Search Results (71)

This study focuses on a subtropical evergreen broad-leaved forest in China, utilizing a large permanent plot established in the Yaoluoping National Nature Reserve. By integrating data from a full-stem census and total station surveying, we analyzed the phylogenetic structure of the plant community as a whole and across different life-history stages (saplings, juveniles, and adults) while quantitatively assessing microtopographic variables and an interspecific competition index. The results indicate that the overall community in the Yaoluoping plot exhibited a weakly overdispersed pattern, and key microtopographic factors—including aspect, terrain position index (TPI), terrain ruggedness index (TRI), roughness, and flow direction—significantly influenced the evolution of phylogenetic structure. Distinctions were also observed among saplings, juveniles, and adults in phylogenetic structuring across life-history stages. Specifically, saplings displayed a higher degree of phylogenetic clustering, significantly influenced by density, elevation, TPI, and flow direction—suggesting that environmental filtering predominates at this stage, possibly due to lower environmental tolerance, limited dispersal ability, and conspecific negative density dependence. In contrast, juveniles and adults showed a more dispersed phylogenetic structure, with density, interspecific competition, aspect, TRI, TPI, and roughness significantly correlated with phylogenetic patterns, indicating that competition and niche differentiation become increasingly important as trees mature and establish within the community. Interspecific competition was found to play a crucial role in community structuring: the competition index was generally negatively correlated with the net relatedness index (NRI) and nearest taxon index (NTI) in juveniles and adults, implying that intense competition leads to the exclusion of some species and reduces overall diversity, with the strength and significance of competitive effects differing across stages. This study enhances our understanding of the complex interplay between microtopography and interspecific competition in shaping the phylogenetic structure and diversity of subtropical evergreen broad-leaved forests, elucidates the coupled mechanisms among microtopography, phylogenetic structure, and competition, and provides a scientific basis for forest conservation and management. Full article

Territorial crustaceans exhibit a complex set of personality traits and behavioral characteristics that are critical for their survival, growth, and overall welfare. This study aimed to systematically investigate the interplay between two essential personality traits—boldness and aggression—in Chinese mitten crabs (Eriocheir sinensis), during various developmental stages under conditions of crowding stress and food odor stimuli. Using behavioral assays, we found that adults displayed significantly higher levels of boldness and aggression compared to juveniles. Notably, bold adult crabs demonstrated lower aggression than their shy counterparts, revealing a significant negative correlation between boldness and aggression under crowding stress. Furthermore, juvenile and adult crabs exhibited negative correlations between the stability of their boldness and aggression with individual levels of boldness and aggression, respectively. The study also found that while juvenile boldness did not significantly correlate with body size, larger individuals displayed higher boldness under stress, contrasting with adult crabs, where boldness negatively correlated with body size, although aggression levels were unaffected by size; the stability of adult boldness demonstrated a positive correlation with body size under crowding stress. These findings elucidate the intricate dynamics of personality traits in territorial crustaceans, laying the groundwork for future research into their adaptive behavioral strategies in response to environmental cues like group stress and food odors. Full article

Background: Spinal muscular atrophy (SMA) is a severe neuromuscular disorder characterized by the degeneration of alpha motor neurons in the spinal cord, leading to progressive proximal muscle weakness and paralysis. SMA is clinically categorized into four phenotypes based on age of onset and motor function achieved. Patients with SMA type 3 (juvenile, Kugelberg-Welander disease) initially have the ability to walk unaided, but experience a gradual decline in motor abilities over time. However, their lifespan is not affected by the presence of the disease. Leptin, a cytokine-like hormone secreted by adipocytes, has receptors widely distributed in musculoskeletal tissues. Several studies suggest that adiponectin deficiency contributes to the development of insulin resistance, with lower adiponectin levels closely associated with greater insulin resistance and hyperinsulinemia. However, the role of adiponectin in different types of sarcopenia and its connection to insulin sensitivity remains controversial. The purpose of this study was to measure leptin and adiponectin levels in patients with SMA type 3 and explore their association with markers of insulin sensitivity. Methods: This cross-sectional study included 23 adult patients with SMA type 3 (SMA group) and 18 community-based healthy volunteers (control group), conducted from July 2020 to September 2024. Anthropometric parameters, body composition, body fat percentage, surrogate markers of insulin sensitivity (Homeostasis model assessment of insulin resistance index—HOMA-IR and ISI Matsuda), and circulating levels of leptin and adiponectin were measured in all participants. Results: Insulin resistance was present in 91.3% of patients with SMA type 3, as determined by HOMA-IR and ISI Matsuda insulin sensitivity markers. In the control group, 64.7% had insulin resistance (IR) according to HOMA-IR, while 44.4% met the ISI Matsuda criterion for IR, showing a significant difference in peripheral insulin sensitivity between groups. A significant difference in serum adiponectin levels was observed between patients with SMA type 3 and the control group, whereas there was no significant difference in serum leptin concentrations. High adiponectin levels were observed in 50% of patients with SMA type 3. In the healthy control group, adiponectin levels positively correlated with ISI Matsuda and negatively correlated with HOMA-IR, confirming the insulin-sensitizing role of adiponectin. However, this correlation was not observed in patients with SMA type 3. Conclusions: Our results suggest that in this specific type of hereditary neuromuscular disease, the interplay between sarcopenia and insulin leads to adiponectin resistance, challenging the canonical narrative between insulin sensitivity and adiponectin, and indicating a need for further research. Full article

