Embryonic Survival Research Articles

Pleomorphic adenoma gene (PLAG1) in reproduction and implication for embryonic survival in cattle: A review.

The pleomorphic adenoma gene (PLAG1) encodes a DNA-binding, C2H2 zinc finger protein which acts as a transcription factor that regulates the expression of diverse genes across different organs and tissues; hence, the name pleomorphic. Rearrangements of the PLAG1 gene, and/or overexpression, are associated with benign tumors and cancers in a variety of tissues. This is best described for pleomorphic adenoma of the salivary glands in humans. The most notable expression of PLAG1 occurs during embryonic and fetal development, with lesser expression after birth. Evidence has accumulated of a role for PLAG1 protein in normal early embryonic development and placentation in mammals. PLAG1 protein influences the expression of the IGF2 gene and production of IGF2 protein. IGF2 is an important mitogen in ovarian follicles/oocytes, embryos, and fetuses. The PLAG1-IGF2 axis, therefore, provides one pathway whereby PLAG1 protein can influence embryonic survival and pregnancy. PLAG1 also influences over 1,000 other genes in embryos including those associated with ribosomal assembly and proteins. Brahman (Bos indicus) heifers homozygous for the PLAG1 variant, rs109815800 (G>T), show greater fertility than contemporary heifers with either one, or no copy, of the variant. Greater fertility in heifers homozygous for rs109815800 could be the result of early puberty and/or greater embryonic survival. The present review first looks at the broader roles of the PLAG1 gene and PLAG1 protein and then focuses on the emerging role of PLAG1/PLAG1 in embryonic development and pregnancy. A deeper understanding of factors which influence embryonic development is required for the next transformational increase in embryonic survival and successful pregnancy for both in vivo and in vitro derived embryos in cattle.

Collective effects of rising average temperatures and heat events on oviparous embryos.

Survival of the immobile embryo in response to rising temperature is important to determine a species' vulnerability to climate change. However, the collective effects of 2 key thermal characteristics associated with climate change (i.e., rising average temperature and acute heat events) on embryonic survival remain largely unexplored. We used empirical measurements and niche modeling to investigate how chronic and acute heat stress independently and collectively influence the embryonic survival of lizards across latitudes. We collected and bred lizards from 5 latitudes and incubated their eggs across a range of temperatures to quantify population-specific responses to chronic and acute heat stress. Using an embryonic development model parameterized with measured embryonic heat tolerances, we further identified a collective impact of embryonic chronic and acute heat tolerances on embryonic survival. We also incorporated embryonic chronic and acute heat tolerance in hybrid species distribution models to determine species' range shifts under climate change. Embryos' tolerance of chronic heat (T-chronic) remained consistent across latitudes, whereas their tolerance of acute heat (T-acute) was higher at high latitudes than at low latitudes. Tolerance of acute heat exerted a more pronounced influence than tolerance of chronic heat. In species distribution models, climate change led to the most significant habitat loss for each population and species in its low-latitude distribution. Consequently, habitat for populations across all latitudes will shift toward high latitudes. Our study also highlights the importance of considering embryonic survival under chronic and acute heat stresses to predict species' vulnerability to climate change.

Cardiac-specific deletion of heat shock protein 60 induces mitochondrial stress and disrupts heart development in mice

Congenital heart diseases are the most common birth defects around the world. Emerging evidence suggests that mitochondrial homeostasis is required for normal heart development. In mitochondria, a series of molecular chaperones including heat shock protein 60 (HSP60) are engaged in assisting the import and folding of mitochondrial proteins. However, it remains largely obscure whether and how these mitochondrial chaperones regulate cardiac development. Here, we generated a cardiac-specific Hspd1 deletion mouse model by αMHC-Cre and investigated the role of HSP60 in cardiac development. We observed that deletion of HSP60 in embryonic cardiomyocytes resulted in abnormal heart development and embryonic lethality, characterized by reduced cardiac cell proliferation and thinner ventricular walls, highlighting an essential role of cardiac HSP60 in embryonic heart development and survival. Our results also demonstrated that HSP60 deficiency caused significant downregulation of mitochondrial ETC subunits and induced mitochondrial stress. Analysis of gene expression revealed that P21 that negatively regulates cell proliferation is significantly upregulated in HSP60 knockout hearts. Moreover, HSP60 deficiency induced activation of eIF2α-ATF4 pathway, further indicating the underlying mitochondrial stress in cardiomyocytes after HSP60 deletion. Taken together, our study demonstrated that regular function of mitochondrial chaperones is pivotal for maintaining normal mitochondrial homeostasis and embryonic heart development.

