RESUMEN

Acanthoic acid, a diterpene isolated from the root bark of Acanthopanax koreanum Nakai, possesses diverse pharmacological activities, including anti-inflammatory, anti-diabetic, gastrointestinal protection, and cardiovascular protection. This study is the first to investigate the egg-hatching rates of Drosophila melanogaster affected by acanthoic acid. Notably, male flies supplemented with 10 µM acanthoic acid exhibited a strong increase in hatching rates compared with controls under adverse temperature conditions, suggesting a potential protective effect against environmental stressors. Molecular docking simulations revealed the binding affinities and specific interactions between acanthoic acid and proteins related to male infertility, including SHBG, ADAM17, and DNase I, with binding affinity values of -10.2, -6.8, and -5.8 kcal/mol, respectively. Following the docking studies, molecular dynamic simulations were conducted for a duration of 100 ns to examine the stability of these interactions. Additionally, a total binding energy analysis and decomposition analysis offered insights into the underlying energetic components and identified key contributing residues.

RESUMEN

The sterile insect technique (SIT) involves releasing large numbers of sterile males to outcompete wild males in mating with females, leading to a decline in pest populations. In the current study, we conducted a suppression trial in Greece against the invasive dengue vector mosquito Aedes albopictus (Skuse) through the weekly release of sterile males for 22 weeks from June to September 2019. Our approach included the long-distance transport of sterile mosquitoes, and their release at a density of 2,547 ± 159 sterile males per hectare per week as part of an area-wide integrated pest management strategy (AW-IPM). The repeated releases of sterile males resulted in a gradual reduction in egg density, reaching 78% from mid-June to early September. This reduction remained between 70% and 78% for four weeks after the end of the releases. Additionally, in the SIT intervention area, the ovitrap index, representing the percentage of traps containing eggs, remained lower throughout the trial than in the control area. This trial represents a significant advance in the field of mosquito control, as it explores the viability and efficacy of producing and transporting sterile males from a distant facility to the release area. Our results provide valuable insights for future SIT programmes targeting Ae. Albopictus, and the methodology we employed can serve as a starting point for developing more refined and effective release protocols, including the transportation of sterile males over long distances from production units to intervention areas.

Title: Essai sur le terrain de la Technique de l'Insecte Stérile (TIS) ciblant la suppression d'Aedes albopictus en Grèce. Abstract: La technique de l'insecte stérile (TIS) consiste à libérer un grand nombre de mâles stériles pour supplanter les mâles sauvages lors de l'accouplement avec les femelles, entraînant ainsi un déclin des populations de nuisibles. Dans la présente étude, nous avons mené un essai de suppression en Grèce contre le moustique vecteur invasif de la dengue, Aedes albopictus (Skuse), par le biais de la libération hebdomadaire de mâles stériles pendant 22 semaines de juin à septembre 2019. Notre approche comprenait le transport sur de longues distances de moustiques stériles, et leur lâcher à une densité de 2 547 ± 159 mâles stériles par hectare et par semaine dans le cadre d'une stratégie de lutte intégrée contre les nuisibles à l'échelle de la zone (AW-IPM). Les lâchers répétés de mâles stériles ont entraîné une réduction progressive de la densité des œufs, atteignant 78 % de la mi-juin au début septembre. Cette réduction est restée entre 70 % et 78 % pendant quatre semaines après la fin des lâchers. De plus, dans la zone d'intervention de la TIS, l'indice d'oviposition, représentant le pourcentage de pièges contenant des œufs, est resté plus faible que dans la zone témoin tout au long de l'essai. Cet essai représente une avancée significative dans le domaine de la lutte contre les moustiques, car il explore la viabilité et l'efficacité de la production et du transport de mâles stériles depuis une installation éloignée vers la zone de lâcher. Nos résultats fournissent des informations précieuses pour les futurs programmes de TIS ciblant Ae. albopictus et la méthodologie que nous avons utilisée pourra servir de point de départ pour développer des protocoles de libération plus raffinés et plus efficaces, y compris le transport de mâles stériles sur de longues distances depuis les unités de production jusqu'aux zones d'intervention.

Asunto(s)

RESUMEN

The life cycle of Thaparocleidus vistulensis (Siwak, 1932), a host-specific monogenean parasite of European catfish (Silurus glanis Linnaeus, 1758), was investigated by detailed observation of infection dynamics, egg development, hatching rate and in vitro survival rates of the parasite at different life stages at 23 °C. A total of 30 naive fingerlings were infected in three exposure trials by co-habitation with donor fish carrying adult parasites. Two fish were dissected every two days during the 10-day experimental period to explore the development of larvae and juvenile parasites on the host gills. Freshly laid eggs by adult monogeneans were collected and observed daily under a light microscope until hatching. A total of 445 eggs were collected and distributed into wells of 96-well microtiter plates containing filtered fish tank water to determine their hatching rates. A similar method was used to investigate the survival rates of isolated parasites at different developmental stages (larvae, juveniles, and adults). T. vistulensis populations on the European catfish in fish tanks increased markedly within ten days, dependent on the severity of the initial infection levels of the donor fish. The first eggs hatched three to four days after oviposition, and the hatching rate peaked on the fifth day (89.7%). The survival rate for freely swimming oncomiracidia without host was 7.4% after five days, whereas isolated juvenile and adult parasites showed a higher dependence of host contact (survival rates three days post-isolation of 0.9% and 1.6%, respectively). The data allows prediction of parasite-host dynamics and may improve control of gill-disease in cultured European catfish stocks in fish farms.

