Dynamics of the control of body pattern in the development of Xenopus laevis

Development ◽  
1985 ◽  
Vol 88 (1) ◽  
pp. 113-133
Author(s):  
Jonathan Cooke ◽  
John A. Webber
Keyword(s):  
Time Course ◽  
Control Cell ◽  
Bilateral Symmetry ◽  
Normal Range ◽  
Cell Stage ◽  
Developmental Potential ◽  
Cell Pair ◽  
Mesoderm Development ◽  
Cell Numbers ◽  
Population Sizes

Xenopus embryos have been selected in which the first cleavage plane is tending strongly to correspond with that of bilateral symmetry for the future larval pattern. The two blastomeres produced by this cleavage have been separated and allowed to develop as reciprocal pairs of presumptive lateral-half isolates. The early development and the time course of the gastrulation movements, and the qualitative and quantitative aspects of larval mesodermal patterns, have been studied in relation to synchronously fertilized controls. The result is restoration of bilateral symmetry for developmental potential, and production of a pair of small gastrulae and larvae with qualitatively complete body plans but 50 % of control cell numbers each (see Kageura & Yamana, 1983). Most commonly, however, the resulting small patterns deviate from the normal range in their proportions in at least one of two ways. The notochord territory is rarely, if ever, under-represented (i.e. notochords contain at least 50% control cell numbers) but it is frequently over-represented, in some cases approximating that of control whole embryos. Reciprocal pairs of isolates thus tend, on average, to produce more notochordal tissue than they would have if developing normally. Secondly, the balance of cell population sizes assigned to somites up and down the axis is altered so that relatively anterior members of the series are less scaled down than those in trunk and tail regions. The mesodermal plan developed by a lateralhalf isolate is thus characteristically intermediate between that of a small, harmonious larva (the proportional presumptive fates of the materials, apart from loss of bilaterality), and that of the mosaically developing presumptive dorsoanterior cell pair from the 4-cell stage, discussed in the previous paper. A minority of the lateral isolates does develop a harmonious and thus wellregulated body plan, however, and the normality or otherwise of the schedules of gastrulation timing in isolates seems a good predictor of their morphogenetic performance in this respect. The results are discussed as informing us about the dynamics of the interactions, prior to gastrular stages, that underlie the normal mesoderm development.

Recovery of subjective visual horizontal after unilateral vestibular deafferentation by intratympanic instillation of gentamicin

2006 ◽  
Vol 16 (1-2) ◽  
pp. 69-73 ◽  
Author(s):  
Yoshinari Takai ◽  
Toshihisa Murofushi ◽  
Munetaka Ushio ◽  
Shinichi Iwasaki
Keyword(s):  
Healthy Subjects ◽  
Time Course ◽  
Early Stage ◽  
Ccd Camera ◽  
The Other ◽  
Spontaneous Nystagmus ◽  
Vestibular Evoked Myogenic Potentials ◽  
Normal Range ◽  
Intratympanic Gentamicin ◽  
Unilateral Vestibular Deafferentation

The time course of the recovery of subjective visual horizontal (SVH) after unilateral vestibular deafferentation by intratympanic instillation of gentamicin was studied. Six patients who underwent intratympanic gentamicin instillation therapy for Meniere's disease (1 man and 5 women, 32 to 69 years of age) were enrolled in this study. For comparison, SVH in 23 healthy subjects (12 men and 11 woman, 23 to 48 years of age) was also measured. The mean ± SD of SVH in healthy subjects was 0.0 ± 1.1 deg. All of the 6 patients showed significantly deviated SVH toward the injected side-down at the early stage after the therapy. Although one patient showed recovery of SVH to the normal range 25 days after the injection, the other patients required more time for recovery. Three patients did not show recovery to the normal range after 1 year. On the other hand, spontaneous nystagmus observed using an infrared CCD camera in total dark disappeared after 35 days (median). Patients who had normal vestibular evoked myogenic potentials before the therapy showed a tendency of delay of recovery of SVH. The reasons why the recovery of SVH took longer than the disappearance of spontaneous nystagmus are discussed in this report.