Hatching plasticity is associated with a more advanced stage at hatching in an Ambystoma with terrestrial eggs.

Hatching plasticity allows animals to initiate hatching in response to environmental cues including predation, flooding, and hypoxia. In species with terrestrial eggs but aquatic larvae, hatching plasticity often manifests as extended development of embryos when water is not available. Although these effects are taxonomically widespread, little attention has focused on differences in plasticity across closely related species with terrestrial and aquatic embryos. We propose that the terrestrial embryonic environment favors slower and prolonged development and, consequently, that we should see differences in development between closely related species that differ in where they lay their eggs. We test this hypothesis by comparing embryonic development between two mole salamanders, Ambystoma opacum and A. annulatum. Most Ambystoma lay eggs submerged in ponds but A. opacum lays its eggs on land, where hatching is triggered when eggs are submerged by rising pond levels. Embryos of both species were reared under common laboratory conditions simulating both aquatic and terrestrial nest sites. Consistent with our hypothesis, we found that A. opacum embryos exhibited slower development and took longer to hatch than A. annulatum embryos in both rearing environments. Furthermore, we observed in A. opacum a plasticity in hatching stage that was absent in A. annulatum. Our results indicate that the terrestrial-laying A. opacum has evolved slower and prolonged development relative to its aquatic-laying congener and suggest that embryonic survival in the unpredictable terrestrial environment may be facilitated by developmental plasticity.

Automated monitoring of early life‐stage development in Atlantic cod (Gadus morhua) embryos exposed to a reference toxicant

AbstractEarly life stages of fish are widely used for regulatory toxicity testing, and marine fish display high sensitivity to pollutant exposure. Exposure to pollutants during embryogenesis causes acute effects on embryonic development and survival, but also sub‐lethal impacts manifested as maldeveloped larvae. Acquiring time‐ and exposure‐dependent responses to pollutant exposure and other stressors in small organisms is labor intensive and often subjective. This leads to studies obtaining small sample sizes, with measurements often made infrequently during development. Automated monitoring methods can maintain consistency between measurements and allow many more measurements to be made, improving the quantity and quality of such data. We exposed Atlantic cod embryos to 3,4‐dichloroaniline, a reference chemical widely used as a positive control agent in regulatory fish embryo toxicity testing. We monitored their growth through daily imaging with an automated flow‐through imaging system. Biologically relevant sublethal endpoints were estimated from these images with a neural network and traditional machine vision methods. We demonstrate the automated capture and analysis of tens of thousands of images, producing detailed morphometric data from hundreds of fish over a 10‐d study period, and assess the effectiveness of the automated system. The automated method presented allows measurements to be made frequently without sacrificing the sampled organisms, making detailed time series of development obtainable. We show dose‐dependent effects of the toxicant on development and capture nonlinear responses that would not be attainable under a conventional manual sampling regime.

Sensitivity of amphibian embryos to timing and magnitude of present and future thermal extremes.

