221 RNA-Seq ANALYSIS OF INNER CELL MASS AND TROPHECTODERM CELLS OF EQUINE BLASTOCYSTS

2013 ◽  
Vol 25 (1) ◽  
pp. 258
Author(s):  
P. J. Ross ◽  
J. L. Chitwood ◽  
G. Meyers-Brown ◽  
J. F. Roser
Keyword(s):  
Inner Cell Mass ◽  
Global Analysis ◽  
Cell Mass ◽  
Rna Isolation ◽  
Early Embryo ◽  
Dnase Treatment ◽  
Uterine Flushing ◽  
Endoderm Development ◽  
Organic Acid Transport ◽  
San Carlos

The objective of this study was to characterise the transcriptome profiles of inner cell mass (ICM) and trophectoderm (TE) cells from horse blastocysts. Equine blastocysts were collected by uterine flushing 8 days after ovulation in mares superovulated with reFSH and reLH (Meyers-Brown et al. 2011 Anim. Reprod. Sci. 128, 52–59). The ICM were isolated by immunosurgery, whereas polar TE cells were obtained microsurgically. Individual ICM (n = 2) and TE (n = 3) samples were snap frozen in liquid nitrogen and stored at –80°C until processing. Total RNA was extracted from each individual sample using the Arcturus PicoPure RNA isolation kit including DNAse treatment. The RNA was then amplified using the SPIA-based Ovation RNASeq-II kit (NuGEN Inc., San Carlos, CA, USA). Sequencing libraries were prepared using the TruSeq DNA sample preparation kit (Illumina, San Diego, CA, USA). Libraries bearing unique indexes per sample were pooled and sequenced in a single lane of a HiSEqn 2000 apparatus (Illumina) by a single run of 100 bp. Data analysis was performed using CLC Genomics Workbench. Equus caballus genomic sequences and annotation (EquCab2.0) were obtained from the National Center for Biotechnology Information (NCBI). Sequence analysis was performed using CLC Genomics Workbench and differential expression by DeSeq analysis. A total of 196 669 501 reads were produced. After discarding duplicated and bad quality reads, an average of 22 508 594 reads per sample was used for analysis. Using the RNASeq algorithms, 77% of reads mapped to annotated transcripts. Among the 22 380 annotated genes, 11 677 and 11 919 we detected as expressed [reads per kilobase of exon model per million sequences (RPKM) > 0.3] in all ICM and TE samples, respectively. The correlation of RPKM values for all the genes analysed between any pair of ICM or TE samples was >0.97, indicating a high repeatability of the assay. Global analysis of the transcriptome by means of unsupervised clustering indicated that ICM and TE samples clustered to different groups. Genes known to be specific to ICM and TE were expressed primarily in their respective tissue, including KLF4, SOX2, POU5F1, NANOG, DNMT3B, LIN28A, FOXA2, SALL4, and HNF4A for ICM, and CDX2, KRT8, ATP12A, GRHL2, and GRHL1 for TE. In addition, genes related to primitive endoderm development were more highly expressed in ICM than in TE and included GATA4, GATA6, and PDGFRA. The DeSeq analysis between ICM and TE samples indicated that 1934 genes were differentially expressed (adjusted P < 0.01 and fold change >2). Biological functions overrepresented among genes that were overexpressed in ICM cells (n = 1374) included cell-cell adhesion, cell morphogenesis involved in differentiation, negative regulation of DNA binding, and cell proliferation. Among genes overexpressed in TE samples (n = 560), gene ontology analysis indicated that the most overrepresented biological processes were lipid localization, placenta development, and organic acid transport. In summary, this study provides a comprehensive analysis of genes expressed in ICM and TE of equine embryos, which is a fundamental resource to understanding early embryo development in this species.

scholarly journals Interleukin-6 promotes primitive endoderm development in bovine blastocysts

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lydia K. Wooldridge ◽  
Alan D. Ealy
Keyword(s):  
Interleukin 6 ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Types ◽  
Janus Kinase ◽  
Primitive Endoderm ◽  
Cell Numbers ◽  
Downstream Target ◽  
Dependent Signal ◽  
Endoderm Development

