Change of Embryotoxic Effects of Metal Citrates Depending on the Duration of Their Introduction

Given the increase in cadmium in the environment (air, soil, water) through modern industrial processes, the absorption of significant amounts from cigarette smoke is relevant to studying the effect of cadmium compounds on embryogenesis. The purpose of the study: experimental study and comparison of embryolethality and embryotoxicity of metal citrates depending on the duration of their intragastric administration (during 13 and 20 days of gestation). Materials and methods. The study was performed on 120 white adult female Wistar rats that weigh 170-200 g. They were divided into 6 groups due to the intragastric administration of solutions of the studied metals – rats treated with citrates: cadmium at a dose of 1.0 mg/kg – 1st group (nfemale = 20, nemb = 166); cadmium at a dose of 1.0 mg/kg and cerium (1.3 mg/kg) – 2nd group (nfemale = 20, nemb = 185); cadmium in a dose of 1.0 mg/kg and germanium (0.1 mg/kg) – 3rd group (nfemale = 20, nemb = 184); cadmium at a dose of 1.0 mg/kg and zinc (1.5 mg/kg) – 4th group (nfemale = 20, nemb = 179); cadmium at a dose of 1.0 mg/kg and nanocomposite (iodine + sulfur + selenium) at a dose of 2.0 mg/kg – 5th group (nfemale = 20, nemb = 180), 6th group – control (nfemale = 20, nemb = 212) – proportional volume of sterile saline in the same way. Females were divided into 2 subgroups of 10 animals each, depending on the duration of administration of test substances. The embryotoxic and embryolethal effects of the test substances were evaluated according to generally accepted criteria, which were calculated according to well-known formulas. Results and discussion. Cadmium compounds harm the embryogenesis of rats in the experimental groups and increase the rates of embryolethality. The most pronounced differences in these parameters concerning the control were found in animals with isolated exposure to cadmium citrate: the rates of total embryonic mortality increased by 4.0 times in both study periods of embryogenesis and 20% from the 13th to the 20th day; increased pre-implantation mortality by 6.0 times with an increase in post-implantation mortality by 3 times on the 13th day and by 15.0 times and 2.8 times on the 20th day of embryogenesis, respectively. Depending on the duration of introduction, the indicators of pre-implantation mortality increased by 25.0% with an increase in post-implantation mortality by 22.2% in the same period. The experimental group of exposure to cadmium citrate at a dose of 1.0 mg/kg recorded the lowest indicators of the number of live fetuses and intrauterine survival with the highest resorption rate studied of embryonic development. At the same time, in the groups of combined exposure to cadmium citrate with metal citrates, a decrease in the indicators of total embryonic mortality was 50.0% - 30.0%, pre-implantation mortality – 50.0% - 25.0%, post-implantation mortality – 60.0% - 44.4 % and increase in the number of fetuses per female – 12.7% - 25.3%. Conclusion. Analysis of the results shows a pronounced embryotoxic effect of cadmium citrate at a dose of 1.0 mg/kg on the processes of embryogenesis, which is a significant increase in overall embryonic mortality, preimplantation, and postimplantation mortality compared with the control group in all studied terms. In the groups of combined action of cadmium citrate with metal citrates, the data obtained indicate a decrease in the accumulation of cadmium under the influence of the studied citrates, which allows them to be considered as potential bioantagonists of cadmium citrate

Effects of Environmental Stressors on the Early Development of Intertidal and Subtidal Gastropod Embryos

<p>Salinity, temperature and ultraviolet-B (UV-B) radiation are common environmental stressors in coastal habitats. These stressors are likely to increase in intensity due to the effects of climate change and can have important impacts on population and community dynamics for early development in gastropods that deposit egg masses on rocky shores. The aim of this study was to identify the effects of single and multiple stressors on the development of intertidal and shallow subtidal gastropods with encapsulated embryos. In manipulative experiments I exposed egg masses of the gastropod species Siphonaria australis, Ercolania felina, Pleurobranchaea maculata, Aplysia juliana and Doris wellingtonensis to realistic levels of either salinity, temperature or UV-B radiation, or to a combination of stressors, for different lengths of time. Embryos were then subjected to the most stressful levels of each stressor at either early or late stages of development and at different days of embryonic development. Further, egg masses were exposed to sublethal salinity, temperature and UV-B radiation stress simultaneously, simulating tide pool conditions on a warm sunny summer day. Larvae hatching from stressed and unstressed egg masses were subsequently periodically subjected to increased temperature and UV-B radiation and examined over 10 days to detect possible carry-over effects of exposure to stress in the egg mass. The results revealed that for individual stressors, low salinity (20‰), high temperature (25°C) and high UV-B (1.7 W m ⁻ ² s ⁻ ¹, i.e. a level similar to a sunny NZ summer day) all caused the highest embryonic mortality. The response to stressors was species-specific but overall the intertidal species had lower embryonic mortality than the subtidal species. Generally, chronic exposure had higher impacts on the development of embryos than periodic exposure and early embryonic development stages were most vulnerable to stress. UV-B radiation had particularly damaging effects on embryonic and larval stages for the intertidal pulmonate limpet Siphonaria australis. Further, multiple stressors had synergistic effects and caused high embryonic mortality in the egg mass as well as impacting on the vulnerability of larvae to stressors. This study revealed that stress experienced during embryonic stages can result in sub-lethal damage that increases vulnerability to temperature and decreases vulnerability to UV-B radiation experienced in the larval stage. In total, my results suggest that (1) the effects of different environmental stressors on early development of intertidal and subtidal gastropods are complex and depend on the intensity, duration and time of stress, and are generally species-specific; (2) multiple stressors can act synergistically to affect early development and (3) sublethal exposure to stress in the egg mass can have negative carry-over effects on later larval stages.</p>

