Differences In Rate Of Development Research Articles

P-515 The morphokinetic signature of high-level mosaic embryos in time-lapse ART analysis

Abstract Study question Do high-level mosaic embryos exhibit differences in developmental speed compared to euploid or low-level mosaic embryos? Summary answer High-level mosaic embryos exhibit slower development than euploid and low-level mosaic embryos during the blastulation and blastocyst formation stages. What is known already Time-lapse technology (TLT) has facilitated the real-time observation of human embryo development without disrupting culture conditions, generating a wealth of morphokinetic data linked to outcomes such as implantation potential, blastocyst development, and ploidy status. However, the developmental patterns of mosaic embryos based on their aneuploidy level using TLT remain not well understood. Consequently, we aimed to assess the clinical significance of morphokinetic parameters in human embryo development, with a specific focus on embryos categorized by their mosaic status. Study design, size, duration This retrospective study examined 385 blastocysts undergoing preimplantation genetic testing for aneuploidy (PGT-A) between January and December 2022. Out of the total, 191 expansion blastocysts underwent PGT-A biopsy on day 5. The PGT-A results, which categorized embryos into euploid, aneuploid, and mosaic based on their genetic composition, were determined through next-generation sequencing (NGS) by an analysis company. Mosaic embryos were further categorized into two groups: high-level mosaicism (>30% aneuploidy cells) and low-level mosaicism (≤30%). Participants/materials, setting, methods Differences in development rates were assessed through the examination of morphological and morphokinetic parameters. These parameters included the time to second polar body extrusion (tPB2), time to pronuclei appearance and fading (tPNa, tPNf), time to reach 2–8 cells (t2, t3, t4, t5, t6, t7, t8, t9), and time to the onset of blastulation and blastocyst formation (tSB, tB). Statistical analyses, incorporating ANOVA and post-hoc tests, were employed to compare developmental timings across different groups. Main results and the role of chance When categorizing mosaic embryos based on their level, high-level mosaic embryos showed a significantly slower developmental rate than low-level mosaic embryos, evident at both the blastulation stage (tsB, high-level vs. low-level: 101.80h vs. 97.3h, p=0.003) and blastocyst stage (tB, high-level vs. low-level: 109.98h vs. 105.92h, p=0.005). In comparison to euploid embryos, low-level mosaic embryos demonstrated comparable outcomes. Conversely, high-level embryos exhibited a significant difference in both blastulation (tsB, euploidy vs. high-level: 98.85h vs. 101.80h, p=0.026) and blastocyst (tB, euploidy vs. high-level: 106.73h vs. 109.98h, p=0.011) stages. These findings suggested that the mosaic level of embryos might influence developmental kinetics, proposing this approach as an additional tool for the selection of mosaic embryos in the context of embryo transfer. Limitations, reasons for caution This study focused on morphokinetic parameters captured using time-lapse imaging, which may not fully represent the complex cellular dynamics within embryos. Furthermore, the categorization of mosaic embryos into high-level and low-level groups based on the percentage of mosaicism (>30% and ≤30%, respectively) might not capture all embryo developmental potential. Wider implications of the findings The findings suggest valuable predictive potential in assessing the development of aneuploid and mosaic embryos. Further research into the development of euploid, aneuploid, and mosaic embryos, as well as high-level and low-level mosaic embryos, could provide valuable insights for ART practices. This could significantly impact ART decision-making and patient outcomes. Trial registration number not applicable

P-179 The impact of cytoplasmic strings: morphological analysis of the embryo development and quality

