Hatchability Of Fertile Eggs Research Articles

Polystyrene Nanoplastic Exposure Induces Developmental Toxicity by Activating the Oxidative Stress Response and Base Excision Repair Pathway in Zebrafish (Danio rerio).

The widespread accumulation of nanoplastics is a growing concern for the environmental and human health. However, studies on the mechanisms of nanoplastic-induced developmental toxicity are still limited. Here, we systematically investigated the potential biological roles of nanoplastic exposure in zebrafish during the early developmental stage. The zebrafish embryos were subjected to exposure to 100 nm polystyrene nanoplastics with different concentrations (0, 100, 200, and 400 mg/L). The results indicated that nanoplastic exposure could decrease the hatching and survival rates of zebrafish embryos. In addition, the developmental toxicity test indicated that nanoplastic exposure exhibits developmental toxicity via the inhibition of the heart rate and body length in zebrafish embryos. Besides, behavioral activity was also significantly suppressed after 96 h of nanoplastic exposure in zebrafish larvae. Further biochemical assays revealed that nanoplastic-induced activation of the oxidative stress responses, including reactive oxygen species accumulation and enhanced superoxide dismutase and catalase activities, might affect developmental toxicity in zebrafish embryos. Furthermore, a quantitative polymerase chain reaction assay demonstrated that the mRNA levels of the base excision repair (BER) pathway-related genes, including lig1, lig3, polb, parp1, pold, fen1, nthl1, apex, xrcc1, and ogg1, were altered in zebrafish embryos for 24 h after nanoplastic exposure, indicating that the activation of the BER pathway would be stimulated after nanoplastic exposure in zebrafish embryos. Therefore, our findings illustrated that nanoplastics could induce developmental toxicity through activation of the oxidative stress response and BER pathways in zebrafish.

SUPLEMENTACIÓN DE OXÍGENO EN LA INCUBACIÓN DE HUEVOS FÉRTILES DE GALLINA CRIOLLA

This study evaluated the effect of oxygen supplementation on the hatchability of fertile eggs of the Creole hen at 2718 meter above sea level. The experiment was carried out with 1408 hatching eggs obtained at age different of the breeders (25, 30, 34 and 38 wks.). Eggs were assigned to four incubators with different periods of oxygen supplementation: treatment without oxygen supplementation (SS) and oxygen supplementations at week 1, week 3, and weeks 1 and 3. Body weight, hematocrit, and hemoglobin were determined of embryos of 18 days incubation and newborn chicks. Hatching percentage was calculated based on the number of fertile eggs. Early and late embryonic mortality was determined. From the fertile eggs supplemented with oxygen during the first and third weeks, a higher percentage of hatched chicks (82.60%) and lower embryonic mortality were obtained. In the group SS, a low percentage of hatched chicks (28.32%) and high embryonic mortality were found. Oxygen supplementation to fertile creole hen eggs under hypobaric conditions in the Cajamarca valley did not increase hemoglobin concentration or improve body weight of hatched chicken.

Transcriptome Analysis Reveals Key Gene Expression Changes in Blue Catfish Sperm in Response to Cryopreservation.

The hybrids of female channel catfish (Ictalurus punctatus) and male blue catfish (I. furcatus) account for >50% of US catfish production due to superior growth, feed conversion, and disease resistance compared to both parental species. However, these hybrids can rarely be naturally spawned. Sperm collection is a lethal procedure, and sperm samples are now cryopreserved for fertilization needs. Previous studies showed that variation in sperm quality causes variable embryo hatch rates, which is the limiting factor in hybrid catfish breeding. Biomarkers as indicators for sperm quality and reproductive success are currently lacking. To address this, we investigated expression changes caused by cryopreservation using transcriptome profiles of fresh and cryopreserved sperm. Sperm quality measurements revealed that cryopreservation significantly increased oxidative stress levels and DNA fragmentation, and reduced sperm kinematic parameters. The present RNA-seq study identified 849 upregulated genes after cryopreservation, including members of all five complexes in the mitochondrial electron transport chain, suggesting a boost in oxidative phosphorylation activities, which often lead to excessive production of reactive oxygen species (ROS) associated with cell death. Interestingly, functional enrichment analyses revealed compensatory changes in gene expression after cryopreservation to offset detrimental effects of ultra-cold storage: MnSOD was induced to control ROS production; chaperones and ubiquitin ligases were upregulated to correct misfolded proteins or direct them to degradation; negative regulators of apoptosis, amide biosynthesis, and cilium-related functions were also enriched. Our study provides insight into underlying molecular mechanisms of sperm cryoinjury and lays a foundation to further explore molecular biomarkers on cryo-survival and gamete quality.

