Journal articles: 'Cell-Embryo'

1

HOGUE, CHERYL. "EMBRYO STEM CELL SAND RESEARCH." Chemical & Engineering News 79, no. 29 (July 16, 2001): 21. http://dx.doi.org/10.1021/cen-v079n029.p021.

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Barone, Vanessa, and Carl-Philipp Heisenberg. "Cell adhesion in embryo morphogenesis." Current Opinion in Cell Biology 24, no. 1 (February 2012): 148–53. http://dx.doi.org/10.1016/j.ceb.2011.11.006.

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Yang, Yi, Jia-Peng He, and Ji-Long Liu. "Cell–Cell Communication at the Embryo Implantation Site of Mouse Uterus Revealed by Single-Cell Analysis." International Journal of Molecular Sciences 22, no. 10 (May 13, 2021): 5177. http://dx.doi.org/10.3390/ijms22105177.

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As a crucial step for human reproduction, embryo implantation is a low-efficiency process. Despite rapid advances in recent years, the molecular mechanism underlying embryo implantation remains poorly understood. Here, we used the mouse as an animal model and generated a single-cell transcriptomic atlas of embryo implantation sites. By analyzing inter-implantation sites of the uterus as control, we were able to identify global gene expression changes associated with embryo implantation in each cell type. Additionally, we predicted signaling interactions between uterine luminal epithelial cells and mural trophectoderm of blastocysts, which represent the key mechanism of embryo implantation. We also predicted signaling interactions between uterine epithelial-stromal crosstalk at implantation sites, which are crucial for post-implantation development. Our data provide a valuable resource for deciphering the molecular mechanism underlying embryo implantation.

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Liu, Yuan, Xinbo Li, Jing Zhao, Xingchun Tang, Shujuan Tian, Junyi Chen, Ce Shi, et al. "Direct evidence that suspensor cells have embryogenic potential that is suppressed by the embryo proper during normal embryogenesis." Proceedings of the National Academy of Sciences 112, no. 40 (September 22, 2015): 12432–37. http://dx.doi.org/10.1073/pnas.1508651112.

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The suspensor is a temporary supporting structure of proembryos. It has been proposed that suspensor cells also possess embryogenic potential, which is suppressed by the embryo as an effect of the embryo–suspensor interaction. However, data to support this hypothesis are not yet available. In this report, using an in vivo living cell laser ablation technique, we show that Arabidopsis suspensor cells can develop into embryos after removing the embryo proper. The embryo proper plays a critical role in maintaining suspensor cell identity. However, this depends on the developmental stage; after the globular embryo stage, the suspensors no longer possess the potential to develop into embryos. We also reveal that hypophysis formation may be essential for embryo differentiation. Furthermore, we show that, after removing the embryo, auxin gradually accumulates in the top suspensor cell where cell division occurs to produce an embryo. Auxin redistribution likely reprograms the fate of the suspensor cell and triggers embryogenesis in suspensor cells. Thus, we provide direct evidence that the embryo suppresses the embryogenic potential of suspensor cells.

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Yeung, Edward C., and Sandra K. Law. "Embryology of Calypso bulbosa. II. Embryo development." Canadian Journal of Botany 70, no. 3 (March 1, 1992): 461–68. http://dx.doi.org/10.1139/b92-061.

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Calypso bulbosa is a terrestrial orchid that grows in north temperate regions. After fertilization, the zygote enlarges and grows towards the chalazal end of the embryo sac. An unequal cell division gives rise to a smaller terminal cell and a larger basal cell. A constriction forms in the basal cell. Further growth results in a U-shaped embryo. Two patterns of initial terminal cell division have been observed. In a majority of developing embryos, the terminal cell first divides periclinally and then anticlinally. In approximately 5% of the embryos, the initial division of the terminal cell is anticlinal. Despite differences in early cell division patterns, subsequent embryo development is the same. The suspensor consists of a large, highly vacuolated basal cell and a 4-celled filamentous region. Highly conspicuous starch granules are present within the basal cell of the suspensor. At maturity, the embryo proper is small, consisting of approximately 24 cells and lacking marked differentiation of the apical end. Starch and lipid are the main storage products within the embryo proper. Key words: Calypso orchids, embryo development, suspensor.

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Bedzhov, Ivan, Sarah J. L. Graham, Chuen Yan Leung, and Magdalena Zernicka-Goetz. "Developmental plasticity, cell fate specification and morphogenesis in the early mouse embryo." Philosophical Transactions of the Royal Society B: Biological Sciences 369, no. 1657 (December 5, 2014): 20130538. http://dx.doi.org/10.1098/rstb.2013.0538.

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A critical point in mammalian development is when the early embryo implants into its mother's uterus. This event has historically been difficult to study due to the fact that it occurs within the maternal tissue and therefore is hidden from view. In this review, we discuss how the mouse embryo is prepared for implantation and the molecular mechanisms involved in directing and coordinating this crucial event. Prior to implantation, the cells of the embryo are specified as precursors of future embryonic and extra-embryonic lineages. These preimplantation cell fate decisions rely on a combination of factors including cell polarity, position and cell–cell signalling and are influenced by the heterogeneity between early embryo cells. At the point of implantation, signalling events between the embryo and mother, and between the embryonic and extraembryonic compartments of the embryo itself, orchestrate a total reorganization of the embryo, coupled with a burst of cell proliferation. New developments in embryo culture and imaging techniques have recently revealed the growth and morphogenesis of the embryo at the time of implantation, leading to a new model for the blastocyst to egg cylinder transition. In this model, pluripotent cells that will give rise to the fetus self-organize into a polarized three-dimensional rosette-like structure that initiates egg cylinder formation.

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KWON, Ivo. "EU Policy and Legislation on Stem Cell Research." Korean Journal of Medical Ethics 7, no. 2 (December 2004): 247–57. http://dx.doi.org/10.35301/ksme.2004.7.2.247.