Keratinocyte growth factor therapy in murine oleic acid-induced acute lung injury

2005 ◽  
Vol 288 (6) ◽  
pp. L1179-L1192 ◽  
Author(s):  
K. Ulrich ◽  
M. Stern ◽  
M. E. Goddard ◽  
J. Williams ◽  
J. Zhu ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Acute Lung Injury ◽  
Gene Delivery ◽  
Lung Injury ◽  
Time Course ◽  
Lung Compliance ◽  
Alveolar Type ◽  
Protein Therapy ◽  
Cell Numbers ◽  
Atii Cell

Alveolar type II (ATII) cell proliferation and differentiation are important mechanisms in repair following injury to the alveolar epithelium. KGF is a potent ATII cell mitogen, which has been demonstrated to be protective in a number of animal models of lung injury. We have assessed the effect of recombinant human KGF (rhKGF) and liposome-mediated KGF gene delivery in vivo and evaluated the potential of KGF as a therapy for acute lung injury in mice. rhKGF was administered intratracheally in male BALB/c mice to assess dose response and time course of proliferation. SP-B immunohistochemistry demonstrated significant increases in ATII cell numbers at all rhKGF doses compared with control animals and peaked 2 days following administration of 10 mg/kg rhKGF. Protein therapy in general is very expensive, and gene therapy has been suggested as a cheaper alternative for many protein replacement therapies. We evaluated the effect of topical and systemic liposome-mediated KGF-gene delivery on ATII cell proliferation. SP-B immunohistochemistry showed only modest increases in ATII cell numbers following gene delivery, and these approaches were therefore not believed to be capable of reaching therapeutic levels. The effect of rhKGF was evaluated in a murine model of OA-induced lung injury. This model was found to be associated with significant alveolar damage leading to severe impairment of gas exchange and lung compliance. Pretreatment with rhKGF 2 days before intravenous OA challenge resulted in significant improvements in Po2, Pco2, and lung compliance. This study suggests the feasibility of KGF as a therapy for acute lung injury.

scholarly journals Comparative Analyses of Single-Cell Transcriptomic Profiles between In Vitro Totipotent Blastomere-like Cells and In Vivo Early Mouse Embryonic Cells

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3111
Author(s):  
Po-Yu Lin ◽  
Denny Yang ◽  
Chi-Hsuan Chuang ◽  
Hsuan Lin ◽  
Wei-Ju Chen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Single Cell ◽  
Embryonic Cells ◽  
Cell Stage ◽  
Developmental Potential ◽  
Functional Features ◽  
Early Mouse ◽  
Extraembryonic Tissues

The developmental potential within pluripotent cells in the canonical model is restricted to embryonic tissues, whereas totipotent cells can differentiate into both embryonic and extraembryonic tissues. Currently, the ability to culture in vitro totipotent cells possessing molecular and functional features like those of an early embryo in vivo has been a challenge. Recently, it was reported that treatment with a single spliceosome inhibitor, pladienolide B (plaB), can successfully reprogram mouse pluripotent stem cells into totipotent blastomere-like cells (TBLCs) in vitro. The TBLCs exhibited totipotency transcriptionally and acquired expanded developmental potential with the ability to yield various embryonic and extraembryonic tissues that may be employed as novel mouse developmental cell models. However, it is disputed whether TBLCs are ‘true’ totipotent stem cells equivalent to in vivo two-cell stage embryos. To address this question, single-cell RNA sequencing was applied to TBLCs and cells from early mouse embryonic developmental stages and the data were integrated using canonical correlation analyses. Differential expression analyses were performed between TBLCs and multi-embryonic cell stages to identify differentially expressed genes. Remarkably, a subpopulation within the TBLCs population expressed a high level of the totipotent-related genes Zscan4s and displayed transcriptomic features similar to mouse two-cell stage embryonic cells. This study underscores the subtle differences between in vitro derived TBLCs and in vivo mouse early developmental cell stages at the single-cell transcriptomic level. Our study has identified a new experimental model for stem cell biology, namely ‘cluster 3’, as a subpopulation of TBLCs that can be molecularly defined as near totipotent cells.

scholarly journals Three-Dimensional Live Imaging of Bovine Preimplantation Embryos: A New Method for IVF Embryo Evaluation

2021 ◽  
Vol 8 ◽  
Author(s):  
Yasumitsu Masuda ◽  
Ryo Hasebe ◽  
Yasushi Kuromi ◽  
Masayoshi Kobayashi ◽  
Kanako Urataki ◽  
...  
Keyword(s):  
Embryo Transfer ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Three Dimensional ◽  
Preimplantation Embryos ◽  
Infrared Light ◽  
Bovine Embryo ◽  
Bovine Embryos ◽  
Cell Stage ◽  
Developmental Potential