Environmental DNA dynamics during embryonic development in the rare minnow Gobiocypris rarus

AbstractUnderstanding environmental DNA (eDNA) dynamics in the major developmental stages of fish species is fundamental for developing eDNA methods to aid conservation and management of fish species and/or populations. In this study, we used the model fish species, the rare minnow (Gobiocypris rarus), to assess the temporal changes of its mitochondrial and nuclear eDNA concentrations during its embryonic development in a culture dish experiment. Mitochondrial cytochrome b (Cytb) and nuclear internal transcribed spacer‐1 (ITS1), considered as representative DNA fragments, were amplified by quantitative PCR (qPCR). In this embryo culture trial, spikes in mitochondrial (mt‐) and nuclear (nu‐) eDNA concentrations were found just after egg fertilization and after embryo hatching, and a modest but positive relationship was found between the eDNA concentration and the number of hatched individuals, illustrating eDNA may be used to monitor the spawning and hatching events of externally fertilizing fishes. These findings provided basic information on eDNA dynamics during fish embryonic development and a new insight to design eDNA methods to monitor early developmental stages of fish species.

Effects of in ovo application of resveratrol on hatchability, hatching time, yolk sac weight and chick performance in quail

The purpose of this study was to investigate the effects of in ovo resveratrol in hatching quail eggs on hatching traits, organ weights and chick performance. The eggs were randomly distributed into four groups as non-injected group (PC; Positive control), 0.2 ml saline (NC; Negative control), 0.2 ml solution containing 1 nmol of resveratrol (R1) and 0.2 ml solution containing 4 nmol of resveratrol (R4). Hatchability of set eggs (HSE) and hatchability of fertile eggs (HFE), embryonic mortality (EM), chick hatching time, yolk sac weight (YSW), and chick performance characteristics were investigated. The effects of in ovo resveratrol administration on the HSE were insignificant. HFE decreased significantly with in ovo resveratrol treatment. All injected groups were adversely affected in terms of embryonic deaths. The effect of in ovo resveratrol application on chick hatch weight, and YSW (g, %), chick performance was insignificant. It was observed that in ovo resveratrol treatment had no significant effect on the hatching time, except at 408 h of incubation. As a result, in ovo resveratrol application had a negative effect on hatchability and EM, but did not have affected the hatching time, YSW and chick performance.

Effects of kinship matings on embryo losses and hatch-weight in japanese quails

Inbreeding, which is the mating of related individuals, increases homozygosity and leads to depression, especially in traits with low heritability. In this study, parent-offspring, full-sibling and half-sibling mating groups were formed and their effects on embryo loss and hatch weight were investigated. In the study, a total of 2130 fertile Japanese quail eggs were used. Embryo losses were divided into three periods; early period (first 5-day), middle period (6-12th days) and late period (13-17th days). It was observed that mating groups affect all traits subject of this study (P≤0.0001). The lowest hatchability of fertile eggs was observed in dam-male offspring mating (DM), while the highest was observed in half-sibling (HS) and control (C) matings (P≤0.05). However, the highest hatch-weight were found in eggs of DM matings (P≤0.05). DM has also the highest embryo losses for all periods (P≤0.05). Most of the embryo losses, except the half-sibling group, occurred in the early period.

P-196 Assessing human embryo implantation competence through analysis of extracellular vesicles and their contents