Effects of Environmental Stressors on the Early Development of Intertidal and Subtidal Gastropod Embryos

<p>Salinity, temperature and ultraviolet-B (UV-B) radiation are common environmental stressors in coastal habitats. These stressors are likely to increase in intensity due to the effects of climate change and can have important impacts on population and community dynamics for early development in gastropods that deposit egg masses on rocky shores. The aim of this study was to identify the effects of single and multiple stressors on the development of intertidal and shallow subtidal gastropods with encapsulated embryos. In manipulative experiments I exposed egg masses of the gastropod species Siphonaria australis, Ercolania felina, Pleurobranchaea maculata, Aplysia juliana and Doris wellingtonensis to realistic levels of either salinity, temperature or UV-B radiation, or to a combination of stressors, for different lengths of time. Embryos were then subjected to the most stressful levels of each stressor at either early or late stages of development and at different days of embryonic development. Further, egg masses were exposed to sublethal salinity, temperature and UV-B radiation stress simultaneously, simulating tide pool conditions on a warm sunny summer day. Larvae hatching from stressed and unstressed egg masses were subsequently periodically subjected to increased temperature and UV-B radiation and examined over 10 days to detect possible carry-over effects of exposure to stress in the egg mass. The results revealed that for individual stressors, low salinity (20‰), high temperature (25°C) and high UV-B (1.7 W m ⁻ ² s ⁻ ¹, i.e. a level similar to a sunny NZ summer day) all caused the highest embryonic mortality. The response to stressors was species-specific but overall the intertidal species had lower embryonic mortality than the subtidal species. Generally, chronic exposure had higher impacts on the development of embryos than periodic exposure and early embryonic development stages were most vulnerable to stress. UV-B radiation had particularly damaging effects on embryonic and larval stages for the intertidal pulmonate limpet Siphonaria australis. Further, multiple stressors had synergistic effects and caused high embryonic mortality in the egg mass as well as impacting on the vulnerability of larvae to stressors. This study revealed that stress experienced during embryonic stages can result in sub-lethal damage that increases vulnerability to temperature and decreases vulnerability to UV-B radiation experienced in the larval stage. In total, my results suggest that (1) the effects of different environmental stressors on early development of intertidal and subtidal gastropods are complex and depend on the intensity, duration and time of stress, and are generally species-specific; (2) multiple stressors can act synergistically to affect early development and (3) sublethal exposure to stress in the egg mass can have negative carry-over effects on later larval stages.</p>

Effects of Ultraviolet Radiation (UVR) and Other Environmental Stressors on the Development of Intertital Mollusc Embryos

