Cyclooxygenases and prostaglandin E synthases in preimplantation mouse embryos

Zygote ◽  
2005 ◽  
Vol 13 (2) ◽  
pp. 103-108 ◽  
Author(s):  
Hui-Ning Tan ◽  
Ying Liu ◽  
Hong-Lu Diao ◽  
Zeng-Ming Yang

Prostaglandin E2 (PGE2) is shown to be essential for female reproduction. Cyclooxygenase (COX) is a rate-limiting enzyme in prostaglandin synthesis from arachidonic acid and exists in two isoforms: COX-1 and COX-2. Prostaglandin E synthase (PGES) is a terminal prostanoid synthase and can catalyse the isomerization of the COX product PGH2 to PGE2, including microsomal PGES-1 (mPGES-1), cytosolic PGES (cPGES) and mPGES-2. This study examined the protein expression of COX-1, COX-2, mPGES-1, cPGES and mPGES-2 in preimplantation mouse embryos by immunohistochemistry. Embryos at different stages collected from oviducts or uteri were transferred into a flushed oviduct of non-pregnant mice. The oviducts containing embryos were paraffin-embedded and processed for immunostaining. COX-1 immunostaining was at a basal level in zygotes and a low level at the 2-cell stage, reaching a high level from the 4-cell to blastocyst stage. COX-2 immunostaining was at a low level at the zygote stage and was maintained at a high level from the 2-cell to blastocyst stages. A low level of mPGES-1 immunostaining was observed from the zygote to 8-cell stages. The signal for mPGES-1 immunostaining became stronger at the morula stage and was strongly seen at the blastocyst stage. cPGES immunostaining was strongly observed in zygotes, 2-cell and 8-cell embryos. There was a slight decrease in cPGES immunostaining at the 4-cell, morula and blastocyst stages. mPGES-2 immunostaining was at a low level from the zygote to morula stages and at a high level at the blastocyst stage. We found that the COX-1, COX-2, mPGES-1, cPGES and mPGES-2 protein signals were all at a high level at the blastocyst stage. PGE2 produced during the preimplantation development may play roles during embryo transport and implantation.

Development ◽  
1983 ◽  
Vol 78 (1) ◽  
pp. 43-51
Author(s):  
Horst Spielmann ◽  
Robert P. Erickson

The recently improved firefly luciferase assay was used to determine ATP, ADP or AMP in single preimplantation mouse embryos from crosses yielding lethal t12/t12 embryos. Normal values of the three adenylate ribonucleotides were found in freshly collected 2-cell and 4-cell embryos and during in vitro culture to the blastocyst stage. A decrease in adenylate ribonucleotide content was seen in putative t12/t12 embryos only when they were degenerating.


Development ◽  
1978 ◽  
Vol 45 (1) ◽  
pp. 295-301
Author(s):  
Simon B. Fishel ◽  
M. Azim H. Surani

Changes in uptake of radioactive uridine and its incorporation into RNA were determined in preimplantation mouse embryos, from the 2-cell to the blastocyst stage, as a measure of their responsiveness to extracellular conditions. Two media were tested, one contained serum and the other contained bovine serum albumen as a control. An increase in the acid-soluble pool occurred at the 8-cell stage and a marked increase in RNA synthesis occurred at the early blastocyst stage when the embryos were incubated with serum.


Development ◽  
1980 ◽  
Vol 60 (1) ◽  
pp. 71-82
Author(s):  
G. Siracusa ◽  
D. G. Whittingham ◽  
M. De Felici

The sensitivity of early preimplantation mouse embryos to drugs which disrupt microfilament function (cytochalasin B-CB and cytochalasin D-CD) and microtubule assembly (colchicine, colcemid, vinblastine and griseofulvin) was examined. CD inhibited cleavage at a concentration 35-fold lower than CB (3 × 10−7 M ν. 1 × 10−5 M). Treatment of 2-cell embryos for 6 h with 1 × 10−5 M CB or 1 × 10−6 M CD or continuous exposure to lower concentrations of CB or CD did not affect development to the blastocyst stage in vitro. Vinblastine inhibited cleavage at a concentration tenfold lower than colcemid or colchicine (1 × 10−8 M ν. 1 × 10−7 M). The continuous presence of colcemid at 10−8 M did not affect the development of 2-cell embryos to the blastocyst stage, but development was reduced with vinblastine at 1 × 10−8 M and completely inhibited with colchicine at 1 × 10−8 M. The drugs produced similar responses when 2-cell embryos were treated for 6 h with concentrations that inhibited cleavage. Complete inhibition of cleavage was obtained after only a 2 h exposure to 2 × 10−7 M colchicine. A similar concentration of lumicolchicine did not affect cleavage or blastocyst formation. Embryos were less sensitive to griseofulvin; the first cleavage division was unaffected by concentrations as high as 3 × 10−4 M and only 50% of 2-cell embryos failed to cleave in 1 × 10 1 and 3 × 10−4 M griseofulvin. At these concentrations a small proportion of 1-cell embryos and the majority of the 2-cell embryos showed unequal cytoplasmic division probably caused by the formation of multipolar spindles. The continuous exposure of 2-cell embryos to 3 × 10−5 M griseofulvin did not affect blastocyst formation.


