. nov. and its gall is provided through integrative taxonomic study of gall morphology, host plant ecology, wing morphometrics, and reduced-representation genome sequencing.

Seasonal and inter-species variations in nutrient components and taste characteristics of farmed scallops from Northern China

Scallops are considered a healthy seafood due to their abundant nutrition and pleasant taste. However, the biochemical composition of scallops harvested in different seasons varies, which affect their quality. To identify the superior breeding species and optimal harvesting time, the seasonal- and species-specific variations in nutrient and flavor components were investigated for two species of scallops (Chlamys farreri and Patinopecten yessoensis) using accredited methods. Regarding seasonality, the levels of proteins, fat, fatty acids, and water-soluble vitamins were significantly higher in summer. Both species of scallop had superior taste in summer and spring. Conversely, winter scallops had a healthier proportion of unsaturated fatty acids for humans, as well as richer fat-soluble vitamins. As for species differences, C. farreri exhibited higher protein proportion and vitamin B5 content, while P. yessoensis exhibited more fat and essential amino acids. Flavor indexes suggested that P. yessoensis was more delicious than C. farreri in the same season. Overall, a comprehensive assessment of the nutritional quality of scallops, using the integrated biomarker response (IBR) index, revealed that marketable scallops in early summer and late spring exhibited better quality, and P. yessoensis scored higher than C.farreri in terms of nutrition and taste.

Identification of transcription factor binding sites of <i>HSP60</i> and <i>HSP90B1</i> Genes’ promoter in Bubalus bubalis

The gene expression determines cellular homeostasis while spatio-temporal nature of gene expression is regulated by several cis regulatory elements, such as promoter regions which bind to transcription factors. The ever-changing global climatic conditions have raised a necessity to scan heat tolerant livestock especially the riverine buffalo in tropics. The study focuses on characterization of the promoter region of HSP60 and HSP90B1 and looking for the binding sites of transcription factors in Bubalus bubalis and comparison with the nearest relative Bos taurus to gauge the interspecies variations. The results indicated no transcription binding factors in HSP90B1 promoter (550 nucleotides) within the region analyzed except for the Elk-1 and COMP1 in the cattle while promoter region of HSP60 gene (971 nucleotides) varied highly. Nine and seven transcription factor binding sites were specifically unique in Bubalus bubalis and in Bos taurus respectively. Occurrence of 1-Oct, BR-C Z4, Hairy, and HSF was higher in buffalo. Overall, this study provided the framework to explore cis regulatory elements and contributes to decipher the transcriptional regulatory elements of HSP60 and HSP90B1 genes in Bubalus bubalis.

Clinical trials in-a-dish for cardiovascular medicine.

Cardiovascular diseases persist as a global health challenge that requires methodological innovation for effective drug development. Conventional pipelines relying on animal models suffer from high failure rates due to significant interspecies variation between humans and animal models. In response, the recently enacted Food and Drug Administration Modernization Act 2.0 encourages alternative approaches including induced pluripotent stem cells (iPSCs). Human iPSCs provide a patient-specific, precise, and screenable platform for drug testing, paving the way for cardiovascular precision medicine. This review discusses milestones in iPSC differentiation and their applications from disease modelling to drug discovery in cardiovascular medicine. It then explores challenges and emerging opportunities for the implementation of 'clinical trials in-a-dish'. Concluding, this review proposes a framework for future clinical trial design with strategic incorporations of iPSC technology, microphysiological systems, clinical pan-omics, and artificial intelligence to improve success rates and advance cardiovascular healthcare.

Variability of Bile Baseline Excitation-emission Fluorescence of Two Tropical Freshwater Fish Species.

