Number Of Dead Embryos Research Articles

Initial Assessment the Effects of Polyethylene Microplastics on the Growth of Zebrafish Embryos Danio rerio

The aim of this study to evaluate the effect of polyethylene (PE) microplastics to mortality rates and morphological changes of zebrafish (Danio rerio) embryos by determining the mortality ratio of embryos and changes in embryo morphological structure after 24, 48, 72 and 96 h of exposure. Zebrafish were obtained from the Faculty of Biology - Hanoi University of Science. 24-hour-old fish embryos were exposed to PE microplastic concentrations of 5; 10; 20; 50 and 100 µg/mL. The results showed that when exposed to microplastics at concentrations of 10 µg/mL or higher, only about 5-10% of mortality embryos and the ratio did not increase with increasing concentration. These embryos died in the first 24 h and the number of dead embryos did not increase throughout the experiment. A similar trend was also observed when evaluating the ratio of morphologically abnormal embryos, embryos with abnormal pericardial edema were observed throughout the experiment at the highest concentration of 100 µg/mL. The results showed the potential risk in the using plastic products for the ecological environment.

Assessing the phenology and reproductive output of loggerhead turtles in relation to climatic variables at Patara Beach, Türkiye

AbstractLoggerhead turtles (Caretta caretta), being ectothermic organisms, could be especially susceptible to climate change effects, and may exhibit climate‐related variation in their reproductive behaviours such as phenology, annual nest numbers, clutch size, hatching success, incubation period and sex ratio. This study investigated the reproductive phenology and outputs of loggerhead turtles and their relationships with climatic variables over a 5‐year period (2019–2023) at Patara Beach, Türkiye. We found significant fluctuations in atmospheric temperature, sea surface temperature and relative humidity, and that female turtle emergences on Patara Beach could temporarily adjust their phenology in response to these minor environmental changes. We highlight the importance of understanding the impacts of phenological shifts on the ability to satisfy the conditions over the nesting season that determine reproductive output. Our statistical analyses also showed that increasing sea water temperatures and atmospheric temperatures, as well as decreasing precipitation and relative humidity, had direct and/or indirect effects on the nesting phenology and reproductive output of loggerhead turtles. The findings from this study indicate that atmospheric temperature significantly affected incubation period, hatching success rate, the number of dead embryos and the number of empty eggshells. Additionally, relative humidity had a significant impact on the incubation period and the number of empty eggshells. In this context, rising temperatures led to drier nest conditions, decreased incubation periods and increased nest temperatures, resulting in higher proportions of female offspring. In conclusion, there are still gaps in our understanding of the effects of climate change on the reproductive biology of loggerhead turtles, and more studies are needed at both the Mediterranean and global scales to better understand these effects.

A 21‐year recovery trend in green turtle nesting activity: 2002–2022

Abstract Long‐term monitoring and conservation are crucial for effective protection, since sea turtles migrate cyclically every 2–3 years and lay multiple nests during a breeding season. Therefore, this study aimed to investigate the long‐term trend of nesting activities of green turtles over a 21‐year period (2002–2022) on Samandağ beach. An early morning survey was conducted every year during both nesting and hatching seasons. The trend analyses in nesting activities were performed using Mann–Kendall and Sen's slope tests together with the augmented Dickey–Fuller stationarity test. The nest count and female abundance increased significantly, whereas clutch size, fecundity, and hatching success tended to decrease insignificantly. The percentage change between the most recent and oldest 3‐year mean nest count and mean female abundance, which is performed to comply with the Red List assessment method used by the International Union for Conservation of Nature Marine Turtle Specialist Group, was 769% and 764% respectively. Samandağ nesting population accounts for one‐third of the Mediterranean's total nest count and one‐fourth of its total female abundance. The decrease in clutch size and fecundity may be due to the recruitment of individuals with smaller body sizes or malnutrition as a result of population growth. There was an increase in the number of dead embryos and a decline in hatching success. This may be explained by density‐dependent population regulation as a result of an increase in the number of nests. It may be argued that adherence to a uniform strategy and the maintenance of continuous protection through collaboration with governmental and non‐governmental organizations with scientifically rigorous methodology are significant factors contributing to the high recovery. This study emphasizes the necessity of adopting a comprehensive conservation approach encompassing both foraging habitats and the significant role played by the population in Samandağ in the proliferation of Mediterranean green turtles.