Juvenile environments can influence adult phenotypes in holometabolous insects. This study examines the effects of larval rearing substrates on the reproductive outcomes of Black Soldier Flies (BSFs) at a semi-industrial scale. Larvae were reared on five substrates. Larval growth, adult size, and reproductive performance were monitored, with a specific focus on egg production and hatching rates across 17 continuous egg collection days. Egg production was positively correlated with female body weight, while male body weight appeared to influence the egg production peak. Extended larval feeding stages and shorter non-feeding periods were associated with an earlier onset of egg-laying, suggesting life-history traits as predictors for reproductive timing. Diets high in carbohydrates but low in protein and fat positively influenced larval growth, egg production, and female body weight, while diets rich in both protein and carbohydrates negatively affected all measured parameters. Notably, higher fecundity did not necessarily correlate with fertility (i.e., more viable larvae for bioconversion), highlighting the need to optimize diets for both egg quantity and hatchability to maximize productivity. These findings provide valuable insights for optimizing larval nutrition and egg collection practices, enhancing reproductive efficiency and overall productivity in industrial BSF farming. Full article

The Southeastern U.S. Atlantic coast (North Carolina to Florida, U.S.A.) has undergone considerable environmental change in recent decades, including increasing coastal water temperature and human development. The region is also home to a diverse suite of exploited reef fish species, including the southern stock of black sea bass (Centropristis striata). The objective of the current study was to compare trends in black sea bass year class strength and central location captured by trawls (age 0) and traps (age 2) as well as compare those trends to regional bottom temperature. We found no correlation between age 0 and age 2 abundance when comparing the same year class, suggesting that the numbers of trawl-caught juveniles cannot predict the number of adults available to the fishery. Larger year classes observed in traps were correlated with centers of abundance farther south in the region, while smaller year classes corresponded with more northerly centers of abundance. In both trawls and traps, strong year classes occurred following years with below-average regional water temperatures, and a series of recent, weak year classes correspond with recent higher-than-average water temperatures. It is unclear whether correlations between shifting centers of abundance, year class strength, and regional bottom temperature indicate a range contraction for the southern stock of black sea bass or movement into areas previously inhabited by the northern stock of the species. Full article

Eucalyptus globulus Labill. is one of the most important species in the paper industry. Teratosphaeria nubilosa has affected plantations worldwide, infecting young foliage. Genome-wide association studies (GWASs) are essential to identify genomic segments associated with susceptibility to this disease. The inclusion of genomic strategies in breeding programs is key to the sustainability of the species. The aim of this study was to identify genomic regions associated with growth and heteroblasty (change from juvenile to adult foliage: ADFO) in a tree breeding population of E. globulus. Tree growth was measured as total height (TH) and diameter at breast height (DBH). All traits were evaluated at 14 and 21 months. A multi-trait threshold linear model was developed following the single-step genomic selection methodology. Genetic correlations (r_g) and narrow-sense heritability (h²) for all traits were estimated. Windows of 0.2 Mb were used. Only the windows with an estimated variance greater than 1% were considered. The r_g ranged from 0.51 to 0.97. The h² was high for ADFO (0.83–0.84) and lower for HT (0.37) and DBH (0.53). In growth traits, no QTLs were found that explained more than 1% of the variance. However, two genomic regions related to ADFO were identified on chromosomes 3 and 11. Full article

