Peak Abundance Research Articles

Spatio-temporal distribution and biotechnological potential of culturable yeasts in the intertidal sediments and seawater of Aoshan Bay, China.

Marine yeasts play a crucial role in marine microbial ecology, facilitating the biogeochemical cycling of carbon and nitrogen in marine ecosystems, while also serving as important reservoirs of bioactive compounds with extensive applications in pharmaceuticals, agriculture, and various industries. Intertidal flats, characterized by their complex ecological dynamics, are postulated to harbor a wealth of yeast resources. This study employed a culture-dependent approach to assess the diversity, spatio-temporal distribution, and biotechnological potential of yeast communities residing within the intertidal sediments and seawater of Aoshan Bay. A total of 392 yeast strains were identified from 20 distinct genera, encompassing 43 recognized species and four candidate novel species. Notably, 17 of these species were identified as novel occurrences in marine environments, underscoring the rich yeast biodiversity of the Aoshan Bay ecosystem, with Candida emerging as the dominant genus in both sedimentary and aqueous habitats. Yeast community composition exhibited significant spatial and temporal variation, with peak diversity and abundance observed in autumn, the subtidal zone, and the surface soil layer. No clear pattern, however, emerged linking these shifts to specific changes in community composition, highlighting the complex interactions between microbial communities, environmental variables, and anthropogenic disturbance. Although several yeast species isolated here have been previously recognized for their biotechnological potential, their diverse and abundant extracellular enzyme profiles were characterized, further highlighting their crucial role in organic matter decomposition and nutrient cycling within the tidal ecosystem, as well as their potential applicability in the food, fine chemical, textile, and pharmaceutical industries.IMPORTANCEThis study presents groundbreaking insights into the yeast diversity of Aoshan Bay, offering invaluable information on their spatial and temporal distribution patterns, as well as their biotechnological potential in the tidal environment. The findings reveal that the eutrophic intertidal flat is a rich repository of yeasts with abundant extracellular enzymatic activity and an important role in nutrient cycling and decomposition processes. Also, these yeasts serve as crucial indicators of ecosystem health and function and are excellent candidates for biotechnological and industrial applications. Collectively, this study not only expands our knowledge of the diversity and distribution of intertidal yeasts but also highlights their promising potential for biotechnological applications.

The glomerular circadian clock temporally regulates basement membrane dynamics and the podocyte glucocorticoid response.

Kidney physiology shows diurnal variation, and a disrupted circadian rhythm is associated with kidney disease. However, it remains largely unknown whether glomeruli, the filtering units in the kidney, are under circadian control. Here, we investigated core circadian clock components in glomeruli, together with their rhythmic targets and modes of regulation. With clock gene reporter mice, cell-autonomous glomerular clocks which likely govern rhythmic fluctuations in glomerular physiology were identified. Using circadian time-series transcriptomic profiling, the first circadian glomerular transcriptome with 375 rhythmic transcripts, enriched for extracellular matrix and glucocorticoid receptor signaling ontologies, were identified. Subsets of rhythmic matrix-related genes required for basement membrane assembly and turnover, and circadian variation in matrix ultrastructure, coinciding with peak abundance of rhythmic basement membrane proteins, were uncovered. This provided multiomic evidence for interactions between glomerular matrix and intracellular time-keeping mechanisms. Furthermore, glucocorticoids, which are frequently used to treat glomerular disease, reset the podocyte clock and induce rhythmic expression of potential glomerular disease genes associated with nephrotic syndrome that included NPHS1 (nephrin) and NPHS2 (podocin). Disruption of the clock with pharmacological inhibition altered the expression of these disease genes, indicating an interplay between clock gene expression and key genes required for podocyte health. Thus, our results provide a strong basis for future investigations of the functional implications and therapeutic potential of chronotherapy in glomerular health and disease.