Effect of The Recommended Dose of Dimethoate and Its Double on The Embryos and Testicular Tissues in Male Mice

Exposure to pesticides negatively have associated with many public health hazards infecting humans as infertility, therefore, the objective of this study was to investigate the effect of dimethoate on testicular cytoarchitecture of treated mice and on the embryos. Albino mice were divided into three groups of 9 each: the first group served as control and was given distilled water orally, whereas the second and third groups were given dimethoate at doses (0.1 and 0.2 mL dimethoate/100 mL distilled water) respectively for 20 days. At the end of the treatment, six mice from each group were weighed and sacrificed, the testis and epididymis weights were recorded, and histopathological lesions of tests were carried out. The obtained results revealed that dimethoate caused a decrease in the body and epididymis weights. Furthermore, dimethoate led to a significant decrease in the number of dead embryos and their weights. Histopathological examination demonstrated that this pesticide caused marked alterations in the microstructure of testicular tissues appeared as vacuoles, disorganization of the germinal epithelium, and degenerative changes in some seminiferous tubules as well as its effect on the embryos, therefore, more efforts should be conducted to protect our environment and health from these detrimental compounds and the search for safe methods for insect control.

Влияние хронического токсоплазмоза на изменение уровней пред- и постимплантационной гибели в эксперименте

The purpose of the study was to study the effect of chronic toxoplasmosis on changes in the levels of pre- and post-implantation mortality in the experiment. Materials and methods. In the experiment there were 90 female Wistar rats with a body weight of 180-200 g. For the development of pregnancy, females of the control and experimental groups were coupled with males for 3 days. After the onset of pregnancy, females of intact controls were orally injected with 2 ml of 0.2 % starch gel. The females of the experimental groups were infected with an invasive culture of Toxoplasma gondii at a dose of 25 tachyzoites per 1 g of body weight (5,000 tachyzoites per rat) and 50 tachyzoites per 1 g of body weight (10,000 tachyzoites per rat). On the 35th day after infection, females of the experimental groups were coupled with males for 3 days before infection. The effect of Toxoplasma on changes in the levels of pre- and post-implantation death was assessed after killing female rats on the 42nd, 49th and 56th (7th, 14th and 21st days after pregnancy) days after infection. Results and discussion. In animals infected at a dose of 25 tachyzoites per 1 g of body weight, there is a decrease in the number of implantation sites in the uterus, the total number of embryos and the number of living embryos at all stages of the development of Toxoplasma by 1.8-2.1 times compared with the control. In females infected at a dose of 50 tachyzoites per 1 g of body weight, a decrease in the number of implantation sites in the uterus and the total number of embryos at all stages of the development of the parasite was recorded by 2.2-2.5 times compared with the control values. There is a decrease in the number of living embryos by the 42nd day after infection by 4.3 times, by the 49th day – by 3.8 times and by the 56th day – by 5.1 times compared to the control. When compared with the results obtained from females with a lower dose of infection, a decrease in this indicator was revealed on the 42nd day after the development of Toxoplasma by 2.1 times, on the 49th day – by 1.7 times and on the 56th day – by 2.5 times. An increase in the number of dead embryos by 0.2-0.4 times in comparison with intact indicators and the results of experimental animals infected at a dose of 5,000 tachyzoites per rat were recorded. There was an increase in the level of resorptions on the 49th and 56th days by 1.4 and 1.6 times in comparison with the control and animals infected at a dose of 25 tachyzoites per 1 g of body weight. Conclusion. Experimental chronic toxoplasmosis causes an increase in pre-implantation and post-implantation embryo death. The recorded effect of Toxoplasma invasion depends on the dose of infection and the duration of the disease

Description of factors decreasing egg incubation of creole hens (Gallus gallus domesticus)