Abstract Study question Could extracellular vesicles (EVs) derived from spent media serve as a non-invasive quality marker for embryo implantation and pregnancy? Summary answer EVs isolated from spent media derived from human blastocysts that either did or didn’t establish a pregnancy after transfer differ in size, concentration, miRNA expression. What is known already EVs are important for communication from one cell to another, influencing the translation of genes to proteins. They play a regulating role during biological processes, including pregnancy. We hypothesized that EVs released by a high-quality human embryo, which has the potential to create a pregnancy after the transfer, differ from EVs released by poor quality non-implanting embryos. Study design, size, duration Patients scheduled for a fresh single blastoycst transfer in IVF/ICSI cycles using own gametes consented to sampling of spent culture media (n = 102). Spent media from the transferred blastocyst (25 μl) were collected from implanted (hCG+/ET) (n = 45) and non-implanted (hCG-/ET) (n = 51). Spent media from degenerated embryos (n = 21) were collected from 6 patients. Media samples were pooled randomly into three replicates for each group (implanted (I), non-implanted (NI), degenerated (DG)). Participants/materials, setting, methods Extracellular vesicles were isolated by qEV single size exclusion column(SEC):a maximum of 200 µl of implanted or non-implanted or degenerated spent media was loaded onto the qEV SEC. Identification and characterization of EVs was performed by nanoparticle tracking analysis, transmission electron microscopy, and western blotting (CD9, CD63). Next, EV-RNA isolation was performed on these three groups (three replicates from each group) by Norgen Biotek Exosomal RNA Purification Kit, followed by RT-qPCR, and further data analysis. Main results and the role of chance Extracellular vesicles isolated from the SEC column are referred to as I-EVs, NI –EVs, and DG-EVs (implanted, non-implanted, and degenerated, respectively). Western blot confirmed the presence of EV-specific markers (CD63, CD9) in all EV samples (I-EVs, NI-EVs, and DG-EVs). By NTA, a higher particle concentration was observed in I-EVs (2.69±1.9 × 1010 particles/mL) compared to NI-EVs (6.13±0.2 × 1010 particles/mL) (p < 0.05), whereas DG-EVs particle concentration (4.97±0. 2 × 109 particles/mL) was significantly (P < 0.01). I-EVs were also characterized by a larger particle size with an average mean diameter of 180.3±5.4 nm, whereas NI-EVs displayed a smaller particle size with a mean diameter of 141.5±2.5 nm (p < 0.05). TEM confirmed the presence of larger-sized vesicles in I-EVs (≥ 200 nm) compared with NI and DG samples. During earlier work in EVs from bovine blastocysts we found miR-378a-3p to be typically present in blastocyst EVs, with a prominent role in the hatching process of the blastocyst. Here, we compared miR-378a-3p expression levels by RT-qPCR in I-EVs vs. NI-EVs vs DG-EVs. Higher expression of miR-378a-3p was identified in NI-EVs and I-EVs, compared to DG-EVs (log2fc= 30.10, log2fc = 8.94 p < 0.001 respectively), but was not correlated with implantation rate. Limitations, reasons for caution Currently, the methodology is unable to study EVs from a single droplet of spent media, hence pooling of the samples is necessary. As a consequence, data on EV-miRNA from individual blastocyst is lost. Wider implications of the findings Our data demonstrated that EVs and their cargo (miRNAs) have potential to be used as a non-invasive method to predict embryo implantation:miR-378a-3p has been associated with hatching in bovine embryos, but was not related with human implantion. Other embryo-derived miRNAs may be tested as a possible biomarker for human pregnancy. Trial registration number EC 2018/0266 – B670201835577

Ova lipid profiling and egg quality in wild and captive lumpfish, Cyclopterus lumpus (Linnaeus, 1758)

Lumpfish (Cyclopterus lumpus) serves an important role as cleaner fish for removing salmon lice in salmon aquaculture. For this use, cultivated lumpfish are preferred over wild-caught fish to avoid overexploitation of natural stocks and provide a stable production of good quality eggs and larvae. To support this, high quality eggs containing the necessary building blocks to support high fertilization success, development into a normal embryo and high hatching success is needed. Ova from wild-caught and captive lumpfish females were collected and assessed to identify how wild and domesticated lumpfish differ in terms of ova lipid profiles, egg and larvae quality. Wild-caught lumpfish displayed higher fertilization and hatching success compared to captive lumpfish, whereas other biological variables like egg size, egg/larvae dry weight and respiration, and larval morphometry, were not significantly different between wild and captive lumpfish. Ova lipid profiles (total lipid, lipid classes, fatty acid composition and lipidomics) can separate egg batches based on their geographic origin of wild-caught females and composition of diets used for captive broodstock (lipid and carbohydrate content). Multivariate statistics were applied to identify lipid markers that can be used to predict the quality of lumpfish ova. Lumpfish ova lipidomic profiles covaried with several biological parameters, indicating that the former can be used to predict the latter. Lumpfish eggs were mostly composed of triacylglycerides (TAGs) with some phosphatidylethanolamines (PEs) and phosphatidylcholines (PCs), and their lipid profiles were more sensitive to the different origins, mother weight/size and fertilization success than variables such as eggs size or larvae morphometric measures. PC and PE content of lumpfish eggs were positively correlated to both hatching success and fertilization rates, thus the lipidomic profiles, with some key highlighted lipid species were putative predictors of egg quality.