Ongoing climate change is increasing the frequency and intensity of extreme temperature events. Unlike the gradual increase on average environmental temperatures, these short-term and unpredictable temperature extremes impact population dynamics of ectotherms through their effect on individual survival. While previous research has predominantly focused on the survival rate of terrestrial embryos under acute heat stress, less attention has been dedicated to the nonlethal effects of ecologically realistic timing and magnitude of temperature extremes on aquatic embryos. In this study, we investigated the influence of the timing and magnitude of current and projected temperature extremes on embryonic life history traits and hatchling behavior in the alpine newt, Ichthyosaura alpestris. Using a factorial experiment under controlled laboratory conditions, we exposed 3- or 10-day-old embryos to different regimes of extreme temperatures for 3 days. Our results show that exposure to different extreme temperature regimes led to a shortened embryonic development time and an increase in hatchling length, while not significantly affecting embryonic survival. The duration of development was sensitive to the timing of temperature extremes, as early exposure accelerated embryo development. Exposure to temperature extremes during embryonic development heightened the exploratory activity of hatched larvae. We conclude that the timing and magnitude of ecologically realistic temperature extremes during embryogenesis have nonlethal effects on life history and behavioral traits. This suggests that species' vulnerability to climate change might be determined by other ecophysiological traits beyond embryonic thermal tolerance in temperate pond-breeding amphibians.

Effect of antifreeze protein I in the freezing solution on in vivo-derived sheep embryos

This study evaluated the effects of different antifreeze protein type I (AFP I) concentrations added to a slow freezing solution in sheep in vivo-derived embryos. Good-quality embryos were allocated into: AFP-free (CONT); 0.1 μg/mL of AFP I (AFP0.1); or 0.5 μg/mL of AFP I (AFP0.5). After thawing, embryos were in vitro cultured (IVC) for 48 h. At 24 h and 48 h of IVC, dead cells and apoptosis, mitochondrial activity, intracellular reactive oxygen species (ROS), and glutathione (GSH) evaluations were performed. At 24 h, evaluated embryos were submitted to RT-qPCR for metabolism (SIRT2, PRDX1, OCT4, CDX2) and quality (AQP3, CDH1, HSP70, BAX, BCL2) genes. The in vitro survival rate was 56% (22/39) for CONT, 60% (32/53) for AFP0.1, and 53% (23/43) for AFP0.5 (p > 0.05). A tendency (p = 0.09) for a higher blastocyst hatching rate was noted in AFP0.1 (62%) compared to AFP0.5 (33%), and both groups were similar to CONT (50%). An increased (p < 0.05) mitochondrial activity at 24 h was observed in AFP0.1 compared to CONT. No differences (p > 0.05) were observed in oxidative stress homeostasis and viability between treatments. A downregulation (p < 0.05) of CDH1 in AFP0.1 and a downregulation of AQP3 in AFP0.5 were observed in comparison to the other groups. An upregulation (p < 0.05) was detected in HSP70 and BCL2 on AFP0.5 compared to AFP0.1 group. The addition of AFP I in slow freezing solution can benefit cryopreserved sheep in vivo-derived embryos, without affecting embryonic survival.

A Fanca knockout mouse model reveals novel Fancd2 function

Fanconi anemia (FA) is a genetically and clinically heterogenous inherited disorder. Clinically, Fanca subtype patients exhibited milder phenotypes compared to Fancd2 subtypes. Increasing evidence suggests that Fancd2 perform independent functions, but the detailed mechanisms are not well characterized. In this study, we developed a Fanca KO mice model in C57BL/6 background with ATG region deletion, then performed a detailed FA phenotypes characterization and analysis with Fanca KO mice and Fancd2 KO mice in the same congenic background. We found that both the Fanca KO and Fancd2 KO cause severe FA phenotypes in mice. However, Fanca KO mice exhibited milder FA phenotypes comparing to Fancd2 KO mice. Fanca KO mice showed higher embryonic and postnatal survival rate, less congenital eye defects in early development. At adult stage, Fanca KO mice showed increased HSC number and reconstitution function. Furthermore, we did RNA-seq study and identified differential expression of Dlk1 and Dlk1 pathway genes in Fanca KO and Fancd2 KO embryonic cells and adult HSCs. Finally, we revealed that Fancd2 was expressed and physically interact with Dlk1 in Fanca KO cells. Collectively, our findings suggested that Fancd2 has distinct functions in the absence of Fanca.