Largemouth bass (LMB, Micropterus salmoides), a commercially important farmed fish, is vulnerable to heat stress. Breeding heat-resistant LMB is highly desirable in the face of global warming. However, we still lack an efficient method to assess the heat resistance of LMB. In this study, the critical thermal maximum (CTmax) and static exposure methods were first performed to assess the heat resistance of LMB juveniles. The CTmax values of the experimental fish (average body weight 9.87 ± 3.14 g) ranged from 39 to 40 °C but were too close together to differentiate the individual heat resistance. Static exposure experiments with varying temperatures and fish groups also did not provide a clear method for determining the heat resistance. To address these limitations, we developed a tiered exposure method, where the temperature was increased step-wise, starting from 28 to 34 °C at 2 °C increments and then at 0.5 °C increments above 34 °C, with each step lasting one day. The heat resistance of the fish was quantified as the lethal cumulative temperature (LCT), allowing for the classification of fish as sensitive or resistant to heat stress based on their LCT values. To correlate the changes in tissue structure and gene expression with the heat resistance, a new batch of LMB juveniles (average body weight 23.66 ± 6.98 g) were subjected to tiered heat exposure. Brain and liver tissues were collected from the control (without heat exposure), resistant and sensitive (still alive but demonstrated abnormal symptoms) individuals when the temperature was maintained at 35.5 °C for 24 h. The liver tissues of the heat-sensitive individuals showed significant damage and increased cell apoptosis (p < 0.05) relative to those of the resistant ones. The ddit3/chop, bax and casp3 genes demonstrated differential expressions in the liver of the sensitive and resistant fish. Additionally, the LMB juveniles (average body weight 84.06 ± 20.95 g) were found to be more heat resistant than the adults from different sources (average body weight 364.29 ± 84.43 g and 545.71 ± 184.56 g). Through the tiered exposure method, extremely heat-resistant individuals were successfully selected from the population (average body weight 22.69 ± 6.89 g). These findings provide valuable insights into the thermal biology of LMB and the potential for breeding heat-resistant LMB varieties. Full article

Describing home range and resource selection is crucial for understanding ecological needs and creating conservation programs. Still, our knowledge of spatial and behavioural ecology for most species remains limited. Here, we used satellite transmitters to investigate core and home range sizes, habitat selection, and roost characteristics in seven tawny owl males in Western Serbia during the autumn–winter period 2023. Using minimum convex polygon (MCP) and autocorrelated kernel density estimation (AKDE), we found clear variability in core area and home range sizes. Also, adult and heavier males have smaller core area and home ranges than juvenile and lightweight individuals. The Bhattacharyya coefficient showed minor home range overlap in tagged males. The final model for evaluation of habitat selection suggests that the likelihood of owl occurrence was positively correlated with the share of anthropogenic infrastructure and negatively associated with the increase in the proportion of cultivated land within the home range. However, scores of model performance metrics showed moderate predictive accuracy, implying that other unmeasured variables may dictate species presence. Our study illustrates the ecological plasticity and ability of the tawny owl to adapt to a human-modified environment while providing new information about the spatial ecology of this widespread predator in Europe. Full article

Chiggers are the exclusive vector of Orientia tsutsugamushi, which is the causative agent of scrub typhus. Based on the field surveys in southwest China between 2001 and 2022, this paper retrospectively reported the chigger infestation and distribution on the large-eared field mouse (Apodemus latronum), an endemic rodent species in the region, for the first time. A total of 933 chiggers were collected from 501 mice, and these chiggers were identified as 2 families, 8 genera, and 61 species. The overall infestation prevalence (P_M) and mean abundance (MA) of A. latronum with chiggers reached 19.76% and 1.86 mites/per mouse, respectively. The chigger infestation indices on adult A. latronum (P_M = 38.28%, MA = 5.11) were higher than those on juvenile mice (P_M = 12.63%, MA = 0.97) with p < 0.01, showing an age bias of infestation. The relative fatness (K) was used to reflect the nutrition status of the mouse host. The mouse hosts with good nutrition (K = 3.4 ± 0.89 g/cm³) harbored fewer chiggers than the hosts with poor nutrition (K = 2.2 ± 0.90 g/cm³) (p < 0.01). The infestation indices of chiggers on A. latronum obviously fluctuated along different altitude gradients (p < 0.01). With the increase in altitudes, the β diversity of the chigger community showed a gradually increasing tendency. The spillover chord diagram, which was based on indices of PAC (potential for apparent competition), revealed high spillover potentials of dominant chigger species dispersing from high altitude gradients to the lowest one. The chigger abundance was positively correlated with the mean monthly temperature (tmp), mean monthly humidity (hum), the mean monthly precipitation (pre), and the human footprint (hfp), and it was negatively correlated with the altitude (ele) (p < 0.05). The temperature and humidity are the most important factors which influence the chigger infestation. Full article