Zygote ◽  
1996 ◽  
Vol 4 (2) ◽  
pp. 129-137 ◽  
Author(s):  
Mary K. Dienhart ◽  
Stephen M. Downs

SummaryHypoxanthine can block preimplantation mouse embryo development in vitro at the 2- to 4-cell stages, and this has recently been shown to be reversed by cAMP-elevating agents. However, the extent of this hypoxanthine-induced arrest is determined by the culture conditions and strain of mouse. Whitten's and KSOM/AA are two embryo culture media that support preimplantation development to the blastocyst stage. This study was undertaken to examine the influence of several components in these media on hypoxanthine-arrested preimplantation mouse embryos and to test the hypothesis that reversal of the hypoxanthine block by cAMP-elevating agents requires cooperative interaction with the chelator, EDTA. Initial experiments demonstrated that embryo development was blocked in the presence of hypoxanthine in Whitten's medium but not in KSOM/AA; furthermore, removal of EDTA from KSOM/AA rendered this medium incapable of supporting high levels of development to blastocyst (9%), whereas high numbers of blastocysts (80%) formed in Whitten's medium, which does not contain the chelator. Consequently, Whitten's medium was used to test our hypothesis. It has previously been demonstrated that the phosphodiesterase inhibitor, IBMX, can reverse the developmental arrest imposed by hypoxanthine in EDTA-supplemented Earle's basic salt solution, but in the present study the addition of IBMX to Whitten's medium resulted in a block to development and failed to reverse the hypoxanthine arrest. These disparate effects can be explained by the presence or absence of EDTA. Supplementing Whitten's medium with EDTA reverses the IBMX effect, but not the hypoxanthine-induced block. While IBMX alone is unable to reverse the hypoxanthine block in Whitten's medium, development is greatly enhanced by the simultaneous addition of EDTA and IBMX. Similar results were obtained with the cAMP analogue, 8-AHA-cAMP. The data therefore support our hypothesis that the reversal of the hypoxanthine-induced arrest by cAMP-elevating agents is critically dependent on the presence of EDTA. We contrast this with the situation in mouse oocytes, where the hypoxanthine-induced meiotic arrest is not reversed by the addition of EDTA and/or cAMP-elevating agents.


1985 ◽  
Vol 38 (4) ◽  
pp. 421 ◽  
Author(s):  
RG Wales ◽  
NK Khurana ◽  
WR Edirisinghe ◽  
I L Pike

Neither insulin nor epinephrine influenced the incorporation of glucose into the acid-soluble or acid-insoluble glycogen pool of mouse embryos at the morula-early blastocyst stage during 5 h culture in the presence of radiolabelled glucose. During a 5 h chase culture of pulse-labelled embryos at this stage of development, acid-soluble glycogen labelled during the pulse was not utilized by the embryo but acid-insoluble glycogen was reduced. Addition of glucagon, insulin, epinephrine, cAMP, theophylline or caffeine during chase culture had no effect on the turnover of label in the glycogen pools of the embryo. These results indicate that the turnover of embryonic glycogen observed in vivo is not due to the direct effect of the hormones that regulate glycogen metabolism in the mother.


Development ◽  
1993 ◽  
Vol 117 (1) ◽  
pp. 341-345 ◽  
Author(s):  
P.S. Burgoyne

Karyotopic and cell number analysis of 3.5 day post coitum preimplantation mouse embryos was used to determine whether XY embryos had more cells than XX embryos at the late morula/early blastocyst stage. This proved to be the case for the CD1 strain (for which it had previously been shown that XY embryos form a blastocoel earlier than XX embryos) and for the MF1 strain. However, this increased cell number was not seen in MF1 embryos carrying an RIII strain Y in place of the MF1 Y. Furthermore, interstrain crosses between CD1 and the MF1, YRIII strain showed that the cell number increase segregated with the CD1 Y but not with the RIII Y. It is concluded that the CD1 and MF1 Y chromosomes carry a factor that accelerates the rate of preimplantation development.


Sign in / Sign up

Export Citation Format

Share Document