Abstract Background Interleukin-6 (IL6) was recently identified as an embryotrophic factor in bovine embryos, where it acts primarily to mediate inner cell mass (ICM) size. This work explored whether IL6 affects epiblast (EPI) and primitive endoderm (PE) development, the two embryonic lineages generated from the ICM after its formation. Nuclear markers for EPI (NANOG) and PE (GATA6) were used to differentiate the two cell types. Results Increases (P < 0.05) in total ICM cell numbers and PE cell numbers were detected in bovine blastocysts at day 8 and 9 post-fertilization after exposure to 100 ng/ml recombinant bovine IL6. Also, IL6 increased (P < 0.05) the number of undifferentiated ICM cells (cells containing both PE and EPI markers). The effects of IL6 on EPI cell numbers were inconsistent. Studies were also completed to explore the importance of Janus kinase 2 (JAK2)-dependent signaling in bovine PE cells. Definitive activation of STAT3, a downstream target for JAK2, was observed in PE cells. Also, pharmacological inhibition of JAK2 decreased (P < 0.05) PE cell numbers. Conclusions To conclude, IL6 manipulates ICM development after EPI/PE cell fates are established. The PE cells are the target for IL6, where a JAK-dependent signal is used to regulate PE numbers.

Regulation of desmocollin transcription in mouse preimplantation embryos

Development ◽  
1995 ◽  
Vol 121 (3) ◽  
pp. 743-753 ◽  
Author(s):  
J.E. Collins ◽  
J.E. Lorimer ◽  
D.R. Garrod ◽  
S.C. Pidsley ◽  
R.S. Buxton ◽  
...  
Keyword(s):  
Protein Expression ◽  
Molecular Mechanisms ◽  
Inner Cell Mass ◽  
Splice Variants ◽  
Cell Mass ◽  
Cumulus Cells ◽  
Early Embryo ◽  
Preimplantation Embryos ◽  
Cell Stage ◽  
Cleavage Stages

The molecular mechanisms regulating the biogenesis of the first desmosomes to form during mouse embryogenesis have been studied. A sensitive modification of a reverse transcriptase-cDNA amplification procedure has been used to detect transcripts of the desmosomal adhesive cadherin, desmocollin. Sequencing of cDNA amplification products confirmed that two splice variants, a and b, of the DSC2 gene are transcribed coordinately. Transcripts were identified in unfertilized eggs and cumulus cells and in cleavage stages up to the early 8-cell stage, were never detected in compact 8-cell embryos, but were evident again either from the 16-cell morula or very early blastocyst (approx 32-cells) stages onwards. These two phases of transcript detection indicate DSC2 is encoded by maternal and embryonic genomes. Previously, we have shown that desmocollin protein synthesis is undetectable in eggs and cleavage stages but initiates at the early blastocyst stage when desmocollin localises at, and appears to regulate assembly of, nascent desmosomes that form in the trophectoderm but not in the inner cell mass (Fleming, T. P., Garrod, D. R. and Elsmore, A. J. (1991), Development 112, 527–539). Maternal DSC2 mRNA is therefore not translated and presumably is inherited by blastomeres before complete degradation. Our results suggest, however, that initiation of embryonic DSC2 transcription regulates desmocollin protein expression and thereby desmosome formation. Moreover, data from blastocyst single cell analyses suggest that embryonic DSC2 transcription is specific to the trophectoderm lineage. Inhibition of E-cadherin-mediated cell-cell adhesion did not influence the timing of DSC2 embryonic transcription and protein expression. However, isolation and culture of inner cell masses induced an increase in the amount of DSC2 mRNA and protein detected. Taken together, these results suggest that the presence of a contact-free cell surface activates DSC2 transcription in the mouse early embryo.

