Changes in the distribution of membranous organelles during mouse early development

Development ◽  
1985 ◽  
Vol 90 (1) ◽  
pp. 287-309
Author(s):  
Bernard Maro ◽  
Martin H. Johnson ◽  
Susan J. Pickering ◽  
Daniel Louvard
Keyword(s):  
Endoplasmic Reticulum ◽  
Basolateral Membrane ◽  
Early Embryo ◽  
Apical Region ◽  
Basal Region ◽  
Embryonic Cells ◽  
Cell Stage ◽  
Surface Phenotype ◽  
Daughter Cells ◽  
Differentiated Cells

The unfertilized oocyte, fertilized egg and early embryo (2-cell to 16-cell) of the mouse have been examined immunocytochemically for the distribution of antigens associated with the endoplasmic reticulum, the lysosomal and acidic vesicle fraction (100kD antigen), Golgi apparatus (135kD antigen) and coated vesicles (clathrin). The distribution of these antigens has also been examined in isolated 8-cell and 16-cell-stage blastomeres of various ages and phenotypes. Endoplasmic reticulum is detected only weakly in the oocyte and egg, but is seen abundantly at later stages both in association with the nuclear membrane and evenly distributed throughout the cytoplasm, except in regions of cell: cell apposition from which it is excluded. Intracellular clathrin is associated with the spindle in mitotic and meiotic cells. During interphase, clathrin is distributed throughout the cell until the mid-8-cell stage when it is concentrated into the apical region of the cell under the region of membrane at which a surface pole of microvilli will form subsequently. Thus, the cytoplasmic polarization of clathrin precedes overt polarization at the surface. At mitosis, the clathrin relocates to the spindle and is distributed to both daughter cells. It resumes an apical location beneath the surface pole of microvilli in polar daughter 1/16 cells, but remains dispersed in apolar daughter 1/16 cells. Both the lysosomal and Golgi antigens are distributed throughout the cytoplasm until the early 16-cell stage. In pairs of 16-cell blastomeres both antigens aggregate in a single cluster and do so whether the surface phenotype of the blastomeres is polar or apolar. The position of this cluster is not consistently related to the point of contact with the other cell in the pair but there is a suggestion that in cells with a polar surface phenotype the polar foci of Golgi/lysosomal antigens are located between the nucleus and the surface pole at earlier time points, but shift to a position between the basolateral membrane and the nucleus at the later time point. In intact 16-cell embryos also, the aggregated Golgi/lysosomal antigens of polar cells appear to localize to the basal region. The distributions of these various organelles in embryonic cells reported here show a number of differences from those reported previously for mature, differentiated cells.

scholarly journals Tissue-specific control of expression of the tight junction polypeptide ZO-1 in the mouse early embryo

Development ◽  
1991 ◽  
Vol 113 (1) ◽  
pp. 295-304 ◽  
Author(s):  
T.P. Fleming ◽  
M.J. Hay
Keyword(s):  
Tight Junction ◽  
Contact Area ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Subsequent Development ◽  
Early Embryo ◽  
Cell Contact ◽  
Down Regulation ◽  
Cell Stage ◽  
Daughter Cells

The processes governing differential protein expression in preimplantation lineages were investigated using a monoclonal antibody recognising the tight junction polypeptide, ZO-1. ZO-1 localises to the maturing tight junction membrane domain in the polarised trophectoderm lineage from compaction (8-cell stage) onwards, ultimately forming a zonular belt around each trophectoderm cell of the blastocyst (32- to 64-cell stage). The protein is usually undetectable within the inner cell mass (ICM) although, in a minority of embryos, punctate ZO-1 sites are present on the surface of one or more ICM cells. Since ICM cells derive from the differentiative division of polarised 8- and 16-cell blastomeres, the distribution of ZO-1 following differentiative division in isolated, synchronised cell clusters of varying size, was examined. In contrast to the apical cytocortical pole, ZO-1 was found to be inherited by nonpolar (prospective ICM) as well as polar (prospective trophectoderm) daughter cells. Following division, polar cells adhere to and gradually envelop nonpolar cells. Prior to envelopment, ZO-1 localises to the boundary between the contact area and free membrane of daughter cells, irrespective of their phenotype. After envelopment, polar cells retain these ZO-1 contact sites whilst nonpolar cells lose them, in which case ZO-1 transiently appears as randomly-distributed punctate sites on the membrane before disappearing. Thus, symmetrical cell contact appears to initiate ZO-1 down-regulation in the ICM lineage. The biosynthetic level at which ZO-1 down-regulation occurs was investigated in immunosurgically isolated ICMs undergoing trophectoderm regeneration. By 6 h in culture, isolated ICMs generated a zonular network of ZO-1 at the contact area between outer cells, thereby demonstrating the reversibility of down-regulation. This assembly process was unaffected by alpha-amanitin treatment but was inhibited by cycloheximide. These results indicate that the ICM inherits and stabilises ZO-1 transcripts which can be utilised for rapid synthesis and assembly of the protein, a capacity that may have significance both in maintaining lineage integrity within the blastocyst and in the subsequent development of the ICM.