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EU policy on the research of the human embryo and stem cell is based on the 1997 Convention - Convention for the Protection of Human Rights and Dignity of the Human Being with regard to the Application of Biology and Medicine : Convention on Human Rights and Biomedicine. The purpose of this convention is to protect the dignity and identity of all human beings without discrimination, respect for their integrity and other rights and fundamental freedoms with regard to the application of biology and medicine. Applying this convention's view to the human embryo and stem cell research, 1) the human embryo research can only be permitted only if it protect the embryo for the purpose of the health and medicine. 2) Making human embryo is prohibited by any method-IVF or SCNT technique. 3) Other stem cell resources(adult stem cell, cord blood stem cell, etc) can be used under the condition of full informed consent without any financial interest of the donor. 4) In all cases, the privacy and human right as well as health of all related persons should be guaranteed. As a result, the research on the human embryo and stem cell has not been done actively except in few country. But now most member states permit stem cell research using spare embryo, but prohibit therapeutic cloning by SCNT. However EU itself has failed to agree with to fund the scientific research on stem cell using spare embryo. It is hardly to say the decision on stem cell research in the future by EU, but EU will continue to stress on the basic human right, social justice and human freedom in the field of biotechnology and its applications.

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8

Zhang, M., L. Sui, Y. Li, Z. Chen, Y. Zhang, T. Liu, J. Xu, X. Zhang, and Y. Zhang. "96 EFFECT OF TWO DIFFERENT EMBRYO TRANSPORTERS ON DEVELOPMENT OF PORCINE PARTHENOGENETIC EMBRYOS." Reproduction, Fertility and Development 26, no. 1 (2014): 162. http://dx.doi.org/10.1071/rdv26n1ab96.

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In the present study, we investigated two embryo transport methods, including a commercial cell transporter and a self-made, simple embryo transporter, for the pre-implantation development of porcine parthenogenetic embryos. The cleaved embryos were randomly distributed between the two types of embryo transport methods and were conserved in vitro for 2, 3, and 4 h. Embryo development efficiency testing and blastocyst differential staining were utilized to assess embryo developmental quality. There were no significant differences in embryo early development efficiency between the commercial cell transporter group, self-made embryo transporter group, and control group. The blastocyst hatch rate (7.75 ± 2.96%) in the self-made simple embryo transport method maintained for 3 h was significantly higher compared to the other groups (P < 0.05). The results (Table 1) showed that blastocyst differential staining showed that the ratio of inner cell mass (ICM) to total cells in both the 2-h-transport group and 3-h-transport group from the self-made simple embryo transport method and the 4-h-transport group from the commercial cell transporter were significantly higher than other groups (P < 0.05).The self-made simple embryo transporter and commercial cell transporter are both effective for transport and conservation of embryos for 3 h. Table 1.Effect of different modes of transport and transit time on embryo development1

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9

Raz, V., J. H. Bergervoet, and M. Koornneef. "Sequential steps for developmental arrest in Arabidopsis seeds." Development 128, no. 2 (January 15, 2001): 243–52. http://dx.doi.org/10.1242/dev.128.2.243.

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The continuous growth of the plant embryo is interrupted during the seed maturation processes which results in a dormant seed. The embryo continues development after germination when it grows into a seedling. The embryo growth phase starts after morphogenesis and ends when the embryo fills the seed sac. Very little is known about the processes regulating this phase. We describe mutants that affect embryo growth in two sequential developmental stages. Firstly, embryo growth arrest is regulated by the FUS3/LEC type genes, as mutations in these genes cause a continuation of growth in immature embryos. Secondly, a later stage of embryo dormancy is regulated by ABI3 and abscisic acid; abi3 and aba1 mutants exhibit premature germination only after embryos mature. Mutations affecting both developmental stages result in an additive phenotype and double mutants are highly viviparous. Embryo growth arrest is regulated by cell division activities in both the embryo and the endosperm, which are gradually switched off at the mature embryo stage. In the fus3/lec mutants, however, cell division in both the embryo and endosperm is not arrested, but rather is prolonged throughout seed maturation. Furthermore ectopic cell division occurs in seedlings. Our results indicate that seed dormancy is secured via at least two sequential developmental processes: embryo growth arrest, which is regulated by cell division and embryo dormancy.

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10

Srivatsan, Sanjay R., Mary C. Regier, Eliza Barkan, Jennifer M. Franks, Jonathan S. Packer, Parker Grosjean, Madeleine Duran, et al. "Embryo-scale, single-cell spatial transcriptomics." Science 373, no. 6550 (July 1, 2021): 111–17. http://dx.doi.org/10.1126/science.abb9536.

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Spatial patterns of gene expression manifest at scales ranging from local (e.g., cell-cell interactions) to global (e.g., body axis patterning). However, current spatial transcriptomics methods either average local contexts or are restricted to limited fields of view. Here, we introduce sci-Space, which retains single-cell resolution while resolving spatial heterogeneity at larger scales. Applying sci-Space to developing mouse embryos, we captured approximate spatial coordinates and whole transcriptomes of about 120,000 nuclei. We identify thousands of genes exhibiting anatomically patterned expression, leverage spatial information to annotate cellular subtypes, show that cell types vary substantially in their extent of spatial patterning, and reveal correlations between pseudotime and the migratory patterns of differentiating neurons. Looking forward, we anticipate that sci-Space will facilitate the construction of spatially resolved single-cell atlases of mammalian development.

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11

Wasi, Chantapong, Paramet Chaiprasithikul, Lersuang Chavanich, Pilaipan Puthavathana, Prasert Thongcharoen, and Mukda Trishanananda. "PURIFIED CHICK EMBRYO CELL RABIES VACCINE." Lancet 327, no. 8471 (January 1986): 40. http://dx.doi.org/10.1016/s0140-6736(86)91918-5.

