Reproductive Suppression Research Articles

Design, Synthesis, and Nematicidal Activity of Novel Amide Derivatives Containing an 1,2,4/1,3,4-Oxadiazole Moiety against Bursaphelenchus xylophilus.

To discover novel structural nematicides, 79 amide compounds containing 1,2,4/1,3,4-oxadiazole moiety were designed, synthesized, and evaluated for nematicidal efficacy against second-stage juveniles of Bursaphelenchus xylophilus (B. xylophilus). Notably, some compounds exhibited superior nematicidal efficacy, for example, the LC50 values of compounds 11, 39, 40, 48, 49, 51, 52, and 54 were 7.4, 31.0, 35.3, 10.3, 12.7, 6.9, 21.5, and 52.2 mg/L, respectively, with nematicidal activities significantly surpassing that of tioxazafen (79.3 mg/L). Compound 51 exhibited multifaceted nematicidal activity through suppression of motility, feeding, and reproduction, combined with induction of oxidative stress. Compound 51 significantly reduced nematode protein content and impaired antioxidant capacity. Meanwhile, compound 51 demonstrates superior binding energy and interaction mode with succinate dehydrogenase (SDH), showing potent SDH inhibition (IC50 = 15.0 μmol/L). Therefore, compound 51, which may become a potential SDH inhibitor, interferes with nematode energy metabolism by inhibiting SDH activity, resulting in nematode death.

Anaerobic Soil Disinfestation as a Tool for Nematode and Weed Management in Organic Sweetpotato

Anaerobic soil disinfestation (ASD) is a promising alternative to synthetic chemical-driven pest management methods facilitated by incorporating carbon sources into the soil, tarping the soil with plastic mulch, and irrigating to soil saturation. To evaluate the impact of ASD on southern root-knot nematode [Meloidogyne incognita (Kofoid & White), SRKN] and yellow nutsedge (Cyperus esculentus L.) management in organically grown sweetpotato, greenhouse studies were conducted. The treatments were structured as a factorial of two carbon amendments [chicken manure + molasses (CM + M), and no additional carbon (control)] by 20 sweetpotato genotypes with 4 replications using a randomized complete block design. The results suggest that the microcosms receiving the carbon amendment spent the most time under anaerobic conditions (<200 mvh). Planting of sweetpotato genotypes in CM + M-treated microcosms resulted in 60–90% and 56–92% suppression of soil population and egg reproduction of SRKN as compared to no additional carbon. The application of CM + M reduced overall weed cover by 79% relative to the control. Sweetpotatoes in CM + M-treated microcosms had significantly higher dry above-ground biomass (6.8 g) as compared to the control (3.6 g). The results of this study demonstrated that ASD has the potential to manage nematodes and weeds in organic sweetpotato production systems.

Study of the Antiviral Activity of Drugs and Their Combination Against the Influenza A Virus

Relevance. The problem of prevention and treatment of influenza remains relevant due to the consistently high incidence rate of the disease in the population of all age groups, especially children and the elderly. Antiviral drugs have become the most important tools in the fight against influenza viruses. The main problem is the search and development of new antiviral drugs that do not have side effects. The aim of the present study is to investigate the effect of a new synthetic drug candidate based on adamantane (NMG 1110) and its combination with ribavirin on the reproduction of influenza A virus in MDCK cell culture. The aim of the present study is to investigate the effects of drugs and their combinations on the reproduction of influenza A virus in MDCK cell culture. Materials and methods. Determination of cytotoxicity and antiviral activity of drugs on MDCK cell line for influenza A(H3N2)/Aichi/1/68 virus at different schemes of drug introduction into cells: immediately after infection, 2 hours after infection, 4 hours after virus infection of cells. Results. It was found that the drugs were low-toxic for MDCK cell culture at the studied concentrations. Using the influenza A(H3N2)/Aichi/1/68 virus model, it was shown that the time of application of the studied samples did not affect the reproduction of the virus in cell culture. The NMG1110 preparation exhibits high antiviral activity at a concentration of 9.7 µg/ml with the chemotherapeutic index of 16.0. At the same time, ribavirin showed a lower effect with a chemotherapeutic index of 8.0. There is a significant suppression of virus reproduction with the combined use of the preparations. A pronounced antiviral effect of the additive nature is observed in the combination of ribavirin and the drug candidate NMG 1110.