Investigation of cell lineage and differentiation in the extraembryonic endoderm of the mouse embryo

Development ◽  
1982 ◽  
Vol 68 (1) ◽  
pp. 175-198
Author(s):  
R. L. Gardner
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Cell Lineage ◽  
Early Embryo ◽  
Visceral Endoderm ◽  
Primitive Endoderm ◽  
Developmental Potential ◽  
Extraembryonic Endoderm ◽  
Parietal Endoderm ◽  
Endodermal Cells

The technique of injecting genetically labelled cells into blastocysts was used in an attempt to determine whether the parietal and visceral endoderm originate from the same or different cell populations in the early embryo. When the developmental potential of 5th day primitive ectoderm and primitive endoderm cells was compared thus, only the latter were found to colonize the extraembryonic endoderm. Furthermore, single primitive endoderm cells yielded unequivocal colonization of both the parietal and the visceral endoderm in a proportion of chimaeras. However, in the majority of primitive endodermal chimaeras, donor cells were detected in the parietal endoderm only, cases of exclusively visceral colonization being rare. Visceral endoderm cells from 6th and 7th day post-implantation embryos also exhibited a striking tendency to contribute exclusively to the parietal endoderm following blastocyst injection. The above findings lend no support to a recent proposal that parietal and visceral endoderm are derived from different populations of inner cell mass cells. Rather, they suggest that the two extraembryonic endoderm layers originate from a common pool of primitive endoderm cells whose direction of differentiation depends on their interactions with non-endodermal cells.

213 HOXB9 PROTEIN IS PRESENT THROUGHOUT EARLY EMBRYO DEVELOPMENT IN THE BOVINE

2013 ◽  
Vol 25 (1) ◽  
pp. 255
Author(s):  
C. Sauvegarde ◽  
D. Paul ◽  
R. Rezsohazy ◽  
I. Donnay
Keyword(s):  
Embryo Development ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Mature Oocyte ◽  
Blastocyst Stage ◽  
Early Embryo ◽  
Immature Oocyte ◽  
Cell Stage ◽  
Morula Stage ◽  
Oocyte Stage

Hox genes encode for homeodomain transcription factors well known to be involved in developmental control after gastrulation. However, the expression of some of these genes has been detected during oocyte maturation and early embryo development. An interesting expression profile has been obtained for HOXB9 in the bovine (Paul et al. 2011 Mol. Reprod. Dev. 78, 436): its relative expression increases between the immature oocyte and the zygote, further increases at the 5- to 8-cell stage to peak at the morula stage before decreasing at the blastocyst stage. The main objective of this work is to establish the HOXB9 protein profile from the immature oocyte to the blastocyst in the bovine. Bovine embryos were produced in vitro from immature oocytes obtained from slaughterhouse ovaries. Embryos were collected at the following stages: immature oocyte, mature oocyte, zygote (18 h post-insemination, hpi), 2-cell (26 hpi), 5 to 8 cell (48 hpi), 9 to 16 cell (96 hpi), morula (120 hpi), and blastocyst (180 hpi). The presence and distribution of HOXB9 proteins were detected by whole-mount immunofluorescence followed by confocal microscopy using an anti-human HOXB9 polyclonal antibody directed against a sequence showing 100% homology with the bovine protein. Its specificity to the bovine protein was controlled by Western blot on total protein extract from the bovine uterus and revealed, among a few bands of weak intensities, 2 bands of high intensity corresponding to the expected size. Oocytes or embryos were fixed and incubated overnight with rabbit anti-HOXB9 (Sigma, St. Louis, MO, USA) and mouse anti-E-cadherin (BD Biosciences, Franklin Lakes, NJ, USA) primary antibodies and then for 1 h with goat anti-rabbit Alexafluor 555 conjugated (Cell Signaling Technology, Beverly, MA, USA) and goat anti-mouse FITC-conjugated (Santa Cruz Biotechnology Inc., Santa Cruz, CA, USA) secondary antibodies. Embryos were then mounted in Vectashield containing DAPI. HOXB9 is detected from the immature oocyte to the blastocyst stage. At the immature oocyte stage, it is mainly localised in the germinal vesicle with a weak signal in the cytoplasm. At the mature oocyte stage, HOXB9 labelling is present in the cytoplasm. At the zygote stage, a stronger immunoreactivity is observed in the pronuclei than in the cytoplasm. From the 2-cell stage to the morula stage, the presence of HOXB9 is also more important in the nuclei than in the cytoplasm. HOXB9 is also observed at the blastocyst stage where it is localised in the nuclei of the trophectoderm cells, whereas an inconstant or weaker labelling is observed in the inner cell mass cells. In conclusion, we have shown for the first time the presence of the HOXB9 protein throughout early bovine embryo development. The results obtained suggest the presence of the maternal HOXB9 protein because it is already detected before the maternal to embryonic transition that occurs during the fourth cell cycle in the bovine. Finally, the pattern obtained at the blastocyst stage suggests a differential role of HOXB9 in the inner cell mass and trophectoderm cells. C. Sauvegarde holds a FRIA PhD grant from the Fonds National de la Recherche Scientifique (Belgium).