Abstract Study question This study aimed to investigate the influence of cytoplasmic strings (CSs) on the development and quality of the embryo. Summary answer Blastocysts with CSs exhibited accelerated development from t7 to the tB stage and a higher rate of good-quality on day 5. What is known already Time-lapse (TL) culture during in vitro fertilization is an established method for evaluating the morphological and morphokinetic features of embryos. CSs, identified through TL culture, are among the characteristics of developing embryos. Although the impact of CSs on embryo quality is recognized, their specific functions in human embryos remain unclear. Study design, size, duration This retrospective study was conducted from January 2022 to December 2022. A total of 1050 injected oocytes were cultured in the EmbryoScope® (Vitrolife),with images captured every 20 minutes for 5-6 days. CSs are observed the straight lines connecting the inner cell mass to the mural trophectoderm. On days 5-6, the presence of CSs was assessed in 610 blastocysts. Participants/materials, setting, methods The evaluation of differences in development rate and quality related to CSs was conducted using morphological or morphokinetic parameters: the time to second polar body extrusion (tPB2), time to pronuclei appearance and fading (tPNa, tPNf), time to reach 2–8 cells (t2, t3, t4, t5, t6, t7, t8, t9), time to the start of blastulation and blastocyst formation (tSB, tB). Statistical analysis employed Student’s t-test for developmental time and the Chi-square test for quality comparisons. Main results and the role of chance Blastocysts were categorized into Group 1 if they had CSs and Group 2 if they lacked CSs. No differences in developmental rates between the groups were observed until the t6 stage. However, from t7, the pre-cleavage stage, to the tB stage, the Group 1 exhibited a significantly faster developmental compared to the Group 2 (t7: 56.97h vs. 58.82h, p = 0.013; t8: 61.68h vs. 63.39h, p = 0.049; t9: 72.05h vs. 74.63h, p = 0.001; tSC: 82.32h vs. 85.56h, p < 0.001; tM: 92.60h vs. 95.48h, p < 0.001; tSB: 105.11h vs. 107.57h, p = 0.004 and tB: 114.73h vs.117.97h, p = 0.001). In examining of good-quality embryos (GQE) on day 5(≥ grade BB), there was a notable association in Group 1, demonstrating 71.6% compared to 28.4% in the Group 2 (p < 0.001).These findings indicate a positive correlation between the presence of CSs and embryo developmental progress and quality. Limitations, reasons for caution The determination of CSs relies on visual evaluation, containing the potential for subjective bias. Future research requires an automated time course monitoring system for more objective methods for identifying CSs to improve accuracy. Wider implications of the findings This research has advanced our comprehension of the impact of CSs on embryonic development. Moreover, the evaluation of CSs features suggests the possibility of their introduction as novel morphological parameter in future embryonic grading systems. Trial registration number Not Applicable

A Simple Test for Determining the Late‐Maturity Alpha‐Amylase Susceptibility Window in Wheat

AbstractLate‐maturity alpha‐amylase or LMA is a weather‐related event that lowers the quality of affected grain, resulting in sticky breads, cakes, and noodles with unattractive and undesirable textures. Grain that has been affected by LMA, or that is susceptible to LMA, cannot be identified by sight alone due to varietal‐ and environmental‐induced differences in appearance and differences in rates of development. Techniques that allow for rapid identification of the LMA susceptibility window in wheat and knowledge of the weather events that lead to LMA can empower growers to manage and mitigate LMA‐induced profit loss. Earn 0.5 CEUs in Crop Management by reading this article and taking the quiz at https://web.sciencesocieties.org/Learning‐Center/Courses.

Suitability of a Historical, Novel, and Occasional Host for Mountain Pine Beetle (Coleoptera: Curculionidae)

The mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae), recently underwent a notable range-expansion event in western Canada, resulting in access to the novel host jack pine, Pinus banksiana Lamb. We assessed the suitability of jack pine for mountain pine beetle, as well as the historic host lodgepole pine, Pinus contorta Dougl. var. latifolia Engelm., and the non-Pinus host white spruce, Picea glauca (Moench) Voss, to help inform an assessment of the risk of future spread into Canada’s boreal forest and to further our understanding of host use in bark beetles. Several performance traits we measured were similar between lodgepole pine and jack pine, but gallery length and productivity indicated that lodgepole pine was the more suitable host. Development appeared to be faster in jack pine; however, in contrast to previous studies, we attribute it to oviposition arresting earlier in the novel host compared to the other hosts and not a difference in development rate. Initial productivity was surprisingly high in spruce, but we found evidence of a delayed negative effect that manifested as reduced cold tolerance, delayed development, and high mortality of late-instar larvae. Although jack pine is a suitable host for the mountain pine beetle, our results indicate that the beetle’s eruptive potential could be lower in jack pine compared to lodgepole pine, given all other factors are equal. Other factors that may also affect mountain pine beetle population dynamics require additional research and include the composition and structure of jack pine forests, environmental conditions, and biotic interactions.