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12

Lallemand, Yvan, and Philippe Brûlet. "Cell lineages in early mouse embryo." Cell Differentiation and Development 27 (August 1989): 214. http://dx.doi.org/10.1016/0922-3371(89)90647-3.

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13

Polan, Mary Lake. "Embryo Altruism and Stem Cell Research." Journal of Women's Health & Gender-Based Medicine 9, no. 10 (December 2000): 1045. http://dx.doi.org/10.1089/152460900445938.

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14

Jones, Bradley W. "Glial cell development in theDrosophila embryo." BioEssays 23, no. 10 (2001): 877–87. http://dx.doi.org/10.1002/bies.1129.

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15

Schneider, S., K. Herrenknecht, S. Butz, R. Kemler, and P. Hausen. "Catenins in Xenopus embryogenesis and their relation to the cadherin-mediated cell-cell adhesion system." Development 118, no. 2 (June 1, 1993): 629–40. http://dx.doi.org/10.1242/dev.118.2.629.

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In the course of an analysis of cell-cell adhesion in the Xenopus embryo, antibodies directed against alpha- and beta-catenin were applied to investigate their relation to the cadherins occurring early in this system. The results demonstrate that alpha- and beta-catenin are provided maternally and increase in amount throughout embryogenesis. Immunoprecipitations indicate that both of the catenins are complexed to U-cadherin in the early phase of embryogenesis and to E-cadherin, when it appears during gastrulation. An excess of alpha-catenin occurs in free form in the early embryo, whereas all of the beta-catenin seems to be complexed to cadherin. Synthesis of the two components throughout early embryogenesis and their binding to newly synthesized cadherins were demonstrated by metabolic labelling. The spatial distribution of alpha-catenin was analysed by immunohistology. During cleavage alpha-catenin is deposited evenly along the plasma membranes within the embryo, while the cell peripheries at the surface of the embryo remain devoid of alpha-catenin. At later stages, the pattern of alpha-catenin distribution becomes more complex. Quantitative differences in the intensity of staining along the plasma membranes in the different regions of the embryo can be distinguished. Particularly the appearance of E-cadherin in the gastrula ectoderm is accompanied by conspicuous depositions of alpha-catenin along the respective plasma membranes in this layer. All cells in the later embryo, apart from the neural crest cells, carry alpha-catenin on their plasma membranes indicating the universal character of cadherin-mediated cell-cell adhesion in the Xenopus embryo.

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Zakhartchenko, V., E. Wolf, G. A. Palma, and G. Brem. "Effect of donor embryo cell number and cell size on the efficiency of bovine embryo cloning." Molecular Reproduction and Development 42, no. 1 (September 1995): 53–57. http://dx.doi.org/10.1002/mrd.1080420107.

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17

Świerczyńska, Joanna, and Jerzy Bohdanowicz. "Suspensor Development in Gagea Lutea (L.) Ker Gawl., with Emphasis on the Cytoskeleton." Acta Biologica Cracoviensia s. Botanica 56, no. 2 (March 1, 2015): 79–90. http://dx.doi.org/10.2478/abcsb-2014-0023.

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Abstract The study used fluorescence microscopy to examine changes in cytoskeleton configuration during development of the embryo suspensor in Gagea lutea and to describe them in tandem with the development of the embryo proper. During the early phase of embryo suspensor development, tubulin and actin filaments were observed in the cytoplasm of the basal cell from the micropylar to the chalazal ends of the cell. Around the nucleus of the basal cell were clusters of numerous microtubules. These accumulations of tubulin arrays congregated near the nucleus surface; numerous bundles of microtubules radiated from the nucleus envelope. At this time, microfil-aments formed a delicate network in the cytoplasm of the basal cell. In the fully differentiated embryo suspensor, microtubules were observed at the chalazal end of the basal cell. Numerous bundles of microtubules were visualized in the cytoplasm adjacent to the wall separating the basal cell from the embryo proper. Microfilaments formed a dense network which uniformly filled the basal cell cytoplasm. There were some foci of F-actin material in the vicinity of the nucleus surface and at the chalazal end of the basal cell. In all studied phases of embryo suspensor development a prominent cortical network of actin and tubulin skeleton was observed in embryo proper cells.

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Yang, Luhan, Claudia Baumann, Rabindranath De La Fuente, and Maria M. Viveiros. "Bisphenol Exposure Disrupts Cytoskeletal Organization and Development of Pre-Implantation Embryos." Cells 11, no. 20 (October 14, 2022): 3233. http://dx.doi.org/10.3390/cells11203233.

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The endocrine disrupting activity of bisphenol compounds is well documented, but less is known regarding their impact on cell division and early embryo formation. Here, we tested the effects of acute in vitro exposure to bisphenol A (BPA) and its common substitute, bisphenol F (BPF), during critical stages of mouse pre-implantation embryo development, including the first mitotic division, cell polarization, as well as morula and blastocyst formation. Timing of initial cleavage was determined by live-cell imaging, while subsequent divisions, cytoskeletal organization and lineage marker labeling were assessed by high-resolution fluorescence microscopy. Our analysis reveals that brief culture with BPA or BPF impeded cell division and disrupted embryo development at all stages tested. Surprisingly, BPF was more detrimental to the early embryo than BPA. Notably, poor embryo development was associated with cytoskeletal disruptions of the actomyosin network, apical domain formation during cell polarization, actin ring zippering for embryo sealing and altered cell lineage marker profiles. These results underscore that bisphenols can disrupt cytoskeletal integrity and remodeling that is vital for early embryo development and raise concerns regarding the use of BPF as a ‘safe’ BPA substitute.