The quantification of pollutant metabolites in fish bile is an efficient approach to xenobiotic pollution monitoring in freshwaters since these measurements directly address exposure. Fluorescence excitation-emission matrix spectroscopy (EEMS) has demonstrated to be a highly specific and cost-effective technique for polycyclic aromatic hydrocarbon (PAH) and PAH-metabolite identification and quantification. EEMS ability to quantify these compounds strongly depends on the intensity and variability of the bile baseline fluorescence (BBF). We found large differences in BBF among Aequidens metae (AME) individuals and of these with Piaractus orinoquensis (PIO). Moreover, BBF was large enough that solvent dilutions of over 1:400 were needed to avoid inner filter effects. We used parallel factor analysis (PARAFAC) to model the intra- and inter-species BBF variability. PARAFAC successfully decomposed the EEMS set into three fluorophores present in all samples, although in concentrations spreading over ~ 3 orders of magnitude. One of the factors was identified as tryptophan. Tryptophan and Factor 2 were covariant and much more abundant in AME than in PIO, while Factor 3 was ~ 6 times more abundant in PIO than in AME. Also, tryptophan was ~ 10x more abundant in AME specimens immediately caught in rivers than in their laboratory-adapted peers. The PARAFAC decomposition effectiveness was confirmed by the positive proportionality of scores to dilution ratios. A large inner filter indicates that Factor 2 is as strong a light absorber as tryptophan. Our results stress the need to include bile matrix variable components for the detection and quantification of pollutant metabolites using PARAFAC.

Analysis of the nutritional composition, biological activities, and phenolic metabolic bioactive module of cherry tomatoes

This study analyzed the overall nutritional composition of 87 cherry tomato varieties and evaluated the antioxidant, hypoglycemic, and hypolipidemic activities of the top 30 varieties with excellent overall quality. In addition, the phenolic metabolic characteristics of cherry tomatoes were determined via phenolic metabolomics, and the bioactive module “phenolic-DPPH” was identified. There was extensive interspecies variation in total soluble solids, titratable acid, lycopene, chlorophyll, γ-aminobutyric acid, total phenolics, total flavonoids and multivitamins, and different color groups presented unique nutritional compositions. The comprehensive nutritional value of the 56 varieties is greater than that of the Millennium variety. Phenolic substances are closely related to DPPH free radical scavenging activity. A total of 484 phenolic substances were identified, among which 5′-methoxymatairesinoside and 6-hydroxykaempferol-7,6-O-diglucoside are key antioxidant components. Our research provides valuable resources and insights for the selection of functional cherry tomato varieties and the identification of phenolics with important biological activities.

Coniferous Biomass for Energy Valorization: A Thermo-Chemical Properties Analysis

Forest biomass energy, when utilized responsibly, presents a carbon-neutral and viable alternative to fossil fuels for energy storage. This research investigates the energy potential of various coniferous species, focusing on their complex chemical compositions and suitability for energy production. Key characteristics such as moisture content, volatile matter, ash content, and fixed carbon were analyzed, along with elemental composition (including nitrogen, carbon, oxygen, and hydrogen) and both gross and net heating values across different species. The proximate analysis revealed significant interspecies variations. For example, Pseudotsuga menziesii and Chamaecyparis lawsoniana exhibited the lowest moisture contents. Elemental analyses showed a broad range of values, with Larix decidua having the lowest nitrogen content and Sequoiadendron giganteum the highest carbon content. Gross and net heating values also varied considerably, with Podocarpus macrophyllus showing the lowest values and Pinus strobus the highest. Principal component analysis (PCA) was employed to identify underlying patterns, revealing correlations between the analyzed variables and the energy potential of the species. Additionally, PCA combined with cluster analysis allowed for the identification of coherent groups of species with similar characteristics. Overall, these findings highlight the diverse energy valorization potential inherent in coniferous species, underscoring the importance of considering specific chemical compositions for efficient energy production. The insights provided here are valuable for selecting coniferous species for energy valorization, emphasizing the need to consider both chemical composition and calorific potential.

Lamiales epidermal dynamics: Unveiling antimicrobial resilience in a structural symphony.

