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.

scholarly journals Imaging patterns of calcium transients during neural induction in Xenopus laevis embryos

2000 ◽  
Vol 113 (19) ◽  
pp. 3519-3529 ◽  
Author(s):  
C. Leclerc ◽  
S.E. Webb ◽  
C. Daguzan ◽  
M. Moreau ◽  
A.L. Miller
Keyword(s):  
Xenopus Laevis ◽  
Calcium Signalling ◽  
Neural Induction ◽  
Calcium Transients ◽  
Free Calcium ◽  
Treated Animal ◽  
Cell Stage ◽  
Subsequent Formation ◽  
Xenopus Laevis Embryos

Through the injection of f-aequorin (a calcium-sensitive bioluminescent reporter) into the dorsal micromeres of 8-cell stage Xenopus laevis embryos, and the use of a Photon Imaging Microscope, distinct patterns of calcium signalling were visualised during the gastrulation period. We present results to show that localised domains of elevated calcium were observed exclusively in the anterior dorsal part of the ectoderm, and that these transients increased in number and amplitude between stages 9 to 11, just prior to the onset of neural induction. During this time, however, no increase in cytosolic free calcium was observed in the ventral ectoderm, mesoderm or endoderm. The origin and role of these dorsal calcium-signalling patterns were also investigated. Calcium transients require the presence of functional L-type voltage-sensitive calcium channels. Inhibition of channel activation from stages 8 to 14 with the specific antagonist R(+)BayK 8644 led to a complete inhibition of the calcium transients during gastrulation and resulted in severe defects in the subsequent formation of the anterior nervous system. BayK treatment also led to a reduction in the expression of Zic3 and geminin in whole embryos, and of NCAM in noggin-treated animal caps. The possible role of calcium transients in regulating developmental gene expression is discussed.

Sperm-derived factors enhance the in vitro developmental potential of haploid parthenotes

Zygote ◽  
2017 ◽  
Vol 25 (6) ◽  
pp. 697-710 ◽  
Author(s):  
Ramya Nair ◽  
Shahin Aboobacker ◽  
Srinivas Mutalik ◽  
Guruprasad Kalthur ◽  
Satish Kumar Adiga
Keyword(s):  
Strontium Chloride ◽  
Cortical Granules ◽  
Cell Stage ◽  
Developmental Potential ◽  
Activation Rate ◽  
Paternal Factors ◽  
Artificial Activation ◽  
Cortical Distribution

SummaryParthenotes are characterized by poor in vitro developmental potential either due to the ploidy status or the absence of paternal factors. In the present study, we demonstrate the beneficial role of sperm-derived factors (SDF) on the in vitro development of mouse parthenotes. Mature (MII) oocytes collected from superovulated Swiss albino mice were activated using strontium chloride (SrCl2) in the presence or absence of various concentrations of SDF in M16 medium. The presence of SDF in activation medium did not have any significant influence on the activation rate. However, a significant increase in the developmental potential of the embryos and increased blastocyst rate (P < 0.01) was observed at 50 µg/ml concentration. Furthermore, the activated oocytes from this group exhibited early cleavage and cortical distribution of cortical granules that was similar to that of normally fertilized zygotes. Culturing 2-cell stage parthenotes in the presence of SDF significantly improved the developmental potential (P < 0.05) indicating that they also play a significant role in embryo development. In conclusion, artificial activation of oocytes with SDF can improve the developmental potential of parthenotes in vitro.

scholarly journals The kinases PIG-1 and PAR-1 act in redundant pathways to regulate asymmetric division in the EMS blastomere of C. elegans

2017 ◽  
Author(s):  
Malgorzata J. Liro ◽  
Diane G. Morton ◽  
Lesilee S. Rose
Keyword(s):  
Wnt Pathway ◽  
Asymmetric Division ◽  
Spindle Orientation ◽  
Cell Stage ◽  
Spindle Positioning ◽  
C Elegans ◽  
Stage Embryo ◽  
Cell Embryo ◽  
The One