Intraspecific variations in life history traits of two pecky rice bug species from Japan: Mapping emergence dates and number of annual generations.

The mirid bugs Stenotus rubrovittatus and Trigonotylus caelestialium, which cause pecky rice, have become a threat to rice cultivation in Asia. Damage caused by these pests has rapidly become frequent since around 2000 in Japan. Their expansion pattern is not simple, and predicting their future spread remains challenging. Some insects with wide ranges have locally adapted variations in life‐history traits. We performed laboratory rearing experiments to assess the geographical scale of intraspecific variations in life‐history traits of S. rubrovittatus and T. caelestialium. The experiments were aimed at increasing the accuracy of occurrence estimates and the number of generations per year. These results were compared with previous research, and differences in development rates were observed between populations of different latitudes, but not of the same latitude. Finally, plotting the timing of adult emergence and the potential number of generations per year on maps with a 5‐km grid revealed that they differed greatly locally at the same latitude. These maps can be used for developing more efficient methods of managing mirid bugs in integrated pest management.

Comparative Milestones in Rodent and Human Postnatal Central Nervous System Development.

Within the substantially different time scales characterizing human and rodent brain development, key developmental processes are remarkably preserved. Shared processes include neurogenesis, myelination, synaptogenesis, and neuronal and synaptic pruning. In general, altricial rodents experience greater central nervous system (CNS) immaturity at birth and accelerated postnatal development compared to humans, in which protracted development of certain processes such as neocortical myelination and synaptic maturation extend into adulthood. Within this generalization, differences in developmental rates of various structures must be understood to accurately model human neurodevelopmental toxicity in rodents. Examples include greater postnatal neurogenesis in rodents, particularly within the dentate gyrus of rats, ongoing generation of neurons in the rodent olfactory bulb, differing time lines of neurotransmitter maturation, and differing time lines of cerebellar development. Comparisons are made to the precocial guinea pig and the long-lived naked mole rat, which, like primates, experiences more advanced CNS development at birth, with more protracted postnatal development. Methods to study various developmental processes are summarized using examples of comparative postnatal injury in humans and rodents.

Assessment of larval growth patterns: A comparison across five fish species in the Bay of Biscay

Hake, mackerel, horse mackerel, anchovy and sardine larvae were identified from samples of ichthyoplankton collected during eight surveys in the Bay of Biscay between 2000 and 2005. Comparative analyses were carried out to explore the early growth patterns of these species based on differences in body proportion and the interpretation of the otolith microstructure to estimate their age. Statistical differences in development rates were observed for different body proportions. On the one hand, the larvae of hake, mackerel and horse mackerel prioritise the growth of those parts of the body related to feeding (body weight, head and jaw), while those of anchovy and sardine prioritise those related to swimming (body length). We propose that these different strategies are adaptations to reduce larval mortality, each of them focusing on the main factor that controls it during the early stages: starvation and predation. These growth strategies are interpreted from an environmental perspective mainly related to the characteristics of the food and the abundance of predators in the environment in which the larvae develop during this vulnerable life stage.

Effects of Delta-9 Tetrahydrocannabinol (THC) on Oocyte Competence and Early Embryonic Development.

Recent changes in legal status and public perception of cannabis have contributed to an increase use amongst women of reproductive age. Concurrently, there is inadequate evidence-based knowledge to guide clinical practice regarding cannabis and its effects on fertility and early embryonic development. This study aimed to evaluate the effects of the primary psychoactive component of cannabis, delta-9 tetrahydrocannabinol (THC), during oocyte maturation, and its impact on the developing embryo. Bovine oocytes were matured in vitro for 24 h under clinically relevant doses of THC mimicking plasma levels achieved after therapeutic (0.032 μM) and recreational (0.32 and 3.2 μM) cannabis use. THC-treated oocytes were assessed for development and quality parameters at both the oocyte and embryo level. Characteristics of oocytes treated with cannabinoid receptor antagonists were also assessed. Oocytes treated with 0.32 and 3.2 μM THC, were significantly less likely to reach metaphase II (p < 0.01) and consequently had lower cleavage rates at day 2 post-fertilization (p < 0.0001). Treatment with cannabinoid receptor antagonists restored this effect (p < 0.05). Oocytes that did reach MII showed no differences in spindle morphology. Oocytes treated with 0.032 μM THC had significantly lower connexin mRNA (p < 0.05) (correlated with decreased quality), but this was not confirmed at the protein level. At the blastocyst stage there were no significant differences in developmental rates or the proportion of trophectoderm to inner cell mass cells between the control and treatment groups. These blastocysts, however, displayed an increased level of apoptosis in the 0.32 and 3.2 μM groups (p < 0.0001). Our findings suggest a possible disruptive effect of cannabis on oocyte maturation and early embryonic development.