scholarly journals Changes in cell surface and cortical cytoplasmic organization during early embryogenesis in the preimplantation mouse embryo

1977 ◽  
Vol 74 (1) ◽  
pp. 153-167 ◽  
Author(s):  
T Ducibella ◽  
T Ukena ◽  
M Karnovsky ◽  
E Anderson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cell Surface ◽  
Early Embryogenesis ◽  
Apical Region ◽  
Basal Region ◽  
Cell Stage ◽  
Preimplantation Mouse ◽  
Cell Surface Changes ◽  
Scanning Electron

Membrane topography and organization of cortical cytoskeletal elements and organelles during early embryogenesis of the mouse have been studied by transmission and scanning electron microscopy with improved cellular preservation. At the four- and early eight-cell stages, blastomeres are round, and scanning electron microscopy shows a uniform distribution of microvilli over the cell surface. At the onset of morphogenesis, a reorganization of the blastomere surface is observed in which microvilli becomes restricted to an apical region and the basal zone of intercellular contact. As the blastomeres spread on each other during compaction, many microvilli remain in the basal region of imminent cell-cell contacts, but few are present where the cells have completed spreading on each other. Microvilli on the surface of these embryos contain linear arrays of microfilaments with lateral cross bridges. Microtubules and mitochondria become localized beneath the apposed cell membranes during compaction. Arrays of cortical microtubules are aligned parallel to regions of apposed membranes. During cytokinesis, microtubules become redistributed in the region of the mitotic spindle, and fewer microvilli are present on most of the cell surface. The cell surface and cortical changes initiated during compaction are the first manifestations of cell polarity in embryogenesis. These and previous findings are interpreted as evidence that cell surface changes associated with trophoblast development appear as early as the eight-cell stage. Our observations suggest that morphogenesis involves the activation of a developmental program which coordinately controls cortical cytoplasmic and cell surface organization.

scholarly journals AN ELECTRON MICROSCOPE STUDY OF THE GLAND CELLS OF THE MINK ENDOMETRIUM

1963 ◽  
Vol 18 (2) ◽  
pp. 405-418 ◽  
Author(s):  
A. C. Enders ◽  
R. K. Enders ◽  
S. Schlafke
Keyword(s):  
Endoplasmic Reticulum ◽  
Secretory Activity ◽  
The Body ◽  
Apical Region ◽  
Basal Region ◽  
Giant Mitochondria ◽  
Gland Cells ◽  
Delayed Implantation ◽  
Secretion Granules ◽  
Golgi Region

Portions of mink endometrium in delayed implantation, early postimplantation, and pseudo pregnancy were fixed in buffered osmium tetroxide with sucrose, or potassium permanganate. After rapid dehydration the portions of endometrium were embedded in either methacrylate or epoxy resin. Examination of the cells from the body of the glands of the endometrium of delayed implantation revealed the presence of prominent terminal bars, numerous secretion granules, and membrane discs in the apical region of the cell. In the supranuclear and infranuclear regions, mildly dilated cisternae of the endoplasmic reticulum were present, and in many cells unusually large mitochondria were seen. Numerous changes were noted in the gland cells of the post implantation stage. The endoplasmic reticulum in the basal region was extensively dilated, and the nuclei were situated more centrally. Giant mitochondria were no longer present. The large secretion granules were not present, but smaller granules were seen, especially in the Golgi region. Some of the Golgi cisternae were dilated and the pattern of parallel membranes was consequently less distinct. It is suggested that gland cells in the postimplantation and pseudopregnancy stages exhibit evidence of greater secretory activity than those in the delayed implantation stage.