Morphology, developmental stages and quality parameters of in vitro-produced equine embryos

2019 ◽  
Vol 31 (12) ◽  
pp. 1758 ◽  
Author(s):  
Elaine M. Carnevale ◽  
Elizabeth S. Metcalf
Keyword(s):  
Embryo Development ◽  
Developmental Stages ◽  
Inner Cell Mass ◽  
Early Stage ◽  
Cell Mass ◽  
Quality Parameters ◽  
Early Embryo ◽  
Developmental Competence ◽  
Limited Information

Intracytoplasmic sperm injection (ICSI) is used to produce equine embryos invitro. The speed of embryo development invitro is roughly equivalent to what has been described for embryos produced invivo. Morphological evaluations of ICSI-produced embryos are complicated by the presence of debris and the dark nature of equine embryo cytoplasm. Morulas and early blastocysts produced invitro appear similar to those produced invivo. However, with expansion of the blastocyst, distinct differences are observed compared with uterine embryos. In culture, embryos do not undergo full expansion and thinning of the zona pellucida (ZP) or capsule formation. Cells of the inner cell mass (ICM) are dispersed, in contrast with the differentiated trophoblast and ICM observed in embryos collected from uteri. As blastocysts expand invitro, embryo cells often escape the ZP as organised or disorganised extrusions of cells, probably through the hole incurred during ICSI. Quality assessment of invitro-produced early stage equine embryos is in its infancy, because limited information is available regarding the relationship between morphology and developmental competence. Early embryo development invivo is reviewed in this paper, with comparisons made to embryo development invitro and clinical assessments from a laboratory performing commercial ICSI for &gt;15 years.

scholarly journals Epigenetic asymmetry in the mammalian zygote and early embryo: relationship to lineage commitment?

2003 ◽  
Vol 358 (1436) ◽  
pp. 1403-1409 ◽  
Author(s):  
Wolf Reik ◽  
Fatima Santos ◽  
Kohzoh Mitsuya ◽  
Hugh Morgan ◽  
Wendy Dean
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Blastocyst Stage ◽  
Early Embryo ◽  
Lineage Commitment ◽  
Imprinted Genes ◽  
Mammalian Development ◽  
Paternal Genome ◽  
Developmental Defects ◽  
Set Up

Epigenetic asymmetry between parental genomes and embryonic lineages exists at the earliest stages of mammalian development. The maternal genome in the zygote is highly methylated in both its DNA and its histones and most imprinted genes have maternal germline methylation imprints. The paternal genome is rapidly remodelled with protamine removal, addition of acetylated histones, and rapid demethylation of DNA before replication. A minority of imprinted genes have paternal germline methylation imprints. Methylation and chromatin reprogramming continues during cleavage divisions, but at the blastocyst stage lineage commitment to inner cell mass (ICM) or trophectoderm (TE) fate is accompanied by a dramatic increase in DNA and histone methylation, predominantly in the ICM. This may set up major epigenetic differences between embryonic and extraembryonic tissues, including in X–chromosome inactivation and perhaps imprinting. Maintaining epigenetic asymmetry appears important for development as asymmetry is lost in cloned embryos, most of which have developmental defects, and in particular an imbalance between extraembryonic and embryonic tissue development.

scholarly journals A preliminary note upon the question of the nutrition of the early embryo, with special reference to the guinea-pig and man

