An experience of obtaining mature eggs of the Siberian sturgeon (Acipenser baerii (Brandt, 1869)) in non-traditional period

Purpose. To investigate the peculiarities of obtaining ovulated eggs of the Siberian sturgeon in hatchery conditions in non-traditional (winter) period and determine major features of brood fish used for the experiments. Methodology. The material for the study were age-10+ Siberian sturgeon females with body weights of 6.20-8.24 kg grown in conditions of floating cages in a water body with natural temperature regime of the forest-steppe zone of Ukraine. The experiments were conducted with a regulated water temperature regime in the third decade of January with the use of natural gonadotropic drugs for the stimulation of egg maturation in fish. Brood fish were prepared for the experiment in the recirculating aquaculture system. Measurement of fisheries parameters and study of physicochemical factors of the aquatic medium were performed according to generally accepted methods. Experiment results were assessed statistically using standard software. Findings. With water temperature of 14-15оС, depending on the dosage of the gonadotropic drug, different efficiencies of gonad maturation in experimental groups of fish were detected. More than 85% of females matured after dosing of gonadotropic drugs 3.5 and 4.5 mg / kg. In the version with a minimum dose of gonadotropic substance 2.5 mg / kg responded positively to hormonal stimulation 57% of females. The average weight of eggs obtained in some groups of brood fish was 819.5-1079.0 g. Average working fecundity and relative working fecundity in experimental groups of the Siberian sturgeon females varied within 47.95-52.64 thousand eggs and 6.93-7.17 thousand eggs/kg of fish body weight, respectively. The duration of maturation after the second (resolving) administration of the gonadotropic drug until the moment of the occurrence of the ovulation process varied mainly within 15-20 hours. Originality. The peculiarities of obtaining mature eggs of the Siberian sturgeon with the use of methods of industrial reproduction of sturgeons, which are new for the aquaculture of Ukraine, were studied. Practical value. The study results are of interest for the development of modern methods of sturgeon aquaculture in conditions of fish farms of industrial type. Key words: brood Siberian sturgeon, industrial aquaculture, non-traditional technologies, eggs, ovulation, fisheries parameters.

Soybean Foliage Consumption Reduces Adult Western Corn Rootworm (Diabrotica virgifera virgifera)(Coleoptera: Chrysomelidae) Survival and Stimulates Flight

Western corn rootworm, Diabrotica virgifera virgifera LeConte, biology is tied to the continuous availability of its host (corn, Zea mays L.). Annual rotation of corn with a nonhost, like soybean (Glycine max (L.) Merrill) was a reliable tactic to manage western corn rootworm. Behavioral resistance to annual crop rotation (rotation resistance) allowed some eastern U.S. Corn Belt populations to circumvent rotation by laying eggs in soybean and in cornfields. When active in soybean, rotation-resistant adults commonly consume foliage, in spite of detrimental effects on beetle survival. Rotation-resistant beetle activity in soybean is enabled by the expression of certain proteinases and an adapted gut microbiota that provide limited protection from soybean antiherbivore defenses. We investigated the effects of corn and soybean herbivory on rotation-resistant female survival and initiation of flight using mortality assays and wind tunnel flight tests. Among field-collected females tested with mortality assays, beetles from collection sites in a cornfield survived longer than those from collection sites in a soybean field. However, reduced survival due to soybean herbivory could be restored by consuming corn tissues. Field-collected beetles that fed on a soybean tissue laboratory diet or only water were more likely to fly in a wind tunnel than corn-feeding beetles. Regardless of collection site and laboratory diet, 90.5% of beetles that flew oriented their flights upwind. Diet-related changes in the probability of flight provide a proximate mechanism for interfield movement that facilitates restorative feeding and the survival of females previously engaged in soybean herbivory. Rotation-resistant western corn rootworm females feeding on soybean tissues experience reduced survival in mortality assays and display increased flight probability (which may facilitate flight back to a cornfield where consumption of host tissues improves survival potential and facilitates maturation of eggs). The consequences of soybean herbivory provide a proximal mechanism for behavioral resistance to crop rotation. Increased egg-laying probability while feeding on soybean tissues, facilitation of egg maturation while feeding on corn tissues, and interfield movement are previously documented consequences.

