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The International Journal of... Mar 1990The organization and role of the cytoskeletal networks (mainly microtubules and microfilaments) during oogenesis, fertilization and preimplantation development of the... (Review)
Review
The organization and role of the cytoskeletal networks (mainly microtubules and microfilaments) during oogenesis, fertilization and preimplantation development of the mouse are described given the importance of cell-cell interactions and of the subcellular organization in events leading to the formation of the first two lineages of the mouse embryo.
Topics: Animals; Blastocyst; Cell Division; Cytoskeleton; Female; Fertilization; Mice; Models, Biological; Ovum
PubMed: 2203452
DOI: No ID Found -
PloS One 2013This study was undertaken to elucidate detailed event of early embryogenesis in chicken embryos using a noninvasive egg retrieval technique before oviposition. White...
This study was undertaken to elucidate detailed event of early embryogenesis in chicken embryos using a noninvasive egg retrieval technique before oviposition. White Leghorn intrauterine eggs were retrieved from 95 cyclic hens aged up to 54-56 weeks and morphogenetic observation was made under both bright field and fluorescent image in a time course manner. Differing from mammals, asymmetric cleavage to yield preblastodermal cells was observed throughout early embryogenesis. The first two divisions occurred synchronously and four polarized preblastodermal cells resulted after cruciform cleavage. Then, asynchronous cleavage continued in a radial manner and overall cell size in the initial cleavage region was smaller than that in the distal area. Numerous sperms were visible, regardless of zygotic nuclei formation. Condensed sperm heads were present mainly in the perivitelline space and cytoplasm, and rarely in the yolk region, while decondensed sperm heads were only visible in the yolk. In conclusion, apparent differences in sperm dynamics and early cleavage events compared with mammalian embryos were detected in chick embryo development, which demonstrated polarized cleavage with penetrating supernumerary sperm into multiple regions.
Topics: Animals; Chick Embryo; Chickens; Cytokinesis; Embryo, Nonmammalian; Female; Male; Ovum; Sperm-Ovum Interactions; Spermatozoa
PubMed: 24244702
DOI: 10.1371/journal.pone.0080631 -
Poultry Science Nov 2019The purpose of the current study was to investigate the effect of choline as a means of increasing docosahexaenoic acid (22:6 n-3, DHA) deposition in egg yolks of hens...
The purpose of the current study was to investigate the effect of choline as a means of increasing docosahexaenoic acid (22:6 n-3, DHA) deposition in egg yolks of hens fed a high-DHA microalgae product. Fifty-six, 26-wk-old, White Leghorn hens were kept in individual cages and randomly allocated to 1 of 4 dietary treatments, each with 7 replicate groups of 2 hens (n = 7 per treatment). The experimental diets were corn and soybean meal based, with 0% microalgae (control), 1% microalgae and no additional choline chloride (Alg), and Alg plus choline chloride at 0.1% (Ch0.1) and 0.2% (Ch0.2). The feeding trial lasted 16 wk. The data were fit as a general linear mixed model to generate least square means in response to diet. Variables measured multiple times during the study were fit as repeated measures. Using orthogonal contrasts, Alg was compared to control, and Ch0.1 and Ch0.2 were compared separately to Alg. Ch0.1 increased hen day egg production (P < 0.05) and Haugh unit (P < 0.05), and reduced feed conversion ratio (P < 0.05) compared to Alg, but Ch0.2 did not. Alg increased egg DHA (P < 0.001), phosphatidylethanolamine (P < 0.05), and phosphatidylcholine (P < 0.001) compared to control, but Ch0.1 or Ch0.2 had no effect compared to Alg (P > 0.05). In the liver, Alg increased lipid peroxidation products compared to control (P < 0.01), and Ch0.1 reduced them compared to Alg (P < 0.01). Both Ch0.1 and Ch0.2 increased hepatic concentrations of γ- (P < 0.05; P < 0.001) and α-tocopherol (P < 0.01; P < 0.001), and Ch0.1 increased γ-tocopherol concentration in eggs compared to Alg (P < 0.05). The results from the current study suggest that supplemental choline chloride in hen diets containing microalgae can improve production performance and egg quality, and protect the liver from oxidative stress.
