OCT analysis of mouse reproduction and early development in vivo: dynamics of cilia, eggs and sperm (Conference Presentation)

2020 ◽  
Author(s):  
Irina V. Larina
Keyword(s):  
Early Development

Comparison of implantation and early development of human embryos fertilized in vitro versus in vivo using transvaginal ultrasound.

1991 ◽  
Vol 10 (1) ◽  
pp. 31-35 ◽  
Author(s):  
A Pellicer ◽  
C Calatayud ◽  
F Miro ◽  
R M Castellvi ◽  
A Ruiz ◽  
...  
Keyword(s):  
Early Development ◽  
Transvaginal Ultrasound ◽  
Human Embryos

Apoptosis in the early bovine embryo

Zygote ◽  
2000 ◽  
Vol 8 (1) ◽  
pp. 57-68 ◽  
Author(s):  
Christie Matwee ◽  
Dean H. Betts ◽  
W. Allan King
Keyword(s):  
Dna Fragmentation ◽  
Early Development ◽  
P53 Protein ◽  
Chromatin Condensation ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Bovine Embryo ◽  
Neighbouring Cell ◽  
Tunel Labelling

Cell death occurs during early development in vivo and in vitro, although little is known about the mechanism of blastomere death and the relation to embryonic loss. Apoptosis, characterised by chromatin condensation, DNA fragmentation and membrane blebbing, occurs without damage to surrounding cells in contrast to necrosis. Bovine oocytes and in vitro fertilised embryos (total n = 449) were analysed for (1) DNA fragmentation using terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) and (2) morphological features of apoptosis. TUNEL labelling was detected in immature and mature oocytes (7%, n = 57 and 23%, n = 60, respectively), and at least one cell of 8- to 16-cell embryos (5%, n = 57), morulae/early blastocysts (79%, n = 39) and expanded/hatched blastocysts (100%, n = 48). In contrast, TUNEL labelling was not detected in zygotes (n = 61), 2-cell embryos (n = 46) or 3- to 7-cell embryos (n = 81). Chromatin condensation, nuclear fragmentation, absence of neighbouring cell destruction and extrusion of cells was frequent among advanced stage embryos. Although not detected during early cleavage under standard conditions, TUNEL labelling indicative of apoptosis was induced by treatment with 10 μM staurosporine for 30 h in 95% of cleavage stage embryos (n = 59). Determination of the expression and localisation of the p53 tumour suppressor gene using reverse transcription polymerase chain reaction and whole-mount immunofluorescence revealed that although p53 transcripts were present throughout early development, nuclear localisation of p53 protein could not be detected in any blastocyst suggesting p53-independent apoptosis. This study has shown that apoptosis is dependent on embryonic developmental stage after standard culture. This suggests that bovine embryos become more capable of accommodating damaged or abnormal cells as development proceeds.

scholarly journals The effect of darapladib administration to inflammation marker in early development of atherosclerosis: in vivo study for dyslipidemia model

2018 ◽  
Vol 1146 ◽  
pp. 012011
Author(s):  
T Heriansyah ◽  
F N Aini ◽  
Nafisatuzzamrudah ◽  
P N B Saka ◽  
D Sargowo ◽  
...  
Keyword(s):  
Early Development ◽  
In Vivo Study ◽  
Inflammation Marker

scholarly journals In Vivo Imaging of Transport and Biocompatibility of Single Silver Nanoparticles in Early Development of Zebrafish Embryos

ACS Nano ◽  
2007 ◽  
Vol 1 (2) ◽  
pp. 133-143 ◽  
Author(s):  
Kerry J. Lee ◽  
Prakash D. Nallathamby ◽  
Lauren M. Browning ◽  
Christopher J. Osgood ◽  
Xiao-Hong Nancy Xu
Keyword(s):  
Silver Nanoparticles ◽  
Early Development ◽  
In Vivo Imaging ◽  
Zebrafish Embryos

Change in Surface Extensibility of Fundulus Deep Cells During Early Development

1973 ◽  
Vol 13 (3) ◽  
pp. 721-726
Author(s):  
CHERYLL A. TICKLE ◽  
J. P. TRINKAUS
Keyword(s):  
Cell Surface ◽  
Early Development ◽  
Negative Pressure ◽  
Stages Of Development ◽  
Rounded Form ◽  
Early Gastrula

The extensibility of the periphery of the deep cells of the Fundulus blastoderm was investigated by applying negative pressure to the cell surface in culture by means of a micropipette. The relative negative pressure required to produce standard deformations of the surface was measured for cells from embryos in 2 different stages of development. Less negative pressure was required to deform cells from early gastrulae than cells from early blastulae. This finding correlates with the behaviour of deep cells in vivo: early blastula cells are rounded, form blebs, and do not engage in locomotion, whereas early gastrula cells form extended lobopodia and lamellipodia and engage actively in locomotion.