Diversity and Seasonal Variations of Zooplankton in Dudhiya Talab of Sirohi, India

In this study, the seasonal fluctuations of zooplankton and specific physico-chemical parameters were examined in Dudhiya Talab, a significant artificial reservoir located in Sirohi, Rajasthan. During the research period, a total of 41 zooplankton species were identified, comprising 12 species of Rotifera, 14 species of Cladocera, 5 species of Ostracoda, and 4 species of Copepoda. Among these, Rotifera emerged as the predominant group, with a peak abundance of 689 individuals per liter recorded in the summer, while the lowest numbers were noted during the winter season. Additionally, the zooplankton community exhibited correlations with various physico-chemical parameters. The findings of this research suggest that the distribution and density of zooplankton species are significantly affected by the prevailing physical and chemical conditions of the aquatic environment. Key words: Zooplankton, Physico-chemical factors,P Cladocera, Rotifera.

Estimation of bacterio‐, picophyto‐ and nanophytoplankton abundance in the Middle Caspian Sea by flow cytometry

Aim. For the first time, flow cytometry has been used to study the structure and functional characteristics of bacterio‐, pico‐ and nano‐ phytoplankton in the Middle Caspian during the bloom period in early September 2022.Water samples were taken at different horizons (from the surface to the bottom layer) at a series of stations along the western coast of the Caspian Sea on the border between its northern and central parts to quantitatively assess heterotrophic bacterioplankton, picophyto‐ and nanophy‐ toplankton. Sampling was undertaken in early September 2022 under summer hydrological conditions with water surface temperatures ranging from 24.7°C to 26.7°C. Sample analysis was performed using flow cytometry.Extremely high concentrations of picophytoplankton (up to 1.8×105 cells/mL), probably of Synechococcus picocyanobacteria, were detected off the northwestern coast of the Middle Caspian. Very high values of nanophytoplankton abundance (up to 1.6×105 cells/mL), dominated by small flagellates, were also found. A clear spatial uncoupling of pico‐ and nanophytoplankton was revealed. Maximum levels of nanophytoplankton were confined to the area of intensive phytoplankton blooming with high concentrations of chlorophyll a, while picophytoplankton reached peak abundance further south, outside this area. The influence of the thermocline on the vertical structure of microbial communities was detected. The concentrations of picophytoplankton and the proportion of physiologically active HNA‐bacteria decreased sharply under the thermocline.The results obtained indicate the leading role of the smallest phototrophs in the Caspian pelagial and emphasise the need for further comprehensive studies of Caspian microbial communities using modern methods.

Environmental change and connectivity drive coral reef fish abundance in the Western Indian Ocean

Abstract Worldwide, coral reefs are facing risk from climate change. The Western Indian Ocean (WIO) harbours about 16% of global coral reefs with highly reef-dependent local communities. Coastal protection and food security depend on effective conservation management, which requires understanding species abundances. Here, we explore how fish group distribution and abundance across the WIO, categorized by their trophic function, are explained by oceanographic connectivity, sea surface temperature (SST), and chlorophyll a. We designed a proportional oceanographic connectivity metric describing the relative strength of connectivity between all WIO coral reefs and each survey site. We created statistical models for four trophic groups: grazers and detritivores, herbivorous excavators, corallivores, and primary piscivores across 51 sites in the WIO. We show that SST and chlorophyll a are strong predictors of all trophic fish groups and that the proportional oceanographic connectivity metric improved the model predictions significantly for grazers and detritivores and excavators. For excavators, peak abundances were predicted at medium connectivity, and for grazers and detritivores, at low and medium connectivity, suggesting that larvae dispersal predominates at a local scale. Decision making should include connectivity for efficient conservation area prioritization, for which our proportional oceanographic connectivity metric is a valid and useful parameter.

Landscape factors affect relative abundance of rootworm species and pod injury in Georgia peanuts.