Association of Systemic Diseases With Surgical Treatment for Obstructive Sleep Apnea Compared With Continuous Positive Airway Pressure

The efficacy of surgical treatments for obstructive sleep apnea (OSA) is variable when considering only the Apnea Hypopnea Index as the treatment end point. However, only a few studies have shown an association between these procedures and improved clinically relevant outcomes, such as cardiovascular, endocrine, and neurological sequelae of OSA. To evaluate the association of surgery for OSA with clinically relevant outcomes. This retrospective cohort study used the Truven MarketScan Database from January 1, 2007, to December 31, 2015, to identify all patients diagnosed with OSA who received a prescription of continuous positive airway pressure (CPAP), were 40 to 89 years of age, and had at least 3 years of data on file. Data were analyzed September 19, 2019. Soft tissue and skeletal surgical procedures for the treatment of OSA. The occurrence of cardiovascular, neurological, and endocrine complications was compared in patients who received CPAP alone and those who received surgery. High-dimensionality propensity score matching was used to adjust the models for confounders. Kaplan-Meier survival analysis with a log-rank test was used to compare differences in survival curves. A total of 54 224 patients were identified (33 405 men [61.6%]; mean [SD] age, 55.1 [9.2] years), including a cohort of 49 823 patients who received CPAP prescription alone (mean [SD] age, 55.5 [9.4] years) and 4269 patients who underwent soft tissue surgery (mean [SD] age, 50.3 [7.0] years). The median follow-up time was 4.47 (interquartile range, 3-8) years after the index CPAP prescription. In the unadjusted model, soft tissue surgery was associated with decreased cardiovascular (hazard ratio [HR], 0.92; 95% CI, 0.86-0.98), neurological (HR, 0.49; 95% CI, 0.39-0.61), and endocrine (HR, 0.80; 95% CI, 0.74-0.86) events. This finding was maintained in the adjusted model (HR for cardiovascular events, 0.91 [95% CI, 0.83-1.00]; HR for neurological events, 0.67 [95% CI, 0.51-0.89]; HR for endocrine events, 0.82 [95% CI, 0.74-0.91]). Skeletal surgery (n = 114) and concomitant skeletal and soft tissue surgery (n = 18) did not demonstrate significant differences in rates of development of systemic complications. In this cohort study, soft tissue surgery for OSA was associated with lower rates of development of cardiovascular, neurological, and endocrine systemic complications compared with CPAP prescription in a large convenience sample of the working insured US adult population. These findings suggest that surgery should be part of the early treatment algorithm in patients at high risk of CPAP failure or nonadherence.

The effect of the hibernation on the larval development of Troglostrongylus brevior in the land snail Cornu aspersum