Supplemental effects of amino acid-complexed trace minerals on broiler breeder hen performance

A broiler breeder hen study was conducted to evaluate the replacement of trace element sources from inorganic minerals (IM) by amino acid complexed minerals (AACM) sources. Zn, Mn, Cu, and Fe sulfate, Na selenite and K iodate were the inorganic sources whereas the organic were supplemented from amino acid complexed sources. A total of 84 Cobb 500 38-week-old broiler breeder hens were individually caged and fed diets as follows: T1- Control IM sources with Zn, Mn, Cu, Fe, Se and I at 100, 100, 20, 60, 0.35 and 2 ppm, respectively; T2- same total mineral content as in T1 in a combination of IM and AACM sources (Zn: 60/40, Mn: 60/40, Cu: 13/7, Fe: 40/20, Se: 0.20/0.15, and I: 0/2 ppm); T3- only IM sources content from T2; T4- only AACM sources content from T2; T5- IM sources with Zn, Mn, Cu, Fe, Se and I at 120, 120, 25, 70, 0.40 and 3 ppm, respectively; T6- Same total mineral content as in T5 in a combination of IM and AACM sources (Zn: 60/60, Mn: 60/60, Cu: 13/2, Fe: 40/30, Se: 0.20/0.20, and I: 0/3 ppm); T7- only AACM mineral source content from T6. Evaluation was done from week 40–51. There were no significant effects of the treatments for egg production, incubation, egg quality and hatching chicks (P > 0.05) during this period. One exception occurred for eggshell thickness, which was increased when hens were fed partial and total replacement of AACM (P < 0.05). Contrasts between total replacement with AACM and IM supplemented diets showed an increase in settable eggs when breeders were fed AACM. Higher hatchability of fertile eggs was observed in partial replacements with AACM treatments when compared to IM (P < 0.05). Also, hatching chick had higher length and more chicks with leg score 1 in total replacement of AACM compared to the partial AACM replacement and IM groups (P < 0.05), and IM groups (P < 0.05), respectively. In conclusion, totally or partially replacement with IM by AACM led to improvements in eggshell and chick quality.

Effect of magnetic field on productive and hysiological performance in broiler breeder

The experiment was conducted to determine the effect of magnetic field on the productive and physiological performance of Ross 308. The experimental flock consist of 60 hens and 10 cocks of broiler breeders, which randomly divided into four groups and distributed on the treatments with three replicates for each treatment. The treatments included the control treatment (T1), exposure the stored semen to 803 gauss magnetic field for 24 hours (T2), exposure the fertile eggs to 250 gauss magnetic field for 72 hours before entered the incubator (T3) and exposure the individual cages to 250 gauss magnetic field for 8 weeks (T4), and the performance traits of hen day egg production, egg weight, recorded from magnetization cages group and compared with control group. The results showed a significant decrease (P≤0.05) in fertility and hatchability of total eggs in T2 compared with other groups, and there was no significant difference in the hatchability of fertile eggs and embryonic mortality among treatments, egg weight and the hen day egg production. (HD).

Exposure of embryonating eggs to Enterococcus faecalis and Escherichia coli potentiates E. coli pathogenicity and increases mortality of neonatal chickens