Extraembryonic metabolism of corticosterone protects against effects of exposure

When females experience stress during reproduction, developing embryos can be exposed to elevated levels of glucocorticoids, which can permanently affect offspring development, physiology, and behavior. However, the embryo can regulate exposure to glucocorticoids. In placental species, the placenta regulates embryonic exposure to maternal steroids via metabolism. In a comparable way, recent evidence has shown the extraembryonic membranes of avian species also regulate embryonic exposure to a number of maternal steroids deposited in the yolk via metabolism early in development. However, despite the known effects of embryonic exposure to glucocorticoids, it is not yet understood how glucocorticoids are metabolized early in development. To address this knowledge gap, we injected corticosterone into freshly laid chicken (Gallus gallus) eggs and identified corticosterone metabolites, located metabolomic enzyme transcript expression, tracked metabolomic enzyme transcript expression during the first six days of development, and determined the effect of corticosterone and metabolites on embryonic survival. We found that yolk corticosterone was metabolized before day four of development into two metabolites: 5β-corticosterone and 20β-corticosterone. The enzymes, AKR1D1 and CBR1 respectively, were expressed in the extraembryonic membranes. Expression was dynamic during early development, peaking on day two of development. Finally, we found that corticosterone exposure is lethal to the embryos, yet exposure to the metabolites is not, suggesting that metabolism protects the embryo. Ultimately, we show that the extraembryonic membranes of avian species actively regulate their endocrine environment very early in development.

Warming and pollution interact to alter energy transfer efficiency, performance and fitness across generations in zebrafish (Danio rerio)

Energy transfer efficiency across different trophic levels, from food to new biomass, can determine population dynamics and food-web function. Here we show that the energy needed to produce a unit of new biomass increases with warming and exposure to bisphenol A (BPA), an endocrine disrupting compound. These environmental effects are at least partially transmitted across generations via DNA methylation. We raised parental (F0) and their offspring (F1) zebrafish (Danio rerio) of two genotypes (DNA methyltransferase 3a knock-out [DNMT3a−/−] and wild type [DNMT3a+/+]) at different temperatures (24 and 30 °C), with and without BPA (0 and 10 μg l−1) to test whether the effects of BPA are i) temperature specific, ii) mediated by DNA methylation, and iii) transmitted across generations even if offspring are not exposed. All experimental factors interacted to influence growth in length and mass, and metabolic rates with the result that wild-type F0 and F1 fish experienced the greatest energetic cost of growth under warm conditions in the presence of BPA. However, this response was not observed in DNMT3a−/− fish, indicating that DNA methylation is at least partly responsible for mediating these effects. Under the same conditions (warm + BPA) wild-type parents had reduced swimming performance, and reduced fecundity, and offspring embryonic survival was reduced significantly; genotype affected these responses significantly. Our results indicate that the conditions that are becoming increasingly common globally - warming and endocrine disrupting compounds from plastic pollution and production - can have detrimental effects on energy transfer efficiency and thereby potentially on food-web structure. These effects can be transmitted across generations even if offspring are not exposed to the pollutant, and are likely to have ramifications for conservation and fisheries.

Embryonic and larval development of reciprocal diploid and triploid hybrids of Caspian trout (Salmo caspius) and rainbow trout (Oncorhynchus mykiss)