Troglostrongylus brevior, a lungworm affecting wild felids, has been increasingly reported in domestic cats from Europe. Troglostrongylosis is a relevant disease that may result in a potentially life-threatening bronchopneumonia, especially in kittens. The life cycle of T. brevior is indirect with terrestrial gastropods acting as intermediate host. The widely distributed spread land snail Cornu aspersum (former Helix aspersa) is competent for T. brevior development and may transmit the nematode in natural conditions. The present study evaluated the larval development of T. brevior in C. aspersum at two different environmental temperature conditions, with a focus on the effect of hibernation. One hundred and seventy snails were infected with 500 first stage larvae (L1) of T. brevior and kept in vivaria at 25 ± 2 °C. Fifteen days post infection (p.i.), 20 specimens were digested to evaluate the overall larval developmental rate from L1 to L3 (2.5 % on days 15 p.i.) and then the snails were divided in two groups, i.e. G1 kept at 25 ± 2 °C and G2 that were hibernated at 4 ± 2 °C. The developmental rate of T. brevior was evaluated in these groups on 30 and 60 days p.i. by snail digestion at each time-point. An additional batch of 40 snails (G2-1) was hibernated on D15 and digested on D60. Larvae recovered were morphologically and morphometrically examined. The infective third larval stage (L3) was detected in the muscular foot of C. aspersum at different rates depending on the environmental temperature. In particular, T. brevior showed a higher developmental rate in hibernated snails (G2: 6.9 % and 14.1 % on days 30 and 60 p.i; G2-1: 4%; G2 + G2-1 overall mean percentage: 9%) compared to non-hibernated snails (G1: 4% and 5.2 % on days 30 and 60 p.i.), indicating that lower temperatures may positively influence the developmental in C. aspersum. These data are suggestive for a seasonal pattern of T. brevior infections under field conditions, with snails containing higher parasitic burdens after their natural hibernation occurring in winter. Studies on the larval development of T. brevior in other mollusc species in field surveys evaluating differences in developmental rates and transmission patterns in different seasons are warranted.

Automated minute scale RNA-seq of pluripotent stem cell differentiation reveals early divergence of human and mouse gene expression kinetics.

Pluripotent stem cells retain the developmental timing of their species of origin in vitro, an observation that suggests the existence of a cell-intrinsic developmental clock, yet the nature and machinery of the clock remain a mystery. We hypothesize that one possible component may lie in species-specific differences in the kinetics of transcriptional responses to differentiation signals. Using a liquid-handling robot, mouse and human pluripotent stem cells were exposed to identical neural differentiation conditions and sampled for RNA-sequencing at high frequency, every 4 or 10 minutes, for the first 10 hours of differentiation to test for differences in transcriptomic response rates. The majority of initial transcriptional responses occurred within a rapid window in the first minutes of differentiation for both human and mouse stem cells. Despite similarly early onsets of gene expression changes, we observed shortened and condensed gene expression patterns in mouse pluripotent stem cells compared to protracted trends in human pluripotent stem cells. Moreover, the speed at which individual genes were upregulated, as measured by the slopes of gene expression changes over time, was significantly faster in mouse compared to human cells. These results suggest that downstream transcriptomic response kinetics to signaling cues are faster in mouse versus human cells, and may offer a partial account for the vast differences in developmental rates across species.

Field Relevant Variation in Ambient Temperature Modifies Density-Dependent Establishment of Plasmodium falciparum Gametocytes in Mosquitoes.

The relationship between Plasmodium falciparum gametocyte density and infections in mosquitoes is central to understanding the rates of transmission with important implications for control. Here, we determined whether field relevant variation in environmental temperature could also modulate this relationship. Anopheles stephensi were challenged with three densities of P. falciparum gametocytes spanning a ~10-fold gradient, and housed under diurnal/daily temperature range (“DTR”) of 9°C (+5°C and −4°C) around means of 20, 24, and 28°C. Vector competence was quantified as the proportion of mosquitoes infected with oocysts in the midguts (oocyst rates) or infectious with sporozoites in the salivary glands (sporozoite rates) at peak periods of infection for each temperature to account for the differences in development rates. In addition, oocyst intensities were also recorded from infected midguts and the overall study replicated across three separate parasite cultures and mosquito cohorts. While vector competence was similar at 20 DTR 9°C and 24 DTR 9°C, oocyst and sporozoite rates were also comparable, with evidence, surprisingly, for higher vector competence in mosquitoes challenged with intermediate gametocyte densities. For the same gametocyte densities however, severe reductions in the sporozoite rates was accompanied by a significant decline in overall vector competence at 28 DTR 9°C, with gametocyte density per se showing a positive and linear effect at this temperature. Unlike vector competence, oocyst intensities decreased with increasing temperatures with a predominantly positive and linear association with gametocyte density, especially at 28 DTR 9°C. Oocyst intensities across individual infected midguts suggested temperature-specific differences in mosquito susceptibility/resistance: at 20 DTR 9°C and 24 DTR 9°C, dispersion (aggregation) increased in a density-dependent manner but not at 28 DTR 9°C where the distributions were consistently random. Limitations notwithstanding, our results suggest that variation in temperature could modify seasonal dynamics of infectious reservoirs with implications for the design and deployment of transmission-blocking vaccines/drugs.