Background: Understanding population genetic structures is crucial for planning and implementing conservation programmes to preserve species’ adaptive and evolutionary potential and thus ensure their long-term persistence. The grey mullet (Mugil cephalus) is a globally distributed coastal fish. Its populations in waters surrounding Taiwan on the western Pacific fringe are divided into at least two stocks (migratory and residential), but questions remain regarding their genetic divergence and gene flow. Methods and Results: To cast more light on this, allozyme variations at 21 presumptive gene loci of 1217 adult grey mullets from 15 localities in Japan, Taiwan and mainland China, and four gene loci from 1470 juveniles from three localities in Taiwan were used to investigate patterns of genetic variation. The mean expected heterozygosity (He) was 0.128—ranging from 0.031 (Matsu) to 0.442 (Kaoping)—and the mean observed heterozygosity (Ho) was 0.086—ranging from 0.017 (Kaohsiung) to 0.215 (Kaoping). Both AMOVA and the high overall mean FST of 0.252 indicated enormous genetic differentiation among populations and the positive mean value of FIS was 0.328, indicating a deficiency of heterozygotes. PCoA indicated that the samples of M. cephalus could be split into three groups and STRUCTURE analysis showed that all individuals were grouped into three genetic clusters. The results of mutation-drift equilibrium tests did not suggest that the populations experienced any recent genetic bottleneck. The results from all localities in the present investigation showed significant change in the GPI-A genotype frequencies with latitudes—e.g., increases in GPI-A*135/135 homozygote frequencies and GPI-A*100/100 frequencies were highly correlated with latitudinal cline. All migratory populations with the GPI-A genotype were almost exclusively the GPI-A*100/100 homozygote. During the life history of M. cephalus, the GPI-A*100/135 heterozygote frequency significantly decreases with age. Conclusions: Based on these data, we suggest that each GPI-A genotype represents trait combinations of higher fitness in some portions of the environment. Furthermore, the genotypic frequencies change in accordance with life stages, suggesting that selection occurs throughout the life span. Full article

The Mediterranean tortoise Testudo hermanni inhabits different regions bordering the northwestern Mediterranean. This species is vulnerable, protected by legislation, and involved in various breeding and reintroduction programs. Wild populations face numerous environmental and anthropogenic stressors that can potentially interfere with their conservation. While seasonal changes in stress-response biomarkers, such as glucocorticoids and thyroid hormones, have been widely studised in mammals and birds, there is a paucity of research in reptile species. Therefore, the present study aimed to evaluate the seasonal fluctuations in corticosterone and total triiodothyronine levels in adult and juvenile Hermann’s tortoises (Testudo hermanni) as a measure of the physiological stress response. Blood samples were collected seasonally (winter, spring, summer, and autumn) and posteriorly analyzed by using a specific and validated enzyme immunoassay for both hormones, respectively. The results showed that corticosterone levels varied seasonally and differed between sexes, whereas total triiodothyronine levels changed seasonally but did not differ between sexes. Notably, juveniles exhibited no seasonal changes in either corticosterone or total triiodothyronine levels. Additionally, no correlation between blood extraction duration and hormonal concentrations was observed. This study is pioneering in its comprehensive evaluation of corticosterone and total triiodothyronine changes across all four seasons, including winter, and its focus on juvenile Hermann’s tortoises. Full article