Objective: To describe the factors that affect the incubation of fertile eggs of Creole hens (Gallus gallus domesticus) at Mezquital Valley, Hidalgo, Mexico. Design/Methodology/Approach: 448 eggs of Creole hens were incubated in a Casser model 7622 incubator, in which the number of infertile and fertile eggs was evaluated; within the number of fertile eggs, the number of dead embryos was determined; due to dehydration or damage caused by fungi and bacteria. From the live hatched chickens, those that died due to omphalitis were recorded. Results: 272 of 448 incubated eggs were fertile; 119 of them hatched and 153 were dead embryos. While 176 were infertile. Among the dead embryos, 84 of dehydration, 69 due to fungal and bacterial infection and 11 live hatched chicks due to omphalitis. Limitations/implications: The literature review found little information on factors affecting the hatching of fertile Creole chicken eggs in backyard flocks. Findings/conclusions: Infection by fungi and bacteria increase embryonic mortality, while omphalitis increases mortality during the first days of life of the backyard Creole chickens. High storage temperature in the nest or incubator causes embryo dehydration.

Assessment of the toxicity effects of nicotine on sperm and IVF and the potential protective role of silymarin\u2014an experimental study in mice

BackgroundMale infertility is usually caused via the inability to produce adequate quantities of healthy and active sperms. Nicotine (NIC) is an alkaloid organic compound, predominantly found in the leaves of the tobacco plant. The major part of the nicotine is not ionized, so it can easily pass through cell membranes. Meanwhile, most of the disorders are caused by oxidative stress due to oxygen free radicals and other reactive species. Antioxidant supplements and antioxidant-rich foods can reduce induced oxidative stress without becoming destabilized themselves. This study aimed to examine spermato-protective potential of silymarin (SIL), on sperm and in vitro fertility (IVF) rate in nicotine-treated mice.ResultsOur results show a significant increase in the number of abnormal sperm morphology after nicotine exposure, when compared to control groups (p < 0.05). On the other hand, SIL had a significant effect on the sperm count at each of the treated doses. Further, in the mice that received nicotine plus silymarin, the viable sperm percentage and the progressive sperm motility were significant (p < 0.05). Also, a significant reduction in the number of two-cell embryos and blastocyst-derived embryo was seen with increment in the number of dead embryos in mice receiving nicotine alone (p < 0.05).ConclusionsIn conclusion, SIL could support prevention of the adverse reproductive effects of nicotine. Moreover, SIL200 mg/kg may be therefore considered as a spermato-protective agent in dietary and herbal supplements.

Acute Toxicity of Imidacloprid on the Developmental Stages of Common Carp Cyprinus carpio

The objective of the present study was to elucidate the toxic effects of imidacloprid on the embryonic and larval stages of common carp (Cyprinus carpio). Each of the 1000 fertilized eggs and larvae were exposed to six different concentrations (0, 10, 30, 100, 300, and 1000 µg/L) of imidacloprid in 30 plastic bowls. Each of the control and treatment was maintained in five replicates. Results showed that hatching rate of fertilized eggs and number of dead embryos and larvae significantly decreased with increasing imidacloprid concentrations. The 24-, 48-, and 72-h LC50 value of imidacloprid for common carp embryos were estimated to be 12,708.8, 611, and 274.9 µg/L, respectively and the 24-, 48-, 72-, and 96-h LC50 of imidacloprid for common carp larvae were estimated to be 93719, 21691, 2352.7, and 1292.6 µg/L, respectively. Furthermore, results showed several malformations of common carp embryos and larvae induced by the toxicity of imidacloprid when exposed to 300 and 1000 µg/L. The results suggest that the minimum concentration of 10 µg/L imidacloprid in the aquatic environment may have adverse effects on the embryonic and larval stages of common carp.