The present study aims to evaluate the viability of reciprocal crosses between Caspian trout (Salmo caspius) and rainbow trout (Oncorhynchus mykiss), and the effect of triploidization on embryonic development, growth and survival of hybrid embryos and larvae. This experiment included six groups of crosses: (1) pure O. mykiss (2nR); (2) pure S. caspius (2nC); (3) diploid and (4) triploid ♀O. mykiss×♂S. caspius hybrids (2nR × C and 3nR × C); (5) diploid and (6) triploid ♀S. caspius×♂O. mykiss hybrids (2nC × R and 3nC × R). Triploidy was induced by a thermal shock after fertilization. Fertilization, hatching, and embryonic development were studied. Hatching rate was more than 90% in 2nR and 2nC, 35% in 2nR × C group, 45% in 3nR × C group, whereas all embryos died before the eyed stage in 2nC × R and 3nC × R groups. Chromosome number ranged between 57 and 61 and 78–81 in 2nR and 2nC groups, 69–71 in 2nR × C and 99–103 in 3nR × C. The time before blastopore closure was the most important point in the embryonic phases when most deaths occurred in all groups. Hatching occurred earlier in 2nR and 3nR × C groups than in 2nC group. The highest final weight and specific growth rate were observed in 2nR and 3nR × C groups. We have demonstrated that triploidy induction can increase the survival rate of distant hybrid (♀O. mykiss×♂S. caspius) and identified the key embryonic stages that could help introduce this hybrid into aquaculture. The hybrid could be easily commercialized if they show significant improvement in growth, survival and disease resistance.

Intracellular fraction of zona pellucida protein 3 is required for the oocyte-to-embryo transition in mice.

In oocyte biology, the zona pellucida has long been known to operate three extracellular functions downstream of the secretory pathway, namely, encasing the oocytes in ovarian follicles, mediating sperm-oocyte interaction, and preventing premature embryo contact with oviductal epithelium. The present study uncovers a fourth function that is fundamentally distinct from the other three, being critical for embryonic cell survival in mice. Intriguingly, the three proteins of the mouse zona pellucida (ZP1, ZP2, ZP3) were found abundantly present also inside the embryo 4 days after fertilization, as shown by mass spectrometry, immunoblotting, and immunofluorescence. Contrary to current understanding of the roles of ZP proteins, ZP3 was associated more with the cytoskeleton than with secretory vesicles in the subcortical region of metaphase II oocytes and zygotes, and was excluded from regions of cell-cell contact in cleavage-stage embryos. Trim-away-mediated knockdown of ZP3 in fertilized oocytes hampered the first zygotic cleavage, while ZP3 overexpression supported blastocyst formation. Transcriptome analysis of ZP3-knockdown embryos pointed at defects of cytoplasmic translation in the context of embryonic genome activation. This conclusion was supported by reduced protein synthesis in the ZP3-knockdown and by the lack of cleavage arrest when Trim-away was postponed from the one-cell to the late two-cell stage. These data place constraints on the notion that zona proteins only operate in the extracellular space, revealing also a role during the oocyte-to-embryo transition. Ultimately, these data recruit ZP3 into the family of maternal factors that contribute to developmental competence of mouse oocytes.

Exercise-induced circular RNA circUtrn is required for cardiac physiological hypertrophy and prevents myocardial ischaemia-reperfusion injury.

Regular exercise training benefits cardiovascular health and effectively reduces the risk for cardiovascular disease. Circular RNAs (circRNAs) play important roles in cardiac pathophysiology. However, the role of circRNAs in response to exercise training and biological mechanisms responsible for exercise-induced cardiac protection remain largely unknown. RNA sequencing was used to profile circRNA expression in adult mouse cardiomyocytes that were isolated from mice with or without exercise training. Exercise-induced circRNA circUtrn was significantly increased in swimming-trained adult mouse cardiomyocytes. In vivo, circUtrn was found to be required for exercise-induced physiological cardiac hypertrophy. circUtrn inhibition abolished the protective effects of exercise on myocardial ischaemia-reperfusion remodelling. circUtrn overexpression prevented myocardial ischaemia-reperfusion-induced acute injury and pathological cardiac remodelling. In vitro, overexpression of circUtrn promoted H9 human embryonic stem cell-induced cardiomyocyte growth and survival via protein phosphatase 5 (PP5). Mechanistically, circUtrn directly bound to PP5 and regulated the stability of PP5 in a ubiquitin-proteasome-dependent manner. Hypoxia-inducible factor 1α-dependent splicing factor SF3B1 acted as an upstream regulator of circUtrn in cardiomyocytes. The circRNA circUtrn is upregulated upon exercise training in the heart. Overexpression of circUtrn can prevent myocardial I/R-induced injury and pathological cardiac remodelling.

