Serotonin localization and its functional significance during mouse preimplantation embryo development

Zygote ◽  
2004 ◽  
Vol 12 (3) ◽  
pp. 205-213 ◽  
Author(s):  
Gabriela Il'ková ◽  
Pavol Rehák ◽  
Jarmila Veselá ◽  
štefan Čikoš ◽  
Dušan Fabian ◽  
...  
Keyword(s):  
Embryo Development ◽  
Functional Significance ◽  
Cell Number ◽  
Blastocyst Stage ◽  
Embryo Cell ◽  
Preimplantation Embryos ◽  
Preimplantation Embryo Development ◽  
Receptor Mrna ◽  
Mouse Oocytes ◽  
Mouse Embryo Development

Serotonin is a neurotransmitter functioning also as a hormone and growth factor. To further investigate the biological role of serotonin during embryo development, we analysed serotonin localization as well as the expression of specific serotonin 5-HT1D receptor mRNA in mouse oocytes and preimplantation embryos. The functional significance of serotonin during the preimplantation period was examined by studying the effects of serotonin on mouse embryo development. Embryo exposure to serotonin (1 μM) highly significantly reduced the mean cell number, whereas lower concentrations of serotonin (0.1 μM and 0.01 μM) had no significant effects on embryo cell numbers. In all serotonin-treated groups a significant increase in the number of embryos with apoptotic and secondary necrotic nuclei was observed. Expression of serotonin 5-HT1D receptor mRNA in mouse oocytes and preimplantation embryos was confirmed by in situ hybridization showing a clearly distinct punctate signal. Immunocytochemistry results revealed the localization of serotonin in oocytes and embryos to the blastocyst stage as diffuse punctate cytoplasmic labelling. It appears that endogenous and/or exogenous serotonin in preimplantation embryos could be involved in complex autocrine/paracrine regulations of embryo development and embryo-maternal interactions.

277 EFFECTS OF ERYTHROCYTE AND ERYTHROCYTE HEMOLYSATE ON BOVINE PREIMPLANTATION EMBRYO DEVELOPMENT IN VITRO UNDER REACTIVE OXYGEN SPECIES CONDITION

2010 ◽  
Vol 22 (1) ◽  
pp. 295
Author(s):  
A. Ideta ◽  
K. Tsuchiya ◽  
Y. Nakamura ◽  
M. Urakawa ◽  
M. Murakami ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Embryo Development ◽  
Reactive Oxygen ◽  
Hemoglobin Concentration ◽  
Blastocyst Stage ◽  
Preimplantation Embryos ◽  
Oxygen Species ◽  
Preimplantation Embryo Development ◽  
Presence And Absence

Reactive oxygen species (ROS) damage preimplantation embryos by increasing DNA fragmentation, leading to early embryonic death. Erythrocytes have been shown to protect other cells and tissues against ROS. In mice, erythrocytes were recently found to improve the early development of embryos by their antioxidant effect. The purpose of the present study was to examine the effect of erythrocytes on the in vitro development of bovine IVF embryos in medium supplemented with ROS. COCs were aspirated from ovaries collected from a local slaughterhouse and were cultured for 22 h in TCM-199 containing 5% fetal bovine serum. IVF was performed using an IVF100 (Research Institute for the Functional Peptides, Yamagata, Japan) according to the manufacturer’s instructions. In experiment 1, IVF embryos were cultured in CR1aa medium supplemented with an oxidizing agent, 0.5 mM hypoxanthine and 0.01 U mL-1 xanthine oxidase (HX/XOD), in the presence and absence of erythrocytes (5 × 104, 5× 105, 5×106, and 5 × 107 erythrocytes mL-1). In experiments 2 and 3, the development of embryos under the condition without ROS was assessed in the presence and absence of erythrocytes (5 × 106 erythrocytes mL-1) or erythrocyte hemolysate (hemoglobin concentration of 1.9 g L-1), respectively. At 7 days after in vitro culture, the development to the blastocyst stage of IVF embryos was examined using a stereomicroscope. Data were analyzed using Fisher’s PLSD test and Student’s t-test In experiment 1, the presence of HX/XOD significantly inhibited embryo development to the blastocyst stage in vitro (P < 0.05). The addition of erythrocytes to medium supplemented with HX/XOD markedly improved preimplantation development (Table 1). In experiments 2 and 3, supplementation of erythrocytes or erythrocyte hemolysate promoted the development of embryos to the blastocyst stage (experiment 2: erythrocyte 42.4 ± 3.1%, control 28.5 ± 5.7%, P < 0.1; experiment 3: erythrocyte hemolysate 39.1 ± 3.3%, control 30.2 ± 1.0%, P < 0.1). In conclusion, we suggest that the addition of erythrocytes to culture medium can counteract the negative effects of ROS on embryo development and blastocyst formation. Table 1.Effect of HX/XOD and erythrocyte supplementation on embryo development to blastocyst stage