Защита сперматогенеза β-каротином при радиационных воздействиях. Сообщение 2: обогащение каротиноидом рациона при однократном остром внешнем γ-облучении

Purpose: Experimental evaluation of the efficiency of β-carotene by single acute γ-irradiation of spermatogenesis correction radiation-induced disorders in males (♂) of Wistar rats during prolonged carotenoid enrichment of a diet. Material and methods: Single external gamma irradiation ♂ was performed at the IGUR facility (137Cs, dose rate 0.029 Gy/s). The carotenoid used up on feeding ♂ in a mixture with cottage cheese for 2 months before irradiation, then – throughout the study period three times a week. During the days that ♂ were in cells with intact ♀ β-carotene was administered ♂ orally by a probe in the form of a suspension in vegetable oil. The damage and effectiveness of protection of spermatogenesis of irradiated ♂ were judged by the state of their reproductive function. Results: β-carotene in intact ♂ rats reduced the overall, pre- and postimplantation embryonic mortality, respectively, from 29 to 14, from 22 to 9, and from 10 to 5 %. At the stage of mature sperm following irradiation ♂ dose of 3 Gy – total and pre-implantation mortality from 45 to 29, and from 23 to 9 %. After irradiation at a dose of 5 Gy – total, an pre- and postimplantation induced embryonic death, respectively, from 67 to 56, from 23 to 13 % and from 56 to 43 %. At the stage of spermatids after irradiation in dose 1 Gy – pre-implantation mortality from 23 to 9 %; in the dose of 3 Gy – the number of dead embryos in pregnant ♀ from 12 to 3; at a dose of 5 Gy total embryonic mortality from 57 to 49 %. Carotenoid enrichment of a diet of ♂ irradiated at doses of 3 and 5 Gy, has not corrective impact on the state indicators of their reproductive function, evaluated at fertilization of ♀ sperm irradiated at the stage of spermatocyte. At the stage of spermatogonia after irradiation at a dose of 3 Gy β-carotene increased fertility of ♂ 7 to 12 living embryos and reduced the overall, before – induced postimplantation mortality, respectively, with 63 and 43, from 42 to 25 and from 35 to 19 %. No statistically significant effect of β-carotene on the weight loss of the gonads irradiated ♂ was revealed. Compared to short-term regimen, long-term enrichment of a diet of irradiated ♂ β-carotene more effectively reduced embryonic mortality of their offspring. Conclusions: Correction effects of β-carotene enrichment of the diet in radiation-induced disturbances by single acute external γ-irradiation at doses of 3 and 5 Gy of spermatogenesis in Wistar rats at stages of mature spermatozoa, spermatids and spermatogonia have been established.

Biological effects of cell-phone radiofrequency waves exposure on fertilization in mice; an in vivo and in vitro study

Abstract Increasing use of cell-phone is one of the most important risk factors for population health. We designed an experimental study aimed at evaluating the effects of cell-phone radiofrequency (RF) waves exposure on fertilization in mice. Two hundred male and female NMRI-mice were used. One hundred males divided in five groups (n = 20) as control and exposed groups. Those irradiated with cell-phone RF in “Standby-mode” 1, 5 and 10 h daily named groups II, III and IV; respectively. Group V irradiated with cell-phone on “Active-mode” one hour daily. After 30 days irradiation, 50 males and 50 females were kept 24 h to assess their embryos. Fifty males were scarified to evaluate both in vitro and in vivo parameters, and 50 females received PMSG & HCG for both quantitative and qualitative evaluation. Comparing groups III, IV and V with control-group showed significantly decreased in the number of two-cell embryos (p = .000); however, a significant increase was found in the number of dead embryos (p = .000). Furthermore, 5 h daily irradiation significantly decreased grade-A embryos (p = .015); while, it significantly increased grade-B, C and D embryos (p-values = 0.026, 0.007, 0.006; respectively). Moreover, comparing groups IV and V to control-group, significant increase was found in pregnancy duration (p = .005, p = .009; respectively). However, in the mentioned groups a significant decrease was seen in number of newborn mice (p = .001, p = .004; respectively). In conclusion our findings showed that the cell-phone radiation can affect development of embryos as well as the number of newborn and pregnancy duration in NMRI-mouse, which might be a significant cause of reproductive failure.