This research on Lamiales epidermal anatomy not only provides in-depth understanding of their structural traits but also highlights the significance of uncovering the inherent antimicrobial resilience embedded within these plants. Such insights hold promise for advancing natural product-based approaches in medicine, potentially contributing to the development of novel antimicrobial agents inspired by Lamiales unique biological defense mechanisms. Scanning microscopic tools were utilized to conduct foliar epidermal anatomy of nine species that belong to seven genera and four families within the Lamiales order, Plantaginaceae, Scrophulariaceae, Verbenaceae, and Lamiaceae. This approach aimed to gather both qualitative and quantitative data, facilitating the assessment of taxonomic microanatomical significance. The shape of epidermal cells and their anticlinal walls; number of epidermal cells, stomata, and trichomes; type of stomata and trichomes; length and width of epidermal cells, trichomes, stomatal pore, guard cells, and subsidiary cells; and stomatal index were determined statistically. Most of the species examined were amphistomatous and showed extensive array of trichomes diversity. The exploration of Lamiales epidermal micromorphology and their antimicrobial potential were significant for their implications in multidisciplinary fields. The pharmacological research to utilize sustainable agricultural practices prompts avenues to strengths of Lamiales order for the development of novel antimicrobial solutions and ecological benefits. RESEARCH HIGHLIGHTS: Diverse trichome morphometry reveals a wide array of trichome structures across Lamiales species. Epidermal microscopic architecture variability of epidermal cell shapes and sizes signifies the interspecies variability. Secondary metabolite localization within microanatomical structures elucidates potential hotspots for antimicrobial compound production.

Structural interspecies variability of mammals' hairs.

Hairs are fundamental structures for mammals, serving crucial functions such as thermal insulation and hydrophobicity. In domestic animals, hair is also a valuable source of high-performance fibers for the textile industry, which has led to intensive study. However, there is limited comparative knowledge about the physical properties of hair across different wild mammalian species. In our lab, we are investigating the physical properties of hairs from a diverse range of wild mammalian species, laying the groundwork for an in-depth comparative study. These physical properties can be linked to the internal structures of the hairs. Using polarized light microscopy, we can visualize the internal structure of hairs, which are composed of a hollow channel (medulla) surrounded by a cortex and a keratin cuticle(1). By examining the brown hairs of three distinct mammals-the Patagonian mara, the brown bear, and the Amur tiger-we observe striking differences in their internal structures. We speculate that these structural differences correspond to varying physical properties, which we are currently investigating.

Per- and Polyfluoroalkyl Substances (PFAS) Accumulation, Reproductive Impairment, and Associations with Nestling Body Condition in Great (Parus major)- and Blue Tits (Cyanistes caeruleus) Living near a Hotspot in Belgium.

Due to the limited number of field studies investigating associations between environmentally relevant per- and polyfluoroalkyl substances (PFAS) mixtures and reproductive impairment, there is uncertainty as to whether birds are affected by PFAS pollution, whether species differ in sensitivity to PFAS, and whether the observed reproductive impairment is caused by PFAS or rather due to other potential confounding variables. Therefore, we investigated PFAS concentrations in eggs and blood plasma of great tit (Parus major) and blue tit (Cyanistes caeruleus) nestlings near a PFAS hotspot in Belgium, reproductive impairment, and associations between the accumulated levels and nestling body condition. In total, 29 eggs and 22 blood plasma samples of great tit clutches, and 10 egg and 10 blood plasma samples of blue tit clutches, were collected. Despite more types of PFAS being detected in eggs compared to plasma, only minor differences in profiles were observed between species. On the other hand, tissue-specific differences were more pronounced and likely reflect a combination of maternal transfer and dietary exposure post-hatching. Despite the high concentrations detected in both species, limited reproductive impairment was observed. Our results support previous findings that great tits and blue tits may not be very susceptible to PFAS pollution and provide evidence that other factors, including ecological stoichiometry, may be more important in explaining inter-species variation in PFAS accumulation and reproductive impairment.

A Comparative Study of the Rapid (IKr) and Slow (IKs) Delayed Rectifier Potassium Currents in Undiseased Human, Dog, Rabbit, and Guinea Pig Cardiac Ventricular Preparations.