267 EXPRESSION OF RELAXIN FAMILY PEPTIDE RECEPTORS RXFP1 AND RXFP2 IN PIG PREIMPLANTATION EMBRYOS AND DEVELOPMENTAL EFFECTS OF RELAXIN HORMONE

2010 ◽  
Vol 22 (1) ◽  
pp. 290
Author(s):  
J. M. Feugang ◽  
J. C. Rodriguez-Muñoz ◽  
R. Black ◽  
S. Willard ◽  
P. Ryan
Keyword(s):  
Embryo Development ◽  
Protein Level ◽  
Cell Number ◽  
Blastocyst Stage ◽  
Membrane Receptors ◽  
Preimplantation Embryos ◽  
Control Group ◽  
Fluorescence Signal ◽  
Developmental Effects ◽  
Relaxin Family

Relaxin is a polypeptide hormone secreted by male and female reproductive tissues to facilitate spermatozoa progression in the female tract and parturition. Relaxin secretions are found in the vicinity of oocytes and embryos, and exert their effects through membrane receptors, which have not yet been described in porcine embryos. Here, we determined the presence of RXFP1 and RXFP2 receptors in porcine gametes and embryo, and evaluated the developmental effects of porcine relaxin (pRLX; Yan et al. 2006 Reproduction 131, 943-950). Cumulus-oocyte complexes (COC) were aspirated from sows ovaries collected at a local abattoir. Homogeneous COC were selected for IVM (44 h) and fertilization (6 to 8 h). Presumptive zygotes were cultured in NCSU-23 + 0.4% BSA for up to 7 days. All procedures were done at 39°C, under 5% CO2 in a humidified atmosphere. Matured oocytes, BTS-diluted spermatozoa, and embryos were collected for gene expression studies. For developmental studies, COC were matured (experiment 1), or embryos cultured from the zygote stage (experiment 2) in the presence ofpRLX (0, 20, or 40 ng mL-1). In experiment 3, zygotes derived from oocytes matured in the presence of pRLX (40 ng mL-1) were cultured with pRLX (20 or 40 ng mL-1). The pRLX effects were assessed on cleaved embryos and blastocysts recorded on Days 2 and 7 postinsemination, respectively. The total cell numbers of Day-7 blastocysts were also evaluated. All data were analyzed using ANOVA. Gametes and embryos expressed RXFP1 and RXFP2 at both the mRNA and protein level. The amounts of both gene transcripts were higher in mature oocytes (metaphase II) compared with spermatozoa (P < 0.05). The RXFP1/2 mRNA ratios were in favor of RXFP2 in mature oocytes (0.9×), zygotes (0.8 ×), and cleaved embryos (0.8×), and for RXFP1 in spermatozoa (1.1 ×) and blastocysts (1.1 ×). A similar pattern during embryo development was revealed at the protein level, showing a higher RXFP2 fluorescence signal in cleaved embryos and a lower signal in blastocysts compared with RXFP1 protein. In experiment 1, COC exposed to 40 ng mL-1 pRLX resulted in fewer cleaved embryos (36 ± 4%) compared with controls (42 ± 5%, P < 0.05). Of the 40 ng mL-1 pRLX-derived cleaved embryos, a greater proportion developed to the blastocyst stage (38 ± 6%; P < 0.05) compared with control and 20 ng mL-1 pRLX-derived cleaved embryos (26 ± 4% and 17 ± 8%, respectively). In experiment 2, however, 40 ng mL-1 pRLX induced higher cleavage but lower blastocyst rates (51 ± 5% and 20 ± 4%, respectively) compared with the control group (37 ± 4% and 32 ± 7%, respectively) (P < 0.05). In experiment 3, the exposure of both oocytes and derived embryos did not affect the developmental rates (P > 0.05). Nevertheless, pRLX significantly increased the mean cell number of blastocysts in all experiments (P < 0.05). We concluded that pig embryos express RXFP1 and RXFP2 receptors, which may facilitate a role for pRLX during oocyte maturation and embryo development in the pig. This work was supported by the USDA-ARS Biophotonics Initiative project# 58-6402-3-0120 and the Mississippi Agricultural and Forestry Experiment Station (MAFES).