1905 ◽  
Vol 76 (508) ◽  
pp. 164-165 ◽  
Keyword(s):  
Guinea Pig ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Early Embryo ◽  
Uterine Horn ◽  
Dense Layer ◽  
Preliminary Note ◽  
Trophoblastic Cells ◽  
Decidual Cells ◽  
Uterine Secretion

During the progress of a research into the earliest implantation of the embryo of the guinea-pig, I have been particularly struck with the way in which the nutrition of the embryo is anticipated and provided for during the time it remains free in the uterine horn. The so-called yolk-granules of the ovum are obviously insufficient to provide for the growth of the embryo to the stage prior to differentiation of the inner cell-mass, to which it attains during the five or six days which elapse before it comes into contact with the maternal tissues. It is clear that it must derive nourishment from the medium in which it lies―the product of the secretion of the uterine or other glands, which, during the period of pro-œstrum, exhibit such marked activity. I suggest that this secretion, which consists of mucus and probably albumin, is assimilated by the embryo after having undergone a process of digestion, the result of a secretory activity on the part of the outermost cells of the embryo―the cells of the Trophoblast. This suggestion I base on my observations in the guinea-pig, where I am able to demonstrate a breaking-down of maternal cells before the Trophoblastic cells are in actual contact; likewise in human placentation where a more or less dense layer of fibrin and broken-down leucocytes and decidual cells, the result of Trophoblastic activity, affords a barrier interposed between the invading Trophoblastic cells and the Decidua. This layer I purpose naming the “Protective Layer.” Looked at from a comparative point of view, there is in all probability a close analogy between the uterine secretion of mammals, and the secretion of the oviducts of the lower vertebrata. In the case of birds the analogy is very striking, on account of the direct and important share in the nutrition of the embryo afforded by this secretion, commonly known as the white of the egg. In the case of the frog the ovum receives in its passage down the oviduct, corresponding to the uterine horn of the guinea-pig, a coating of mucus and probably albumin, comparable to the uterine secretion referred to above; when it reaches the water and becomes fertilised, this swells up by absorption, forming a gelatinous covering. The embryo for nutriment depends upon the yolk contained in the ovum before fertilisation, upon the covering of mucus and probably albumin, and lastly upon the water in which it lies. In certain mammals, as, for example, the rabbit and the mole, a distinct gelatinous envelope is described as surrounding the embryo before implantation occurs; this envelope is, I suggest, possibly due to some digestive action of the cells of the Trophoblast upon the adjacent medium, producing a form of coagulation.

scholarly journals Tissue-specific control of expression of the tight junction polypeptide ZO-1 in the mouse early embryo

Development ◽  
1991 ◽  
Vol 113 (1) ◽  
pp. 295-304 ◽  
Author(s):  
T.P. Fleming ◽  
M.J. Hay
Keyword(s):  
Tight Junction ◽  
Contact Area ◽  
Inner Cell Mass ◽  
Cell Mass ◽  
Subsequent Development ◽  
Early Embryo ◽  
Cell Contact ◽  
Down Regulation ◽  
Cell Stage ◽  
Daughter Cells

The processes governing differential protein expression in preimplantation lineages were investigated using a monoclonal antibody recognising the tight junction polypeptide, ZO-1. ZO-1 localises to the maturing tight junction membrane domain in the polarised trophectoderm lineage from compaction (8-cell stage) onwards, ultimately forming a zonular belt around each trophectoderm cell of the blastocyst (32- to 64-cell stage). The protein is usually undetectable within the inner cell mass (ICM) although, in a minority of embryos, punctate ZO-1 sites are present on the surface of one or more ICM cells. Since ICM cells derive from the differentiative division of polarised 8- and 16-cell blastomeres, the distribution of ZO-1 following differentiative division in isolated, synchronised cell clusters of varying size, was examined. In contrast to the apical cytocortical pole, ZO-1 was found to be inherited by nonpolar (prospective ICM) as well as polar (prospective trophectoderm) daughter cells. Following division, polar cells adhere to and gradually envelop nonpolar cells. Prior to envelopment, ZO-1 localises to the boundary between the contact area and free membrane of daughter cells, irrespective of their phenotype. After envelopment, polar cells retain these ZO-1 contact sites whilst nonpolar cells lose them, in which case ZO-1 transiently appears as randomly-distributed punctate sites on the membrane before disappearing. Thus, symmetrical cell contact appears to initiate ZO-1 down-regulation in the ICM lineage. The biosynthetic level at which ZO-1 down-regulation occurs was investigated in immunosurgically isolated ICMs undergoing trophectoderm regeneration. By 6 h in culture, isolated ICMs generated a zonular network of ZO-1 at the contact area between outer cells, thereby demonstrating the reversibility of down-regulation. This assembly process was unaffected by alpha-amanitin treatment but was inhibited by cycloheximide. These results indicate that the ICM inherits and stabilises ZO-1 transcripts which can be utilised for rapid synthesis and assembly of the protein, a capacity that may have significance both in maintaining lineage integrity within the blastocyst and in the subsequent development of the ICM.