Effect of Soaking Java barb (Baryoniums gonionotus) Eggs in Jatropha Leaf Solution (Jatropha curcas L.) on Their Hatching and Survival Rate

The biggest problem that often found in barb hatcheries are the poor hatching rate of eggs. One of the causes of low hatchability is infestation of fungi such as Saprolegnia sp. Prevention of the infestation of fungi could be done by adding natural ingredients such as plants leaves that contain antifungal, such as Jatropha leaf. Soaking Jatropha leaf solution aims to protect the chorion from being infestated by fungi so that it can minimize hatching failure of eggs. The purpose of this study was to determine the effect of soaking Jatropha (Jatropha curcas L.) leaf solution on the hatching rate and survival rate of Java barb (Barbonymus gonionotus) eggs. The testing eggs which were used on this study were originated from male and female broodstock aged 1-1.5 years. Experimental method was carried out using a completely randomized design (CRD) consisting of 4 treatments and 5 replications. The treatments were Jatropha leaf solution at dosages of A (0 g/l), B (2 g/l), C (4 g/l), and D (6 g/l). The data observed were embryonic development, hatching rate (HR), survival rate (SR), and water quality. The results showed that treatments C and D demonstrated fastest embryonic development and hatching phase achieved at 475 minutes. Furthermore, treatment C showed the best value with HR (84.00±3.16%), SR (85.24±1.00%). It can be concluded that soaking eggs using Jatropha leaf solution at concentration of 4 g/L significantly improved hatching rate and survival rate of Java barb (Barbonymus gonionotus). Keywords: Jatropha, Java barb eggs, hatchability, fungi

Embryonic development, survival and growth of triploid Zebra Clam II strain of the Manila clam Ruditapes philippinarum

Triploid breeding with large individuals, high yield, and excellent disease resistance is widely used in aquaculture. However, the functional roles of triploid in the Zebra Calm II strain of Manila clam Ruditapes philippinarum has not been highlighted. In this study, the Zebra Clam II strain of the Manila clams were treated with cytochalasin B (CB) at a final concentration of 0.5 mg/L at 26 °C for 17 min to induce triploidity. The results showed that triploid induction rate of first-hatched D-larvae was 64.73 % and the triploid proportion of 180-day-old larvae was 72.5 %. Furthermore, the hatching rate in triploid (60.54 ± 2.19 %) was significantly lower than that in the control group (92.47 ± 0.58 %) (p < 0.05). Moreover, the development time of D-larvae in the experimental group was delayed by 145 min, and the survival rate of 15-day-old larvae in experimental group (46.08 ± 4.49 %) was significantly lower than that in the control group (62.57 ± 2.68 %) (p < 0.05), but have no significantly changes in the survival rate of triploids in larval to adult stages (p > 0.05). However, the daily relative growth rate of experimental group was significantly higher than that the control group at all daily ages except 360 days (p < 0.05). Moreover, at 480 days of larvae, the growth of the shell length and shell width in the experimental group was 19.2 % and 22.3 % higher than that in the control group, respectively. Altogether, the results in this study provide a scientific basis for the triploid breeding of Zebra Clam Ⅱ, which has great potential to improve the quality and efficiency of clam farming.

Interaction effect of mutations in the genes (piwi and aub) of the Argonaute family and hobo transposons on the integral survival parameters of Drosophila melanogaster.