Enterococci and Escherichia coli are opportunistic pathogens of poultry and are associated with embryo and neonatal chick mortality. We have recently demonstrated that 56% of dead broiler chicken embryos in commercial hatcheries in western Canada were due to the coinfection of Enterococcus species and E. coli. The objective of this study was to investigate the host-pathogen interactions of Enterococcus faecalis and E. coli in developing chicken embryos. Embryonating eggs at 12 d of incubation were dipped in a solution of E. faecalis and/or E. coli for 30 s to expose the eggshell to study the migration and colonization of E. faecalis and E. coli in the internal organs of chicken embryos and subsequent neonatal chicken mortality following hatch. A multidrug-resistant E. faecalis isolate from a dead chicken embryo and an E. faecalis isolate from a case of yolk sac infection were able to colonize the internal organs of chicken embryos rapidly compared to an E. faecalis isolate from a healthy chicken without affecting viability or hatchability of embryos. Although E. faecalis colonized internal organs of chicken embryos, no evidence of inflammation of these organs nor the expression of virulence genes of E. faecalis was observed. Although E. faecalis and E. coli alone did not affect the viability of embryos, a significantly high neonatal chicken mortality (27%) was observed following exposure of embryos to both E. faecalis and E. coli. Upregulation of IL-1 and CXCR4 was evident 48 h before peak mortality of neonatal chickens; this could suggest a possible link of cytokine dysregulation to increased mortality in coinfected neonatal chickens. However, further studies are warranted to investigate this issue vis-à-vis coinfection with E. faecalis and E. coli in chicken embryos and neonatal chickens.

Evaluating the Performance of a Small‐Scale Culture System for Delta Smelt

AbstractSince 2008, a refuge population of Delta Smelt Hypomesus transpacificus has been cultured in a conservation hatchery to help protect the imperiled species from extinction. Culture techniques for this population have thus far focused on maximizing genetic diversity in conjunction with large‐scale operations (40 larval tanks, 5,954‐L larval system, 224,000 larvae capacity), which includes rearing multiple family groups within the same tanks. However, Delta Smelt production and associated research projects would benefit from also being able to rear fish on a smaller scale, such as in individual family groups. Recently, a new culture system and modified culture practices were developed for rearing small groups of larval Delta Smelt. We (1) determined the performance of the small‐scale “experimental” rearing system from embryo to 80 d posthatch (dph) and (2) tested whether the performance of the experimental system met the standard set by the large‐scale “refuge” rearing system at critical culturing life stages in terms of embryo hatching rate (10 d postfertilization) and larval survival, length, and weight (40 and 80 dph). From 1,000 embryos, the experimental system produced a mean ± SE of 376 ± 44 late‐stage larvae. The hatching rate of embryos did not differ between systems. Early‐stage larvae (0–40 dph) reared in the experimental system did not differ in survival rate but were longer and heavier than those reared in the refuge system. In contrast, late‐stage larvae (41–80 dph) reared in the experimental system had poorer survival and were shorter and lighter than refuge‐reared larvae. Thus, the experimental system met the refuge‐system benchmark for embryo hatching and exceeded the benchmark in early‐larval production, but it could be improved for late‐larval rearing. Nevertheless, this small‐scale rearing system will provide much‐needed flexibility to enhance Delta Smelt culture practices and facilitate future research.

Role of Histone Chaperone APLF in Mammalian Embryo Development

Embryonic development involves orchestrated events regulated by a plethora of factors. Epigenetic regulation is one such key aspect regulating embryonic development. We are investigating the role played by Aprataxin and PNK‐like factor (APLF), a histone chaperone, in regulating cellular transitions in the context of embryonic development. APLF is documented as a DNA damage‐specific histone chaperone and has already been studied in our lab in the context of the generation of induced pluripotent stem cells and breast cancer metastasis as a regulator of epithelial to mesenchymal transition.We are looking into the expression profile, functional role, and mechanism of action of APLF in embryonic development. The expression study in pre‐and post‐implantation mouse embryos and mouse trophoblast stem cells (TS) through different days of differentiation showed a dynamic expression pattern of APLF, clearly indicating prospective functional significance. The localization of APLF in mouse embryos was enhanced in trophectoderm (TE) and lineages derived from TE, which contributes to the extraembryonic lineage crucial for developing a proper maternal‐fetal connection. Functional studies by sh RNA mediated knockdown (KD) of Aplf in mouse embryos by microinjection induced the hatching of embryos in vitro at E3.75, with a significant increase in Cadherin 1 (Cdh1) and Caudal‐type homeobox 2 (Cdx2) expression. Hatching is a crucial event whereby the embryo breaks out of the protective sheath called zona pellucida and prepares itself to attach itself to the uterine wall by the process of implantation. The Aplf KD embryos failed to implant in vivo. Rescue experiments neutralized the effects of AplfKD both in vitro and in vivo. We used differentiated TS cells as our model system to understand the mechanism behind the observed phenotype in Aplf KD embryos. Reduced expression of Snail Family Transcriptional Repressor 2 (Snai2) and TEA Domain Transcription Factor 4 (Tead4), and the gain in Cdh1 level, marked the differentiation of AplfKD TS cells. Embryo implantation is one of the pioneer developmental stages where EMT comes into action. Significantly high level of epithelial marker Cdh1 and downregulation of mesenchymal marker Snai2 in Aplf KD TS cells would have impaired the crucial EMT process operational during implantation.Further studies are being conducted to unravel the underlying mechanism completely. Hence, our findings suggest a novel role for APLF during the implantation and post‐implantation development of mouse embryos. As we observed these phenotypes in the mouse embryo, we checked APLF expression in the human placenta, and interestingly, our preliminary studies showed its expression in cytotrophoblast and syncytiotrophoblast cells. As we have seen that a delicate balance of APLF is crucial to achieve implantation and attain proper pregnancy, we anticipate that it would contribute to establishing a felicitous maternal‐fetal connection.