Transcriptome and proteome dynamics during the embryonation of Fasciola hepatica eggs

Fasciola hepatica is a global parasite of livestock which also causes a neglected zoonosis in humans. The parasite’s communication with the host during its complicated lifecycle is based on an ingenious enzymatic apparatus which includes a variety of peptidases. These enzymes are implicated in parasite migration, pathogenesis of the disease, and modification of host immune response. Although the dynamics of proteolytic machinery produced by intra-mammalian F. hepatica life stages has been previously investigated in great detail, peptidases of the eggs so far received little scientific attention. In this study, we performed a comparative RNA-seq analysis aimed at identification of peptidases expressed in F. hepatica eggs at different ages and employed mass spectrometry in order to identify and quantify peptidases translated in F. hepatica egg lysates. Finally, we measured and classified proteolytic activities in extracts from F. hepatica eggs using a library of fluorogenic substrates and peptidase class-selective inhibitors. Using these methods, we observed significant changes in the composition of peptidases during egg maturation.

Ovigeny strategy of the parasitic wasp Cosmocomoidea annulicornis (Hymenoptera: Mymaridae): effect of female age, feeding and host availability on reproductive traits

The reproductive traits of the mymarid wasp Cosmocomoidea annulicornis (Ogloblin) (Hymenoptera: Mymaridae) attacking eggs of the sharpshooter Tapajosa rubromarginata (Signoret) (Hemiptera: Cicadellidae) were evaluated under laboratory conditions. Bioassays were carried out to estimate the realized fecundity and egg load of females. The ovigeny index was calculated and different biological traits, such as body size, oöcyte length, gaster length and wing length, were analysed to assess significant associations between these traits and the species fitness. In addition, the effect of host availability and feeding on longevity and potential fecundity throughout life and the effect of female age on egg maturation dynamics were assessed. The results showed that C. annulicornis is a strongly synovigenic species. A positive correlation was found between fecundity and longevity of the females and between body size and oöcyte length. Contrary to expected, body size was not related to fecundity and longevity. Females lived significantly longer in the presence of hosts and honey than when they were host-deprived and honey-fed or both host and honey deprived. Host availability had a significant effect on the amount of eggs laid by C. annulicornis females. Female age was negatively associated with oöcyte length. Furthermore, females were able to mature additional eggs as they aged, nevertheless, when host-deprived, senescent females presented significantly less mature eggs than younger ones, suggesting a possible egg oosorption. These results might contribute to a better understanding of the reproductive potential of this species as a biocontrol agent.

Effects of climate warming on the pine processionary moth at the southern edge of its range: a retrospective analysis on egg survival in Tunisia

In recent years, ectotherm species have largely been impacted by extreme climate events, essentially heatwaves. In Tunisia, the pine processionary moth (PPM), Thaumetopoea pityocampa, is a highly damaging pine defoliator, which typically lays eggs in summer. Its geographical range is expanding northwards in Europe while retracting from South Tunisia where summer temperatures can reach extremely high values. In this study, we aimed at exploring the effects of climate change on this species at its southern range edge. We investigated variations of fecundity and causes of egg mortality over time using historical and contemporary collections of egg masses from different Tunisian sites to seek relationships with regional climate change over three decades (1990-2019). Our results suggest negative effects of summer heat on egg survival, reflected in a decrease of hatching rate down to 0% in one site during a heatwave. Such a high hatching failure was found to result from both high egg sterility (our results did not allow distinguishing impeded mating success from failed egg maturation or early death of the embryo) and increased abortion of more developed embryos, but little effects of parasitism rate, thereby suggesting vulnerability to heat during embryonic development. We also observed decreasing female fecundity (i.e., number of eggs laid per female) in regions where data were available both in the 1990s and the 2010s, which was associated with a decrease in parasitism rate, while the climatic variability increased. This study investigated direct hatching failure in nature that may be related to the magnitude of warming in summer. Previous studies have confirmed the thermal sensitivity of early instars of the PPM to temperatures observed in the present work, including one population from South Tunisia. However, further work is required to evaluate the relative importance of warming summers among populations because the risk of heat stress depends on the phenology of sensitive instars, and populations from the warmest areas may not necessarily be the most vulnerable to climate change if they already evolved phenological heat avoidance. In addition to heat-induced mortality, the ultimate fitness of individuals that survive challenging heat stresses during early developmental stages should also be explored to determine potential carry-over effects on subsequent life stages.