The southern corn rootworm, Diabrotica undecimpunctata howardi Barber, is native to the US where it is a pest of peanut, Arachis hypogaea. The banded cucumber beetle, Diabrotica balteata LeConte, is native to the neotropics, but its range has expanded and currently includes most of the US peanut production area. The purpose of this study was to: (i) define seasonal variation in adult rootworm populations in peanut fields, and (ii) determine the effect(s) of proximity to a putative early season host (i.e., corn, Zea mays) and the presence of irrigation on rootworm infestation and pod injury in peanut. Seasonal abundance of adult rootworms in commercial peanut fields in Georgia was monitored in 2021 and 2022 using plant volatile lures attached to yellow sticky traps. Traps were located at 45, 90, and 180 m from the field edge in irrigated and nonirrigated peanut fields with and without a corn border. Two peaks in abundance were observed for both species in each year. Though peak abundance for the two species occurred nearly simultaneously, D. balteata was more abundant than D. u. howardi. Beetle abundance was highest in fields bordered by corn, but presence of irrigation was not as important for D. balteata as it was for D. u. howardi. Pod injury was greater in fields bordered by corn in both years, but there was no difference in pod injury between irrigated and nonirrigated fields. The number of beetles captured and incidence of pod injury within a field did not differ with distance from the field border.

Long-term measurements reveal a 100-day lag between peaks in phytoplankton chlorophyll and benthic bacterial abundance in the Fram Strait

Abstract Repeated measurements of benthic and pelagic parameters in the rapidly changing Arctic Ocean provide a unique insight into spatial and interannual trends and changes in the ecosystem. Here, we compiled biogenic and biogeochemical measurements collected from sediment cores at the Long-Term Ecological Research Observatory HAUSGARTEN located in the Fram Strait. A total of 21 stations were visited yearly over a period of 18 years (2002–2019). The time series highlighted an increase in bacterial numbers for samples collected 50 days after the peak phytoplankton bloom. Although bacterial abundances were not bathymetric depth-dependent when viewed across all years, we observed a seasonal trend in benthic microbial abundance closely related to the timing of the phytoplankton bloom with a time-lag of 100 days between the surface phytoplankton peak and the peak in bacterial abundance in the sediment. Considering the residence time of phytoplankton in the upper ocean and the water depth, we estimated an average settling velocity for phytodetritus of 30 m.d−1, which is similar to previous observations from Fram Strait. This suggests that settling organic matter promotes vertical microbial connectivity and benthic bacterial abundance in the deep ocean, shaping the microbial biogeography, diversity, and biogeochemical processes.

Exploring the response and prediction of phytoplankton to environmental factors in eutrophic marine areas using interpretable machine learning methods

Coastal marine areas are frequently affected by human activities and face ecological and environmental threats, such as algal blooms and climate change. The community structure of phytoplankton—primary producers in marine ecosystems—is highly sensitive to environmental factors, such as temperature, salinity, and nutrients. However, traditional methods for exploring the relationship between phytoplankton communities and environmental factors in eutrophic marine areas are limited by various factors. Therefore, this study employed interpretable machine learning models, integrating high-dimensional data analysis and complex system modeling, to quantitatively and thoroughly analyze the dynamic relationship between phytoplankton communities and environmental variables in high-frequency samples collected over 53 weeks from eutrophic marine areas. The cell abundance of phytoplankton exhibited a distinct “two-peak pattern” variation. Interpretable machine learning model analysis revealed the dynamic contributions of different environmental factors during changes in the phytoplankton community structure. The results showed that temperature was a key environmental factor that affected phytoplankton growth during peak periods. In addition, the contribution of salinity increased during the second peak in phytoplankton abundance, highlighting its central role in the ecological dynamics of this phase. During green tide outbreaks, particularly in Area 01, the contributions of factors such as temperature and salinity increased, whereas those of phosphates and silicates decreased, indicating that green tide outbreaks substantially altered the nutritional dynamics of the ecosystem. Furthermore, different phytoplankton species, such as Skeletonema costatum, Thalassiosira spp., and Nitzschia spp., exhibit varying responses to environmental factors. Hence, the predictions made using random forest and generalized additive models for phytoplankton cell abundance in two marine areas revealed complex nonlinear relationships between environmental factors, such as temperature, salinity, and phytoplankton abundance.