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Corral-Martínez, Patricia, Charlotte Siemons, Anneke Horstman, Gerco C. Angenent, Norbert de Ruijter, and Kim Boutilier. "Live Imaging of embryogenic structures in Brassica napus microspore embryo cultures highlights the developmental plasticity of induced totipotent cells." Plant Reproduction 33, no. 3-4 (July 10, 2020): 143–58. http://dx.doi.org/10.1007/s00497-020-00391-z.

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Key message In vitro embryo development is highly plastic; embryo cell fate can be re-established in tissue culture through different pathways. Abstract In most angiosperms, embryo development from the single-celled zygote follows a defined pattern of cell divisions in which apical (embryo proper) and basal (root and suspensor) cell fates are established within the first cell divisions. By contrast, embryos that are induced in vitro in the absence of fertilization show a less regular initial cell division pattern yet develop into histodifferentiated embryos that can be converted into seedlings. We used the Brassica napus microspore embryogenesis system, in which the male gametophyte is reprogrammed in vitro to form haploid embryos, to identify the developmental fates of the different types of embryogenic structures found in culture. Using time-lapse imaging of LEAFY COTYLEDON1-expressing cells, we show that embryogenic cell clusters with very different morphologies are able to form haploid embryos. The timing of surrounding pollen wall (exine) rupture is a major determinant of cell fate in these clusters, with early exine rupture leading to the formation of suspensor-bearing embryos and late rupture to suspensorless embryos. In addition, we show that embryogenic callus, which develops into suspensor-bearing embryos, initially expresses transcripts associated with both basal- and apical-embryo cell fates, suggesting that these two cell fates are fixed later in development. This study reveals the inherent plasticity of in vitro embryo development and identifies new pathways by which embryo cell fate can be established.

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Tax, Frans E., and James H. Thomas. "Cell-Cell Interactions: Receiving signals in the nematode embryo." Current Biology 4, no. 10 (October 1994): 914–16. http://dx.doi.org/10.1016/s0960-9822(00)00203-7.

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Bossinger, Olaf, and Einhard Schierenberg. "Cell-cell communication in the embryo of Caenorhabditis elegans." Developmental Biology 151, no. 2 (June 1992): 401–9. http://dx.doi.org/10.1016/0012-1606(92)90180-o.

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Haniffa, Muzlifah, Aidan Maartens, and Sarah A. Teichmann. "How developmental cell atlases inform stem cell embryo models." Nature Methods 20, no. 12 (December 2023): 1849–51. http://dx.doi.org/10.1038/s41592-023-02072-x.

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Zaki, M., and J. Kuijt. "Ultrastructural studies on the embryo sac of Viscum minimum: II. Megagametogenesis." Canadian Journal of Botany 72, no. 11 (November 1, 1994): 1613–28. http://dx.doi.org/10.1139/b94-199.

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Embryo sac development of Viscum minimum was investigated using light and electron microscopy. Stages described involve uninucleate, binucleate, four-nucleate, and mature embryo sacs following cellularization. During the early stage of development, prior to mitosis, numerous small vacuoles are initiated in the cytoplasm of a uninucleate functional megaspore. The centrally located nucleus undergoes the first mitotic division and results in formation of two identical nuclei sharing a common cytoplasm. As the vacuole increases rapidly in size, the two nuclei become separated and move to opposite poles where the second mitotic division takes place. A remarkable elongation of the embryo sac is observed between the second and third mitotic division. Eventually, the embryo sac reaches its final length, two-thirds of the length of the ovary, at cellularization. Elongation of the embryo sac is closely related to the increase in vacuole size. Factors involved in vacuole formation and in the elongation of the embryo sac are discussed along with changes accompanying the transition from a sporophytic to a gametophytic pattern of development. Ultrastructural studies on the mature embryo sac, following cellularization, suggest that the egg cell is the least active cell in the megagametophyte. On the other hand, the synergids appear metabolically very active, being rich in plastids, mitochondria, dictyosomes, numerous vesicles, polysomes, and reserves. The central cell is the largest cell in the embryo sac. In a mature embryo sac the central cell has two adjacent nuclei, suggesting that fusion of the nuclei is completed following pollination and fertilization. The antipodals possess a complete set of organelles, numerous free and aggregated ribosomes, and endoplasmic reticulum. It is believed the antipodals play a significant nutritive role during the development of the embryo sac of V. minimum. Modification of the wall between antipodals and central cell and its role in nutrient transportations are discussed. Key words: embryo sac, embryogenesis, gametogenesis, megagametogenesis, mistletoes, ultrastructure.

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Takahashi-Nakaguchi, Azusa, Tsuyoshi Hiraoka, and Kikuo Iwabuchi. "An ultrastructural study of polyembryonic parasitoid embryo and host embryo cell interactions." Journal of Morphology 271, no. 6 (March 9, 2010): 750–58. http://dx.doi.org/10.1002/jmor.10831.

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Hutter, H., and R. Schnabel. "Establishment of left-right asymmetry in the Caenorhabditis elegans embryo: a multistep process involving a series of inductive events." Development 121, no. 10 (October 1, 1995): 3417–24. http://dx.doi.org/10.1242/dev.121.10.3417.

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Bilateral pairs of blastomeres derived from the founder cell AB, the anterior blastomere of the 2-cell stage, in the Caenorhabditis elegans embryo are initially equivalent in their developmental potential. Recently, we showed that an induction at the 12-cell stage by a blastomere called MS is necessary to establish the differences between left and right pairs of blastomeres in the anterior part of the embryo. Further analysis of the process of creating left-right asymmetry reveals that the induction at the 12-cell stage is only the first of a series of inductions establishing the left-right asymmetry of the embryo. We describe here two further inductions that create additional asymmetries in the posterior part of the embryo. One induction occurs at the 24-cell stage among AB descendants themselves. This induction is restricted to the left side of the embryo as a consequence of the fate changes induced by MS at the 12-cell stage. The second induction requires again blastomeres of the MS lineage and also occurs around the 24-cell stage. Together these inductions establish the fate differences observed in the development of left-right pairs of blastomeres in the embryo.