Reproductive Ontogeny and the Evolution of Morphological Diversity in Conifers and Other Plants.

Biologists often study morphological evolution through form and function relationships. But biological structures can perform multiple functional roles, complicating efforts to understand the evolutionary significance of any one relationship. Plant reproductive organs perform multiple roles in a sequence, however, which provides a unique opportunity to understand how structures evolve to meet multiple functional demands. Using conifers as a study group, we discuss how a shared developmental trajectory links the performance of sequential functional roles. Variation in development among lineages can underlie morphological diversity; pollination-stage seed cones in Pinaceae conifers function similarly but show diverse forms reflecting differences in developmental rate. As cones develop further, the morphologies that they use to perform later functional roles are influenced by the specific developmental patterns used to meet earlier demands, which may ultimately limit morphological diversity. However, we also show how selective pressures relating to the final functional stage (seed dispersal) may influence cone anatomy and morphology over all previous stages, highlighting the complex linkages among form, function, and development. We end by discussing the potential relationships between functional ontogeny and morphological disparity in plant reproductive structures more broadly, suggesting that the complex functional roles associated with seed plant reproduction probably underlie the high disparity in this group.

Anthropogenic nest sites provide warmer incubation environments than natural nest sites in a population of oviparous reptiles near their northern range limit.

Oviposition site choice affects a host of offspring phenotypes and directly impacts maternal fitness. Recent evidence suggests that oviparous reptiles often select nest sites where the landscape has been altered by anthropogenic activity, whereas natural nest sites are less often used. We leverage a long-term study of snapping turtle (Chelydra serpentina) to identify natural nest sites and anthropogenic nest sites and to compare habitat variables among nest site types. Natural and anthropogenic nest sites did not differ in average canopy closure, distance to nearest water, substrate composition, or aspect. However, anthropogenic nest sites had less ground-level vegetation and greater soil brightness, and were 3.3°C warmer than natural nests during incubation. We used the Schoolfield model of poikilotherm development to assess differences in development rate between natural and anthropogenic nests. Because of the difference in temperature, embryos in anthropogenic nests were predicted to have undergone nearly twice as much development as embryos in natural nests during incubation. We outline why the evolution of fast embryonic development rate cannot compensate indefinitely for the low temperature incubation regimes that become increasingly prevalent at northern range margins, thereby underlining why maternal nest site choice of relatively warm anthropogenic sites may help oviparous reptiles persist in thermally constrained environments. Future research should aim to quantify both the thermal benefits of anthropogenic nest sites, as well as associated fitness costs (e.g., increased adult mortality) to elucidate whether anthropogenic disturbance of the landscape can be an ecological trap or serve a net benefit to some reptiles in northern environments.

Age-related differences in kinematics and kinetics of sprinting in young female.

This study aimed to investigate the age-related differences in sprinting performance, kinematic and kinetic variables in girls aged between 7.0 and 15.3years. Step-to-step spatiotemporal variables and ground reaction impulses during sprinting were collected in 94 Japanese girls across a 50m inground force platesystem. From the results, a difference in rate of development in sprinting performance in girls over 12.7years compared with younger girls (YG) was observed. The older girls (OG) became slightly slower each year (-0.09m/s/y) compared to the YG (0.24m/s/y) who increased their running speed. Moreover, height increased by 6.3cm/y in YG and only 3.6cm/y in OG, while step length during the maximal speed phase increased by 0.08m/y in YG and plateaued in OG (0.01m/y). Propulsive impulse during the initial acceleration phase was the kinetic variable to differ in rate of development between the age groups with an increase of 0.024Ns/y in the YG compared to -0.010Ns/y in OG. The development of sprinting ability in Japanese girls was more rapid before age 12.7years. The difference in rate of development in sprinting ability can be primarily attributed to greater growth rates in YG, contributing to increases in the propulsive impulse during the initial acceleration phase and step length during the maximal speed phase. The limited gains in step length and the propulsive impulse in OG may reflect their reduced growth rate in height and the fact that increases in fat mass with maturation impaired relative force production.