The induced sector Arabidopsis apical embryonic fate map

Development ◽  
2002 ◽  
Vol 129 (14) ◽  
pp. 3403-3410 ◽  
Author(s):  
Alexandria Saulsberry ◽  
Paula R. Martin ◽  
Tim O’Brien ◽  
Leslie E. Sieburth ◽  
F. Bryan Pickett
Keyword(s):  
Cell Division ◽  
Heat Shock ◽  
Apical Cell ◽  
Apical Region ◽  
Fate Map ◽  
Cell Stage ◽  
Daughter Cells ◽  
Apical Cells ◽  
Stage Embryo ◽  
Genetic Chimerism

Creation of an embryonic fate map may provide insight into the patterns of cell division and specification contributing to the apical region of the early Arabidopsis embryo. A fate map has been constructed by inducing genetic chimerism during the two-apical-cell stage of embryogenesis to determine if the orientation of the first anticlinal cell division correlates with later developmental axes. Chimeras were also used to map the relative locations of precursors of the cotyledon and leaf primordia. Genetic chimeras were induced in embryos doubly heterozygous for a heat shock regulated Cre recombinase and a constitutively expressed β-glucuronidase (GUS) gene flanked by the loxP binding sites for Cre. Individual cells in the two-apical-cell stage embryo responding to heat shock produce GUS-negative daughter cells. Mature plants grown from seed derived from treated embryos were scored for GUS-negative sector extent in the cotyledons and leaves. The GUS-negative daughters of apical cells had a strong tendency to contribute primarily to one cotyledon or the other and to physically adjacent true leaf margins. This result indicated that patterns of early cell division correlate with later axes of symmetry in the embryo and that these patterns partially limit the fates available for adoption by daughter cells. However, GUS-negative sectors were shared between all regions of the mature plant, suggesting that there is no strict fate restriction imposed on the daughters of the first apical cells.

Fine-structural studies of the gametes and embryo of Fucus vesiculosus L. (Phaeophyta). III. Cytokinesis and the multicellular embryo

1977 ◽  
Vol 24 (1) ◽  
pp. 275-294
Author(s):  
S.H. Brawley ◽  
R.S. Quatrano ◽  
R. Wetherbee
Keyword(s):  
Endoplasmic Reticulum ◽  
Rough Endoplasmic Reticulum ◽  
Daughter Cell ◽  
Fucus Vesiculosus ◽  
Complete Disappearance ◽  
Annulate Lamellae ◽  
Nuclear Pores ◽  
Cell Stage ◽  
Golgi Bodies ◽  
Daughter Cells

Condensation of the chromosomes during the first cell division following fertilization of the brown alga Fucus vesiculosus L. is accompanied by the almost complete disappearance of the nuclear envelope. Golgi vesicles and other small vesicles appear within the spindle, which has paired centrioles at each end. A large amount of rough endoplasmic reticulum is in the surrounding cytoplasm during mitosis, and many vesicles at the spindle margin are encircled by stacks of endoplasmic reticulum. Annulate lamellae are observed during mitosis. The envelope which initially reforms around the chromatin in telophase has unevenly spaced nuclear pores. Cytokinesis results primarily by vesicle addition to a centripetal furrow. Mitochondria and chloroplasts concentrate around the partition site, possibly in association with microfilaments. Fibrillar material is added rapidly to the space between the daughter cells from vesicle discharge of both cells and seems to spread into the older cell wall surrounding the embryo. The rhizoid daughter cell contains numerous mitochondria and hypertrophied Golgi bodies whose vesicles increasingly pack the cell. The thallus daughter cell is packed with a variety of vesicles, and the nucleus is surrounded by many dilated cisternae of rough endoplasmic reticulum. By the four-cell stage, chloroplasts of the rhizoid cells have weakly staining lamellae, while chloroplasts of the thallus cells are actively dividing with deeply staining lamellae.