Integrin alpha 6 expression is required for early nervous system development in Xenopus laevis

Development ◽  
1996 ◽  
Vol 122 (8) ◽  
pp. 2539-2554 ◽  
Author(s):  
T.E. Lallier ◽  
C.A. Whittaker ◽  
D.W. DeSimone
Keyword(s):  
Nervous System ◽  
Early Development ◽  
System Development ◽  
Cranial Nerves ◽  
Nervous System Development ◽  
Neural Plate ◽  
Pronephric Duct ◽  
Axial Defects ◽  
Integrin Alpha 6

The integrin alpha 6 subunit pairs with both the beta 1 and beta 4 subunits to form a subfamily of laminin receptors. Here we report the cDNA cloning and primary sequence for the Xenopus homologue of the mammalian integrin alpha 6 subunit. We present data demonstrating the spatial and temporal expression of alpha 6 mRNA and protein during early development. Initially, alpha 6 transcripts are expressed in the dorsal ectoderm and future neural plate at the end of gastrulation. Later in development, alpha 6 mRNAs are expressed in a variety of neural derivatives, including the developing sensory placodes (otic and olfactory) and commissural neurons within the neural tube. Integrin alpha 6 is also expressed in the elongating pronephric duct as well as a subset of the rhombencephalic neural crest, which will form the Schwann cells lining several cranial nerves (VII, VIII and X). In vivo expression of an alpha 6 antisense transcript in the animal hemisphere leads to a reduction in alpha 6 protein expression, a loss of adhesion to laminin, and severe defects in normal development. In 35% of cases, reduced levels of alpha 6 expression result in embryos that complete gastrulation normally but arrest at neurulation prior to the formation of the neural plate. In an additional 22% of cases, embryos develop with severe axial defects, including complete loss of head or tail structures. In contrast, overexpression of the alpha 6 subunit by injection of full-length mRNA has no apparent effect on embryonic development. Co-injection of antisense and sense plasmid constructs results in a partial rescue of the antisense-generated phenotypes. These data indicate that the integrin alpha 6 subunit is critical for the early development of the nervous system in amphibians.

Challenging Dogmas - Or How Much Evidence Is Necessary To Claim That There Is a Direct Developmental and Functional Link Between The Primordial Germ Cell (PGC) Lineage and Hematopoiesis?

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 1215-1215 ◽  
Author(s):  
Magdalena Kucia ◽  
Magda Maj ◽  
Kasia Mierzejewska ◽  
Dong-Myung Shin ◽  
Janina Ratajczak ◽  
...  
Keyword(s):  
Stem Cells ◽  
Early Development ◽  
Sex Hormones ◽  
Hormone Receptors ◽  
Brdu Incorporation ◽  
Quiescent State ◽  
Functional Link ◽  
Hematopoietic Stem