176 Effect of epigallocatechin-3-gallate on bovine oocyte in vitro maturation, fertilization, and development

Epigallocatechin-3-gallate (EGCG) is a major ingredient of catechin polyphenols, and a strong antioxidant compound. Huang et al. (2018 Asian-australas. J. Anim. Sci.) reported that adding 50μM EGCG can improve the bovine oocyte maturation rate. In this research, we investigated the effect of EGCG supplementation on different periods in bovine IVF. Cumulus-oocyte complex (COC) collected from ovaries of slaughtered cows were cultured in maturation medium (20 to 30 oocytes per 100-µL droplet), which consisted of TCM-199 with Earle’s salts and 25mM HEPES supplemented with 10% (vol/vol) fetal bovine serum (FBS), 1µg mL−1 oestradiol, 0.02mg mL−1 FSH, and antibiotics at 38.5°C in a humidified atmosphere of 5% CO2 in air for 24h (in vitro maturation, IVM). After IVM, COC were fertilized in the fertilization medium (modified Brackett-Oliphant media supplemented with 10 µgmL−1 heparin, 10mM caffeine, and 3mg mL−1 BSA) for 6h using semen of one bull at final sperm concentration of 1×107 mL−1 (IVF). After IVF, COC were denuded and cultured in culture medium [CR1aa supplemented with 10% (vol/vol) FBS and antibiotics] at 38.5°C in a humidified atmosphere of 5% O2, 5% CO2, and 90%N2 for 8 days (in vitro culture, IVC). The EGCG was supplemented at 10, 25, 50, and 100M in IVM medium; 25 and 50 µM in IVF medium; and 50 and 100 µM in IVC medium. After 24h in IVM medium, COC were denuded by pipetting, fixed in 3:1 ethanol:acetic acid for 24h and then checked for nuclear and polar body by using aceto-orcein stain. After 18h in IVF, the pronucleus in zygote was fixed in 3:1 ethanol:acetic acid for 24h and checked by aceto-orcein staining. Embryo development was evaluated by counting the total number of embryos that had reached compacted morula by 6 to 8 days after IVF. Significant differences were analysed by chi-squared test and residual analysis. A P-value&amp;lt;0.05 was considered statistically significant. When EGCG was added to IVM, there was no significant difference of oocyte maturation rate between all concentrations (0v. 10v. 25v. 50v. 100 μM: 73.9% v. 56.7% v. 76.7% v. 72.7% v. 63.5%). When EGCG was added to IVF, there was no significant difference of fertilized rate (0v. 25v. 50 μM: 59.4% v. 73.7% v. 64.9%). When EGCG was added to IVC, there was no significant difference in development rate (0v. 50v. 100 μM: 26.2% v. 15.7% v. 22.0%). In this research, EGCG addition did not affect bovine in vitro fertilization.

The movement of fly (Diptera) larvae within a feeding aggregation

AbstractDipteran larvae from a number of families feed in aggregations. Rotation of blow fly (Diptera: Calliphoridae) larvae within an aggregation has been reported anecdotally many times. However, there is a lack of quantitative data on such larval movement, which is necessary to better understand the advantage of this gregarious behaviour. A recent development in tagging methods provided an opportunity to address this gap in knowledge. In 15 aggregations of 500 Lucilia sericata (Meigen) (Diptera: Calliphoridae) larvae, the location of four-tagged individuals was recorded at 10-minute intervals. All larvae were seen to rotate, alternating between the periphery and within. There was much variation in the relative proportions that larvae were seen in these two locations among aggregations (χ2=78.4, df=58, P=0.038), perhaps as a result of differences in mass shape and, therefore, surface area: volume ratio. There were also differences between larvae within aggregations (χ2=25.6, df=14, P=0.029), which may give rise to differences in development rate, perhaps as a result of intraspecific competition. Further work would be required to verify this competition, and to establish whether the limited resource is temperature, food, oxygen, or some other requirement.