The Argonaute family genes (piwi and aub) involved in the production of small RNAs are responsible for the regulation of many cellular processes, including the suppression of genome instability, modulation of gene activity, and transposable elements. Dysfunction of these genes and the associated activation of transposable elements adversely affect reproductive development and quality of life. The role of transposons in contrast to retrotransposons and their interaction with genes of the Argonaute family in aging processes have not been studied. This study considers a scenario in which the piwi and aub genes in the presence of functional hobo transposons can modify the effects from the level of DNA damage to lifespan. The simultaneous presence of mutation (piwi or aub) and hobo (regardless of size) in the genome has practically no effect or (less often) leads to a decrease in the level of DNA damage in ovarian cells. A high level of sterility and low ovarian reserve were noted mainly with a combination of mutations and full-sized hobo elements. The combination of these two genetic factors negatively affects the fertility of young females and embryonic survival. Isolated cases of restoration of reproductive functions with age were noted but only in females that had low fertility in the early period of life. The presence of hobo transposons contributed to an increase in the lifespan of both mutant and non-mutant females. Dysfunction of the piwi and aub genes (without hobo) can reduce the lifespan of both sexes. Together, each mutation and hobo transposons act antagonistically/additively (in females) and synergistically/antagonistically (in males) to change the lifespan. In parameters of locus-specific instability, hobo activation was more pronounced in piwi gene dysfunction. The results obtained complement data on the study of new functions of Argonaute family genes and their interactions with transposable elements in the aging process.

Influence of superovulation on the production of native Vietnamese pig embryos in vivo and embryonic survival after vitrified-thawed

We aimed to evaluate the influence of superovulation on the production of native Vietnamese pig embryos in vivo and embryonic survival after vitrified-thawed. The average number of follicles, corpora lutea, and recovered embryos of the superovulation group was higher than non-superovulation group (13.56 vs. 7.45, 12.32 vs. 6.12, and 10.91 vs. 5.67; P < 0.05, respectively). The average number of follicles of 4th repeated superovulation was lower than the first, second, and third repeated superovulation (10.57 vs. 13.56, 12.91, and 12.32, P < 0.05, respectively). The average number of corpora lutea and recovered embryos of 4th and third repeated superovulation was lower than first and second superovulation (9.57 and 7.58 vs. 12.32 and 11.84, 10.91 and 9.28 vs. 6.86 and 5.42, P < 0.05, respectively). The average number of follicles of the Co Binh Thuan pig was higher compared to Muong Te pig (16.78 vs. 14.58, P > 0.05, respectively) and Kieng Sat pig (16.78 vs. 13.56, P < 0.05, respectively). The average number of corpora lutea and recovered embryos of the Co Binh Thuan pig was higher than Muong Te pig and Kieng Sat pig (16.14 vs. 12.36, and 12.32, 14.34 vs. 10.98 and 10.91, P < 0.05, respectively). There was no difference in survival and hatching blastocyst rates of native Vietnamese pig embryos in vivo after thawing between breeds (P > 0.05). When vitrified-thawed pig embryos in vivo were transferred, 3 out of 5 recipients became pregnant at Day 60 and one recipient miscarried at Day 31 after embryo transfer. In conclusion, superovulation improved the production of native Vietnamese pig embryos in vivo, the highest number of repeated superovulation on the native Vietnamese pig breeds was four times and the breed affected the superovulation parameters evaluated. We successfully created pregnant pigs after transferring vitrified-thawed embryos in vivo of native Vietnamese pigs for the first time.