Topics: Animal Feed; Animals; Chickens; Choline; Diet; Dietary Supplements; Docosahexaenoic Acids; Dose-Response Relationship, Drug; Female; Liver; Microalgae; Ovum; Oxidative Stress; Random Allocation; Reproduction
PubMed: 31222319
DOI: 10.3382/ps/pez339 -
Journal of Assisted Reproduction and... 2007Exposure to visible light (400-700 nm wavelengths) is an unnatural stress factor to preimplantation embryos cultured in vitro. This study investigated the spectral...
Exposure to visible light (400-700 nm wavelengths) is an unnatural stress factor to preimplantation embryos cultured in vitro. This study investigated the spectral composition and intensity of light during IVF procedures, and calculated radiation doses reaching the embryo during handling and manipulation. The study shows that normal IVF procedure may result in stressing radiation doses, unless filters are applied. This is at present not sufficiently recognised. No Danish IVF clinics use filters to protect embryos against visible light. 95% of the radiation was from microscopes. Ambient light, in contrast, was not a significant contributor to light stress and the use of dark laboratories is not justified.
Topics: Blastocyst; Embryo Culture Techniques; Embryonic Development; Fertilization in Vitro; Humans; Light; Ovum
PubMed: 17216346
DOI: 10.1007/s10815-006-9081-x -
Fertility and Sterility 1958
Topics: Disorders of Sex Development; Gonads; Humans; Male; Oocytes; Ovum; Seminiferous Tubules
PubMed: 13501267
DOI: 10.1016/s0015-0282(16)32943-0 -
PloS One 2012Clonorchis sinensis is a carcinogenic human liver fluke. The present study monitored eggs produced by long-term maintained adult worms of C. sinensis to confirm their...
Clonorchis sinensis is a carcinogenic human liver fluke. The present study monitored eggs produced by long-term maintained adult worms of C. sinensis to confirm their egg productivity in vitro. The worms from infected rabbits were incubated in vitro in 1× Locke's solution and broth media (RPMI-1640, DMEM and IMDM). Numbers of expelled eggs were counted sequentially and their morphological changes were monitored by microscopy after 1, 30, 60, and 90 days of cultivation. On the 1-3 days of cultivation, the eggs counted maximum 4,756±202 eggs/worm/day in IMDM medium. The number of eggs gradually decreased less than 1,000 at 7-14 days and below 100 at 21days but continued to pass eggs after 56 days in all media. Length of the eggs were reduced about 1 µm at 30 days, and the length/width ratio was maintained around 1.8 at 30 days but decreased to 1.7 at 60 days and 1.5 at 90 days. Faust-Meleney index (FMI) decreased as the cultivation duration increased and lowest FMI (5662.9±974.7) observed in IMDM media at day 90 (P = 0.001). Microscopic findings of the eggs recognized the miracidium in most of eggs at 60 days but not in those at 90 days. Instead, the eggs contained dark granules or vacuoles in the deformed shell at 90 days. Scanning electron microscopy revealed partial loss of wrinkles on the deformed egg surface and prominent abopercular knob. Eggs viability decreased as the cultivation progressed and showed significant positive correlation with FMI and length/width ratio. In conclusion, the cultivated worms pass only the eggs which are preformed in their uterus before cultivation. One gravid C. sinensis contains about 37,000 eggs in its uterus and produces about 4,000 eggs every day. The deformed eggs with FMI less than 7,000 and length/width ratio lower than 1.7 are non-viable.
Topics: Animals; Cell Survival; Clonorchis sinensis; Male; Ovum; Rabbits; Reproduction
PubMed: 23285144
DOI: 10.1371/journal.pone.0052676 -
Poultry Science Jun 2012Genetic parameters were estimated for egg defects, egg production, and egg quality traits. Eggs from 11,738 purebred brown-egg laying hens were classified as salable or...