RESUMEN

Recent research has provided compelling evidence demonstrating that paternal exposure to different stressors can influence their offspring's phenotypes. We hypothesized that paternal stress can negatively impact the progeny, altering different miRs and triggering different physiological alterations that could compromise offspring development. To investigate this, we exposed zebrafish male siblings to a chronic stress protocol for 21 days. We performed RNA-sequencing (RNA-seq) analyses to identify differentially expressed small noncoding RNAs in 7-day postfertilization (dpf) larvae derived from paternally stressed males crossed with control females compared with the control progeny. We found a single miRNA differentially expressed-miR-29a-which was validated in larva and was also tested in the sperm, testicles, and brain of the stressed progenitors. We observed a vertical transmission of chronic stress to the unexposed larvae, reporting novel consequences of paternally inherited chronic stress at a molecular level. The deregulation of mi-R29a in those larvae could affect relevant biological processes affecting development, morphogenesis, or neurogenesis, among others. Additionally, these disruptions were associated with reduced rates of survival and hatching in the affected offspring.

Asunto(s)

RESUMEN

During last several years, Kuwait Institute for Scientific Research (KISR), Kuwait has been trying to develop a sustainable culture technique for silver pomfret (Pampus argenteus). This paper reports the recent research advances in the breeding and rearing of silver pomfret fry at KISR. The eggs collected from wild silver pomfret during spawning seasons of 2012 to 2015 were artificially fertilized under laboratory condition. The average hatching rates of artificially fertilized eggs collected from wild silver pomfrets were 25.6%, 44.8%, 76.7%, and 53.5.0% and average survival rates of metamorphosed fry produced from these eggs were 3.7%, 5.7%, 4.4% and 3.8% for the spawning seasons 2012, 2013, 2014, and 2015, respectively. For captive brood stocks, observation on the spawning time at hourly interval by collecting eggs from the nets set at out-flow of brood tanks showed that the spawning time for captive silver pomfret starts at the time of sunset. In 2012, two groups of captive silver pomfret broods spawned a total of 62x103 and 66x103 eggs, but the eggs were unfertilized. No captive spawning occurred during 2013 and 2014 spawning season. In 2015, captive silver pomfret broods in three tanks spawned about 653x103, 673x103 and 270x103 eggs, and in 2016, the broods in four tanks spawned about 669x103, 22x103, 3x103 and 366x103 eggs. However, from these eggs only 1,400 and 1,000 fertilized eggs were collected which produced 300 and 123 hatched larvae in July 2015 and June 2016, respectively. The larvae produced from the 2015 broods did not survive beyond 56 days of metamorphosed stage while larvae produced from 2016 captive broods survived for 9 days only. The mortality of the larvae from captive brood could be related to the poor egg or milt quality. However, efforts are continued to improve the eggs and sperm quality through proper brood management.

RESUMEN

BACKGROUND: In a recent study using DNA barcoding, we identified the plants fed upon by four Afro-tropical mosquito species that vector dengue, malaria, and Rift Valley fever. Herein, we have expanded on this study by investigating the role of three of the plants, Pithecellobium dulce (Fabaceae), Leonotis nepetifolia (Lamiaceae), and Opuntia ficus-indica (Cactaceae), on the survival, fecundity, and egg viability of the dengue vector Aedes aegypti. METHODS: We tested these effects using females that received (i) an initial three rations of blood meals and (ii) no blood meal at all. Two controls were included: age-matched females fed on glucose solution with or without an initial blood meal and those fed exclusively on blood meals. Data were collected daily over a 30-day period. The amino acid contents of Ae. aegypti guts and their respective diets were detected by coupled liquid chromatography-mass spectrometry. RESULTS: Females fed on P. dulce and an exclusively blood meal diet had a shorter survival than those fed on glucose. On the other hand, females fed on L. nepetifolia survived longer than those fed exclusively on blood meals, whereas those fed on O. ficus-indica had the shortest survival time. With an initial blood meal, females fed on L. nepetifolia laid 1.6-fold more eggs while those fed on the other diets laid fewer eggs compared to those fed exclusively on blood meals. Hatching rates of the eggs laid varied with the diet. Mass spectroscopic analysis of gut contents of mosquitoes exposed to the different diets showed qualitative and quantitative differences in their amino acid levels. CONCLUSION: Our findings highlight the central role of plant nutrients in the reproductive fitness of dengue vectors, which may impact their disease transmission potential.

Asunto(s)

RESUMEN

Substantial variations are reported for egg production and hatching rates of copepods exposed to elevated carbon dioxide concentrations (pCO2). One possible explanation, as found in other marine taxa, is that prior parental exposure to elevated pCO2 (and/or decreased pH) affects reproductive performance. Previous studies have adopted two distinct approaches, either (1) expose male and female copepoda to the test pCO2/pH scenarios, or (2) solely expose egg-laying females to the tests. Although the former approach is more realistic, the majority of studies have used the latter approach. Here, we investigated the variation in egg production and hatching success of Acartia tonsa between these two experimental designs, across five different pCO2 concentrations (385-6000 µatm pCO2). In addition, to determine the effect of pCO2 on the hatching success with no prior parental exposure, eggs produced and fertilized under ambient conditions were also exposed to these pCO2 scenarios. Significant variations were found between experimental designs, with approach (1) resulting in higher impacts; here >20% difference was seen in hatching success between experiments at 1000 µatm pCO2 scenarios (2100 year scenario), and >85% at 6000 µatm pCO2. This study highlights the potential to misrepresent the reproductive response of a species to elevated pCO2 dependent on parental exposure.