Effect of zinc and copper on preimplantation mouse embryo development in vitro and metallothionein levels

Zygote ◽  
1993 ◽  
Vol 1 (3) ◽  
pp. 225-229 ◽  
Author(s):  
Francesca Vidal ◽  
Juan Hidalgo
Keyword(s):  
Embryo Development ◽  
Developmental Stages ◽  
Blastocyst Stage ◽  
Preimplantation Embryos ◽  
Mrna Levels ◽  
Mouse Embryo Development ◽  
Preimplantation Mouse Embryo ◽  
Preimplantation Mouse ◽  
Development In Vitro

The effect of zinc and copper on the in vitro development of mouse preimplantation embryos and on metallothionein (MT) levels was studied by exposing the embryos to 100 μM concentrations of the metals for 24 h at the 1-cell,2-cell, 6-8-cell, morula and blastocyst stages. Zinc affected embryo development in the early but not in the late stages, whereas copper affected it more generally. The combined presence of both metals caused a stronger embryotoxicity. MT levels were measured by radioimmunoassay and were found to be similar at all developmental stages, though possibly higher at the blastocyst stage. The exposure of embryos to zinc and copper increased MT levels significantly only at the blastocyst stage, supporting previously published results on MT mRNA levels.

scholarly journals Inhibition of DRP1 Impedes Zygotic Genome Activation and Preimplantation Development in Mice

2021 ◽  
Vol 9 ◽  
Author(s):  
Yuanyuan Li ◽  
Ning-Hua Mei ◽  
Gui-Ping Cheng ◽  
Jing Yang ◽  
Li-Quan Zhou
Keyword(s):  
Embryo Development ◽  
Preimplantation Embryo ◽  
Preimplantation Embryos ◽  
Dependent Manner ◽  
Zygotic Genome Activation ◽  
Preimplantation Embryo Development ◽  
Cell Embryo ◽  
Embryo Stage ◽  
Genome Activation ◽  
Zygotic Genome

Mitochondrion plays an indispensable role during preimplantation embryo development. Dynamic-related protein 1 (DRP1) is critical for mitochondrial fission and controls oocyte maturation. However, its role in preimplantation embryo development is still lacking. In this study, we demonstrate that inhibition of DRP1 activity by mitochondrial division inhibitor-1, a small molecule reported to specifically inhibit DRP1 activity, can cause severe developmental arrest of preimplantation embryos in a dose-dependent manner in mice. Meanwhile, DRP1 inhibition resulted in mitochondrial dysfunction including decreased mitochondrial activity, loss of mitochondrial membrane potential, reduced mitochondrial copy number and inadequate ATP by disrupting both expression and activity of DRP1 and mitochondrial complex assembly, leading to excessive ROS production, severe DNA damage and cell cycle arrest at 2-cell embryo stage. Furthermore, reduced transcriptional and translational activity and altered histone modifications in DRP1-inhibited embryos contributed to impeded zygotic genome activation, which prevented early embryos from efficient development beyond 2-cell embryo stage. These results show that DRP1 inhibition has potential cytotoxic effects on mammalian reproduction, and DRP1 inhibitor should be used with caution when it is applied to treat diseases. Additionally, this study improves our understanding of the crosstalk between mitochondrial metabolism and zygotic genome activation.

scholarly journals 153EXPRESSION OF TGF-BETA I AND TYPE I AND TYPE II OF TGF-BETA RECEPTORS IN BOVINE EMBRYOS

2004 ◽  
Vol 16 (2) ◽  
pp. 198
Author(s):  
B.K. Kim ◽  
H.J. Chung ◽  
B.C. Yang ◽  
D.H. Kim ◽  
J.H. Woo ◽  
...  
Keyword(s):  
Embryo Development ◽  
Expression Patterns ◽  
Blastocyst Stage ◽  
Preimplantation Embryos ◽  
Type I ◽  
Bovine Embryo ◽  
Type Ii ◽  
Bovine Embryos ◽  
Mrna And Protein Expression ◽  
Bovine Oocytes