<p>Ozone depletion is a humaninduced global phenomenon that allows increased ultraviolet radiation (UVR) to the Earth's surface. Although UVR is known to be harmful, relatively little is known about how increased UVR impacts natural ecosystems. Ecosystems in New Zealand are particularly at risk, because ozone depletion is much greater here, with levels of biologically harmful UVR up to two times greater than in northern latitudes. In the intertidal environment, potentially negative abiotic stressors are associated with low tide; and organisms inhabiting this environment are particularly vulnerable to UVR. Furthermore, embryos and larvae deposited in this habitat are especially susceptible to these stressors. The aim of this study is to identify the effect of UVR and other environmental stressors on the development of mollusc embryos in New Zealand. Surveys of microhabitats in which egg mass deposition occurs, and what effect this site of deposition has on the survivorship of embryos, revealed that encapsulated embryos of the two common pulmonate limpets Benhamina obliquata and Siphonaria australis are highly vulnerable to the environmental stressors associated with different microhabitats. In particular, egg masses deposited in the sun for both species suffered high mortality. Although, B. obliquata is more susceptible to UVR damage than is S. australis, B. obliquata predominantly deposits egg masses in dry shaded microhabitats while S. australis deposits the majority of its offspring in sunny tidal pools, which surprisingly equated to highest embryonic mortality. Results of manipulative experiments reflected those found in the surveys: egg masses exposed to full spectrum light incurred the greatest embryonic mortality; additionally environmental stressors (e.g. tidal pool conditions and desiccation) synergistically enhanced this mortality. UVR in North America is significantly lower compared to New Zealand; this allowed a unique opportunity to use identical methods to examine the responses of ecologically similar, related species (bubble shell snails in the genus Haminoea), from two regions where UVR naturally differs. Results from surveys and manipulative experiments revealed that the New Zealand species Haminoea zelandiae suffered high embryonic mortality under full spectrum light and this mortality was enhanced by periods of desiccation. The North American species Haminoea vesicula also suffered significant mortality during periods of desiccation, but there were no signs of UVR damage. These results appear to be driven by speciesspecific vulnerability to these stressors and not to ambient UVR intensity in the regions at the time of study. Relative concentrations of the chemical sunscreen compounds, mycosporinelike amino acids (MAAs), varied depending on several factors, but the biggest differences were among species. Analyses revealed that B. obliquata had the highest concentration of MAAs despite suffering high embryonic mortality when exposed to direct sunlight. MAA concentrations in S. australis were intermediate, with H. zelandiae having the lowest concentrations of all three species. MAA concentration for B. obliquata was dependent on stage of development and initial sun exposure at egg mass deposition site, suggesting interactions between MAAs, environmental conditions and embryonic development that need to be further explored. MAA concentrations were higher in S.australis egg masses deposited in spring compared to those deposited in early autumn, which may be driven by a shift in diet or nutrient levels. MAA concentrations did not appear to be correlated with ambient levels of UVR or embryonic survival in S.australis. However, MAA concentrations were related to UV irradiance in both Haminoea species with higher MAA concentrations observed in egg masses initially deposited in the sun compared to those found in the shade. Combined these results suggest: (1) increased UVR due to ozone depletion together with increases in temperatures due to climate change are likely to have strong impacts on the early life stages of these species, unless behavioural and physiological adaptations occur; (2) New Zealand species may be at particularly high risk from UVR damage compared to those from the Northern hemisphere; (3) the role of MAAs as photo-protection in these mollusc species is likely to be species specific, with a variety of abiotic and biotic factors influencing their uptake and sequestration. These experiments in part demonstrate how New Zealand's mollusc species are responding to humaninduced changes in UVR levels.</p>

Effects of Ultraviolet Radiation (UVR) and Other Environmental Stressors on the Development of Intertital Mollusc Embryos