Reproductive-Triggered Sterol Competition Exacerbates Age-Related Intestinal Barrier Damage in Drosophila Females.

The trade-off between reproduction and lifespan has been documented across a wide array of organisms, ranging from invertebrates to mammals. In malnourishing dietary conditions, inhibition of the reproductive processes generally extends the lifespan of females. However, the underlying mechanisms through which nutritional competition driven by reproduction accelerates aging remain poorly understood. Here, using female Drosophila melanogaster as a model, we show that among various dietary conditions lacking specific nutrients, only sterol deficiency significantly exacerbated both the incidence and severity of intestinal barrier deterioration during aging. Sterile mutation specifically ameliorated such damage in sterol-deprived diets, but failed to alleviate age-related intestinal barrier deterioration under other nutritional conditions. Additionally, we demonstrate that the lifespan extension and intestinal barrier amelioration, accompanied by a reproductive suppression effect, through the pharmacological inhibition of mTOR or Ras-Erk signaling using rapamycin or trametinib, were significantly modulated by cholesterol levels. Our study also identifies the morphological changes in excreta as a sensitive biomarker for early intestinal dysfunction. Collectively, these results suggest that the impairment of the intestinal barrier caused by reproductive-induced sterol competition constitutes a significant factor limiting female lifespan in nutritionally unbalanced diets. This work elucidates a salient aspect of the complex interplay between reproductive resource allocation and somatic maintenance, thereby enhancing our understanding of how diet impacts the aging process.

Strategic use of male alternative reproductive tactics in cooperatively breeding banded mongoose groups.

Alternative reproductive tactics (ARTs) allow less competitive individuals to reproduce by avoiding direct fights through sneaky strategies. Within cooperatively breeding groups ARTs are rarely reported, potentially owing to observational difficulties or reproductive suppression by group members. In societies where mating opportunities cannot be monopolized by one male, young males could use sneaky tactics as an intermediate 'stepping-stone' tactic to gain limited reproductive success while growing in resource-holding potential (RHP). Using decades of pedigree, weight, group demography and behavioural data, we investigated the use of sneaky 'sneaker' ARTs in wild male banded mongooses. In this species, groups typically contain more adult males than breeding females, leading to intense male-male competition. Instead of as a stepping-stone, sneaking tactics were typically used by males who had been displaced from mate-guarding status by stronger rivals. Additionally, sneakers had lower siring success compared with mate guards, despite similar weight loss costs, which may explain why males typically avoided reproductive activity entirely rather than sneaking. However, young sneakers gain access to older, higher fecundity females in the group and sneaking may even facilitate inbreeding avoidance. Overall, ARTs in stable social groups can predictively emerge from changes in relative RHP and social status over the lifetime.

Adverse multigeneration combined effects of nano-sized plastics and mercury on growth and reproduction in a planktonic copepod Pseudodiaptomus annandalei.

Adverse multigeneration combined effects of nano-sized plastics and mercury on growth and reproduction in a planktonic copepod Pseudodiaptomus annandalei.

Dietary dopamine supplementation has no effect on ovary activity in queen-less or queen-right honeybee (Apis mellifera) workers

Eusociality in honeybees (Apis mellifera) is characterised by a reproductive division of labour, where the queen monopolises reproduction while worker reproduction is constrained. This constraint is mediated by queen mandibular pheromone (QMP), which inhibits worker ovary development through Notch signalling and possibly oocyte apoptosis. Dopamine has been implicated in regulating reproduction in worker honeybees, with prior studies suggesting that dietary dopamine enhances ovary activity in queen-less workers. This study aimed to test whether dopamine supplementation could overcome QMP-mediated reproductive constraint in worker honeybees. Using caged honeybee experiments, we administered dopamine and its precursor L-dopa at a range of concentrations, both in the presence and absence of QMP. Results showed that neither dopamine nor L-dopa supplementation affected ovary development, survival rates, or food intake, which contrasts with a previous study. These findings suggest that dopamine may not be a major factor in QMP-mediated reproductive inhibition. Instead, we suggest that the multifaceted nature of QMP’s components together with the complexity of neuroendocrine signalling makes it likely that multiple redundant mechanisms regulate worker reproduction. Future research should investigate the interplay between nutrition, dopamine and QMP components to fully understand the regulation of ovary activation in honeybee workers.