Although the effects of TGFβ1, as an important factor in the mice embryo development have been reported, little information relevant to this subject is known in the bovine embryo. The objectives of this study were to investigate the presence and expression patterns of TGFβ1 and TGFβ1 receptors, types I and II, in unfertilized oocytes and fertilized bovine embryos in normal and NT embryo development. We postulated that TGFβ1 may have a beneficial effect on the preimplantation embryo and show different expression patterns at different stages of bovine embryo development. Immature bovine oocytes were aspirated from follicles of ovaries obtained from a local abattoir and they were cultured for up to 24h and fertilized in vitro. Reverse transcription-polymerase chain reaction (RT-PCR) and immunocytochemistry were used to investigate the presence of TGFβ1 and type I and type II of TGFβ1 receptors (the essential components of the TGFβ1 signaling pathway) in unfertilized oocytes and preimplantation embryos. Also, mRNA and protein expression patterns of TGFβ1 and their receptors at various stages of embryos were examined. It was found that both receptors, as well as TGFβ1, were present in the unfertilized bovine oocytes, indicating that TGFβ1 is a maternally expressed protein. Although the type I TGFβ1 receptor was present at the morulae and blastocyst stages, the type II TGFβ1 receptor was not present at both stages. It was also confirmed that the expression level of TGFβ1 was high at the 8-cell stage, and mRNA and protein expression patterns of TGFβ1 and their receptors were not coincident. Interestingly, TGFβ1 protein was not detected at blastocyst stage of embryos, whereas the mRNA expression level was high at this stage. The results of this experiment indicate that TGFβ1 protein may be needed by embryos after the blastocyst stage and may be expressed in hatched embryos for implantation. These findings support the hypothesis that there may be an interaction between the TGFβ1 and TGFβ1 receptors in the unfertilized oocytes and preimplantation embryos, and that TGFβ1 signaling may be important for the development of the oocytes and the preimplantation embryos.

Effects of changing culture medium on preimplantation embryo development in rabbit

Zygote ◽  
2021 ◽  
pp. 1-6
Author(s):  
Haixia Wang ◽  
Wenbin Cao ◽  
Huizhong Hu ◽  
Chenglong Zhou ◽  
Ziyi Wang ◽  
...  
Keyword(s):  
Embryo Development ◽  
Embryo Culture ◽  
Culture Medium ◽  
Cell Number ◽  
Apoptotic Index ◽  
Total Cell ◽  
Toxic Substances ◽  
Total Cell Number ◽  
Preimplantation Embryo Development

Summary Many studies have focused on the optimization of the composition of embryo culture medium; however, there are few studies involving the effect of a culture medium changing procedure on the preimplantation development of embryos. In this study, three groups were designed: a non-renewal group, a renewal group and a half-renewal group. The levels of reactive oxygen species (ROS), apoptotic index, blastocyst ratio and blastocyst total cell number were analyzed in each group. The results showed that the ROS level and the apoptotic index of blastocyst in the non-renewal group were significantly higher than in the renewal group and the half-renewal group (P < 0.05). The blastocyst ratio and blastocyst total cell number were significantly higher in the half-renewal group than that in non-renewal group and the renewal group (P < 0.05). These results demonstrated that the procedure of changing the culture medium influenced ROS level, apoptotic index, blastocyst ratio and total cell number of blastocysts. In addition, the result suggested that changing the culture medium may lead to a loss of important regulatory factors for embryos, while not changing the culture medium may lead to the accumulation of toxic substances. Half-renewal can alleviate the defects of both no renewal and renewal, and benefit embryo development. This study will be of high value as a reference for the optimization of embryo culture in vitro, and is very significant for assisted reproduction.

scholarly journals Amino acid depletion and appearance during porcine preimplantation embryo development in vitro

Reproduction ◽  
2005 ◽  
Vol 130 (5) ◽  
pp. 655-668 ◽  
Author(s):  
Paul J Booth ◽  
Peter G Humpherson ◽  
Terry J Watson ◽  
Henry J Leese
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Embryo Development ◽  
Preimplantation Embryos ◽  
Type I ◽  
Preimplantation Embryo Development ◽  
Type Iv ◽  
Stage Of Development ◽  
Amino Acid Depletion