<p>Ozone depletion is a humaninduced global phenomenon that allows increased ultraviolet radiation (UVR) to the Earth's surface. Although UVR is known to be harmful, relatively little is known about how increased UVR impacts natural ecosystems. Ecosystems in New Zealand are particularly at risk, because ozone depletion is much greater here, with levels of biologically harmful UVR up to two times greater than in northern latitudes. In the intertidal environment, potentially negative abiotic stressors are associated with low tide; and organisms inhabiting this environment are particularly vulnerable to UVR. Furthermore, embryos and larvae deposited in this habitat are especially susceptible to these stressors. The aim of this study is to identify the effect of UVR and other environmental stressors on the development of mollusc embryos in New Zealand. Surveys of microhabitats in which egg mass deposition occurs, and what effect this site of deposition has on the survivorship of embryos, revealed that encapsulated embryos of the two common pulmonate limpets Benhamina obliquata and Siphonaria australis are highly vulnerable to the environmental stressors associated with different microhabitats. In particular, egg masses deposited in the sun for both species suffered high mortality. Although, B. obliquata is more susceptible to UVR damage than is S. australis, B. obliquata predominantly deposits egg masses in dry shaded microhabitats while S. australis deposits the majority of its offspring in sunny tidal pools, which surprisingly equated to highest embryonic mortality. Results of manipulative experiments reflected those found in the surveys: egg masses exposed to full spectrum light incurred the greatest embryonic mortality; additionally environmental stressors (e.g. tidal pool conditions and desiccation) synergistically enhanced this mortality. UVR in North America is significantly lower compared to New Zealand; this allowed a unique opportunity to use identical methods to examine the responses of ecologically similar, related species (bubble shell snails in the genus Haminoea), from two regions where UVR naturally differs. Results from surveys and manipulative experiments revealed that the New Zealand species Haminoea zelandiae suffered high embryonic mortality under full spectrum light and this mortality was enhanced by periods of desiccation. The North American species Haminoea vesicula also suffered significant mortality during periods of desiccation, but there were no signs of UVR damage. These results appear to be driven by speciesspecific vulnerability to these stressors and not to ambient UVR intensity in the regions at the time of study. Relative concentrations of the chemical sunscreen compounds, mycosporinelike amino acids (MAAs), varied depending on several factors, but the biggest differences were among species. Analyses revealed that B. obliquata had the highest concentration of MAAs despite suffering high embryonic mortality when exposed to direct sunlight. MAA concentrations in S. australis were intermediate, with H. zelandiae having the lowest concentrations of all three species. MAA concentration for B. obliquata was dependent on stage of development and initial sun exposure at egg mass deposition site, suggesting interactions between MAAs, environmental conditions and embryonic development that need to be further explored. MAA concentrations were higher in S.australis egg masses deposited in spring compared to those deposited in early autumn, which may be driven by a shift in diet or nutrient levels. MAA concentrations did not appear to be correlated with ambient levels of UVR or embryonic survival in S.australis. However, MAA concentrations were related to UV irradiance in both Haminoea species with higher MAA concentrations observed in egg masses initially deposited in the sun compared to those found in the shade. Combined these results suggest: (1) increased UVR due to ozone depletion together with increases in temperatures due to climate change are likely to have strong impacts on the early life stages of these species, unless behavioural and physiological adaptations occur; (2) New Zealand species may be at particularly high risk from UVR damage compared to those from the Northern hemisphere; (3) the role of MAAs as photo-protection in these mollusc species is likely to be species specific, with a variety of abiotic and biotic factors influencing their uptake and sequestration. These experiments in part demonstrate how New Zealand's mollusc species are responding to humaninduced changes in UVR levels.</p>

Direct and Latent Effects of Pathogen Exposure Across Native and Invasive Amphibian Life Stages

Emerging infectious diseases are one of the multiple factors contributing to the current “biodiversity crisis”. As part of the worldwide biodiversity crisis, amphibian populations are declining globally. Chytridiomycosis, an emerging infectious disease, caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), is a major cause of amphibian population declines. This fungus primarily affects keratinized structures in larval, juvenile, and adult amphibians as well as heart function. However, we know little about how Bd can impact embryos as well as potential latent effects of Bd exposure over ontogeny. Using two different Bd strains and multiple exposure times, we examined the effects of Bd exposure in Pacific chorus frog (Pseudacris regilla), Western toad (Anaxyrus boreas) and American bullfrog (Lithobates catesbeianus) life stages. Using a factorial experimental design, embryos of these three species were exposed to Bd at early and late embryonic stages, with some individuals re-exposed after hatching. Embryonic Bd exposure resulted in differential survival as a function of host species, Bd strain and timing of exposure. P. regilla experienced embryonic mortality when exposed during later developmental stages to one Bd strain. There were no differences across the treatments in embryonic mortality of A. boreas and embryonic mortality of L. catesbeianus occurred in all Bd exposure treatments. We detected latent effects in A. boreas and L. catesbeianus larvae, as mortality increased when individuals had been exposed to any of the Bd strains during the embryonic stage. We also detected direct effects on larval mortality in all three anuran species as a function of Bd strain, and when individuals were double exposed (late in the embryonic stage and again as larvae). Our results suggest that exposure to Bd can directly affect embryo survival and has direct and latent effects on larvae survival of both native and invasive species. However, these impacts were highly context dependent, with timing of exposure and Bd strain influencing the severity of the effects.

Experimental Estimation of Embryotoxic Risks of Cadmium Chloride with Isolated Administration and in Combination with Salts of Citrate and Nanocomposite on its Basis