To understand the large inter-species variations in drug effects on repolarization, the properties of the rapid (IKr) and the slow (IKs) components of the delayed rectifier potassium currents were compared in myocytes isolated from undiseased human donor (HM), dog (DM), rabbit (RM) and guinea pig (GM) ventricles by applying the patch clamp and conventional microelectrode techniques at 37 °C. The amplitude of the E-4031-sensitive IKr tail current measured at -40 mV after a 1 s long test pulse of 20 mV, which was very similar in HM and DM but significant larger in RM and GM. The L-735,821-sensitive IKs tail current was considerably larger in GM than in RM. In HM, the IKs tail was even smaller than in DM. At 30 mV, the IKr component was activated extremely rapidly and monoexponentially in each studied species. The deactivation of the IKr component in HM, DM, and RM measured at -40 mV. After a 30 mV pulse, it was slow and biexponential, while in GM, the IKr tail current was best fitted triexponentially. At 30 mV, the IKs component activated slowly and had an apparent monoxponential time course in HM, DM, and RM. In contrast, in GM, the activation was clearly biexponential. In HM, DM, and RM, IKs component deactivation measured at -40 mV was fast and monoexponential, while in GM, in addition to the fast component, another slower component was also revealed. These results suggest that the IK in HM resembles that measured in DM and RM and considerably differs from that observed in GM. These findings suggest that the dog and rabbit are more appropriate species than the guinea pig for preclinical evaluation of new potential drugs expected to affect cardiac repolarization.

Evaluation of several routine methods for fosfomycin and mecillinam susceptibility testing of Enterobacterales urine isolates.

Performance evaluation of routine laboratory methods to determine the susceptibility of Enterobacterales urinary isolates to fosfomycin (oral administration) and mecillinam. We collected 347 Enterobacterales isolates from monomicrobial midstream urine samples from women with significant bacteriuria and leukocyturia. Mostly non-Escherichia coli isolates (i.e. Klebsiella spp., Citrobacter koseri, Enterobacter cloacae complex and Proteus mirabilis) were included (n = 298). Performance of VITEK®2, ETEST®, and disc diffusion to determine fosfomycin and mecillinam susceptibility was evaluated following International Organization for Standardization (ISO) 20776-2:2021 (or 20776-2:2007 for disc diffusion) in comparison with the agar dilution reference method. For fosfomycin testing, VITEK®2 and ETEST® were close to reaching ISO requirements (essential agreement ≥ 90%; bias ±30%) for C. koseri, E. coli and P. mirabilis. Categorical agreement (CA) and major error rates were acceptable for disc diffusion. Fosfomycin displayed lower activity against E. cloacae complex and Klebsiella spp., with MIC50 (minimum inhibitory concentration required to inhibit the growth of 50% of tested isolates) equal to the E. coli EUCAST breakpoint (8 mg/L). For these species, the three alternative techniques overestimated MICs and resistance, and did not meet performance criteria. For mecillinam testing of Enterobacterales isolates, apart from P. mirabilis, ETEST® nearly fulfilled ISO requirements, and CA rates were acceptable for disc diffusion. ISO criteria were reached for C. koseri and E. coli testing with VITEK®2, apart from too high rates of very major errors. For P. mirabilis, performances were unacceptable, whatever the routine method used. Commercially available tests may serve as alternatives to agar dilution to assess fosfomycin (oral) and mecillinam susceptibility of Enterobacterales urinary isolates, with important interspecies variabilities. Additional studies comprising more fosfomycin- and mecillinam-resistant isolates are needed to strengthen our conclusions.

Determination of Species Identity and Genetic Diversity of Aedes aegypti and Other Medically Important Mosquitoes of India Using DNA Barcoding.