AbstractThe PAR-1 kinase of C. elegans is localized to the posterior of the one-cell embryo and its mutations affect asymmetric spindle placement and partitioning of cytoplasmic components in the first cell cycle. However, unlike mutations in the posteriorly localized PAR-2 protein, par-1 mutations do not cause failure to restrict the anterior PAR polarity complex. Further, it has been difficult to examine the role of PAR-1 in subsequent divisions due to the early defects in par-1 mutant embryos. Here we show that the PIG-1 kinase acts redundantly with PAR-1 to restrict the anterior PAR-3 protein for polarity maintenance in the one-cell embryo. By using a weak allele of par-1 that exhibits enhanced lethality when combined with a pig-1 mutation we have further explored roles for these genes in subsequent divisions. We find that both PIG-1 and PAR-1 regulate spindle orientation in the EMS blastomere of the four-cell stage embryo to ensure that it undergoes an asymmetric division. In this cell, PIG-1 and PAR-1 act in parallel pathways for spindle positioning, PIG-1 in the MES-1/SRC-1 pathway and PAR-1 in the Wnt pathway.

scholarly journals Porcine embryo development and fragmentation and their relation to apoptotic markers: a cinematographic and confocal laser scanning microscopic study

Reproduction ◽  
2005 ◽  
Vol 129 (4) ◽  
pp. 443-452 ◽  
Author(s):  
Bart Mateusen ◽  
Ann Van Soom ◽  
Dominiek G D Maes ◽  
Isabelle Donnay ◽  
Luc Duchateau ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Confocal Laser Scanning ◽  
Confocal Laser ◽  
Embryo Morphology ◽  
Fragmentation Pattern ◽  
Cell Stage ◽  
Developmental Potential ◽  
Developmental Arrest ◽  
Porcine Embryo

Porcine embryo selection prior to transfer is mainly influenced by morphological criteria. However, the relationship between embryonic morphology, developmental potential and cell death by apoptosis in porcine embryos is still unclear. The aim of this study was to establish embryo quality parameters for in vivo fertilised porcine embryos based on timing of development in vitro, embryo morphology and the presence of apoptosis. The kinetics of development and morphological parameters were investigated in a time-lapse cinematographic experiment. Possible links between embryo morphology and apoptosis were examined via a confocal laser scanning experiment, analysing nuclear changes, annexin V and terminal dUTP nick-end labelling. The timing of early cleavages was firmly linked to embryo developmental competence in vitro. Attainment of at least the 5-cell stage before 77 h post insemination and attainment of the morula stage before 102 h post insemination significantly increased the odds for reaching the early blastocyst stage. Overall, a negative effect of fragmentation percentage and fragmentation pattern on subsequent embryonic development was observed, but the developmental potential of embryos experiencing slight fragmentation (0–5%) was not different from embryos without fragmentation. Correlations detected between developmental arrest and fragmentation, and fragmentation and apoptosis were 0.60 and 0.87 (P < 0.05) respectively. Only a minority of the embryos arrested between the 1- and 4-cell stage displayed biochemical characteristics of apoptosis. Consequently, a significant correlation (0.57) between developmental arrest and apoptosis could only be established for embryos arrested after embryonic genome activation.

scholarly journals Distinct role of histone chaperone Asf1a and Asf1b during fertilization and pre-implantation embryonic development in mice

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Xuemei Wang ◽  
Lu Wang ◽  
Jie Dou ◽  
Tianjiao Yu ◽  
Pengbo Cao ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Histone Chaperone ◽  
Blastocyst Stage ◽  
Nuclear Accumulation ◽  
Cell Stage ◽  
Developmental Potential ◽  
Oct4 Expression ◽  
Real Time Quantitative Pcr ◽  
Histone H3.3

Abstract Background Asf1 is a well-conserved histone chaperone that regulates multiple cellular processes in different species. Two paralogous genes, Asf1a and Asf1b exist in mammals, but their role during fertilization and early embryogenesis remains to be investigated further. Methods We analyzed the dynamics of histone chaperone Asf1a and Asf1b in oocytes and pre-implantation embryos in mice by immunofluorescence and real-time quantitative PCR, and further investigated the role of Asf1a and Asf1b during fertilization and pre-implantation development by specific Morpholino oligos-mediated knock down approach. Results Immunofluorescence with specific antibodies revealed that both Asf1a and Asf1b were deposited in the nuclei of fully grown oocytes, accumulated abundantly in zygote and 2-cell embryonic nuclei, but turned low at 4-cell stage embryos. In contrast to the weak but definite nuclear deposition of Asf1a, Asf1b disappeared from embryonic nuclei at morula and blastocyst stages. The knockdown of Asf1a and Asf1b by specific Morpholino oligos revealed that Asf1a but not Asf1b was required for the histone H3.3 assembly in paternal pronucleus. However, knockdown of either Asf1a or Asf1b expression decreased developmental potential of pre-implantation embryos. Furthermore, while Asf1a KD severely reduced H3K56 acetylation level and the expression of Oct4 in blastocyst stage embryos, Asf1b KD almost eliminated nuclear accumulation of proliferating cell marker-PCNA in morula stage embryos. These results suggested that histone chaperone Asf1a and Asf1b play distinct roles during fertilization and pre-implantation development in mice. Conclusions Our data suggested that both Asf1a and Asf1b are required for pre-implantation embryonic development. Asf1a regulates H3K56ac levels and Oct4 expression, while Asf1b safeguards pre-implantation embryo development by regulating cell proliferation. We also showed that Asf1a, but not Asf1b, was necessary for the assembly of histone H3.3 in paternal pronuclei after fertilization.