Features of development of visceral organs in embryos of egg cross chickens ‘Lohmann Brown’ under red and green monochromatic LED lighting

New data on the features of development of visceral organs in embryos of egg cross chickens Lohmann Brown under red and green monochromatic LED lighting were obtained. The effect of two continuous LED lighting modes has been studied: experimental modes - r ed and green light, control - d arkness. The absolute values of weight dimensions and specific growth rate (according to the Schmalhausen-Brody formula) of heart, muscular stomach, liver of chicken embryos were estimated using morphometric methods. The studies proved that red and green LED lighting has a stimulating effect on the embryonic development of visceral organs (heart, muscular stomach, liver) in Lohmann Brown egg cross compared to the control (darkness). Under red and green LED stimulation, chicken embryos prevailed in the heart mass from the 14th to the 20th day of embryogenesis. The muscular stomach and liver of chicken embryos developed more intensively under red illumination on the 18th and 20th days, and under green illumination - a similar effect on the muscular stomach was noted on the 19th and 20th days, on the liver - o n the 20th day. It has been established that in the early ontogenesis of Lohmann Brown chickens there were several critical stages (phases). They fall on different days of development and characterize the features of rhythmicity in growth processes of visceral organs in chicken embryogenesis under LED stimulation of red and green spectrum. Chicken embryos under red and green illumination had the highest growth rate of heart on the 17th and 20th day, respectively; muscular stomach under red illumination - o n the 17th and 20th days, liver - on the 16th and 17th day under red and green illumination. By the hatching period on the 20th day, there were no differences in the development of visceral organs of chicken embryos depending on red and green light spectrum. The hatching of Lohmann Brown chicken embryos exposed to red and green light occurred on the 20th day of incubation - a day earlier than under control conditions (darkness). The proposed biological causes underlying the effect of monochromatic light of different color spectrum on embryogenesis of chicken embryo and organs are discussed.

New 18β-Glycyrrhetinic Acid-Emodin Esters Synthetized by a One-Step Innovative Route, Its Structural Characterization, and in Vivo Toxicity Assessed on Zebrafish Models.

To integrate the active advantages of 18β-glycyrrhetinic acid (18β-GA) and emodin, improve bioavailability, increase efficiency, and reduce toxicity, a one-step innovative synthetic route was set up for the first time: 4-dimethylaminopyridine (DMAP) was used as catalyst, 1-ethyl-(3-dimethylaminopropyl)carboimide hydrochloride (EDCI) as condensation agent, dry dichloromethane (DCM) as solvent at 25 °C for 12 h, the three target products were obtained and purified by high performance liquid chromatography (HPLC), the chemical structures of them were characterized by nuclear magnetic resonance (NMR) technique and high resolution electron ionization mass spectrometry (HREI-MS), namely, 18β-glycyrrhetinic acid-3-emodin ester (1, yield 78.83 %, known), di-18β-glycyrrhetinic acid-1-emodin ester (2, yield 6.49 %, new), and di-18β-glycyrrhetinic acid-8-emodin ester (3, yield 1.81 %, new). To estimate their effects of the products on toxicity in zebrafish embryos and juvenile fishes, the two precursors and three target products were assayed involving in hatching rate, survival rate, morphology, heart rate, and apoptosis of cardiomyocytes. The results showed that the target products enhanced the hatching and survival rate of zebrafish embryos, decreased the malformation rate and the apoptosis of cardiomyocytes. It should be suggested that the one-step synthesis route with high yield makes the industrial application of the target products possible due to significantly reduced toxicity. The two new by-products provide potential candidates for the applications of pharmaceutical industry in the future.