Conception rates for transferred bovine embryos are lower than those for artificial insemination. Embryo transfer (ET) is widely used in cattle but many of the transferred embryos fail to develop, thus, a more effective method for selecting bovine embryos suitable for ET is required. To evaluate the developmental potential of bovine preimplantation embryos (2-cell stage embryos and blastocysts), we have used the non-invasive method of optical coherence tomography (OCT) to obtain live images. The images were used to evaluate 22 parameters of blastocysts, such as the volume of the inner cell mass and the thicknesses of the trophectoderm (TE). Bovine embryos were obtained by in vitro fertilization (IVF) of the cumulus-oocyte complexes aspirated by ovum pick-up from Japanese Black cattle. The quality of the blastocysts was examined under an inverted microscope and all were confirmed to be Code1 according to the International Embryo Transfer Society standards for embryo evaluation. The OCT images of embryos were taken at the 2-cell and blastocyst stages prior to the transfer. In OCT, the embryos were irradiated with near-infrared light for a few minutes to capture three-dimensional images. Nuclei of the 2-cell stage embryos were clearly observed by OCT, and polynuclear cells at the 2-cell stage were also clearly found. With OCT, we were able to observe embryos at the blastocyst stage and evaluate their parameters. The conception rate following OCT (15/30; 50%) is typical for ETs and no newborn calves showed neonatal overgrowth or died, indicating that the OCT did not adversely affect the ET. A principal components analysis was unable to identify the parameters associated with successful pregnancy, while by using hierarchical clustering analysis, TE volume has been suggested to be one of the parameters for the evaluation of bovine embryo. The present results show that OCT imaging can be used to investigate time-dependent changes of IVF embryos. With further improvements, it should be useful for selecting high-quality embryos for transfer.

The analysis of chromatin organisation allows selection of mouse antral oocytes competent for development to blastocyst

Zygote ◽  
2002 ◽  
Vol 10 (1) ◽  
pp. 73-78 ◽  
Author(s):  
Maurizio Zuccotti ◽  
Rubén H. Ponce ◽  
Michele Boiani ◽  
Stefano Guizzardi ◽  
Paolo Govoni ◽  
...  
Keyword(s):  
Developmental Competence ◽  
Farm Animals ◽  
Cell Stage ◽  
Developmental Potential ◽  
Different Types ◽  
Chromatin Organisation ◽  
Selection For ◽  
Gamete Selection ◽  
Selection Of

Mouse antral oocytes can be classified in two different types termed SN or NSN oocytes, depending on the presence or absence, respectively, of a ring of Hoechst 33342-positive chromatin surrounding the nucleolus. The aim of the present study was to test the developmental competence to blastocyst of the two types of oocytes. Here we show that following isolation, classification and culture of cumulus-free antral oocytes, 14.7% and 74.5% of NSN and SN oocytes, respectively, reached the metaphase II stage. When fertilised and further cultured none of the metaphase II NSN oocytes developed beyond the 2-cell stage whilst 47.4% of the metaphase II SN oocytes reached the 4-cell stage and 18.4% developed to blastocyst. The findings reported in this paper may contribute to improved procedures of female gamete selection for in vitro fertilisation of humans and farm animals. Furthermore, the selection of oocytes with better developmental potential may be of interest for studies on nuclear/cytoplasm interaction, particularly in nuclear-transfer experiments.

Specification of anterior-posterior differences within the AB lineage in the C. elegans embryo: a polarising induction

Development ◽  
1995 ◽  
Vol 121 (5) ◽  
pp. 1559-1568 ◽  
Author(s):  
H. Hutter ◽  
R. Schnabel
Keyword(s):  
Cell Fate ◽  
Tissue Type ◽  
Cell Stage ◽  
Anterior Portion ◽  
Developmental Potential ◽  
C Elegans ◽  
The Third ◽  
Inductive Signal ◽  
Anterior Posterior ◽  
Lineage Analysis

In a C. elegans embryo the third cleavages of descendants of the anterior blastomere AB of the 2-cell stage create pairs of blastomeres that develop differently. By laser ablation experiments we show that the fates of all the posterior daughters of this division depend on an induction occurring three cleavages before these blastomeres are born. The time of induction precludes a direct effect on cell fate. Alternatively, we suggest that the induction creates a heritable cell polarity which is propagated through several divisions. We suggest a model to demonstrate how a signal could be propagated through several rounds of cell division. An important implication of our observations is that this early induction acts to specify blastomere identity, not tissue type. A detailed lineage analysis revealed that altering the inductive signal alters complex lineage patterns as a whole. The induction described here, together with two inductions described previously can be used to illustrate how the anterior portion of the C. elegans embryo can be successively subdivided into blastomeres with unique developmental potential.