Cadmium compounds that enter living organisms pose the potential for serious health effects as they exhibit mutagenic, carcinogenic, gonadotoxic, teratogenic, allergenic and embryotoxic effects. It is important to study the mechanisms of their toxic effect on embryonic development and structural and functional formation of organs of living organisms and to search for their bioantogonists. The purpose of the study was to highlight the results of intragastric administration of cadmium chloride (1.0 mg/kg) with isolated administration and in combination with metal citrates (cerium, germanium, zinc, and nanocomposite (iodine + sulfur + selenium citrates)) on the overall course of rat embryogenesis. Materials and methods. For the study, young female Wistar rats weighing 170-200 g were used. They were divided into 6 groups, depending on the test substances, which they received from the 1st to the 19th day of gestation. Results and discussion. The analysis of the results of the experimental study showed the negative effect of cadmium chloride on the analyzed indicators of embryogenesis (preimplantation mortality, postimplantation mortality, total embryonic mortality), indicators of intrauterine survival, morphological (anatomical) malformations, as well as general delay in fetal development), both on the 13th and 20th days of pregnancy relative to the control group. In particular, the indicators of total embryonic mortality significantly increased by 4.2 times (13th day) and 3.7 times (20th day), with significant increase preimplantation mortality by 6.5 times, postimplantation mortality by 3.0 times on the 13th day of embryonic development, and on the 20th day, the preimplantation mortality indicator was by 14.0 times higher (p <0.01), and the postimplantation mortality indicator was insignificantly by 2.5 times higher than the control group. In the groups of the combined effect of cadmium chloride with metal citrates, there was a proven decrease in the indicators of total embryonic mortality (18.18% - 38.10%), preimplantation mortality (21.43% - 53.85%), postimplantation mortality (20.0% - 66.7%), an increase in the number of fetuses per female (12.66% -36.0%). Conclusion. In groups of the combined effect of cadmium chloride with metal citrates, the obtained data indicate a decrease in the accumulation of cadmium under the influence of the studied citrates, which allows them to be considered as potential bioantagonists of cadmium chloride

PENGARUH PENGGUNAAN EKSTRAK DAUN JAMBU BIJI (Psidium guajava L.) TERHADAP MORTALITAS EMBRIO, DAYA TETAS, DAN SALEABLE ITIK HIBRIDA

This study aimed to determine the effect of immersion of hybrid duck eggs using guava leaf extract at different concentrations on embryo mortality, hatchability, and saleable duck. The research was conducted in March - April 2020. Guava leaf extract was made at the Animal Production and Reproduction Laboratory, Department of Animal Husbandry, Faculty of Agriculture, University of Lampung. The dyeing and hatching treatments were carried out in Hajimena Village, Natar District, South Lampung. This study used a completely randomized design (CRD) with four treatments, namely without immersing guava leaf extract (P0), immersing with guava leaf extract concentrations of 10% (P1), 20% (P2), and 30% (P3). The results showed that the percentage of embryo mortality without dyeing and immersing guava leaf extract concentrations of 10, 20, and 30% were 40.00%, 24.00%, 16.00%, and 28.00%, respectively. Hatchability of hybrid duck eggs in the treatment without immersion and immersion in guava leaf extract concentrations of 10, 20, and 30% were 60.00, 76.00, 84.00, and 72%, respectively. Saleable duck duck eggs without immersion 93.34% and immersion in guava leaf extract with concentrations of 10, 20, and 30% respectively were 100.00%. It was concluded that immersion of hybrid duck eggs using guava leaf extract at concentrations of 10.00, 20.00, and 30.00% decreased the percentage of mortality, increased hatchability, and increased the salable duck. Keywords: Hybrid duck, Guava leaves extract, Embryonic mortality, Hatchability, Saleable duck

​Color Doppler Ultrasonographic Characteristics of Embryonic Development and Mortality in Dairy Cows

Background: Embryonic mortality is one of the major factors leading to reproductive failure, decreased fertility and delayed pregnancy in cattle. Method: The study was aimed for investigating the incidence of embryonic mortality(EM), differentiate embryonic development and mortality based on color Doppler ultrasonographic characteristics. Different characteristics correlated were corpus luteum(CL) vascularity, embryonic development and EM features, monitored on day 21 post-insemination. Result: The overall incidence of EM was recorded to be 25%, with 15% and 10% mortality occurred between days 21-28 and 28-35 of gestation. Color Doppler analysis stated that, the CL in pregnant cows had a higher percentage of luteal tissue with positive Doppler signals on initial examination (day 21) differing significantly (P less than 0.01) from non-pregnant and consistently increased till the end of the examination. However, cows with EM had a significantly lower CL vascularity than pregnant (P less than 0.05) but significantly higher (P less than 0.05) than non-pregnant cows on day 21. Embryos from pregnant cows (detected by 28 days) increased in size along the days of examination. However, cows diagnosed with EM showed signs (day 28), which included reduced intra-uterine allantoic fluid, absence of embryo proper with an embryonic heartbeat, hyperechoic free-floating embryonic debris in the uterus and distorted allanto-chorionic membrane. In conclusion, the present study firmly supports color Doppler ultrasonography in diagnosis of pregnant cows based on CL vascularity, visualizing the different characteristics signs of EM, and detecting non-pregnant animals undergoing EM as early as day 21.