Constraining modified gravity with weak lensing peaks

Abstract It is well established that maximizing the information extracted from upcoming and ongoing stage-IV weak-lensing surveys requires higher-order summary statistics that complement the standard two-point statistics. In this work, we focus on weak-lensing peak statistics to test two popular modified gravity models, f(R) and nDGP, using the FORGE and BRIDGE weak-lensing simulations, respectively. From these simulations we measure the peak statistics as a function of both cosmological and modified gravity parameters simultaneously. Our findings indicate that the peak abundance is sensitive to the strength of modified gravity, while the peak two-point correlation function is sensitive to the nature of the screening mechanism in a modified gravity model. We combine these simulated statistics with a Gaussian Process Regression emulator and a Gaussian likelihood to generate stage-IV forecast posterior distributions for the modified gravity models. We demonstrate that, assuming small scales can be correctly modelled, peak statistics can be used to distinguish GR from f(R) and nDGP models at the two-sigma level with a stage-IV survey area of $300 \, \rm {deg}^2$ and $1000 \, \rm {deg}^2$, respectively. Finally, we show that peak statistics can constrain log10(|fR0|) = −6 to 2% precision, and log10(H0rc) = 0.5 to 25% precision.

Comparative transcriptomics of Venus flytrap (Dionaea muscipula) across stages of prey capture and digestion.

The Venus flytrap, Dionaea muscipula, is perhaps the world's best-known botanical carnivore. The act of prey capture and digestion along with its rapidly closing, charismatic traps make this species a compelling model for studying the evolution and fundamental biology of carnivorous plants. There is a growing body of research on the genome, transcriptome, and digestome of Dionaea muscipula, but surprisingly limited information on changes in trap transcript abundance over time since feeding. Here we present the results of a comparative transcriptomics project exploring the transcriptomic changes across seven timepoints in a 72-hour time series of prey digestion and three timepoints directly comparing triggered traps with and without prey items. We document a dynamic response to prey capture including changes in abundance of transcripts with Gene Ontology (GO) annotations related to digestion and nutrient uptake. Comparisons of traps with and without prey documented 174 significantly differentially expressed genes at 1 hour after triggering and 151 genes with significantly different abundances at 24 hours. Approximately 50% of annotated protein-coding genes in Venus flytrap genome exhibit change (10041 of 21135) in transcript abundance following prey capture. Whereas peak abundance for most of these genes was observed within 3 hours, an expression cluster of 3009 genes exhibited continuously increasing abundance over the 72-hour sampling period, and transcript for these genes with GO annotation terms including both catabolism and nutrient transport may continue to accumulate beyond 72 hours.

Assessing Antioxidant and Pour Point Depressant Capacity of Turmeric Rhizome Extract in Biolubricants

Natural polyphenols found in plants are secondary metabolites and act as natural antioxidants. Phenols prevent lipid oxidation by donating their hydrogen to free radicals generated between reactions of oxygen with unsaturated fatty acids. This work aims to examine turmeric extract for its capacity to act as an antioxidant and pour point depressant additive in biolubricants. The study involved extracting turmeric rhizome and analyzing the extract using the gas chromatography-mass spectrometry (GC-MS) and Fourier-transform infrared spectroscopy (FTIR) techniques to identify phenolic compounds and the nature of bonds in terms of abundance peak areas. The yield of concentrated turmeric rhizome extract by weight was 3.7%. The FTIR analysis revealed O-H band at 3336 cm−1, C-H asymmetric and symmetric stretching at 2940 and 2834 cm−1, C=C cyclic ring at 1680–1515 cm−1. The phenols detected by the GC-MS technique are phenol, 2 -methoxy-3-(2-propenyl) occupying 36.3% area at 16.5 min retention time and Phenol, 2-methoxy-4-(2-propenyl)-, acetate having 3.8% area at 3.8 min retention time. The results show promising capacity of turmeric rhizome extract to act as antioxidant and pour point depressant additive in biolubricants.