Expression pattern ofBrachyuryin the molluscPatella vulgatasuggests a conserved role in the establishment of the AP axis in Bilateria

Development ◽  
2002 ◽  
Vol 129 (6) ◽  
pp. 1411-1421 ◽  
Author(s):  
Nicolas Lartillot ◽  
Olivier Lespinet ◽  
Michel Vervoort ◽  
André Adoutte
Keyword(s):  
Expression Pattern ◽  
Bilateral Symmetry ◽  
Growth Zone ◽  
Posterior Pole ◽  
Axis Formation ◽  
Posterior Edge ◽  
Cell Stage ◽  
Posterior Growth Zone ◽  
Erk Activity ◽  
Anterior Posterior

We report the characterisation of a Brachyury ortholog (PvuBra) in the marine gastropod Patella vulgata. In this mollusc, the embryo displays an equal cleavage pattern until the 32-cell stage. There, an inductive event takes place that sets up the bilateral symmetry, by specifying one of the four initially equipotent vegetal macromeres as the posterior pole of all subsequent morphogenesis. This macromere, usually designated as 3D, will subsequently act as an organiser. We show that 3D expresses PvuBra as soon as its fate is determined. As reported for another mollusc (J. D. Lambert and L. M. Nagy (2001) Development128, 45-56), we found that 3D determination and activity also involve the activation of the MAP kinase ERK, and we further show that PvuBra expression in 3D requires ERK activity. PvuBra expression then rapidly spreads to neighbouring cells that cleave in a bilateral fashion and whose progeny will constitute the posterior edge of the blastopore during gastrulation, suggesting a role for PvuBra in regulating cell movements and cleavage morphology in Patella. Until the completion of gastrulation, PvuBra expression is maintained at the posterior pole, and along the developing anterior-posterior axis. Comparing this expression pattern with what is known in other Bilateria, we advocate that Brachyury might have a conserved role in the regulation of anterior-posterior patterning among Bilateria, through the maintenance of a posterior growth zone, suggesting that a teloblastic mode of axis formation might be ancestral to the Bilateria.

Quantitative aspects of RNA synthesis and polyadenylation in 1-cell and 2-cell mouse embryos

Development ◽  
1983 ◽  
Vol 74 (1) ◽  
pp. 169-182
Author(s):  
Kerry B. Clegg ◽  
Lajos Pikó
Keyword(s):  
Time Course ◽  
Specific Activity ◽  
Average Length ◽  
State Level ◽  
Mouse Embryos ◽  
High Rate ◽  
Rna Sequences ◽  
Cell Stage ◽  
New Synthesis ◽  
Cell Embryo

Mouse embryos at the late 1-cell and late 2-cell stages were labelled with [3H]adenosine for periods of up to 320 min during which the specific activity of the ATP pool was constant. The time course of the molar accumulation of adenosine was calculated for tRNA, high-molecular-weight poly(A)− RNA and poly(A) tails versus internal regions of poly(A)+ RNA. Most of the adenosine incorporation into tRNA is due to turnover of the 3′-terminal AMP but some new synthesis of tRNA also appears to take place in both 1-cell and 2-cell embryos at a rate of about 0·2 pg/embryo/h. In the poly(A)- RNA fraction, an unstable component which is assumed to be heterogeneous nuclear RNA is synthesized at a high rate and accumulates at a steady-state level of about 1·5 pg/embryo in the 1-cell embryo and about 3·0 pg/embryo in the 2-cell embryo. Both 1-cell and 2-cell embryos synthesize relatively stable heterogeneous poly(A)− RNA, assumed to be mRNA, at a rate of about 0·3 pg/embryo/h; 2-cell embryos also synthesize mature ribosomal RNA at a rate of about 0·4 pg/embryo·h. Internally labelled poly(A)+ RNA is synthesized at a low rate in the 1-cell embryo, about 0·045 pg/embryo/h, but the rate increases to about 0·2 pg/embryo/h by the 2-cell stage. A striking feature of the 1-cell embryo is the high rate of synthesis of poly(A) tails, about 2·5 × 106 tails/embryo/h of an average length of (A)43, due almost entirely to cytoplasmic polyadenylation. This and other evidence suggests a turnover of the poly(A)+ RNA population in 1-cell embryos as a result of polyadenylation of new RNA sequences and degradation of some of the pre-existing poly(A)+ RNA. In the 2-cell embryo, the rate of synthesis of poly(A) tails (average length (A)93) is estimated at about 0·8 × 106tails/embryo/h and a significant fraction of poly(A) synthesis appears to be nuclear.