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Jurisicova, Andrea, and Beth M. Acton. "Deadly decisions: the role of genes regulating programmed cell death in human preimplantation embryo development." Reproduction 128, no. 3 (September 2004): 281–91. http://dx.doi.org/10.1530/rep.1.00241.

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Human preimplantation embryo development is prone to high rates of early embryo wastage, particularly under currentin vitroculture conditions. There are many possible underlying causes for embryo demise, including DNA damage, poor embryo metabolism and the effect of suboptimal culture media, all of which could result in an imbalance in gene expression and the failed execution of basic embryonic decisions. In view of the complex interactions involved in embryo development, a thorough understanding of these parameters is essential to improving embryo quality. An increasing body of evidence indicates that cell fate (i.e. survival/differentiation or death) is determined by the outcome of specific intracellular interactions between pro- and anti-apoptotic proteins, many of which are expressed during oocyte and preimplantation embryo development. The recent availability of mutant mice lacking expression of various genes involved in the regulation of cell survival has enabled rapid progress towards identifying those molecules that are functionally important for normal oocyte and preimplantation embryo development. In this review we will discuss the current understanding of the regulation of cell death gene expression during preimplantation embryo development, with a focus on human embryology and a discussion of animal models where appropriate.

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Folsom, M. W., and D. D. Cass. "Changes in transfer cell distribution in the ovule of soybean after fertilization." Canadian Journal of Botany 64, no. 5 (May 1, 1986): 965–72. http://dx.doi.org/10.1139/b86-130.

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The presence of transfer cells in various regions of the postfertilization ovule of soybean is described. A developmental study shows that transfer cells, occurring in the micropylar nucellus, are formed after fertilization but destroyed by expansion of the embryo sac during transition from the zygote to the two-celled embryo. Subsequently wall ingrowths appear in five additional sites: (i) in the region where the embryonic basal cell wall is associated with the degenerated synergid, projecting into the basal cell; (ii) on the chalazal embryo sac wall projecting into the central cell; (iii) on the embryo sac wall projecting into the basal cell; (iv) on common walls of micropylar suspensor cells; and (v) on some cell walls at the micropylar end of the inner integuments. It is our opinion that these transfer cells are all involved in augmenting metabolite transport and that their orderly appearance in different areas of the ovule signifies changes in the nutritional environment of the young embryo and endosperm of soybean. Because these transfer cells are closely associated with the embryo sac wall, it is proposed that this wall is a common apoplast functioning as both a sink for metabolites from the nucellus and source for all solutes taken up by the cells of the embryo sac.

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Kola, Ismail, and Leeanda Wilton. "Preimplantation embryo biopsy: Detection of trisomy in a single cell biopsied from a four-cell mouse embryo." Molecular Reproduction and Development 29, no. 1 (May 1991): 16–21. http://dx.doi.org/10.1002/mrd.1080290104.

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Boscq, Samuel, Bernard Billoud, and Bénédicte Charrier. "Cell-Autonomous and Non-Cell-Autonomous Mechanisms Concomitantly Regulate the Early Developmental Pattern in the Kelp Saccharina latissima Embryo." Plants 13, no. 10 (May 13, 2024): 1341. http://dx.doi.org/10.3390/plants13101341.

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Brown algae are multicellular organisms that have evolved independently from plants and animals. Knowledge of the mechanisms involved in their embryogenesis is available only for the Fucus, Dictyota, and Ectocarpus, which are brown algae belonging to three different orders. Here, we address the control of cell growth and cell division orientation in the embryo of Saccharina latissima, a brown alga belonging to the order Laminariales, which grows as a stack of cells through transverse cell divisions until growth is initiated along the perpendicular axis. Using laser ablation, we show that apical and basal cells have different functions in the embryogenesis of this alga, with the apical cell being involved mainly in growth and basal cells controlling the orientation of cell division by inhibiting longitudinal cell division and thereby the widening of the embryo. These functions were observed in the very early development before the embryo reached the 8-cell stage. In addition, the growth of the apical and basal regions appears to be cell-autonomous, because there was no compensation for the loss of a significant part of the embryo upon laser ablation, resulting in smaller and less elongated embryos compared with intact embryos. In contrast, the orientation of cell division in the apical region of the embryo appears to be controlled by the basal cell only, which suggests a polarised, non-cell-autonomous mechanism. Altogether, our results shed light on the early mechanisms of growth rate and growth orientation at the onset of the embryogenesis of Saccharina, in which non-cell-specific cell-autonomous and cell-specific non-cell-autonomous processes are involved. This complex control differs from the mechanisms described in the other brown algal embryos, in which the establishment of embryo polarity depends on environmental cues.

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Gardner, DK, L. Selwood, and M. Lane. "Nutrient uptake and culture of Sminthopsis macroura (stripe-faced dunnart) embryos." Reproduction, Fertility and Development 8, no. 4 (1996): 685. http://dx.doi.org/10.1071/rd9960685.

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Glucose and pyruvate uptake by individual embryos were measured in a marsupial species (stripe-faced dunnart) and a eutherian species (mouse). At each stage of development, nutrient uptake by the dunnart embryo was around an order of magnitude greater than that of the mouse embryo. The pattern of glucose uptake by the dunnart embryo was not like that for any eutherian embryo, all of which have a low glucose uptake before the blastocyst stage. Rather, in the dunnart embryo there was a significant increase in glucose uptake after the third cleavage division, increasing from 13.6 pmol embryo h-1 at the 4-cell stage to 34.9 pmol embryo h-1 by the 8-cell stage. This increase in glucose uptake before blastocyst formation may be attributed to an increased energy demand associated with the movement of cells within the dunnart embryo. Using a new culture system, it was possible to culture 66% of dunnart embryos at the 2-4-cell stage and 80% of those at the 8-16-cell stage to the unilaminar blastocyst stage. Embryos cultured from the 2-cell to the 4-cell stage were retarded by around 12 h when they reached the blastocyst stage. Developmental retardation was also reflected in the pattern of nutrient uptake, which lagged behind that of embryos developed in vivo. The present study has shown that it is possible to culture the early marsupial embryo to the blastocyst stage in a serum-free culture system, while concomitantly quantifying embryonic nutrient requirements. Such an approach is essential for species where there is a paucity of material for study.