Aedes aegypti-borne viruses (i.e., dengue, chikungunya, and Zika) have become endemic to India, posing a severe threat to public health. Vector control remains the mainstay of disease management due to nonavailability of licensed vaccines/therapeutics. Conventional morpho-taxonomical methods cannot differentiate between closely related sibling species or species complexes, and hence we evaluated two molecular markers, mitochondrial cytochrome c oxidase subunit 1 (Cox1) and nuclear DNA internal transcribed spacer 2 (-2) gene sequences, to characterize seven populations of Ae. aegypti and four medically important mosquito species (Aedes albopictus, Anopheles stephensi, Culex tritaeniorhyncus, and Culex murrelli). DNA extracted from the 11 mosquito populations (two mosquitoes per population) was polymerase chain reaction amplified, sequenced, and analyzed. Molecular characterization was found to be congruent with morphological identification, suggesting no variants or cryptic species exist in Ae. aegypti and the other mosquitoes studied. Phylogenetic analysis with sequences obtained with Cox1 gene of Ae. aegypti and other Aedes and non-Aedes mosquito species showed clustering of sequences from different species representing different clades, distinctly separating one taxon from the other, whereas ITS-2 sequences of Aedes aegypti from across the world clustered tightly. Nucleotide divergence values revealed a low percentage of intraspecies variation and a higher percentage of interspecies variation. The present study authenticates the applicability of Cox1 and ITS-2 in the precise identification of Ae. aegypti mosquitoes against cryptic or sibling species. Cox1 appeared to be a more reliable marker because it showed distinct clustering of mosquito species, and some sequence variations to represent genetic diversity.

Selective capture of PM2.5 by urban trees: The role of leaf wax composition and physiological traits in air quality enhancement

Human health risks from particles with a diameter of less than 2.5 µm (PM2.5) highlight the role of urban trees as bio-filters in air pollution control. However, whether the size and composition of particles captured by various tree species differ or not remain unclear. This study investigates how leaf attributes affect the capture of PM2.5, which can penetrate deep into the lungs and pose significant health risks. Using a self-developed particulate matter (PM) resuspension chamber and single-particle aerosol mass spectrometer, we measured the size distribution and mass spectra of particles captured by ten tree species. Notably, Cinnamomum camphora (L.) J.Presl and Osmanthus fragrans Lour. are more effective at capturing particles under 1 µm, which are most harmful because they can reach the alveoli, whereas Ginkgo biloba L. and Platanus × acerifolia (Aiton) Willd. tend to capture larger particles, up to 1.6 µm, which are prone to being trapped in the upper respiratory tract. Leaf physiological traits such as stomatal conductance and water potential significantly enhance the capture of larger particles. The Adaptive Resonance Theory neural network (ART-2a) algorithm classified a large number of single particles to determine their composition. Results indicate distinct inter-species variations in chemical composition of particles captured by leaves. Moreover, we identified how specific leaf wax compositions—beyond the known sticky nature of hydrophobic waxes—contribute to particle adhesion, particularly highlighting the roles of fatty acids and alkanes in adhering particles rich in organic carbon and heavy metals, respectively. This research advances our understanding by linking leaf physiological and wax characteristics to the selective capture of PM2.5, providing actionable insights for urban forestry management. The detailed exploration of particle size and composition, tied to specific tree species, enriches the current literature by quantifying how and why different species contribute variably to air quality improvement. This adds a crucial layer of specificity to the general knowledge that trees serve as bio-filters, offering a refined strategy for planting urban trees based on their particulate capture profiles.

Exemplifying interspecies variation of liposome in vivo fate by the effects of anti-PEG antibodies

The different fate of liposomes among species has been discovered and mentioned in many studies, but the underlying mechanisms have not been explored. In the present work, we concentrated on the in vivo fate of PEGylated liposomes (sLip) in three commonly used species (mice, rats, and dogs). It was exhibited that the accelerated blood clearance (ABC) phenomenon and hypersensitivity in large animals (beagle dogs) were much more significant than that in rodents. We demonstrated that anti-PEG IgM (partially) and complement (mostly) determined the elimination of sLip and linked the distinct interspecies performances with the diverse complement capacity among species. Based on the data from animals and clinical patients, it was revealed that the fate of sLip in large animals was closer to that in humans, for the sufficient complement capacity could expose the potential adverse reactions caused by anti-PEG antibodies. Our results suggested that the distinctive interspecies performances of sLip were highly related to the physiological variabilities among species, which should not be overlooked in the innovation and translation of nanomedicines.