Preimplantation embryos can consume and produce amino acids in a manner dependent upon the stage of development that may be predictive of subsequent viability. In order to examine these relationships in the pig, patterns of net depletion and appearance of amino acids byin vitroproduced porcine preimplantation embryos were examined. Cumulus oocyte complexes derived from slaughterhouse pre-pubertal pig ovaries were matured for 40 h in defined TCM-199 medium (containing PVA) before being fertilised (Day 0) with frozen-thawed semen in Tris–based medium. After 6 h, presumptive zygotes were denuded and cultured in groups of 20, in NCSU-23 medium modified to contain 0.1 mM glutamine plus a mixture of 19 amino acids (aa) at low concentrations (0.02–0.11 mM) (NCSU-23aa). Groups of 2–20 embryos were removed (dependent on stage) on Day 0 (1 cell), Day 1 (two- and four-cells), Day 4 (compact morulae) and Day 6 (blastocysts) and placed in 4 μl NCSU-23aafor 24 h. After incubation, the embryos were removed and the spent media was analysed by HPLC. The net rate of amino acid depletion or appearance varied according to amino acid (P< 0.001) and, apart from serine and histidine, stage of development (P< 0.014). Glycine, isoleucine, valine, phenylalanine, tryptophan, methionine, asparagine, lysine, glutamate and aspartate consistently appeared, whereas threonine, glutamine and arginine were consistently depleted. Five types of stage-dependent trends could be observed: Type I: amino acids having high rates of net appearance on Day 0 that reached a nadir on Day 1 or 4 but subsequently increased by Day 6 (glycine, glutamate); Type II: those that exhibited lower rates of net appearance on Days 0 and 6 compared with the intermediate Days 1 and 4 (isoleucine, valine, phenylalanine, methionine, arginine); Type III: amino acids which showed a continuous fall in net appearance (asparagine, aspartate); Type IV: those that exhibited a steady fall in net depletion from Day 0 to Day 6 (glutamine, threonine); Type V: those following no discernable trend. Analysis of further embryo types indicated that presumptive polyspermic embryos on Day 0 had increased (P< 0.05) net rates of leucine, isoleucine, valine and glutamate appearance, and reduced (P< 0.05) net rates of threonine and glutamine depletion compared with normally inseminated oocytes. These data suggest that the net rates of depletion and uptake of amino acids by pig embryos vary between a) amino acids, b) the day of embryo development and, c) the type of embryos present at a given stage of development. The results also suggested that the net depletion and appearance rates of amino acids by early pig embryos might be more similar to those of the human than those of the mouse and cow.

22 EFFECT OF OOCYTE AGE ON THE DEVELOPMENT OF MOUSE PARTHENOGENETIC EMBRYOS AND EFFECT OF OXYGEN CONCENTRATION ON EMBRYO DEVELOPMENT IN VITRO

2006 ◽  
Vol 18 (2) ◽  
pp. 119
Author(s):  
H. Bagis ◽  
S. Arat ◽  
H. Odaman ◽  
A. Tas
Keyword(s):  
Embryo Development ◽  
Formation Rate ◽  
Cell Number ◽  
Blastocyst Formation ◽  
Group 4 ◽  
Mouse Embryo Development ◽  
O2 Concentration ◽  
Group 3 ◽  
Development In Vitro

The objective of this study was to investigate the effects of two parameters on mouse embryo development in vitro. These parameters were the effect of oocyte age on activation and the effect of O2 concentration in culture. In the first experiment, oocytes were recovered from superovutated mice at 15 h (group 1) or 20 h (group 2) after human chorionic gonadotropin (HCG) injection. All oocytes were activated for 6 h with 10 mM Sr2+ in Ca2+ free medium in the presence of 5 �g/mL of cytochalasin B. After activation, embryos were cultured in KSOM.aa medium for 4.5-5.5 days. Zygotes from naturally bred mice were used as control. Differences in blastocyst formation rate and blastocyst cell number among treatments were analyzed by one-way ANOVA after arcsin square transformation. In the first experiment, blastocyst formation rate in the first group was higher than in the second group (62.6% vs. 47.1%; P < 0.05). In addition, blastocyst cell number was also higher in the first group than in the second one (69.4 � 3.2 vs. 52.4 � 2.2; P < 0.05). However, both values were higher in control group (80%, 76.2 � 1.2; P < 0.05) than in the experimental groups. These results showed that young oocytes were activated more effectively than aged oocytes. In the second experiment, mouse zygotes were cultured in a humidified atmosphere of 5% CO2 in air (group 3) or 5% CO2, 5% O2, and 90% N2 (group 4). Blastocyst formation rate and blastocyst cell number of zygotes cultured in low O2 concentration (group 4) for 4.5 days were higher than for group 3 (76.3% vs. 56.4 and 69.0 � 3.4 vs. 52.8 � 2.3; P < 0.05). There was a significant difference in blastocyt formation rate of embryos for 5.5 days between the two groups (25.8% for group 4 vs. 14.4% for group 3; P < 0.05). This suggests that the embryos developed more slowly in high O2 concentration. These results showed that low O2 concentration provided a more suitable environment for mouse embryo development in vitro. The same experiment was repeated with parthenogenetic embryos recently in our laboratory. This study was supported by a grant from TUBITAK, Turkey (VHAG-1022).