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Posfai, Eszter, Isidora Rovic, and Andrea Jurisicova. "The mammalian embryo’s first agenda: making trophectoderm." International Journal of Developmental Biology 63, no. 3-4-5 (2019): 157–70. http://dx.doi.org/10.1387/ijdb.180404ep.

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One of the bottlenecks for a successful pregnancy in mammalian species is the implantation of the early embryo into the wall of the mother’s uterus. The first cell lineage the embryo sets aside following fertilization is the trophectoderm – a specialized cell type that establishes contact with the mother and mediates embryo implantation. We summarize the events that lead to the formation of the trophectoderm lineage in the preimplantation embryo and highlight key features of this cell type, which could be useful in the clinical setting for prediction of implantation outcomes.

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Pavani, Krishna, An Hendrix, Wim Van Den Broeck, Liesbeth Couck, Katarzyna Szymanska, Xiaoyuan Lin, Jenne De Koster, Ann Van Soom, and Bart Leemans. "Isolation and Characterization of Functionally Active Extracellular Vesicles from Culture Medium Conditioned by Bovine Embryos In Vitro." International Journal of Molecular Sciences 20, no. 1 (December 21, 2018): 38. http://dx.doi.org/10.3390/ijms20010038.

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Extracellular vesicles (EVs) play a possible role in cell–cell communication and are found in various body fluids and cell conditioned culture media. The aim of this study was to isolate and characterize EVs in culture medium conditioned by bovine embryos in group and to verify if these EVs are functionally active. Initially, ultracentrifuged bovine serum albumin (BSA) containing medium was selected as suitable EV-free embryo culture medium. Next, EVs were isolated from embryo conditioned culture medium by OptiPrepTM density gradient ultracentrifugation. Isolated EVs were characterized by nanoparticle tracking analysis, western blotting, transmission, and immunoelectron microscopy. Bovine embryo-derived EVs were sizing between 25–230 nm with an average concentration of 236.5 ± 1.27 × 108 particles/mL. Moreover, PKH67 EV pre-labeling showed that embryo-secreted EVs were uptaken by zona-intact bovine embryos. Since BSA did not appear to be a contaminating EV source in culture medium, EV functionality was tested in BSA containing medium. Individual embryo culture in BSA medium enriched with EVs derived from conditioned embryo culture medium showed significantly higher blastocyst rates at day 7 and 8 together with a significantly lower apoptotic cell ratio. In conclusion, our study shows that EVs play an important role in inter embryo communication during bovine embryo culture in group.

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Lefèvre, Pavine L. C., Marie-France Palin, Gary Chen, Gustavo Turecki, and Bruce D. Murphy. "Polyamines Are Implicated in the Emergence of the Embryo from Obligate Diapause." Endocrinology 152, no. 4 (February 8, 2011): 1627–39. http://dx.doi.org/10.1210/en.2010-0955.

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Abstract Embryonic diapause is a poorly understood phenomenon of reversible arrest of embryo development prior to implantation. In many carnivores, such as the mink (Neovison vison), obligate diapause characterizes each gestation. Embryo reactivation is controlled by the uterus by mechanisms that remain elusive. Because polyamines are essential regulators of cell proliferation and growth, it was hypothesized that they trigger embryo reactivation. To test this, mated mink females were treated with α-difluoromethylornithine, an inhibitor of ornithine decarboxylase 1, the rate-limiting enzyme in polyamine biosynthesis, or saline as a control during the first 5 d of reactivation. This treatment induced polyamine deprivation with the consequence of rearrest in embryo cell proliferation. A mink trophoblast cell line in vitro subjected to α-difluoromethylornithine treatment likewise displayed an arrest in cell proliferation, morphological changes, and intracellular translocation of ornithine decarboxylase 1 protein. The arrest in embryo development deferred implantation for a period consistent with the length of treatment. Successful implantation and parturition ensued. We conclude that polyamine deprivation brought about a reversible rearrest of embryo development, which returned the mink embryo to diapause and induced a second delay in embryo implantation. The results are the first demonstration of a factor essential to reactivation of embryos in obligate diapause.

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Pereira, Rosa Maria, Carla Cruz Marques, Maria da Conceição Baptista, Maria Irene Vasques, and António Eduardo Horta. "Effect of arachidonic acid supplementation and cyclooxygenase/lipoxygenase inhibition on the development of early bovine embryos." Revista Brasileira de Zootecnia 35, no. 2 (April 2006): 422–27. http://dx.doi.org/10.1590/s1516-35982006000200012.

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The effect of arachidonic acid (AA) cascade on bovine embryo development in a granulosa cell co-culture system was studied. Arachidonic acid (100 µM) was supplemented from 1-cell to 8-16 cell block stage (first three days of co-culture) and from 1-cell to hatching. Specific cyclooxygenase (indomethacin, 28 µM) and lipoxygenase (nordihydroguaiaretic acid - NDGA, 28 µM) inhibitors were used from 1-cell to 8-16 cell block stage with AA. Embryo development was assessed by cleavage, day 7-day 8 and hatched embryo rates and by measuring growth rates through development stages found in days 7-10 of culture (day 0 = insemination day). Embryo quality was scored at day 8. A 6.5-10.4% increase on cleavage rate after AA supplementation was found. This AA supplementation from 1-cell to hatching delayed embryo growth rate beyond day 7 and a reduction on hatching rate was detected. When AA supplementation was restricted to the first three days of co-culture those negative effects were overcome. Also, indomethacin and NDGA prevented the positive effect of AA and induced a significant reduction on cleavage, respectively. NDGA further decreased day 7 embryo rate and quality. Results suggest that AA has a two-phase action on bovine embryos, promoting early development and impairing embryo growth from day 7 onwards and hatching rates. Both cyclooxygenase and lipoxygenase were found to be important pathways to promote cleavage.