scholarly journals Role of Src homology 2 domain-mediated PTK signaling in mouse zygotic development

Reproduction ◽  
2006 ◽  
Vol 132 (3) ◽  
pp. 413-421 ◽  
Author(s):  
Li Meng ◽  
JinPing Luo ◽  
Chunhua Li ◽  
William H Kinsey
Keyword(s):  
Marine Invertebrates ◽  
Sh2 Domain ◽  
Calcium Oscillations ◽  
Src Family Kinases ◽  
Developmental Potential ◽  
Fyn Kinase ◽  
Src Homology 2 ◽  
Src Homology ◽  
Src Homology 2 Domain

Fyn and other Src-family kinases play an essential role at several steps during egg activation following fertilization of externally fertilizing species, such as marine invertebrates, fish, and frogs. Recent studies demonstrate that the requirement for Src-family kinases in activation of the mammalian egg is different from lower species, and the objective of this study was to test the role of the Fyn kinase in the mouse egg activated by intracytoplasmic sperm injection (ICSI). An Src homology 2 (SH2) domain containing fusion protein was used to suppress Fyn function in the mouse zygote following ICSI. Eggs injected with the Fyn SH2 domain at an intracellular concentration of 4–8 μM exhibited reduced developmental potential with 100% of the zygotes being arrested following the first or the second cleavage. At higher concentrations, the protein blocked pronuclear congression and the zygotes remained at the pronuclear stage. The SH2 domain had no effect on sperm-induced calcium oscillations in distinct contrast to its effect on the eggs of lower species. The results indicate that the SH2 domain of Fyn kinase plays an important role in pronuclear congression as well as early cleavage events and that this effect appears not to involve disruption of calcium oscillations.

scholarly journals Fast revascularization of the injured area is essential to support zebrafish heart regeneration

2016 ◽  
Vol 113 (40) ◽  
pp. 11237-11242 ◽  
Author(s):  
Rubén Marín-Juez ◽  
Michele Marass ◽  
Sebastien Gauvrit ◽  
Andrea Rossi ◽  
Shih-Lei Lai ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Cell Types ◽  
Dominant Negative ◽  
Heart Regeneration ◽  
Cardiomyocyte Proliferation ◽  
Cell Stage ◽  
Injured Area ◽  
Fibrotic Scar ◽  
The One ◽  
Different Cell Types

Zebrafish have a remarkable capacity to regenerate their heart. Efficient replenishment of lost tissues requires the activation of different cell types including the epicardium and endocardium. A complex set of processes is subsequently needed to support cardiomyocyte repopulation. Previous studies have identified important determinants of heart regeneration; however, to date, how revascularization of the damaged area happens remains unknown. Here, we show that angiogenic sprouting into the injured area starts as early as 15 h after injury. To analyze the role of vegfaa in heart regeneration, we used vegfaa mutants rescued to adulthood by vegfaa mRNA injections at the one-cell stage. Surprisingly, vegfaa mutants develop coronaries and revascularize after injury. As a possible explanation for these observations, we find that vegfaa mutant hearts up-regulate the expression of potentially compensating genes. Therefore, to overcome the lack of a revascularization phenotype in vegfaa mutants, we generated fish expressing inducible dominant negative Vegfaa. These fish displayed minimal revascularization of the damaged area. In the absence of fast angiogenic revascularization, cardiomyocyte proliferation did not occur, and the heart failed to regenerate, retaining a fibrotic scar. Hence, our data show that a fast endothelial invasion allows efficient revascularization of the injured area, which is necessary to support replenishment of new tissue and achieve efficient heart regeneration. These findings revisit the model where neovascularization is considered to happen concomitant with the formation of new muscle. Our work also paves the way for future studies designed to understand the molecular mechanisms that regulate fast revascularization.