Ultrastructure of sex-pheromone gland cells and cuticle before and during release of pheromone in female eastern spruce budworm, Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae)

1974 ◽  
Vol 52 (6) ◽  
pp. 695-705 ◽  
Author(s):  
Jean E. Percy
Keyword(s):  
Endoplasmic Reticulum ◽  
Sex Pheromone ◽  
Rough Endoplasmic Reticulum ◽  
Choristoneura Fumiferana ◽  
Epidermal Cells ◽  
Apical Region ◽  
Basal Region ◽  
Apical Surface ◽  
Gland Cells ◽  
Pore Canals

The sex-pheromone-producing gland of Choristoneura fumiferana, as in other moths, is a modified intersegmental membrane between the eighth and ninth abdominal segments. Gland cells differ from epidermal cells in unmodified intersegmental membranes in their size, shape, and structure. One to 2 days before emergence of the adult, the gland cells have few microvilli and the cytoplasm contains mainly rough endoplasmic reticulum. By 1 h before emergence, the cells have the adult characteristics. The basal region below the nucleus contains Golgi complexes, lipid droplets, glycogen deposits, and rough endoplasmic reticulum. The apical region contains many microbodies and extensive smooth tubular endoplasmic reticulum. The apical surface has numerous well-developed microvilli, each of which contains a core of smooth endoplasmic reticulum. In contrast to gland cells, unmodified epidermal cells only contain rough endoplasmic reticulum and their apical projections are small and ill-defined. Cuticle of the gland and unmodified intersegmental membrane does not change after deposition but continues to resemble that of the developing gland 1 to 2 days before emergence. Pore canals are present as gaps in the endocuticle and follow the helicoidal arrangement of the microfibrils. Near the microvilli the pore canals contain a filamentous structure which is replaced by epicuticular filaments near the first lamella of the endocuticle. Groups of epicuticular filaments terminate at an oval depression in the dense epicuticle. Each oval depression opens at the surface of the inner cuticulin. Epicuticular filaments are not the immediate precursors of the pheromone. The probable role of the epicuticular filaments in pheromone synthesis and release is discussed.

Changes in cell dimensions and intercellular contacts during cleavage-stage cycles in mouse embryonic cells

Development ◽  
1980 ◽  
Vol 58 (1) ◽  
pp. 231-249
Author(s):  
E. Lehtonen
Keyword(s):  
Surface Area ◽  
Time Lapse ◽  
Parental Cell ◽  
Embryonic Cells ◽  
Cell Stage ◽  
Cell Pair ◽  
Daughter Cells ◽  
Cell Dimensions ◽  
Intercellular Contacts ◽  
The Relationship

The cleavage behaviour of cells isolated from 1- to 8-cell-stage mouse embryos was studied with time-lapse video equipment; changes in cellular dimensions and their timing were recorded. The division of an isolated cell results in the formation of a twin-cell pair. The divisions of these two cells were always asynchronous. In each division the volume of a daughter cell was approximately half of that of the parental cell but its apparent surface area was 59-65% of that of the parental cell. Consequently, the ratio of apparent surface area to volume increased in each division by 25-30%. The most noticeable changes were observed in the relationship between the two daughter cells of each division. After cytokinesis, the intercellular contact area gradually increased during the following cell cycle in the 2/8- and 2/16-cell pairs, whereas it hardly changed in the 2/2- and 2/4-cell pairs. The comparison of the behaviour of the daughter cells on different substrates suggested that the zona pellucida and the mid body might have a role in the contact development at the early stages. Scanning electron microscopy was used for studying changes in the density of cell surface microvilli in an attempt to explain how the cells regulate their intercellular contacts.

scholarly journals Characterization of Endoplasmic Reticulum (ER) in Human Pluripotent Stem Cells Revealed Increased Susceptibility to Cell Death upon ER Stress

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1078
Author(s):  
Tae Won Ha ◽  
Ji Hun Jeong ◽  
HyeonSeok Shin ◽  
Hyun Kyu Kim ◽  
Jeong Suk Im ◽  
...  
Keyword(s):  
Stem Cells ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Pluripotent Stem Cells ◽  
Meta Analysis ◽  
Embryonic Stem ◽  
Structural Features ◽  
Human Pluripotent Stem Cells ◽  
Differentiated Cells ◽  
Induced Apoptosis