Homoplastic ovarian transplant

Homoplastic ovarian transplantation is recommended by Sippel (Zntrlb. F. Gyn., 1924, No. 1-2) in the treatment of infertility, which is based on disorders and irregularities in egg maturation processes with a tendency to premature rupture of follicles, followed by atresia or small cyst-like degeneration.

P–656 Examination of the clinical significance of the two-step ovulation induction method (DuoStim)

Study question Do culture results of eggs obtained by double stimulation (DuoStim), where eggs are collected twice in one cycle, differ from a conventional fertility drug method? Summary answer The culture results of eggs acquired via the DuoStim cycle versus those acquired via a widely used conventional fertility drug method did not differ significantly. What is known already For patients with reduced ovarian reserve, the random start method, in which ovarian stimulation can start at any time during the menstrual cycle, is being used. As the pituitary gland is suppressed by progesterone during the luteal phase, endogenous luteinizing hormone surges are less likely to occur and ovulation is more easily avoidable. Previous reports showed that ovarian stimulation during the follicular and luteal phases of the same menstrual cycle resulted in similar blastocyst formation rates with normal chromosome numbers, which seems to be time-consuming. The DuoStim method is considered useful in cases in which time is at a premium. Study design, size, duration Between June 2019–December 2020, 562 egg collection cycles were performed in women ≥36 years. Ovulation cycles were evaluated in the conventional ovulation induction cycle (Co) group and DuoStim cycle (DS) group (subclassified into D1 group [first egg collection in cycle] and D2 group [second egg collection]. Post-insemination culture results were evaluated. Participants/materials, setting, methods Participants were women ≥36 years. Infusion method was IVF, and blastocysts of Gardner classification 3BB or higher were designated as good blastocysts, and blastocysts of 3AA or higher were designated as the best blastocysts. Confirmation of the fetal sac was defined as clinical pregnancy for the single freeze-thaw blastocyst transplant cycle. Chi-square and t-tests were used for statistical analysis. P ≤ 0.05 indicated statistical significance. Main results and the role of chance The average number of eggs acquired per cycle was 6.9 in the Co group and 3.5 in the DS group, and the egg maturation rate was 88.0% in the Co group and 95.7% in the DS group, which showed significant differences. The 2PN rate, blastocyst arrival rate, and Day 5 good blastocyst arrival rate in the obtained mature eggs were 66.5%, 66.5%, and 38.3% in the Co group and 70.9%, 70.5%, and 34.4% in the DS group and were not significantly different. Similarly, when a comparative study was conducted between the D1 group and D2 group, rates were 67.5%, 69.0%, and 31.0% in the D1 group and 74.4%, 71.9%, and 37.5% in the D2 group, with no significant difference noted. Rates of clinical pregnancy and post-transplantation miscarriage were 41.1% and 17.8% in the Co group and 16.6% and 0% in the DS group, respectively, with no significant difference, although rates in the Co group tended to be better. Limitations, reasons for caution The fertilization method was evaluated only by IVF. The transplantation method was freeze-thaw embryo transfer by hormone replacement cycle, and the target age was 36 years or older. Wider implications of the findings: DuoStim, which increases the number of acquired eggs, is useful when eggs must be collected as soon as possible. Regarding the clinical pregnancy rate after transplantation, better results were obtained for eggs acquired by the conventional fertility method, but it was necessary to repeat the number of attempts. Trial registration number Not applicable