Changes of Eggshell Characteristics during Embryo Development in Western Capercaillie (Tetrao Urogallus)

The influence of a developing bird embryo on eggshell thinning is well known, however this phenomenon has been described mainly for poultry, and in wild birds is poorly understood. This study focussed on Capercaillie ( Tetrao urogallus), in which the effect of a developing embryo on the change of eggshell thickness has not been described. However, problems relating to a large number of dead embryos and eggs cracking during incubation are observed in captive breeding centres giving us the opportunity to test how the developing embryo affects the eggshell and thereby its properties, including eggshell strength and thickness. In total, 196 unhatched eggs, including 146 infertile and 50 eggs with embryos which died at various stages of development, were analysed in relation to eggshell shape, thickness and strength. Moreover, 102 posthatched eggshells were also examined. Although the strength of eggshell was affected by egg shape and shell thickness, contrary to expectations, the stage of embryonic development had no significant influence on eggshell strength. As has been demonstrated in other species, etching of eggshells by the developing embryo reduces shell thickness in Capercaillie but it has minimal effect on the strength of the eggshell. Egg viability is not compromised during the later stages of development by contact incubation with the female. The eggshell of infertile eggs or eggs containing early-dead embryos were 10% thicker than posthatched eggshells and eggs with late-dead embryos, confirming that eggshell thinning in Capercaillie is typical for precocial species.

Inhibition of in vitro gamete adhesion and in vivo fertility in mice by immunization with a synthetic peptide

Problem: To evaluate the contraceptive ability of a synthetic peptide in in vitro and in vivo fertility in the mouse. Method of study: A synthetic peptide segment: GELRERAPGQGTNG (SP) was used to immunize female B6CF1 (C57BL/6 × BALB/c) mice. A peptide with an amino acid sequence QQPLSIQQHERG (p2control) was used as control. Anti-SP and anti-p2control antisera were used to evaluate sperm function inhibition in vitro. Fertility of immunized mice was determined by microscopic evaluation of the number and state of preimplantation embryos (8–16 cell stage). Results: In the mouse, anti-SP antisera recognized surface antigens in the acrosome region of mature and capacitated sperm. Anti-SP antisera inhibited in vitro sperm binding to zona pellucida. In vivo, immune response against SP in Freund's adjuvant resulted in a significant increase ( P < 0.01) in the number of dead embryos and eggs (a mean of 66%, in contrast with <25% in control mice). Fertility inhibition in vivo and in vitro was not observed when the p2control peptide was used in the immunizations. Conclusions: These results would suggest that the SP sequence is involved in gamete adhesion, and an antifertility vaccine against the SP peptide segment could be feasible.

Percutaneous Retinoid Absorption and Embryotoxicity

A single application of 17 micrograms/kg or 8.7 mg/kg all-trans-[10,11-3H2]-retinoic acid dissolved in acetone to shaved dorsal hamster skin resulted in rapid absorption and dose-dependent rates of elimination. An equation describing a two-compartment open model with a very brief lag time and first-order uptake and elimination was used to describe the central plasma compartment kinetics. Unchanged all-trans-retinoic acid represented less than or equal to 4% of the total circulating radio-activity. Peak circulating concentrations of parent all-trans-retinoic acid were less than those observed after an equivalent oral dose, but prolonged absorption from the skin appears to contribute to high total bioavailability of topical retinoid. Topical administration to intact skin of up to three consecutive doses of 10.5 mg/kg/d all-trans-retinoic acid or a single 5 mg/kg dose of etretinate (Ro 10-9359) during a critical stage of embryogenesis in hamsters caused erythema and/or dose-dependent epidermal hyperplasia at the site of application, but failed to induce a significant teratogenic response. Topical application of 0.01-1.0 mg/kg arotinoid Ro 13-6298 resulted in dose-dependent mucocutaneous toxicity and an increase in the numbers of dead embryos and malformed offspring. The marked skin toxicity and attenuated concentrations in maternal blood, compared to the oral route, limit the amounts of retinoid that can reach the hamster embryo. It is thus more important to compare the retinoid systemic values (absorbed dose) than it is to compare the oral or topical (applied) dose, when interpreting the results of conventional teratogenicity bioassays. The data suggest that in the human it is skin toxicity that limits the amounts of retinoid that can be applied and subsequently reach the embryo. In the rodent, overt skin toxicity under continued dosing could increase the amounts of retinoid penetrating the skin and reaching the embryo.