INFLUENCE OF ABIOTIC FACTORS ON DYNAMICS OF WHEAT PHYTONEMATODE IN MUGHAN PART OF AZERBAIJAN

The article deals with the impact of abiotic factors on the dynamics of wheat phytonematode in the Mughan part of Azerbaijan. To study the population dynamics of phytonematodes of wheat and its rootstock soil under Azerbaijan conditions, soil and plant samples were collected by stationary method monthly from March to June during 2018-2023. In the wheat field, 45 species of nematodes were recorded during the vegetation period. In both roots and rootstock of wheat, the highest number of phytonematode individuals was observed at the beginning of the study (March), then their density began to decrease sharply and reached a minimum at the end of the growing season (June). In aboveground parts, the highest peak of phytonematode abundance occurs in mid-spring (April), followed by a decline in abundance at the following dates. The lowest abundance is recorded in summer before harvesting. The recorded phytonematodes were distributed in the following ecological groups: polytrophs - 8 species, typical saprobionts - 2, devisaprobionts - 15, potential parasites - 12, true parasites - 8 species. Ecological groups of phytonematodes respond differently to changes in the conditions of existence. At the same time, the effect of ecological factors depended on the habitat of phytonematodes. It is known that in the Mughan region of Azerbaijan, the influence of abiotic factors on the dynamics of wheat phytonematodes mainly includes elements such as soil structure, climatic conditions, sunlight and water supply. These abiotic factors determine the level and distribution of nematode populations and affect the yield of crops. As a result of the changing influence of various abiotic factors, the population levels of nematodes also change, which affects the effectiveness in the crop field. In this regard, the understanding and management of these factors is important for improving the quality and production of wheat products. Preventive and preventive measures, depending on the completeness and timeliness of this information, allow you to create optimal conditions and get a stable harvest from plants. The above-mentioned issues have been extensively investigated and reflected in the article.

Evolution and distribution of antibiotic resistance genes in submerged macrophytes and biofilm systems: From seasonal monitoring to mesocosm experiments

The aquatic ecosystem has been extensively investigated as a hotspot for the spread of antibiotic resistance genes (ARGs); yet, the evolution and distribution of ARGs profiles in submerged macrophytes biofilms and surrounding water remained unclear. In this study, the dynamic distribution and seasonal variations of microbial communities and ARGs profiles were investigated, alongside their assembly processes and mutual interactions. Bacitracin and multidrug resistance genes were predominant, constituting more than 60% of the total ARGs abundance. The deterministic processes (<65%), influenced by the physicochemical properties of the river environment, governed the assembly and composition of ARGs profiles, exhibiting significant seasonal variation. The peak diversity (21 types) and abundance (0.316 copy ratios) of ARGs were detected during the summer. Proteobacteria and Actinobacteria were the dominant bacterial phyla, accounting for 38.41–85.50% and 4.03–27.09% of the microbial community, respectively. Furthermore, Proteobacteria, especially genera such as Acinetobacter, Burkholderia, and Pseudomonas, with various resistance sequences, were the primary carriers of multiple ARGs. Notably, the genetic exchanges between biofilms and surrounding water facilitated the further propagation of high-risk ARGs, posing greater ecological risks. Redundancy analysis indicated that the total nitrogen and temperature in water determined the fate of pathogenic-resistant species. These findings provided theoretical support for the mitigation of ARGs contamination in aquatic environments.

Distribution of lobster larvae, Homarus americanus, and zooplankton prey in the gulf of maine and georges bank stock area