A combination of growth factors and cytokines alter preimplantation mouse embryo development, foetal development and gene expression profiles

2020 ◽  
Vol 26 (12) ◽  
pp. 953-970
Author(s):  
Kathryn H Gurner ◽  
Thi T Truong ◽  
Alexandra J Harvey ◽  
David K Gardner
Keyword(s):  
Embryo Development ◽  
Preimplantation Embryo ◽  
Culture Media ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Cell Number ◽  
Foetal Development ◽  
Mouse Embryo Development ◽  
Preimplantation Mouse Embryo ◽  
Preimplantation Mouse

Abstract Within the maternal tract, the preimplantation embryo is exposed to an array of growth factors (GFs) and cytokines, most of which are absent from culture media used in clinical IVF. Whilst the addition of individual GFs and cytokines to embryo culture media can improve preimplantation mouse embryo development, there is a lack of evidence on the combined synergistic effects of GFs and cytokines on embryo development and further foetal growth. Therefore, in this study, the effect of a combined group of GFs and cytokines on mouse preimplantation embryo development and subsequent foetal development and gene expression profiles was investigated. Supplementation of embryo culture media with an optimised combination of GFs and cytokines (0.05 ng/ml vascular endothelial GF, 1 ng/ml platelet-derived GF, 0.13 ng/ml insulin-like GF 1, 0.026 ng/ml insulin-like GF 2 and 1 ng/ml granulocyte colony-stimulating factor) had no effect on embryo morphokinetics but significantly increased trophectoderm cell number (P = 0.0002) and total cell number (P = 0.024). Treatment with this combination of GFs and cytokines also significantly increased blastocyst outgrowth area (P &lt; 0.05) and, following embryo transfer, increased foetal weight (P = 0.027), crown-rump length (P = 0.017) and overall morphological development (P = 0.027). RNA-seq analysis of in vitro derived foetuses identified concurrent alterations to the transcriptional profiles of liver and placental tissues compared with those developed in vivo, with greater changes observed in the GF and cytokine treated group. Together these data highlight the importance of balancing the actions of such factors for the regulation of normal development and emphasise the need for further studies investigating this prior to clinical implementation.

scholarly journals Phosphatidylinositol 3-kinase signaling in mammalian preimplantation embryo development

Reproduction ◽  
2008 ◽  
Vol 136 (2) ◽  
pp. 147-156 ◽  
Author(s):  
Chris O'Neill
Keyword(s):  
Embryo Development ◽  
Normal Development ◽  
Preimplantation Embryo ◽  
Preimplantation Embryos ◽  
External Information ◽  
Ph Domain ◽  
Phosphatidylinositol 3 Kinase ◽  
Preimplantation Embryo Development ◽  
Wide Range ◽  
Phosphatidylinositol 3

The development of the preimplantation mammalian embryo is an autopoietic process; once initiated development proceeds without an absolute requirement for external information or growth cues. This developmental autonomy is partly explained by the generation of autocrine trophic ligands that are released and act back on the embryo via specific receptors. Several embryotrophic ligands cause receptor-dependent activation of 1-o-phosphatidylinositol 3-kinase. This enzyme phosphorylates phosphatidylinositol-4,5-bisphosphate to form phosphatidylinositol-3,4,5-trisphosphate. Genetic or pharmacological ablation of this enzyme activity disrupts normal development of preimplantation embryos. Phosphatidylinositol-3,4,5-trisphosphate is a membrane lipid that acts as a docking site for a wide range of proteins possessing the pleckstrin homology (PH) domain. Such proteins are important regulators of cell survival, proliferation, and differentiation. RAC-α serine/threonine protein kinase is an important PH domain protein and its activity is required for normal preimplantation embryo development and survival. The activity of a range of PH domain proteins is also implicated in the normal development of the embryo. This review critically examines the evidence for the activation of 1-o-phosphatidylinositol 3-kinase in the generation of pleiotypic trophic response to embryotrophins in the autopoietic development of the preimplantation embryo.

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