THE CHARACTERISTICS OF SECRETION OF ADIPONECTIN AND ITS RELATIONSHIP WITH PARTICULAR INDICESOF METABOLISM IN MALES OF ABLE-BODIED AGE IN CASE OF OBESITY

The sampling consisted of 79 examined males of able-bodied age. The arterial hypertension stage I and II was established in 58% of them; obesity of various degree of severity was diagnosed in 63% of them; metabolic syndrome according criteria ATP-III was noted in 46.8% of examined patients. The general clinical and anthropometric examination was carried out. The laboratory analyses included estimation of lipidogram, fasting glycaemia and also hormones adiponectin and insulin with following calculation of index of insulin resistance HOMA-IR (Homeostasis Model Assessment of Insulin Resistance). The study was organized to investigate effecting of obesity on secretion of adiponectin and its relationship with indices of lipidogram and level of insulin resistance. The comparative analysis of groups with and absence of obesity established no significant difference in level of adiponectin and indices of lipidogram. the significant differences were established in the levels of basal insulin hence in value of index NOMA-IR that points to hyperinsulinemia and expressed insulin resistance in patients with obesity. The patients were separated in two groups depending on presence of manifestations of metabolic syndrome: with metabolically healthy obesity and metabolically complicated obesity. The analysis established a significant decreasing of level of adiponectin in the group of metabolically complicated obesity accompanied by insulin resistance, dyslipidemia and increased level of glycaemia. The study established no effect of degree of obesity on decreasing of level of adiponectin. The significant differences between levels of adiponectin in comparison between group without obesity and group of metabolically healthy obesity. The correlation analysis in group with obesity demonstrated back-coupling between level of adiponectin and content of total cholesterol, low density lipoproteins and coefficient of atherogenicity. The comparison of groups according median of adiponectin established significant differences in rate of development of metabolic syndrome and value of coefficient of atherogenicity.

Hydric environmental effects on turtle development and sex ratio

Experimental and field studies of different turtle species suggest that moisture influences embryonic development and sex ratios, wetter substrates tend to produce more males, and drier substrates produce more females. In this study, we used Trachemys scripta elegans to test the effect of moisture on embryonic development and sex ratios. T. s. elegans eggs were incubated under different temperature and moisture regimes. We monitored embryonic development until stage 22 (after sex determination) and, for the first time, we estimated sex ratios using a male-specific transcriptional molecular marker, Sox9. Among treatments, we found differences in developmental rates, egg mass, and sex ratio. Embryos developed slowly in cooler and wetter sand substrate while water uptake by the eggs was significantly greater on wetter substrates. Developmental differences were due to moisture interacting with temperature where increased water content of the sand resulted in temperatures that were 2–3°C lower than air temperatures. The coolest and the wettest substrates produced 100% males compared to 42% males from the warmest and driest treatment. Further, we found that embryonic growth appears to be more sensitive to temperature at earlier stages of development and to moisture at later stages. This study shows how moisture may change the incubation conditions inside nests by changing the temperature experienced by eggs, which affects development, growth and sex ratios. The results of this study highlight the importance of including moisture conditions when predicting embryo growth and sex ratios and in developing proxies of embryonic development.

Bioconversion of sorghum and cowpea by black soldier fly (Hermetia illucens (L.)) larvae for alternative protein production

The larvae and prepupae of the black soldier fly,Hermetia illucens (L.) (Diptera: Stratiomyidae) have been explored as a means for alternate protein production for feed for animals that are raised for human food. However, processes for production of these and other insects must be refined if cultivation is to become widespread and efficient. In this study, black soldier fly larvae were fed one of six diets, consisting of the Gainesville house fly diet (control), and five diets of varying ratios of sorghum and cowpea. Effects on life-history traits and nutritional content of prepupae were observed. Flies were able to successfully complete larval development on all diets tested. There were significant differences in development rates based on diet, particularly the diets containing a higher percentage of sorghum. In general, larvae reared on the sorghum diets (which were lower in protein than that of the cowpea diets), developed slower (3-9 days longer from larval eclosion to the prepupal stage) than those on the cowpea diets. Diet treatment did not consistently influence weight or length of prepupae. Higher protein diets (7.73% protein) translated to higher protein content of prepupae (43.70-47.29% protein) and lower protein diets (3.51% protein) resulted in greater gross energy content of prepupae (5.22-6.21 Kcal/g). These differences suggest that macro-nutrient content of prepupae can be influenced by larval diet. This study provides further evidence of the viability of black soldier flies for protein production.