Abstract Background The recent hot debate on the existence in bone marrow (BM) of developmentally early stem cells with broader specification challenged the hierarchy within the stem cell compartment in murine BM. Evidence has accumulated that hematopoietic stem cells (HSCs) can become specified from a population of migrating primordial germ cells (PGCs) during embryogenesis. In support of this intriguing possibility, HSCs and PGCs are highly migratory cells, and specification of the first primitive HSCs in yolk sac blood islands as well as the origin of definitive HSCs in the aorta–gonado–mesonephros (AGM) region are chronologically and anatomically correlated with the developmental migration of PGCs in extra- and intra-embryonic tissues. Furthermore, several papers have described the sharing of chromosomal aberrations between germline tumors and leukemias or lymphomas, which suggests their clonal origin. Moreover, our recent work demonstrated the presence of quiescent, small, Oct-4+Nanog+Sca-1+Lin–CD45– stem cells in adult murine BM that express several markers shared with migratory PGCs (Leukemia 2010;24:1450) and can be specified into the hematopoietic lineage (Exp.Hematology 2011;39:225). These cells were named very small embryonic-like stem cells (VSELs). Hypothesis The aim of our study was to test the hypothesis that VSELs are related to PGCs, which would support a potential developmental link between hematopoiesis and the germ line. Experimental strategies We employed transmission electron microscopy (TEM), immunohistochemical staining, RQ-PCR analysis of mRNA and miRNA expression, gene array studies, and promoter methylation analysis to evaluate the expression of genes characteristic of PGC specification. We evaluated the expression of sex hormone receptors in VSELs and HSCs, and by direct in vitro and in vivo studies, we studied the effect of androgens and pituitary gonadotropins on proliferation and expansion of VSELs and HSCs. Salient Results The TEM studies revealed VSELs to be small cells with a high nuclear/cytoplasmic ratio, euchromatin, and few mitochondria. VSELs isolated under steady-state conditions from BM highly express, at the mRNA and protein levels, genes involved in specification of the epiblast (e.g., Stella, Fragilis, Blimp1) in addition to genes involved in PGC specification, such as Dppa2, Dppa4, and Mvh, which characterize late-migratory PGCs. The expression of some of these genes has been confirmed at the protein level and at the promoter level to confirm chromatin structure characteristic of actively transcribed genes. To explain highly quiescent state of VSELs, we observed that VSELs, like migrating PGCs, modify imprinting of some early-development parentally imprinted gene loci, including Igf2-H19 and KCNQ1/p57Kip2, which results in their resistance to Igf-1/Igf-2 signaling and upregulation of the cyclin-dependent kinase inhibitor p57KIP2. In parallel, VSELs express several miRNAs that attenuate Igf-1/Igf-2 signaling in these cells (mir681, mir470, mir669b) as well as upregulate expression of p57KIP2 (mir25.1, mir19b, mir92). More importantly, we observed that VSELs and HSCs express mRNA for several pituitary and gonadal hormone receptors as well as highly express Sall4, an early-development marker shared by germ and hematopoietic cells. Finally, in direct in vitro and in vivo experiments, we confirmed that the quiescent population of BM-residing VSELs responds to stimulation by androgens (danazol) and pituitary gonadotropins (PSMG, FSH, and LH). In particular, we found that 10-day administration of all the sex hormones evaluated in this study directly stimulated expansion (∼2–3x) of VSELs and HSPCs in BM and enhanced BrdU incorporation (Figure 1). Conclusions Our data support the challenging, alternative concept that HSCs can be specified during development from epiblast/migrating PGCs and that VSELs that express several unique PGCs markers, are the most primitive population of stem cells in BM. Moreover, changes in the epigenetic signature of imprinted genes as well as the miRNA network involved in resistance of these cells to Igf-1/Igf-2 signaling keeps these cells quiescent in adult tissues and prevents teratoma formation. Finally, our in vitro and in vivo data clearly show that both VSELs and HSCs proliferate in response to sex hormones. Thus, we conclude that the PGC origin of HSCs warrants further study. Disclosures: Ratajczak: Neostem Inc.: Membership on an entity’s Board of Directors or advisory committees, Research Funding.

Curtailed respiration by repeated vs. isolated hypoxia in maturing piglets is unrelated to NTS ME or SP levels

1997 ◽  
Vol 83 (2) ◽  
pp. 522-529 ◽  
Author(s):  
Karen A. Waters ◽  
André Laferrière ◽  
Julie Paquette ◽  
Cynthia Goodyer ◽  
Immanuela R. Moss
Keyword(s):  
Heart Rate ◽  
Substance P ◽  
Arterial Pressure ◽  
Early Development ◽  
In Vivo Microdialysis ◽  
Hypoxic Exposure ◽  
Electromyographic Activity ◽  
Arterial Ph ◽  
Respiratory Responses

Waters, Karen A., André Laferrière, Julie Paquette, Cynthia Goodyer, and Immanuela R. Moss. Curtailed respiration by repeated vs. isolated hypoxia in maturing piglets is unrelated to NTS ME or SP levels. J. Appl. Physiol. 83(2): 522–529, 1997.—In early development, respiratory disorders can produce recurring hypoxic episodes during sleep. To examine possible effects of daily repeated vs. isolated hypoxic hypoxia, cardiorespiratory functions and central, respiratory-related neuromodulator levels in 21- to 32-day-old, chronically instrumented, unsedated piglets were compared between a fifth sequential daily hypoxia and an isolated hypoxia (10% O2-90% N2 for 30 min). Diaphragmatic electromyographic activity, heart rate and arterial pressure, and pH and gas tensions were measured. In vivo microdialysis, via chronically implanted guides, served to sample interstitial substance P (SP) and methionine-enkephalin (ME) at the level of the respiratory-related nucleus tractus solitarii (NTS). Compared with an isolated hypoxia, repeated hypoxia resulted in 1) lower respiratory frequency (f), ventilation equivalent, and arterial pH, higher arterial [Formula: see text]during hypoxia, and lower f in recovery from hypoxia; and 2) increased SP concentrations but no change in ME concentrations. We conclude that, in these maturing swine, repeated vs. isolated hypoxic exposure curtails respiratory responses to hypoxia by a mechanism(s) unrelated to SP or ME levels at the NTS.

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