The American lobster, Homarus americanus H. Milne-Edwards, 1837 supports a valuable fishery subject to rapid warming of the Gulf of Maine (GOM) and Georges Bank (GBK). Comprehensive information related to large-scale larval distribution is lacking due to the logistical challenge of sampling their hyper-dispersed larvae. In 2021, we established seasonal abundance patterns of larvae and their prey in the GOM on an unprecedented spatial scale with a season-long survey at transects spanning approximately 300 km of coastline. We compared the current distribution of larvae with historical surveys with respect to differences between inshore and offshore (5 versus 40 km), and between eastern and western hydrographic regions. We also examined spatial and temporal patterns in the abundance of zooplankton prey. The distribution of recently hatched stage I larvae extended offshore at the transect off Rye, NH and was consistent with the reported movement of ovigerous lobsters offshore to hatch their eggs. By contrast, stage I larvae were most abundant nearshore and rare offshore at other transects along the coast. Our results confirmed historical patterns of high abundance of competent stage IV larvae in the western Gulf of Maine and low abundance in the east. We also identified the potential for a temporal mismatch between the abundance of larvae and the biovolume of copepods at transects in Milbridge, ME and Rye, NH with peak copepod abundance occurring either well before or after the peak abundance of lobster larvae. The data collected fill a gap in our understanding of larval distributions and seasonal progression in the Gulf of Maine, establish a baseline for future studies, and provide an opportunity to validate established biophysical models of larval transport. Yet a longer time series of broad-scale surveys is needed to better understand intricacies of factors influencing larval abundance and distribution. The project was an industry-led collaboration with government and academic scientists providing proof of concept for future collaborative research.

Lure specificity, phenology, and damage caused by Epiphyas moths (Lepidoptera: Tortricidae) in Western Australian apple orchards.

Multiple Epiphyas species inhabit southwestern Western Australia, including Light Brown Apple Moth (LBAM) Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), a globally significant, polyphagous pest. This study evaluated the efficacy and specificity of lures designed for 3 Epiphyas species: E. postvittana, Epiphyas pulla (Turner), and the undescribed Epiphyas sp. (1) (Common). Additionally, the study sought to determine the presence and distribution of Epiphyas species in 3 significant apple-growing localities. Trapping, together with partial sequencing of the mitochondrial COI gene, found LBAM to be restricted to the Perth Hills and E. pulla, to apple orchards near Manjimup and Pemberton. This geographic disjunction remains unexplained. Epiphyas sp. (1) was not recorded despite using a specifically designed lure. The E. pulla and LBAM traps demonstrated superior efficacy in capturing their target species, while the catch in Epiphyas sp. (1) traps did not significantly differ between the 2. Both E. pulla and LBAM exhibited peak abundance from late spring to the end of summer (October-February), with variations in timing and peak catch of male moths across species, locations, and years. Surveys conducted in April during the harvest period (February-May), when moth traps caught an average of 1-1.8 moths/trap/week, found no Epiphyas larvae or damage on 140,400 mature apples or on 26,000 leaves. While E. pulla and LBAM traps effectively monitor their target moths, genetic identification of trap catch would be necessary if they co-occurred. Encouragingly, the results indicate that both species become relatively rare as harvest season approaches, and neither inflicts significant damage to mature apples under existing management.

Seasonal dynamics of toxigenic Microcystis in a large, shallow Lake Peipsi (Estonia) using microcystin mcyE gene abundance.

Large and temperate Lake Peipsi is the fourth largest lake in Europe, where the massive cyanobacterial blooms are composed mostly of Microcystis spp., which have been common for several decades now. The seasonal dynamics of potentially toxic Microcystis were studied using microscopy and quantitative polymerase chain reaction (qPCR) by assessing the microcystin-encoding microcystin synthetase gene E (mcyE) abundances. Water samples were analyzed over the lake areas, varying in depth, trophic level, and cyanobacterial composition during the growing period of 2021. The Microcystis mcyE genes were detected through the growing period (May-October), forming peak abundances in September with decreasing temperatures (8.9-11.1°C). Total phosphorus (TP) and nitrate (NO3-) were the most relevant environmental variables influencing the Microcystis biomass as well as mcyE abundances. Comparison with previous years (2011, 2012) indicated that the abundance and seasonal dynamics of toxigenic Microcystis can be highly variable between the years and lake areas, varying also in dominant Microcystis species. Contrary to expectations, based on mcyE abundances, the increased risk of toxin-producing Microcystis can occur in Peipsi through the growing period, independently of the water temperature and biomasses of Microcystis.

Using barcoding to reveal ecological patterns of nivicolous myxomycetes in the German Alps: How do they deal with varying snow conditions?