Autogenous and anautogenous Culex pipiens bioforms exhibit insulin-like peptide signaling pathway gene expression differences that are not dependent upon larval nutrition

Culex pipiens form pipiens and Cx. pipiens form molestus differ in their ability to produce eggs without a bloodmeal. Autogenous mosquitoes, such as the molestus bioform of Cx. pipiens, depend on nutrition acquired as larvae instead of a bloodmeal to fuel the energy intensive process of vitellogenesis, which requires abundant production of yolk proteins. In anautogenous mosquito systems, ovary ecdysteroidogenic hormone (OEH) and insulin-like peptides (ILPs) transduce nutritional signals and trigger egg maturation in response to a bloodmeal. It is unclear to what extent the process is conserved in autogenous mosquitoes and how the bloodmeal trigger has been replaced by teneral reserves. Here, we measured the effects of a series of nutritional regimens on autogeny, time to pupation, and survival in Cx. pipiens form molestus and form pipiens. We find that abundant nutrients never result in autogenous form pipiens and extremely poor food availability rarely eliminates autogeny from form molestus. However, the number of autogenous eggs generated increases with nutrient availability. Similarly, using qPCR to quantify gene expression, we find several differences in the expression levels of ilps between bioforms that are reduced and delayed by poor nutrition, but not extinguished. Changes in OEH expression do not explain bioform-specific differences in autogeny. Surprisingly, the source of most of the gene expression differences correlated with autogeny is the abdomen, not the brain. Overall, our results suggest that autogeny is modulated by nutritional availability, but the trait is encoded by genetic differences between forms and these impact the expression of ILPs.

RNA-Seq analysis of blood meal induced gene-expression changes in Aedes aegypti ovaries

Background Transmission of pathogens by vector mosquitoes is intrinsically linked with mosquito’s reproductive strategy because anautogenous mosquitoes require vertebrate blood to develop a batch of eggs. Each cycle of egg maturation is tightly linked with the intake of a fresh blood meal for most species. Mosquitoes that acquire pathogens during the first blood feeding can transmit the pathogens to susceptible hosts during subsequent blood feeding and also vertically to the next generation via infected eggs. Large-scale gene-expression changes occur following each blood meal in various tissues, including ovaries. Here we analyzed mosquito ovary transcriptome following a blood meal at three different time points to investigate blood-meal induced changes in gene expression in mosquito ovaries. Results We collected ovaries from Aedes aegypti that received a sugar meal or a blood meal on days 3, 10 and 20 post blood meal for transcriptome analysis. Over 4000 genes responded differentially following ingestion of a blood meal on day 3, and 660 and 780 genes on days 10 and 20, respectively. Proteins encoded by differentially expressed genes (DEGs) on day 3 include odorant binding proteins (OBPs), defense-specific proteins, and cytochrome P450 detoxification enzymes. In addition, we identified 580 long non-coding RNAs that are differentially expressed at three time points. Gene ontology analysis indicated that genes involved in peptidase activity, oxidoreductase activity, extracellular space, and hydrolase activity, among others were enriched on day 3. Although most of the DEGs returned to the nonsignificant level compared to the sugar-fed mosquito ovaries following oviposition on days 10 and 20, there remained differences in the gene expression pattern in sugar-fed and blood-fed mosquitoes. Conclusions Enrichment of OBPs following blood meal ingestion suggests that these genes may have other functions besides being part of the olfactory system. The enrichment of immune-specific genes and cytochrome P450 genes indicates that ovaries become well prepared to protect their germ line from any pathogens that may accompany the blood meal or from environmental contamination during oviposition, and to deal with the detrimental effects of toxic metabolites.