Use of the chick embryo for pharmacological screening of retinoids.

Retinoic acid and some selected analogs were tested to evaluate their effect on skin morphogenesis and toxicity in the chick embryo. Retinoids dissolved in dimethyl sulfoxide were injected at doses varying from 10 pmol to 10 mumol into the amniotic cavity of 10-day-old chick embryos (n = 20). At 16 days of incubation, the eggs were opened to record the number of dead embryos and the number of embryos presenting club-shaped feathers. A lethal embryotoxic dose (LED50d16) which, at 16 days of incubation, provokes the death of 50% of the embryos and an effective dose (ED50) which induces production of club-shaped feathers in 50% of surviving embryos were then calculated using log-probit analysis. Retinoids could be classified according to their ED50. For example, arotinoid Ro 13-7410 appears approximately 1,000 times more active than all transretinoic acid. However, the analogs which are more active are also more toxic. The assay described in the present study appears to be a simple and useful model for the screening of retinoids.

Dietary deprivation induces fetal loss and abortion in rabbits

We assessed the effects of a pared diet (20, 60 or 150 g/day for days 6–20 after coitus) on the course of pregnancy in rabbits. Dams receiving 20 g/day manifested a marked weight loss, 5 of 6 animals aborted and in the remaining dam, the litter size, fetal and placental weight were significantly lower than in the controls. In the 60 g/day group, the maternal body weight remained stable throughout the observation period; the number of dead embryos on fetuses was significantly higher, that of live fetuses lower, than in the controls. Feedings on the 150 g/day group did not markedly differ from the controls, indicating that pregnant rabbits require at least 150 g of food/day.

Influence of prostaglandin F 2α on the development of the chick embryo: morphological and biochemical aspects

Summary Fertile eggs were incubated for 48, 72 or 96 hours. Experimental eggs were treated with 10, 40 or 100 μg PGF 2α in 10 μl of saline while controls received either the saline alone or were left unopened. All embryos were recovered at day 9 of incubation. The number of dead embryos were noted, and all living embryos were staged for growth and examined for external malformations. Treatment of the embryos with the prostaglandin did not significantly affect their development. A small number of embryos incubated for 96 hours and treated with 40 μg PGF 2α , received 50 μd of 3 H-thymidine or 3 H-proline at periods of 3, 6 or 24 hours following exposure to the prostaglandin. The uptake of the radiolabelled precursors, as well as the total protein content, was significantly reduced in the treated embryos compared to the corresponding controls.

Delayed Hatching Time of Chicks from Dams Fed Excess Vitamin A and from Eggs Injected with Vitamin A

A high level of vitamin A fed to laying chickens depressed the rate of egg production, egg size and hatchability. Average incubation time of chicks was prolonged when the dams were fed 210,000 I.U. of vitamin per kg. of diet. After feeding this level of vitamin A for 11 months eggs laid contained an average of 2,080 I.U. of vitamin A. Eggs laid by control birds receiving 10,000 I.U. of vitamin A per kg. of diet contained an average of 370 I.U. of vitamin A. Vitamin A alcohol, injected into eggs prior to incubation at a level of 1,070 I.U. per egg, depressed hatchability markedly, whereas injection of 8,000 I.U. of vitamin A palmitate had little effect. Developmental abnormalities were noted in a number of dead embryos from vitamin A-injected eggs and haemorrhaging appeared to be a frequent cause of embryonic death. Injection of either form of the vitamin prolonged incubation time.

Effects of treatment with hypervitaminosis A in pregnant mice : 1.Number of dead embryos, survival rate and body weight of live fetuses

Effects of treatment with hypervitaminosis A in pregnant mice : 1.Number of dead embryos, survival rate and body weight of live fetuses