A transect in the German limestone Alps was monitored over ten years for nivicolous myxomycetes to test if species display stable altitudinal belts for fruiting. The data set comprised 1368 barcoded specimens assigned to 112 ribotypes forming 51 ribogroups. Ribogroups were largely consistent with 35 identified morphospecies, although in eleven cases a morphospecies included several ribogroups. Fructification abundance correlated with duration of the snow cover inferred from data loggers placed at ground height. Morphospecies, ribogroups, and ribotypes showed a peak of fructification abundance at different elevations in different years. Species composition, not abundances, showed a high overlap with soil metabarcoding data. Thirteen ribogroups detected in the metabarcoding data set were never found as fructifications. This survey demonstrates that nivicolous myxomycetes are opportunists, which are likely to persist as trophic or resting stages independent from snow cover, but fruit only in altitudes and years with snow cover stable over several months.

Genome-wide identification of PAR domain protein 1 (PDP1) targets through ChIP-seq reveals the regulation of diapause-specific characteristics in Culex pipiens.

Insects use seasonal diapause as an alternative strategy to endure adverse seasons. This developmental trajectory is induced by environmental cues like short-day lengths in late summer and early fall, but how insects measure day length is unknown. The circadian clock has been implicated in regulating photoperiodic or seasonal responses in many insects, including the Northern house mosquito, Culex pipiens, which enters adult diapause. To investigate the potential control of diapause by circadian control, we employed ChIP-sequencing to identify the downstream targets of a circadian transcription factor, PAR domain protein 1 (PDP1), that contribute to the hallmark features of diapause. We identified the nearest genes in a 10 kb region of the anticipated PDP1 binding sites, listed prospective targets and searched for PDP1-specific binding sites. By examining the functional relevance to diapause-specific behaviours and modifications such as metabolic pathways, lifespan extension, cell cycle regulation and stress tolerance, eight genes were selected as targets and validated using ChIP-qPCR. In addition, qRT-PCR demonstrated that the mRNA abundance of PDP1 targets increased in the heads of diapausing females during the middle of the scotophase (ZT17) compared with the early photophase (ZT1), in agreement with the peak and trough of PDP1 abundance. Thus, our investigation uncovered the mechanism by which PDP1 might generate a diapause phenotype in insects.

Phenology and seasonal dynamics of Corythucha arcuata (Hemiptera: Tingidae) on four autochthonous oak species in Serbia

Summary The oak lace bug, Corythucha arcuata (Say, 1832), is a widespread invasive species infesting various oaks in Europe and Asia. In this observational study, we explored phenology and investigated seasonal population dynamics of C. arcuata on four oak species native to Europe and widespread in Serbia. It was found that the species has three generations in Serbia. There was a population peak in July and high abundance was maintained in August and September. Leaf damage, the total number of eggs laid and insects collected varied greatly between the different oak species and the feeding preference of C. arcuata for certain oak species we studied was not clear. The sex ratio of the oak lace bug was predominantly female-biased. Five successive phases could be distinguished in the population dynamics of C. arcuata, following the annual sequence of species development. It was suggested that the different exposure of a tree to the sun influences the aggregation patterns of insects in the canopy.

Innovative insights into organic nitrogen degradation through protein family domains analysis in chicken and pig manure composting using metagenomic sequencing

The nitrogen loss in composting is primarily driven by the transformation of organic nitrogen, yet the mechanisms underlying the degradation process remain incompletely understood. This study employed protein family domains (Pfams) analysis based on metagenomic sequencing to investigate the functional characteristics, key microorganisms, and environmental parameters influencing organic nitrogen degradation in chicken manure and pig manure composting. 154 Pfams associated with ammonification function were identified. Predominant Pfams: proteolytic peptidase, followed by chitin/cell wall degraders, least involved in nucleic acid degradation. Ammonifying microbial diversity was basically consistent among compost types, particularly in the thermophilic stage with the peak of abundance of dominant ammonifying microorganisms. Viruses played an important role in ammonification process, especially Uroviricota. 26 key ammonifying genera were identified by the microbial network. pH dominated the metabolic activity of ammonifying microorganisms in various manure compost types, primarily consisting of protein-degrading bacteria with stable community structures.