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35

Nilsson, Eric, Millissia Ben Maamar, and Michael K. Skinner. "Environmental impacts on sperm and oocyte epigenetics affect embryo cell epigenetics and transcription to promote the epigenetic inheritance of pathology and phenotypic variation." Reproduction, Fertility and Development 33, no. 2 (2021): 102. http://dx.doi.org/10.1071/rd20255.

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Previous studies have demonstrated that exposure to environmental factors can cause epigenetic modifications to germ cells, particularly sperm, to promote epigenetic and transcriptome changes in the embryo. These germ cell and embryo cell epigenetic alterations are associated with phenotypic changes in offspring. Epigenetic inheritance requires epigenetic changes (i.e. epimutations) in germ cells that promote epigenetic and gene expression changes in embryos. The objective of this perspective is to examine the evidence that germ cell epigenome modifications are associated with embryo cell epigenetic and transcriptome changes that affect the subsequent development of all developing somatic cells to promote phenotype change. Various epigenetic changes in sperm, including changes to histone methylation, histone retention, non-coding RNA expression and DNA methylation, have been associated with alterations in embryo cell epigenetics and gene expression. Few studies have investigated this link for oocytes. The studies reviewed herein support the idea that environmentally induced epigenetic changes in germ cells affect alterations in embryo cell epigenetics and transcriptomes that have an important role in the epigenetic inheritance of pathology and phenotypic change.

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Hutter, H., and R. Schnabel. "glp-1 and inductions establishing embryonic axes in C. elegans." Development 120, no. 7 (July 1, 1994): 2051–64. http://dx.doi.org/10.1242/dev.120.7.2051.

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Two successive inductions specify blastomere identities, that is complex cell lineages and not specific tissues, in a major part of the early C. elegans embryo. The first induction acts along the anterior-posterior axis of the embryo and the second along the left-right axis. During the first induction a specific lineage program is induced in the posterior of the two AB blastomeres present in the four cell embryo. During the second induction, almost all of the left-right differences of the embryo are specified by interactions between a single signalling blastomere, MS, and the AB blastomeres that surround it. In both cases the inductions break the equivalence of pairs of blastomeres. The inductions correlate with the cell-cell contacts to the inducing blastomeres. The stereotype cleavage patterns of the early embryo results in invariant cell-cell contacts that guarantee the specificity of the inductions. Both inductions are affected in embryos mutant for glp-1 suggesting that in both cases glp-1 is involved in the reception of the signal.

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37

Nilsson, Eric, Millissia Ben Maamar, and Michael K. Skinner. "Environmental impacts on sperm and oocyte epigenetics affect embryo cell epigenetics and transcription to promote the epigenetic inheritance of pathology and phenotypic variation." Reproduction, Fertility and Development 33, no. 2 (2021): 102. http://dx.doi.org/10.1071/rd20255.

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Abstract:

Previous studies have demonstrated that exposure to environmental factors can cause epigenetic modifications to germ cells, particularly sperm, to promote epigenetic and transcriptome changes in the embryo. These germ cell and embryo cell epigenetic alterations are associated with phenotypic changes in offspring. Epigenetic inheritance requires epigenetic changes (i.e. epimutations) in germ cells that promote epigenetic and gene expression changes in embryos. The objective of this perspective is to examine the evidence that germ cell epigenome modifications are associated with embryo cell epigenetic and transcriptome changes that affect the subsequent development of all developing somatic cells to promote phenotype change. Various epigenetic changes in sperm, including changes to histone methylation, histone retention, non-coding RNA expression and DNA methylation, have been associated with alterations in embryo cell epigenetics and gene expression. Few studies have investigated this link for oocytes. The studies reviewed herein support the idea that environmentally induced epigenetic changes in germ cells affect alterations in embryo cell epigenetics and transcriptomes that have an important role in the epigenetic inheritance of pathology and phenotypic change.

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38

Lackie, Sharon, and Edward C. Yeung. "Zygotic embryo development in Daucus carota." Canadian Journal of Botany 74, no. 7 (July 1, 1996): 990–98. http://dx.doi.org/10.1139/b96-123.

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After fertilization, the zygote divided unequally, giving rise to a larger basal cell and a smaller terminal cell. Derivatives from the basal cell gave rise to the suspensor and the terminal cell gave rise to the embryo proper. The suspensor usually consisted of a uniseriate file of 10–12 cells. However, additional anticlinal and oblique divisions resulted in some suspensors having more than one cell file. Cuticular substance was not present in the suspensor cell wall. The embryo proper was derived from the terminal four cells of the eight-celled embryo. The protoderm differentiated first, and subsequent to its formation cuticular substance could be detected in the outer tangential walls using the Nile red stain. This staining pattern intensified as the embryo matured. A defined cell lineage was not associated with tissue and meristem differentiation. Meristems began to form at the heart stage and became clearly defined at the late heart – early cotyledon stage. Keywords: cuticular material, Daucus carota, fluorescence, suspensor, zygotic embryogenesis.

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39

Saiz, Néstor, and Berenika Plusa. "Early cell fate decisions in the mouse embryo." REPRODUCTION 145, no. 3 (March 2013): R65—R80. http://dx.doi.org/10.1530/rep-12-0381.