CRIOTOLERANCIA DE EMBRIONES BOVINOS CULTIVADOS INDIVIDUALMENTE EN UN MEDIO SUPLEMENTADO CON L-CARNITINA

&lt;p&gt;&lt;strong&gt;Background:&lt;/strong&gt; L-carnitine is a lipid metabolism enhancer and a potent antioxidant that prevents oxidative damage and improves cryotolerance of bovine embryos. &lt;strong&gt;Objective:&lt;/strong&gt; To determine the effect of L-carnitine during oocyte maturation on developmental competence and cryotolerance of single bovine embryo cultured. &lt;strong&gt;Methodology:&lt;/strong&gt; Embryos were produced in vitro using abattoir-derived cumulus-oocyte complexes (COCs). In experiment 1, two individual maturation, fertilization and culture systems were used in 24-well plates with 20 µL drops of medium covered with mineral oil and 96-well plates with 30 µL drops of medium. In experiment 2, oocytes were randomly distributed into two groups and single matured in 96-well plates in medium supplemented or not with 0.6mg/mL L-carnitine. On day 7 post fertilization, blastocysts were vitrified on solid surface in Fiberplug. Non-vitrified blastocysts were used as control. Embryonic survival after devitrification was determined by blastocysts re-expansion and hatching rate at 24 and 48 hours of post-devitrification culture. Total cell number and apoptotic rate by TUNEL-DAPI staining were used as quality and cryotolerance indicator. In both cases, cleavage and blastocyst rates were evaluated at 48 hours and 7 days post fertilization, respectively. &lt;strong&gt;Results:&lt;/strong&gt; No significant differences were found for embryonic development between single culture systems. There was no effect of L-carnitine supplementation during maturation on embryo development, but embryo survival had increased (P &amp;lt; 0.05) at 24- and 48-hours post devitrification. &lt;strong&gt;Implications:&lt;/strong&gt; Treatment with L-carnitine had increased (P &amp;lt; 0.05) post-thaw re-expansion rates (86.8 ± 3.0 vs 70.0 ± 4.4) and it was similar to non-vitrified control (89.7 ± 2.6). Mean cell number and apoptotic cell index, were similar for all treatment groups. &lt;strong&gt;Conclusion:&lt;/strong&gt; L-carnitine supplementation during maturation, does not improve division rate and subsequent development of single cultured embryos, however increases cryotolerance post devitrification.&lt;/p&gt;

Newt A1 cell-derived extracellular vesicles promote mammalian nerve growth

Newts have the extraordinary ability to fully regenerate lost or damaged cardiac, neural and retinal tissues, and even amputated limbs. In contrast, mammals lack these broad regenerative capabilities. While the molecular basis of newts’ regenerative ability is the subject of active study, the underlying paracrine signaling factors involved remain largely uncharacterized. Extracellular vesicles (EVs) play an important role in cell-to-cell communication via EV cargo-mediated regulation of gene expression patterns within the recipient cells. Here, we report that newt myogenic precursor (A1) cells secrete EVs (A1EVs) that contain messenger RNAs associated with early embryonic development, neuronal differentiation, and cell survival. Exposure of rat primary superior cervical ganglion (SCG) neurons to A1EVs increased neurite outgrowth, facilitated by increases in mitochondrial respiration. Canonical pathway analysis pinpointed activation of NGF/ERK5 signaling in SCG neurons exposed to A1EV, which was validated experimentally. Thus, newt EVs drive neurite growth and complexity in mammalian primary neurons.

Sphk1 deficiency induces apoptosis and developmental defects and premature death in zebrafish.

The sphk1 gene plays a crucial role in cell growth and signal transduction. However, the developmental functions of the sphk1 gene during early vertebrate zebrafish embryo remain not completely understood. In this study, we constructed zebrafish sphk1 mutants through CRISPR/Cas9 to investigate its role in zebrafish embryonic development. Knockout of the sphk1 gene was found to cause abnormal development in zebrafish embryos, such as darkening and atrophy of the head, trunk deformities, pericardial edema, retarded yolk sac development, reduced heart rate, and premature death. The acetylcholinesterase activity was significantly increased after the knockout of sphk1, and some of the neurodevelopmental genes and neurotransmission system-related genes were expressed abnormally. The deletion of sphk1 led to abnormal expression of immune genes, as well as a significant decrease in the number of hematopoietic stem cells and neutrophils. The mRNA levels of cardiac development-related genes were significantly decreased. In addition, cell apoptosis increases in the sphk1 mutants, and the proliferation of head cells decreases. Therefore, our study has shown that the sphk1 is a key gene for zebrafish embryonic survival and regulation of organ development. It deepened our understanding of its physiological function. Our study lays the foundation for investigating the mechanism of the sphk1 gene in early zebrafish embryonic development.