This study used skeletochronology to assess the relationships between age and body length among individuals in a population of the Tavas Frog (Rana tavasensis), located in the Çakıroluk plateau, Tavas district, Denizli province. The age varied from 3 to 12 years in both adult males and females. The age was 2 years in two subadult males, while it was 1 year in one juvenile specimen. The mean SVL and age of the adult individuals of the Çakıroluk population were 62.75 mm and 6.70 years in male specimens and 58.04 mm and 6.12 years in female specimens. A positive correlation was found between body size (SVL) and age in adult female and male individuals of the species. Because the number of individuals of the species is rapidly decreasing, species protection measures, based on knowledge related to the age structure and breeding features of these frogs, must be put into action urgently. Full article

Swiss stone pine (Pinus cembra) is a feasible solution for increasing the resistance of future mixed spruce–pine stands to windfall at the upper altitudinal limit of Romanian forests. This study aims to analyze the adaptability of ten full-sib families in two different environmental conditions and their evolution in time for predicting forward selection. At a seedling age of 33, evaluations were carried out for survival rate (Sr), growth (diameter at breast height—Dbh, and trees’ height), and branch traits, as well as for stem straightness. The high level of genetic variability, inheritance rate, and trait–trait correlations, registered in both trials, ensure the success of the breeding program. The Swiss stone pine shows a very good adaptation on high-sloping lands from the upper altitudinal limit of Romania’s forests, with the cross-pollinated (CP) families registering a 28.5% better survival in the Rodna trial (34° slope) compared to the Păltiniș experiment (7° slope). The consanguineous families registered only an 11% Sr in Păltiniș, while in the Rodna trial, the Sr was four times higher (in both trials, consanguineous trees were dominated). The juvenile–adult correlations of growth traits were significant, indicating that early selection could be efficient. The forward selection of the best 10% of CP families for Dbh could be applied, ensuring a 9% to 15% genetic gain. Full article

The evolution of the population ecosystem is closely related to resources and the environment. Assuming that the environmental capacity of a predator population is positively correlated with the number of prey, and that the prey population has a sheltered effect, we investigated a predator–prey model with a juvenile–adult two-stage structure. The dynamical behaviour of the model was examined from two distinct environmental perspectives, deterministic and stochastic, respectively. For the deterministic model, the conditions for the existence of equilibrium points were obtained by comprehensive use of analytical and geometric methods, and the local and global asymptotic stability of each equilibrium point was discussed. For the stochastic system, the effect of noise intensity on the long-term dynamic behavior of the population was investigated. By constructing appropriate Lyapunov functions, the criteria that determined the extinction of the system and the ergodic stationary distribution were given. Finally, through concrete examples and numerical simulations, the understanding of the dynamic properties of the model was deepened. The results show that an improvement in the predator living environment would lead to the decrease in the prey population, while more prey shelters could lead to the decline or even extinction of predator populations. Full article

Cardiomyopathy is the predominant defect in Barth syndrome (BTHS) and is caused by a mutation of the X-linked Tafazzin (TAZ) gene, which encodes an enzyme responsible for remodeling mitochondrial cardiolipin. Despite the known importance of mitochondrial dysfunction in BTHS, how specific TAZ mutations cause diverse BTHS heart phenotypes remains poorly understood. We generated a patient-tailored CRISPR/Cas9 knock-in mouse allele (Taz^PM) that phenocopies BTHS clinical traits. As Taz^PM males express a stable mutant protein, we assessed cardiac metabolic dysfunction and mitochondrial changes and identified temporally altered cardioprotective signaling effectors. Specifically, juvenile Taz^PM males exhibit mild left ventricular dilation in systole but have unaltered fatty acid/amino acid metabolism and normal adenosine triphosphate (ATP). This occurs in concert with a hyperactive p53 pathway, elevation of cardioprotective antioxidant pathways, and induced autophagy-mediated early senescence in juvenile Taz^PM hearts. However, adult Taz^PM males exhibit chronic heart failure with reduced growth and ejection fraction, cardiac fibrosis, reduced ATP, and suppressed fatty acid/amino acid metabolism. This biphasic changeover from a mild-to-severe heart phenotype coincides with p53 suppression, downregulation of cardioprotective antioxidant pathways, and the onset of terminal senescence in adult Taz^PM hearts. Herein, we report a BTHS genotype/phenotype correlation and reveal that absent Taz acyltransferase function is sufficient to drive progressive cardiomyopathy. Full article