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During mammalian preimplantation development, the fertilised egg gives rise to a group of pluripotent embryonic cells, the epiblast, and to the extraembryonic lineages that support the development of the foetus during subsequent phases of development. This preimplantation period not only accommodates the first cell fate decisions in a mammal's life but also the transition from a totipotent cell, the zygote, capable of producing any cell type in the animal, to cells with a restricted developmental potential. The cellular and molecular mechanisms governing the balance between developmental potential and lineage specification have intrigued developmental biologists for decades. The preimplantation mouse embryo offers an invaluable system to study cell differentiation as well as the emergence and maintenance of pluripotency in the embryo. Here we review the most recent findings on the mechanisms controlling these early cell fate decisions. The model that emerges from the current evidence indicates that cell differentiation in the preimplantation embryo depends on cellular interaction and intercellular communication. This strategy underlies the plasticity of the early mouse embryo and ensures the correct specification of the first mammalian cell lineages.

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40

Cui, Yihui, Peng Zhao, Hongqiang An, Nan Lv, Zifeng Zhang, Wei Pei, and Wanjun Wang. "Initiation and Cytological Aspects of Somatic Embryogenesis in Dendrobium candidum Wall ex Lindl." HortScience 52, no. 8 (August 2017): 1111–16. http://dx.doi.org/10.21273/hortsci10525-17.

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To find the characteristics of somatic embryogenesis of orchids and elucidate the mechanism, we had previously established an efficient plant regeneration system via somatic embryogenesis in Dendrobium candidum Wall ex Lindl. In this study, a detailed cytological investigation was carried out on the initiation and developmental process of somatic embryogenesis. Based on our observations, the somatic embryogenesis in D. candidum originated from the transition of an embryonic callus cell to the initial somatic embryo cell, and the somatic embryos initiated from those cells. During the transition process, condensation and devacuolation successively occurred in the cytoplasm of the embryonic callus cells, giving rise to the formation of a typical initial somatic embryo cell with dense cytoplasm and a clear nucleus. One of the two pathways in somatic embryogenesis is the single-cell-derived somatic embryo which is generated from an inner initial somatic embryo cell in embryonic callus and develops into a globular somatic embryo in a way similar to zygotic embryogenesis and then keeps developing into a protocorm-like body (PLB). The other is a multiple-cell-derived somatic embryo which is generated from peripheral grouped initial somatic cells in embryonic calli and directly forms globular embryo or multicellular somatic proembryo, lacking the typical early stages of embryogenesis. Both pathways were observed in the somatic embryogenesis system, indicating that the culture system in D. candidum can be a useful tool for investigating the mechanisms underlying orchid embryogenesis.

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Hardy, K., S. Spanos, R. Winston, and J. Stark. "From Cell Death to Embryo Arrest: Mathematical Models of Human Preimplantation Embryo Development." Fertility and Sterility 74, no. 3 (September 2000): S3. http://dx.doi.org/10.1016/s0015-0282(00)00730-5.

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42

Hardy, K., S. Spanos, D. Becker, P. Iannelli, R. M. L. Winston, and J. Stark. "From cell death to embryo arrest: Mathematical models of human preimplantation embryo development." Proceedings of the National Academy of Sciences 98, no. 4 (February 13, 2001): 1655–60. http://dx.doi.org/10.1073/pnas.98.4.1655.

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Furton, Edward J., and Micheline M. Mathews-Roth. "Stem Cell Research and the Human Embryo." Ethics & Medics 24, no. 8 (1999): 1–2. http://dx.doi.org/10.5840/em199924816.

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Furton, Edward J. "Stem Cell Research and the Human Embryo." Ethics & Medics 24, no. 9 (1999): 3–4. http://dx.doi.org/10.5840/em199924919.

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Smith, Danielle G., and Roger G. Sturmey. "Parallels between embryo and cancer cell metabolism." Biochemical Society Transactions 41, no. 2 (March 21, 2013): 664–69. http://dx.doi.org/10.1042/bst20120352.

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A key characteristic of cancer cells is the ability to switch from a predominantly oxidative metabolism to glycolysis and the production of lactate even when oxygen is plentiful. This metabolic switch, known as the Warburg effect, was first described in the 1920s, and has fascinated and puzzled researchers ever since. However, a dramatic increase in glycolysis in the presence of oxygen is one of the hallmarks of the development of the early mammalian embryo; a metabolic switch with many parallels to the Warburg effect of cancers. The present review provides a brief overview of this and other similarities between the metabolism in tumours and early embryos and proposes whether knowledge of early embryo metabolism can help us to understand metabolic regulation in cancer cells.

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Bertrand, Julien Y., and David Traver. "Hematopoietic cell development in the zebrafish embryo." Current Opinion in Hematology 16, no. 4 (July 2009): 243–48. http://dx.doi.org/10.1097/moh.0b013e32832c05e4.

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Vogel, G. "Embryo Ruling Keeps Stem Cell Research Legal." Science 327, no. 5961 (December 31, 2009): 25. http://dx.doi.org/10.1126/science.327.5961.25.

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Jurisicova, A., S. Varmuza, and R. F. Casper. "Programmed cell death and human embryo fragmentation." Molecular Human Reproduction 2, no. 2 (1996): 93–98. http://dx.doi.org/10.1093/molehr/2.2.93.

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Hansis, Christoph, and Robert G. Edwards. "Cell differentiation in the preimplantation human embryo." Reproductive BioMedicine Online 6, no. 2 (January 2003): 215–20. http://dx.doi.org/10.1016/s1472-6483(10)61712-9.

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Sugarman, Jeremy. "Human Stem Cell Ethics: Beyond the Embryo." Cell Stem Cell 2, no. 6 (June 2008): 529–33. http://dx.doi.org/10.1016/j.stem.2008.05.005.

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Journal articles on the topic 'Cell-Embryo'

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