Genetic parameters were estimated for egg defects, egg production, and egg quality traits. Eggs from 11,738 purebred brown-egg laying hens were classified as salable or as having one of the following defects: bloody, broken, calcium deposit, dirty, double yolk, misshapen, pee-wee, shell-less, and soft shelled. Egg quality included albumen height, egg weight, yolk weight, and puncture score. Body weight, age at sexual maturity, and egg production were also recorded. Heritability estimates of liability to defects using a threshold animal model were less than 0.1 for bloody and dirty; between 0.1 and 0.2 for pee-wee, broken, misshapen, soft shelled, and shell-less; and above 0.2 for calcium deposit and double yolk. Quality and production traits were more heritable, with estimates ranging from 0.29 (puncture score) to 0.74 (egg weight). High-producing hens had a lower frequency of egg defects. High egg weight and BW were associated with an increased frequency of double yolks, and to a lesser extent, with more shell quality defects. Estimates of genetic correlations among defect traits that were related to shell quality were positive and moderate to strong (0.24-0.73), suggesting that these could be grouped into one category or selection could be based on the trait with the highest heritability or that is easiest to measure. Selection against defective eggs would be more efficient by including egg defect traits in the selection criterion, along with egg production rate of salable eggs and egg quality traits.
Topics: Animal Husbandry; Animals; Chickens; Egg Shell; Egg Yolk; Eggs; Female; Genetic Variation; Models, Biological; Ovum; Phenotype; Quantitative Trait, Heritable; Selection, Genetic; Time Factors
PubMed: 22582285
DOI: 10.3382/ps.2011-02130 -
Poultry Science May 2014Egg producers in the United States are utilizing a variety of commercial egg production systems to provide consumer choice and meet legislative requirements. Consumer...
Egg producers in the United States are utilizing a variety of commercial egg production systems to provide consumer choice and meet legislative requirements. Consumer egg grades in the United States were developed for conventional cage production, and it is unclear what effect alternative production systems might have on egg quality during retail and consumer home storage. The current study was undertaken to determine what changes in egg quality characteristics occur during extended cold storage for commercially produced conventional cage, enriched colony cage, and cage-free aviary eggs. During 12 wk of cold storage, egg weight, albumen height, Haugh unit, static compression shell strength, vitelline membrane strength and deformation, yolk index, shell dynamic stiffness, and whole egg total solids were monitored. Overall, aviary and enriched eggs were significantly (P < 0.05) heavier than conventional cage. Albumen height and Haugh unit (P < 0.05) were significantly greater for conventional cage than enriched eggs. Static compression shell strength was greatest (P < 0.05) for enriched eggs compared with aviary. No overall housing system effects for yolk measurements, shell dynamic stiffness, or whole egg total solids were observed. Albumen height, Haugh unit, and yolk quality measurements were all greatest at 0 and lowest at 12 wk of storage (P < 0.05). The rate of quality change among the housing systems for each measured attribute at 4, 6, and 12 wk was determined. Other than differences in the change of egg weight at 4 wk, no significant differences in the rate of quality decline were found among the housing systems. The results of the current study indicate that current US egg quality standards should effectively define quality for commercially produced conventional cage, enriched colony cage, and cage-free aviary eggs.
Topics: Animal Husbandry; Animals; Chickens; Cold Temperature; Female; Food Storage; Housing, Animal; Ovum
PubMed: 24795324
DOI: 10.3382/ps.2013-03631 -
Poultry Science Aug 2011It is well known that egg storage reduces embryo performance, but the fundamental reasons for reduced embryo quality remain unclear. The objective of this study was to...