A Graphene-Based Lipid Modulation Nanoplatform for Synergetic Lipid Starvation/Chemo/Photothermal Therapy of Oral Squamous Cell Carcinoma.

Chemotherapy is one of the most commonly used treatments for oral squamous cell carcinoma (OSCC), but its use is limited by drug resistance and severe systemic toxicity. To eliminate these side effects and improve anti-tumor efficacy, several therapeutic approaches have been developed for use with chemotherapy. In this study, we developed a graphene-based lipid modulation nanoplatform (NSD) that carries SB-204990, a small molecule inhibitor specific for ATP citrate lyase (ACLY), and doxorubicin (DOX), a chemotherapeutic agent, and the trio enables synergistic treatment of OSCC with lipid starvation, chemotherapy, and photothermal therapy. We first determined whether ACLY expression was upregulated in OSCC, and then assessed the growth inhibitory effects of SB-204990 on SCC-15 cells and changes in lipid (acetyl coenzyme A, free fatty acids, and cholesterol) levels. We characterized NSD and then evaluated the stability, photothermal properties, drug loading, and release ability of NSD. Finally, the therapeutic effects of NSD on OSCC were investigated by in vitro and in vivo experiments, and the changes in lipid levels in OSCC tissues after ACLY inhibition were further evaluated. The results showed that ACLY was highly expressed in OSCC, and ACLY inhibition produced reproductive suppression and decreased lipid levels in SCC-15 cells. The NSD nanoplatform possessed good stability, photothermal properties, high drug loading capacity and controlled release. In addition, the triple therapy achieved satisfactory anticancer effects in both in vivo and in vitro assays, and the inhibition rate of tumors was as high as 99.4% in the NSD+Laser treatment group. The changes in tumor cell lipid levels and cell proliferation arrest induced by ACLY inhibition suggest that ACLY may be a promising target for lipid starvation therapy and resistance to chemoresistance, and its inhibitors are expected to become new anticancer drugs. The NSD nanocarrier system enables synergistic treatment with lipid starvation, chemotherapy, and photothermal therapy, which represents an innovative approach to combating tumors.

The biodegradation of polylactic acid microplastic and their toxic effect after biofouling in activate sludge

The biodegradation of polylactic acid microplastic and their toxic effect after biofouling in activate sludge

Comparative Transcriptomics Revealed Physalis floridana Rydb. Influences on the Immune System of the 28-Spotted Ladybird Beetle (Henosepilachna vigintioctopunctata)

Physalis floridana Rydb., a member of the Solanaceae family, is renowned for its diverse secondary metabolites, including physalins and withanolides. The 28-spotted ladybird beetle (Henosepilachna vigintioctopunctata) is a notorious pest severely damaging Solanaceous crops. This study demonstrates that P. floridana Rydb. significantly impacts on the development and reproductive suppression of H. vigintioctopunctata. A comparative transcriptome analysis was performed by feeding H. vigintioctopunctata larvae on P. floridana Rydb., Solanum nigrum L., Solanum tuberosum L., and Solanum lycopersicum L. The results reveal that larvae fed on P. floridana Rydb. exhibit numerous differentially expressed genes, which are notably enriched in pathways related to energy metabolism, immunity, and detoxification. These functions and pathways are less enriched in larvae fed by other hosts. Weighted Gene Co-expression Network Analysis (WGCNA) indicates that feeding on P. floridana Rydb. influences the expression of specific genes involved in the Toll and IMD signaling pathways, impacting the immune system of H. vigintioctopunctata larvae. This study provides transcriptomic insights into larval responses to different diets and suggests that the effect of P. floridana Rydb. on the immune system of H. vigintioctopunctata is a key defense mechanism against herbivores.