Thermally conductive graphene-based nanofluids, a novel class of cryosolutions for mouse blastocysts vitrification

Limited heating and cooling rates have long been recognized as bottlenecks in improving embryo cryopreservation. As a result, efforts to achieve higher heat transfer rates gave rise to milestones like open cryodevices and minimal media loading. A crucial but commonly ignored variable is heat conduction by cryosolutions. The low heat conductivity of the aqueous media surrounding embryos slows down cooling and heating rates of the embryo, imposing the risk of preventable damages. In this study, we introduce a novel thermally conductive cryosolution based on graphene oxide nanoparticles and test its performance against conventional sucrose-based solutions for vitrification of mouse blastocysts. Replacing sucrose with graphene oxide brought about similar re-expansion, hatching, and implantation rates of post-vitrification embryos while also preventing an array of cellular and molecular stresses. Our results showed significantly reduced oxidative stress, characterized by control-level expression of Sod1 and significant downregulation of Sod2 transcription when graphene oxide was used instead of sucrose. This molecular response was in agreement with the reduced level of reactive oxygen species produced in vitrified/warmed embryos using graphene-based solutions. The downstream impacts of this stress reduction manifested in significant downregulation of two major pro-apoptotic genes, Bax and Trp53, down to the same level as fresh embryos. Interestingly, embryos maintained their spherical shape during dehydration in graphene-based solutions and did not "collapse" when shrinking, like in sucrose-based solutions. These results provide new insights into the benefits of thermally conductive cryosolutions and showcase the potential of graphene oxide as a cryoprotectant in embryo vitrification.

Dietary supplementation with canthaxanthin and 25-hydroxycholecalciferol on the incubation performance and fertility of European quail breeders

This study assessed the effects of combined supplementation with canthaxanthin (Cx) and 25-hydroxycholecalciferol (25-OH-D3) on incubation performance, fertility, and chick quality in European quail breeders. A total of 240 birds were distributed in a completely randomized design with 5 diets and 8 replicates. The animals were fed a basal diet containing 50 µg of vitamin D3 or the basal diet supplemented with 3 ppm Cx and 34.5 µg 25-OH-D3, 6 ppm Cx, and 69 µg 25-OH-D3, 9 ppm Cx and 103.5 µg 25-OH-D3, or 12 ppm Cx and 138 µg 25-OH-D3. Incubation performance was analyzed in 2 periods (32 and 38 wk). Breeders aged 32 wk produced eggs with higher hatchability (P = 0.024), hatchability of fertile eggs (P = 0.026) and lower initial plus mid embryonic mortality (P = 0.021), whereas 38-week-old breeders generated chicks with a higher length at hatching (P < 0.001) and lower final plus pipped embryonic mortality (P = 0.021). In both age groups, Cx + 25-OH-D3 levels had a quadratic effect on egg fertility (P < 0.001), hatchability of total (P < 0.001), and fertile eggs (P < 0.001). The fertility and the number of sperm cells in the perivitelline membrane was analyzed in two periods (26 and 40 wk). A quadratic effect of diet and days after mating on both parameters (P < 0.05) was observed. Eggs from supplementing breeders showed a high fertility (P < 0.001) and sperm cell counts (P < 0.001) for up to 7 and 3 d after mating, respectively, then the control group. Moreover, the supplementation of quail breeder diets with 6 ppm Cx + 69 µg 25-OH-D3 enhances sperm cell longevity in sperm storage tubules, hatchability of total and fertile eggs, fertility, and chick quality, especially in older quail's breeders and reduces embryonic mortality.