Human pluripotent stem cells (hPSCs), such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), have a well-orchestrated program for differentiation and self-renewal. However, the structural features of unique proteostatic-maintaining mechanisms in hPSCs and their features, distinct from those of differentiated cells, in response to cellular stress remain unclear. We evaluated and compared the morphological features and stress response of hPSCs and fibroblasts. Compared to fibroblasts, electron microscopy showed simpler/fewer structures with fewer networks in the endoplasmic reticulum (ER) of hPSCs, as well as lower expression of ER-related genes according to meta-analysis. As hPSCs contain low levels of binding immunoglobulin protein (BiP), an ER chaperone, thapsigargin treatment sharply increased the gene expression of the unfolded protein response. Thus, hPSCs with decreased chaperone function reacted sensitively to ER stress and entered apoptosis faster than fibroblasts. Such ER stress-induced apoptotic processes were abolished by tauroursodeoxycholic acid, an ER-stress reliever. Hence, our results revealed that as PSCs have an underdeveloped structure and express fewer BiP chaperone proteins than somatic cells, they are more susceptible to ER stress-induced apoptosis in response to stress.

scholarly journals Persistent directional growth capability in Arabidopsis thaliana pollen tubes after nuclear elimination from the apex

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kazuki Motomura ◽  
Hidenori Takeuchi ◽  
Michitaka Notaguchi ◽  
Haruna Tsuchi ◽  
Atsushi Takeda ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Pollen Tube ◽  
Sperm Cell ◽  
Pollen Tubes ◽  
Vegetative Nucleus ◽  
Sperm Cells ◽  
Apical Region ◽  
Basal Region ◽  
Specific Expression ◽  
Directional Growth

AbstractDuring the double fertilization process, pollen tubes deliver two sperm cells to an ovule containing the female gametes. In the pollen tube, the vegetative nucleus and sperm cells move together to the apical region where the vegetative nucleus is thought to play a crucial role in controlling the direction and growth of the pollen tube. Here, we report the generation of pollen tubes in Arabidopsis thaliana whose vegetative nucleus and sperm cells are isolated and sealed by callose plugs in the basal region due to apical transport defects induced by mutations in the WPP domain-interacting tail-anchored proteins (WITs) and sperm cell-specific expression of a dominant mutant of the CALLOSE SYNTHASE 3 protein. Through pollen-tube guidance assays, we show that the physiologically anuclear mutant pollen tubes maintain the ability to grow and enter ovules. Our findings provide insight into the sperm cell delivery mechanism and illustrate the independence of the tip-localized vegetative nucleus from directional growth control of the pollen tube.

scholarly journals LIN28 coordinately promotes nucleolar/ribosomal functions and represses the 2C-like transcriptional program in pluripotent stem cells

2021 ◽  
Author(s):  
Zhen Sun ◽  
Hua Yu ◽  
Jing Zhao ◽  
Tianyu Tan ◽  
Hongru Pan ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryo Development ◽  
Pluripotent Stem Cells ◽  
Rna Binding ◽  
Stem Cell Differentiation ◽  
Early Embryo ◽  
Transcriptional Program ◽  
Cell Stage ◽  
Early Embryo Development ◽  
Nucleolar Stress

AbstractLIN28 is an RNA binding protein with important roles in early embryo development, stem cell differentiation/reprogramming, tumorigenesis and metabolism. Previous studies have focused mainly on its role in the cytosol where it interacts with Let-7 microRNA precursors or mRNAs, and few have addressed LIN28’s role within the nucleus. Here, we show that LIN28 displays dynamic temporal and spatial expression during murine embryo development. Maternal LIN28 expression drops upon exit from the 2-cell stage, and zygotic LIN28 protein is induced at the forming nucleolus during 4-cell to blastocyst stage development, to become dominantly expressed in the cytosol after implantation. In cultured pluripotent stem cells (PSCs), loss of LIN28 led to nucleolar stress and activation of a 2-cell/4-cell-like transcriptional program characterized by the expression of endogenous retrovirus genes. Mechanistically, LIN28 binds to small nucleolar RNAs and rRNA to maintain nucleolar integrity, and its loss leads to nucleolar phase separation defects, ribosomal stress and activation of P53 which in turn binds to and activates 2C transcription factor Dux. LIN28 also resides in a complex containing the nucleolar factor Nucleolin (NCL) and the transcriptional repressor TRIM28, and LIN28 loss leads to reduced occupancy of the NCL/TRIM28 complex on the Dux and rDNA loci, and thus de-repressed Dux and reduced rRNA expression. Lin28 knockout cells with nucleolar stress are more likely to assume a slowly cycling, translationally inert and anabolically inactive state, which is a part of previously unappreciated 2C-like transcriptional program. These findings elucidate novel roles for nucleolar LIN28 in PSCs, and a new mechanism linking 2C program and nucleolar functions in PSCs and early embryo development.

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