Signaling pathway from [Ca<sup>2+</sup>]<sub>i</sub> transients to ooplasmic segregation involves small GTPase rho in the ascidian egg

Yoshida, Manabu; Horiuchi, Yuji; Sensui, Noburu; Morisawa, Masaaki

doi:10.1046/j.1524-4725.2003.695.x

Cited by 8 publications

(7 citation statements)

References 22 publications

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“…1A). The fertilized ascidian egg shows cortical contractions with the egg deformations mediated by the cortical network of actin filaments (Sawada and Osanai, 1985), which is also mediated by [Ca 2 þ ] i oscillations (Sensui and Morisawa, 1996;Yoshida et al, 2003;Yoshida et al, 1998). Similar to other ascidian species, egg deformation was also observed during phase I [Ca 2 þ ] i oscillation in the P. mammillata egg.…”

Section: Changes In [Ca 2 þ ] I and Erk And H1k Activities In The Eggmentioning

confidence: 56%

Role of Mos/MEK/ERK cascade and Cdk1 in Ca2+ oscillations in fertilized ascidian eggs

Sensui

Yoshida

Tachibana

2012

Developmental Biology

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Intracellular calcium ion concentration ([Ca(2+)](i)) transients are observed in the fertilized eggs of all species investigated so far, and are critical for initiating several events related to egg activation and cell cycle control. Here, we investigated the role of the Mos/MEK/ERK cascade and Cdk1 on Ca(2+) oscillations in fertilized ascidian eggs. The egg of the ascidian Phallusia nigra shows [Ca(2+)](i) oscillations after fertilization: Ca(2+) waves immediately following fertilization (phase I), and [Ca(2+)](i) oscillations between the first and second polar body extrusions (phase II). Our results show that in P. nigra eggs, ERK activity peaked just before the extrusion of the first polar body, and decreased gradually, eventually disappearing at the extrusion of the second polar body. Cyclin-dependent protein kinase 1(Cdk1) activity decreased to undetectable levels immediately after fertilization, and then periodically increased according to the meiotic and mitotic cell cycle. When the unfertilized eggs were incubated with U0126, an inhibitor of MEK, before insemination, ERK was immediately inactivated, and the phase II [Ca(2+)](i) oscillations disappeared. Alternatively, when the constitutively active Mos protein (GST-Mos) was injected into the unfertilized eggs, ERK activity was preserved for at least 120 min after fertilization, and the phase II [Ca(2+)](i) oscillations lasted for more than 120 min after the second polar body extrusion. These results suggest that ERK activity is necessary for maintaining [Ca(2+)](i) oscillations. GST-ΔN85-cyclin, which maintains Cdk1 activity, caused ERK activity in the eggs to persist for over 120 min after fertilization, and prolonged [Ca(2+)](i) oscillations. Moreover, the effects of GST-ΔN85-cyclin on the egg were abrogated by the application of U0126. Thus, Cdk1-mediated [Ca(2+)](i) oscillations seem to require ERK activity. However, GST-Mos triggered [Ca(2+)](i) oscillations after the second polar body extrusion, whereas GST-ΔN85-cyclin did not, although it prolongs the duration of [Ca(2+)](i) oscillations. Interestingly, GST-ΔN85-cyclin increased the frequency of [Ca(2+)](i) transients in the Mos-induced [Ca(2+)](i) oscillations after the extrusion of the second polar body. Thus, Cdk1 could maintain, but not activate, ERK and [Ca(2+)](i) oscillations. ERK activity and [Ca(2+)](i) oscillations seem to form a negative feedback loop which may be responsible for maintaining the meiotic period.