You Are the One I Want to Communicate With!

2013 ◽  
Vol 44 (1) ◽  
pp. 16-25 ◽  
Author(s):  
Sabrina Pierucci ◽  
Olivier Klein ◽  
Andrea Carnaghi
Keyword(s):  
Memory Bias ◽  
Shared Reality ◽  
Communication Partner ◽  
Shared Reality Theory ◽  
The One ◽  
Study Participants

This article investigates the role of relational motives in the saying-is-believing effect ( Higgins & Rholes, 1978 ). Building on shared reality theory, we expected this effect to be most likely when communicators were motivated to “get along” with the audience. In the current study, participants were asked to describe an ambiguous target to an audience who either liked or disliked the target. The audience had been previously evaluated as a desirable vs. undesirable communication partner. Only participants who communicated with a desirable audience tuned their messages to suit their audience’s attitude toward the target. In line with predictions, they also displayed an audience-congruent memory bias in later recall.

The Formation of Intermediate Product I in a Purified System The Role of Factor IX or of its Precursor and of a Hageman Factor-PTA Fraction

1961 ◽  
Vol 6 (02) ◽  
pp. 224-234 ◽  
Author(s):  
E. T Yin ◽  
F Duckert
Keyword(s):  
Intermediate Product ◽  
Factor Ix ◽  
Assay Method ◽  
Lag Phase ◽  
Factor X ◽  
Haemophilia B ◽  
Hageman Factor ◽  
One Stage ◽  
The One

Summary1. The role of two clot promoting fractions isolated from either plasma or serum is studied in a purified system for the generation of intermediate product I in which the serum is replaced by factor X and the investigated fractions.2. Optimal generation of intermediate product I is possible in the purified system utilizing fractions devoid of factor IX one-stage activity. Prothrombin and thrombin are not necessary in this system.3. The fraction containing factor IX or its precursor, no measurable activity by the one-stage assay method, controls the yield of intermediate product I. No similar fraction can be isolated from haemophilia B plasma or serum.4. The Hageman factor — PTA fraction shortens the lag phase of intermediate product I formation and has no influence on the yield. This fraction can also be prepared from haemophilia B plasma or serum.

The Role of Technology in Higher Education

IJOHMN ◽  
2017 ◽  
Vol 3 (3) ◽  
Author(s):  
Dr. A. SUBRAMANIAN
Keyword(s):  
Professional Development ◽  
Information Systems ◽  
Distance Learning ◽  
Educational Achievement ◽  
Traditional Education ◽  
Developmental Potential ◽  
Professional Development For Teachers ◽  
Paper Technology ◽  
Educational Field

Present status and use for educational purposes, technology is fulfilling an ever increasing role in both the traditional education field, and in other fields which are utilizing technology for educational purposes. Within the educational field we can see technology as a means of removing barriers for students and teachers alike. First, technology can remove financial and geographical barriers through distributed learning. This allows students and teachers to experience educational opportunities that they might have otherwise never been able to encounter. Second, technology is bringing about a new focus on problem and skill based learning. Information databases are being used to assist teachers in the acquisition of new knowledge and provide professional support outside of the traditional professional development seminar. In regards to future action, we should continue to utilize the successful trends in education as a means to fulfil their developmental potential and see increased impacts on our field. In particular, we should continue the use of distance learning as a means of professional development for teachers, by providing more opportunities aimed at improving their job related performance. Distance learning for students should also be an area of focus by providing software that allows for increasing authenticity in simulations, multimedia content, and social connections. We should continue to focus on technology that allows students to interact with other students and environments located outside of their current environment, locality, and culture. Information systems are also in need of continual investment. Information systems perform two important roles for the educational system: Focus on this paper, technology has already served an important role in education in multiple fields. Specifically, technology has been of great use to the educational field in terms of its focus on improving the effectiveness and efficiency of the educational experiences of both students and teachers. Continued use and development of technology can serve to further benefit the educational field and recommendations based on the development of existing trends in education should be pursued for great gains in educational achievement..

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