Rapid increase in mast cell numbers in canine central and peripheral airways

1988 ◽  
Vol 65 (1) ◽  
pp. 445-451 ◽  
Author(s):  
C. R. Turner ◽  
J. Kolbe ◽  
E. W. Spannhake
Keyword(s):  
Mast Cell ◽  
Airway Epithelium ◽  
Time Course ◽  
Isotonic Saline ◽  
Cell Movement ◽  
Cell Number ◽  
Small Airways ◽  
Cell Numbers ◽  
Peripheral Airways ◽  
Cell Counts

In preliminary studies of antigen-induced airway inflammation, we noted an apparent increase in peribronchiolar mast cell number. Experiments were thus undertaken to investigate the nature of this migration of mast cells into the central and peripheral airway epithelium and to determine its time course. The tracheae and small airways of 10 anesthetized mongrel dogs were exposed via a bronchoscope to Ascaris suum antigen (Ag), fMet-Leu-Phe (fMLP), ovalbumin (OVA), and isotonic saline (SAL). In the central airways, all stimuli provoked a significant increase (P less than 0.05) in mast cell numbers at the base of the airway epithelium within 3 h. In the peripheral airways, only Ag aerosol stimulated a significant mast cell increase compared with unexposed tissue. In a second series of experiments, the trachea of seven dogs were exposed to 0.026, 0.26, and 2.6 micrograms of Ag. The tissue was collected at 1, 3, 6, and 10 h after exposure. In these experiments, there was a significant mast cell increase seen within 1 h but it was not dose dependent. By 6-10 h after exposure, mast cell counts were not significantly different from the unexposed condition, which is consistent with the idea that some of the cells either degranulated or migrated into the airway lumen. We conclude that mast cell migration is an acute response that can be demonstrated within 1 h of stimulation with Ag. The observation that nonimmunological stimuli may, in some cases, also stimulate mast cell movement affords the possibility that this process represents a generalized response to airway irritation.

scholarly journals Role of Fyn kinase in oocyte developmental potential

2010 ◽  
Vol 22 (6) ◽  
pp. 966 ◽  
Author(s):  
Jinping Luo ◽  
Lynda K. McGinnis ◽  
William H. Kinsey
Keyword(s):  
Calcium Signalling ◽  
Dominant Negative ◽  
Rapid Decline ◽  
Protein Tyrosine Phosphorylation ◽  
Cell Stage ◽  
Developmental Potential ◽  
Developmental Arrest ◽  
Fyn Kinase ◽  
The One

Fyn kinase is highly expressed in oocytes, with inhibitor and dominant-negative studies suggesting a role in the signal transduction events during egg activation. The purpose of the present investigation was to test the hypothesis that Fyn is required for calcium signalling, meiosis resumption and pronuclear congression using the Fyn-knockout mouse as a model. Accelerated breeding studies revealed that Fyn-null females produced smaller litter sizes at longer intervals and exhibited a rapid decline in pup production with increasing age. Fyn-null females produced a similar number of oocytes, but the frequency of immature oocytes and mature oocytes with spindle chromosome abnormalities was significantly higher than in controls. Fertilised Fyn-null oocytes frequently (24%) failed to undergo pronuclear congression and remained at the one-cell stage. Stimulation with gonadotropins increased the number of oocytes ovulated, but did not overcome the above defects. Fyn-null oocytes overexpressed Yes kinase in an apparent effort to compensate for the loss of Fyn, yet still exhibited an altered pattern of protein tyrosine phosphorylation. In summary, Fyn-null female mice exhibit reduced fertility that appears to result from actin cytoskeletal defects rather than calcium signalling. These defects cause developmental arrest during oocyte maturation and pronuclear congression.

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