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Section: Changes In [Ca 2 þ ] I and Erk And H1k Activities In The Eggmentioning

confidence: 56%

Role of Mos/MEK/ERK cascade and Cdk1 in Ca2+ oscillations in fertilized ascidian eggs

Sensui

Yoshida

Tachibana

2012

Developmental Biology

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“…This calcium wave triggered by a sperm factor has pleiotropic effects (Carroll et al,2003; Whitaker,2006). Within 1–2 min of the onset of the fertilization/calcium wave a cortical contraction is initiated, which is probably mediated by Rho proteins (Yoshida et al,2003). The calcium increase also stimulates mitochondrial respiration and causes the meiotic cell cycle to resume, leading to the emission of a first polar body (Nixon et al,2000; Dumollard et al,2003).…”

Section: Multiple Cortical and Cytoplasmic Reorganizations Between Fementioning

confidence: 99%

From oocyte to 16‐cell stage: Cytoplasmic and cortical reorganizations that pattern the ascidian embryo

Sardet

Paix

Prodon

et al. 2007

Developmental Dynamics

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“…The mRNAs encoding both Rac1 and Cdc42 are present throughout all preimplantation development stages in mice (Natale & Watson 2002). RhoA is also reported to regulate ooplasmic segregation, cytokinesis, and spindle rotation (Yoshida et al 2003, Zhong et al 2005). In addition, some studies have found that Rho-kinase is involved in mouse blastocyst cavity formation (Kawagishi et al 2004).…”

Section: Introductionmentioning

confidence: 99%

Distinct roles of ROCK1 and ROCK2 during development of porcine preimplantation embryos

et al. 2014

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Cell-to-cell contact mediated by cell adhesion is fundamental to the compaction process that ensures blastocyst quality during embryonic development. In this study, we first showed that Rho-associated coiled-coil protein kinases (ROCK1 and ROCK2) were expressed both in porcine oocytes and IVF preimplantation embryos, playing different roles in oocytes maturation and embryo development. The amount of mRNA encoding ROCK1 and the protein concentration clearly increased between the eight-cell and morula stages, but decreased significantly when blastocysts were formed. Conversely, ROCK2 was more abundant in the blastocyst compared with other embryonic stages. Moreover, immunostaining showed that ROCK1 protein distribution changed as the embryo progressed through cleavage and compaction to the morula stage. Initially, the protein was predominantly associated with the plasma membrane but later became cytoplasmic. By contrast, ROCK2 protein was localized in both the cytoplasm and the spindle rotation region during oocyte meiosis, but in the cytoplasm and nucleus as the embryo developed. In addition, ROCK2 was present in the trophectoderm cells of the blastocyst. Treatment with 15 mM Y27632, a specific inhibitor of ROCKs, completely blocked further development of early four-cell stage embryos. Moreover, we did not detect the expression of ROCK1 but did detect ROCK2 expression in blastocysts. Moreover, lysophosphatidic acid an activator of ROCKs significantly improved the rates of blastocyst formation. These data demonstrate that ROCKs are required for embryo development to the blastocyst stage. Together, our results indicate that ROCK1 and ROCK2 may exert different biological functions during the regulation of compaction and in ensuring development of porcine preimplantation embryos to the blastocyst stage.

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Signaling pathway from [Ca²⁺]_i transients to ooplasmic segregation involves small GTPase rho in the ascidian egg

Cited by 8 publications

References 22 publications

Role of Mos/MEK/ERK cascade and Cdk1 in Ca2+ oscillations in fertilized ascidian eggs

Role of Mos/MEK/ERK cascade and Cdk1 in Ca2+ oscillations in fertilized ascidian eggs

From oocyte to 16‐cell stage: Cytoplasmic and cortical reorganizations that pattern the ascidian embryo

Distinct roles of ROCK1 and ROCK2 during development of porcine preimplantation embryos

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Signaling pathway from [Ca2+]i transients to ooplasmic segregation involves small GTPase rho in the ascidian egg

Cited by 8 publications

References 22 publications

Role of Mos/MEK/ERK cascade and Cdk1 in Ca2+ oscillations in fertilized ascidian eggs

Role of Mos/MEK/ERK cascade and Cdk1 in Ca2+ oscillations in fertilized ascidian eggs

From oocyte to 16‐cell stage: Cytoplasmic and cortical reorganizations that pattern the ascidian embryo

Distinct roles of ROCK1 and ROCK2 during development of porcine preimplantation embryos

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Signaling pathway from [Ca²⁺]_i transients to ooplasmic segregation involves small GTPase rho in the ascidian egg