Copper-induced oxidative stress inhibits asexual reproduction of Aurelia coerulea polyps

Copper-induced oxidative stress inhibits asexual reproduction of Aurelia coerulea polyps

Proteomic Profiling in Pediococcus pentosaceus SF11 Exposed to Condensed Tannins from Sainfoin.

The antibacterial mechanism of condensed tannins (CTs) obtained from tea has been elucidated, but the mechanism of legume-derived CTs remains unclear. The mechanisms of legume- and tea-derived CTs probably differ due to the diverse compositions of CTs. Previous research found that sainfoin CTs directly inhibited the growth of Pediococcus. The present study investigated the inhibition mechanism of CTs against Pediococcus pentosaceus SF11 (SF11) through proteomic analysis. The results showed that the minimum inhibitory concentration (MIC) of CTs against SF11 was 1500 mg/L and that CTs increased cell membrane permeability in a dose-dependent manner. In total, 418 differentially expressed proteins (DEPs) were identified between the CT treatment and the control, among which 341 were down-regulated and 77 were up-regulated in the CT treatment. The protein interaction network showed that the expression of only two DEPs was highly different between CT treated and control (|log2FC|> 2); the atpD protein was up-regulated in the CT-treated group, which was involved in ATP synthesis; down-regulated DEPs were most involved in lipoteichoic acid synthesis, peptidoglycan synthesis, and glycine metabolism. Twenty-seven proteins were not detected after CT treatment, which were involved in functions including fatty acid synthesis, RNA synthesis and translation, drug resistance, and cell membrane permeability in SF11. Therefore, the findings suggest that the inhibition mechanism of CTs may be related to cell membrane damage and inhibition of cell reproduction.

The curious case of the hypothalamic-pituitary-gonadal axis dysfunction in subordinate female naked mole-rats (Heterocephalus glaber): No apparent role of opioids and glucocorticoids.

The naked mole-rat (Heterocephalus glaber) is a unique model mammal in which to study socially induced inhibition of the hypothalamic-pituitary-gonadal (HPG) axis. Naked mole-rat groups exhibit a high degree of reproductive bias in which breeding is restricted to one female (the queen) and one male, with subordinate non-breeding colony members rarely, if ever, having the opportunity to reproduce due to a dysfunctional HPG axis. It is posited that aggression directed at subordinates by the queen suppresses reproduction in these subordinates, yet the underlying physiological mechanisms causing this dysfunction are unknown. This study aimed to investigate the possible factors contributing to the dysfunction of the HPG axis in subordinate female naked mole-rats with a specific focus on the role of ovarian feedback and stress-related factors such as circulating glucocorticoid and endogenous opioid peptides. The results showed that stress-related factors appear to not mediate the suppression of reproductive function in subordinate female naked mole rats. Indeed, in some cases, the activation of the stress axis may lead to reproductive activation instead of deactivation. At the same time, the role of ovarian sex steroid feedback in reproductive suppression is likely limited and not clearly delineated. This study highlights the need for detailed studies to elucidate the mechanism of reproductive suppression in this unique model mammalian species which may shed light on, and reveal novel mechanisms, in the social regulation of reproduction.

Temperature and light timing effects on diapause progression in Daphnia magna

Abstract Diapause is a survival strategy for freshwater crustaceans in the genus Daphnia that involves a genetically encoded inhibition of organism growth, development and reproduction. While the environmental triggers for Daphnia to produce diapause‐destined embryos and those that induce hatching are well documented, the influence of environmental challenges during different diapause sub‐phases remains unexplored. In this study, we exposed diapause‐destined embryos of Daphnia magna to different temperatures and light conditions during designated diapause sub‐phases. Our results underscore the importance of the maternal environment for the embryos that are in preparation for diapause. Moreover, we demonstrate a period of obligate developmental arrest during which reinitiation of development cannot be triggered. Additionally, we illustrate the embryos' ability to adjust hatching in response to environmental changes during the hatching process. This study reveals the inherent developmental pattern in Daphnia embryos as they progress through diapause and their adaptability to environmental changes.