Effects of pre-incubation storage duration and nonventilation incubation procedure on embryonic physiology and post-hatch chick performance

This study investigated the effects and possible interactions of storage and nonventilation during incubation for eggs from Sasso broiler breeder flock on pre- and post-hatch incubation results.A total of 1,260 Sasso eggs from a 58-wk-old broiler breeder flock were individually numbered, weighed and stored for 7 d or for 18 d in a climate-controlled room (16°C, 75% RH). After storage, eggs were weighed, and randomly assigned equally into 2 incubators. One of the incubators was ventilated (V) for the entire incubation and the second was nonventilated (NV) for the first 12 d. At d 18, the eggs were weighed, candled, and fertile eggs were transferred from the turning trays to hatching baskets. During the last 3 d of incubation, hatching eggs were checked individually every 3 h for hatching events and hatchability of fertile eggs. After pull out at d 21.5, post-hatch performances was determined until 1 wk of age.Results showed that, embryo weights from eggs in NV incubator was significantly higher (P < 0.05) in both stored eggs compared to those from eggs in ventilated incubator, but embryos from eggs stored for 18 d were smaller (P < 0.05) than those from eggs stored for 7 d. Hatchability was higher (P < 0.0001) in NV incubator compared to V incubator in both 7 d and 18 d stored eggs and an interaction was found between incubation ventilation and storage duration on both hatchability and embryonic mortality (P < 0.0001). Chick weights from NV incubator at 7 d post-hatch was greater (P = 0.0009) than those from V incubator. Serum Tri-iodothyronine (T3) and Thyroxin (T4) concentrations were significantly higher (P < 0.05) in NV compare to V group.It was concluded that the effect of long-term pre-incubation storage on embryonic physiology and post-hatch growth interacted significantly with incubation ventilation and that nonventilation can compensate for the negative effects of storage on some hatching and post-hatch performances.

Toxic Effects and Mechanisms of Silver and Zinc Oxide Nanoparticles on Zebrafish Embryos in Aquatic Ecosystems.

The global application of engineered nanomaterials and nanoparticles (ENPs) in commercial products, industry, and medical fields has raised some concerns about their safety. These nanoparticles may gain access into rivers and marine environments through industrial or household wastewater discharge and thereby affect the ecosystem. In this study, we investigated the effects of silver nanoparticles (AgNPs) and zinc oxide nanoparticles (ZnONPs) on zebrafish embryos in aquatic environments. We aimed to characterize the AgNP and ZnONP aggregates in natural waters, such as lakes, reservoirs, and rivers, and to determine whether they are toxic to developing zebrafish embryos. Different toxic effects and mechanisms were investigated by measuring the survival rate, hatching rate, body length, reactive oxidative stress (ROS) level, apoptosis, and autophagy. Spiking AgNPs or ZnONPs into natural water samples led to significant acute toxicity to zebrafish embryos, whereas the level of acute toxicity was relatively low when compared to Milli-Q (MQ) water, indicating the interaction and transformation of AgNPs or ZnONPs with complex components in a water environment that led to reduced toxicity. ZnONPs, but not AgNPs, triggered a significant delay of embryo hatching. Zebrafish embryos exposed to filtered natural water spiked with AgNPs or ZnONPs exhibited increased ROS levels, apoptosis, and lysosomal activity, an indicator of autophagy. Since autophagy is considered as an early indicator of ENP interactions with cells and has been recognized as an important mechanism of ENP-induced toxicity, developing a transgenic zebrafish system to detect ENP-induced autophagy may be an ideal strategy for predicting possible ecotoxicity that can be applied in the future for the risk assessment of ENPs.

Cathepsin L involved in the freezing resistance of murine normal hatching embryos and dormant embryos

The cryopreservation of mammalian embryos is an important technology in embryo engineering. The discovery and application of the embryo's own high freezing resistance factors are the main methods to improve the utilization of mammalian embryos in cryopreservation. Cathepsin L gene expression in the frozen and thawed dormant embryos displayed a significant difference from those normal hatched ones. The aim of the present study was to dig out the potential role of Cathepsin L in anti-freezing capacity of murine blastocysts by investigating the location and expression of Cathepsin L in frozen and thawed both activated and dormant hatching blastocysts. Different concentrations of Cathepsin L recombinant protein and E-64d were then respectively added into the embryo cryoprotectant and pre-cryo culture medium. Our results found that down-regulation of Cathepsin L improves the freezing resistance of murine normal hatching embryos by reducing apoptosis. Cathepsin L inhibitors can be used to improve the efficiency of cryopreservation and recovery of blastocysts in vitro. Our study provides a theoretical basis for the further development and application of Cathepsin L.