P-629 In vivo follicular activation (IVFA) through repeated ovarian punction: results of an experimental study in a premature ovarian insufficiency rodent model

Abstract Study question Can the new IVFA therapy effectively promote ovarian follicle development and increase oocyte number in a premature ovarian insufficiency (POI) animal model. Summary answer The IVFA technique reveals favourable reproductive outcomes in the animal model, demonstrating increased oocyte retrieval without compromising quality, making a promising advancement in fertility restoration. What is known already POI is characterized by the loss of the primordial follicular pool before the age of 40. Ovarian fragmentation for in vitro follicular activation (IVA) is a technique based on the disruption of the ovarian extracellular matrix, subsequently promoting actin polymerization and interfering with the evolutionarily conserved tumour suppressor Salvador-Hippo-Warts (SHW) signalling pathway. This has been proven to increase expression of downstream growth factors, thus promoting the primordial follicle growth and the generation of mature oocytes. Yet, this procedure is invasive and expensive. Consequently, a demand exists for less invasive in vivo therapies. Study design, size, duration Experimental animal study. Sixty 6-week-old C57BL/6 female mice were divided into control (CT) and POI groups. Each group, was further divided into three subsets (n = 10/group): without ovarian punctures (CT-0 and POI-0), 15 punctures (CT-15 and POI-15), and 22 punctures (CT-22 and POI-22). Twenty-one days after POI induction, the new IVFA technique was performed on the anaesthetized animals. Subsequently, controlled ovarian stimulation (COS) was initiated, followed by euthanasia for the oocyte retrieval and histological ovarian evaluation. Participants/materials, setting, methods POI condition was induced with intraperitoneally injections of 120 mg/kg of cyclophosphamide and 12 mg/kg of busulfan. The IVFA technique involved ovarian punctures using a 30-gauge needle. COS was induced with 10 IU of PMSG and 10 IU of hCG 48 hours later, leading to euthanasia for oocytes and ovaries collection. Ovaries (n = 6/group) were fixed for follicular counts and immunohistochemistry. Oocyte quality assessment included reactive oxygen species (ROS) levels, mitochondrial fluorescence (Mitotracker), and spindle analysis. Main results and the role of chance The control groups subjected to the IVFA technique (CT-15 and CT-22) demonstrated significantly higher mean total oocyte counts compared to the non-intervention group (CT-0) (30.0±9.8 and 27.7±7.9 vs 18.1±11.7, respectively; p-value<0.05 in both comparisons). Similarly, within the POI model, interventions (POI-15 and POI-22) showed significantly elevated mean total oocyte counts than the non-intervention group (POI-0) (8.1±4.4 and 7.2±2.8 vs 3.8±3.6, respectively; p-value<0.05). The intensity of ROS fluorescence, Mitotracker fluorescence, and spindle analysis in retrieved oocytes were not affected by the IVFA therapy, thereby preserving oocyte quality. Notably, the percentage of growing follicles was significantly increased in the intervention groups compared to the non-intervention groups in the control (60±5.7% and 58.1±4.7% vs 41.5±4.5%; p-value<0.001). In the POI model, statistically significant differences were observed for POI-15 vs POI-0 (57.8±9% vs 41.6±13.3%; p-value<0.05), but not for POI-22 vs POI-0 (51.5±14.2% vs 41.6±13.3%, p=n.s.) Moreover, the global Ki67 proliferation marker demonstrated a significant increase in the percentage of proliferative cells in the CT-15 intervention group compared to the CT-0 group (53±11.2% vs 46.1±15.1; p < 0.01). Finally, in the POI model, the percentage of Ki-67 positive cells was also significantly higher in both IVFA groups (39.4±18.5% and 38.1±17.3% vs 32±17.5%, respectively; p < 0.05). Limitations, reasons for caution Since this is an animal model of POI, further validation of the new therapy with human ovarian samples would be required. The magnitude of the effect could vary due to inter-species variability. Wider implications of the findings The positive results of the new therapy in promoting follicle development and increasing oocyte retrieval, without compromising quality, have significant implications for developing new fertility treatments. If validated in humans, this approach could offer a promising solution for women with POI. Trial registration number not applicable