Coat Proteins of the Novel Victoriviruses FaVV1 and FaVV2 Suppress Sexual Reproduction and Virulence in the Pathogen of Fusarium Head Blight.

Fusarium head blight (FHB), a disease inflicted by Fusarium graminearum and F. asiaticum, poses a growing threat to wheat in China, particularly in the face of climate change and evolving agricultural practices. This study unveiled the discovery of the victorivirus FgVV2 from the F. asiaticum strain F16176 and comprehensively characterized the function of the two victoriviruses FaVV1 and FaVV2 in virulence. Through comparative analysis with a virus-free strain, we established that these mycoviruses markedly repress the sexual reproduction and pathogenicity of their fungal hosts. Furthermore, we synthesized the coat protein (CP) genes CP1 from FaVV1 and CP2 from FaVV2, which were fused with the green fluorescent protein (GFP) gene and successfully expressed in Fusarium strains in wild-type isolates of F. asiaticum and F. graminearum. Similar to virus-infected strains, the transformed strains expressing CPs showed a significant decrease in perithecia formation and pathogenicity. Notably, CP2 exhibited a stronger inhibitory effect than CP1, yet the suppression of sexual reproduction in F. graminearum was less pronounced than that in F. asiaticum. Additionally, the pathogenicity of the F. asiaticum and F. graminearum strains expressing CP1 or CP2 was substantially diminished against wheat heads. The GFP-tagged CP1 and CP2 revealed distinct cellular localization patterns, suggesting various mechanisms of interaction with the host. The findings of this study provide a significant research foundation for the study of the interaction mechanisms between FaVV1 and FaVV2 with their hosts, as well as for the exploration and utilization of fungal viral resources.

Emerging threat of marine microplastics: Cigarette butt contamination on Yellow Sea beaches and the potential toxicity risks to rotifer growth and reproduction

Emerging threat of marine microplastics: Cigarette butt contamination on Yellow Sea beaches and the potential toxicity risks to rotifer growth and reproduction

Cannabidiol exposure during embryonic period caused serious malformation in embryos and inhibited the development of reproductive system in adult zebrafish

Cannabidiol exposure during embryonic period caused serious malformation in embryos and inhibited the development of reproductive system in adult zebrafish

Elevated temperature impairs gonadal development by suppressing the expression of the genes for kisspeptin, GnRH1 and GTH subunits in Nile tilapia Oreochromis niloticus

Elevated temperature impairs gonadal development by suppressing the expression of the genes for kisspeptin, GnRH1 and GTH subunits in Nile tilapia Oreochromis niloticus

Ecotoxicity of thallium to two soil animal species with different niches and modification by organic materials

Ecotoxicity of thallium to two soil animal species with different niches and modification by organic materials

Influence of Ultrasonic Cavitation on Botryococcus Braunii Growth

This study investigates ultrasonic energy’s impact on enhancing the growth of Botryococcus braunii (B. braunii) microalgae. Microalgae, known for their advantages in greenhouse gas mitigation and biomass conversion, were subjected to various stressors, including ultrasonic waves, to optimize productivity. Ultrasonic waves induce acoustic cavitation, increasing membrane permeability and substrate conversion. The study examined the impact of energy and maximum pressure resulting from bubble collapse on the relative specific growth rate of B. braunii microalgae. It was observed that reproduction showed a promotive trend until the energy surpassed 30 kJ. However, when ultrasonic energy reached 18.2 kJ, reproduction was inhibited due to the maximum pressure generated during bubble bursting, which reached 5.7 µN/µm2, leading to the suppression of reproduction upon encountering bubble collapse events. Under specific ultrasonic conditions (15.1 kJ energy, maximum pressure of 45.5 × 105 Pa), a maximum specific growth rate of 0.329 ± 0.020 day−1 in a two-day interval boosted B. braunii microalgae biomass productivity. These findings advance our understanding of ultrasonic wave effects on microalgae reproduction and underscore the potential for optimizing ultrasonic parameters to enhance biomass production.