It is well known that egg storage reduces embryo performance, but the fundamental reasons for reduced embryo quality remain unclear. The objective of this study was to investigate possible cellular and molecular mechanisms that might reduce embryo quality after egg storage. Broiler hatching eggs were obtained from the Ross 308 broiler strain, divided into 2 groups, and stored (4 and 14 d) under the same temperature and humidity conditions. Samples of the eggs were used to assess embryo quality by determining daily embryo weight (wet and dry) from 4 to 21 d of incubation. To understand possible cellular and molecular mechanisms that might affect embryo quality, blastoderms (unincubated embryos) were isolated from a sample of eggs from each storage group, dissociated into single cells, and subjected to flow cytometry analysis to differentiate between viable, apoptotic, and necrotic cell populations. Quantitative real-time PCR analysis was used to compare the expression of selected apoptotic genes (Bcl-2 homologous antagonist/killer gene, Bcl-2-associated X gene, Bcl-2-related ovarian killer gene, B-cell lymphoma 2 gene, and B-cell lymphoma xL gene) in blastoderms and embryos (6 d old after incubation). Data were analyzed by the MIXED model procedure of SAS (SAS Institute, Cary, NC), with significance set at P ≤ 0.05. After covariance analysis of initial egg weights, the results showed decreased daily embryo weights (wet and dry), an indication of decreased embryo quality that could affect hatch quality. In addition, a decrease in blastodermal cell viability was associated with an increased percentage of apoptotic cell deaths (P < 0.0001). Expression of pro-apoptotic genes (Bcl-2 homologous antagonist/killer gene, Bcl-2-associated X gene, and Bcl-2-related ovarian killer gene) were upregulated at the blastodermal level as the storage duration increased, but all genes were downregulated after 6 d of incubation. This suggests that an increase in egg storage duration could activate mechanisms of apoptotic cell death at the blastodermal level, which may be one of the molecular mechanisms that leads to reduced daily embryonic weight during incubation. Experimental controls capable of reducing the cellular and molecular mechanisms of egg storage should be used to increase embryo quality.
Topics: Animals; Blastoderm; Cell Death; Cell Survival; Chick Embryo; Chickens; Gene Expression Regulation, Developmental; Ovum; RNA; Time Factors
PubMed: 21753212
DOI: 10.3382/ps.2011-01361 -
Developmental Biology Jun 2003Fertilization-induced intracellular calcium (Ca(2+)) oscillations stimulate the onset of mammalian development, and little is known about the biochemical mechanism by...
Fertilization-induced intracellular calcium (Ca(2+)) oscillations stimulate the onset of mammalian development, and little is known about the biochemical mechanism by which these Ca(2+) signals are transduced into the events of egg activation. This study addresses the hypothesis that transient increases in Ca(2+) similar to those at fertilization stimulate oscillatory Ca(2+)/calmodulin-dependent kinase II (CaMKII) enzyme activity, incrementally driving the events of egg activation. Since groups of fertilized eggs normally oscillate asynchronously, synchronous oscillatory Ca(2+) signaling with a frequency similar to fertilization was experimentally induced in unfertilized mouse eggs by using ionomycin and manipulating extracellular calcium. Coanalysis of intracellular Ca(2+) levels and CaMKII activity in the same population of eggs demonstrated a rapid and transient enzyme response to each increase in Ca(2+). Enzyme activity increased 370% during the first Ca(2+) rise, representing about 60% of maximal activity, and had decreased to basal levels within 5 min from the time Ca(2+) reached its peak value. Single fertilized eggs monitored for Ca(2+) had a mean increase in CaMKII activity of 185%. One and two ionomycin-induced Ca(2+) transients resulted in 39 and 49% mean cortical granule (CG) loss, respectively, while CG exocytosis and resumption of meiosis were inhibited by a CaMKII antagonist. These studies demonstrate that changes in the level of Ca(2+) and in CaMKII activity can be studied in the same cell and that CaMKII activity is exquisitely sensitive to experimentally induced oscillations of Ca(2+) in vivo. The data support the hypothesis that CaMKII activity oscillates for a period of time after normal fertilization and temporally regulates many events of egg activation.
Topics: Animals; Calcium Signaling; Calcium-Calmodulin-Dependent Protein Kinase Type 2; Calcium-Calmodulin-Dependent Protein Kinases; Enzyme Activation; Enzyme Inhibitors; Exocytosis; Female; Fertilization; Fertilization in Vitro; In Vitro Techniques; Ionomycin; Mice; Ovum
PubMed: 12798302
DOI: 10.1016/s0012-1606(03)00133-7