145. TRP53 REGULATES THE FORMATION OF A PLURIPOTENT INNER CELL MASS IN THE EARLY EMBRYO

2009 ◽  
Vol 21 (9) ◽  
pp. 63
Author(s):  
L. Ganeshan ◽  
C. O'Neill
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Embryonic Stem ◽  
Blastocyst Stage ◽  
Early Embryo ◽  
Pluripotent Cells ◽  
Drug Induced ◽  
Developmental Potential

The developmental viability of the early embryo requires the formation of the inner cell mass (ICM) at the blastocyst stage. The ICM contributes to all cell lineages within the developing embryo in vivo and the embryonic stem cell (ESC) lineage in vitro. Commitment of cells to the ICM lineage and its pluripotency requires the expression of core transcription factors, including Nanog and Pou5f1 (Oct4). Embryos subjected to culture in vitro commonly display a reduced developmental potential. Much of this loss of viability is due to the up-regulation of TRP53 in affected embryos. This study investigated whether increased TRP53 disrupts the expression of the pluripotency proteins and the normal formation of the ICM lineage. Mouse C57BL6 morulae and blastocysts cultured from zygotes (modHTF media) possessed fewer (p < 0.001) NANOG-positive cells than equivalent stage embryos collected fresh from the uterus. Blocking TRP53 actions by either genetic deletion (Trp53–/–) or pharmacological inhibition (Pifithrin-α) reversed this loss of NANOG expression during culture. Zygote culture also resulted in a TRP53-dependent loss of POU5F1-positive cells from resulting blastocysts. Drug-induced expression of TRP53 (by Nutlin-3) also caused a reduction in formation of pluripotent ICM. The loss of NANOG- and POU5F1-positive cells caused a marked reduction in the capacity of blastocysts to form proliferating ICM after outgrowth, and a consequent reduced ability to form ESC lines. These poor outcomes were ameliorated by the absence of TRP53, resulting in transmission distortion in favour of Trp53–/– zygotes (p < 0.001). This study shows that stresses induced by culture caused TRP53-dependent loss of pluripotent cells from the early embryo. This is a cause of the relative loss of viability and developmental potential of cultured embryos. The preferential survival of Trp53–/– embryos after culture due to their improved formation of pluripotent cells creates a genetic danger associated with these technologies.

scholarly journals Expression of renin–angiotensin system components in the early bovine embryo

2012 ◽  
Vol 1 (1) ◽  
pp. 22-30 ◽  
Author(s):  
Wioletta Pijacka ◽  
Morag G Hunter ◽  
Fiona Broughton Pipkin ◽  
Martin R Luck
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Renin Angiotensin System ◽  
Early Embryo ◽  
Bovine Embryo ◽  
Ang Ii ◽  
Foetal Development ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Stage Of Development

The renin–angiotensin system (RAS), mainly associated with the regulation of blood pressure, has been recently investigated in female reproductive organs and the developing foetus. Angiotensin II (Ang II) influences oviductal gamete movements and foetal development, but there is no information about RAS in the early embryo. The aim of this study was to determine whether RAS components are present in the pre-implantation embryo, to determine how early they are expressed and to investigate their putative role at this stage of development. Bovine embryos produced in vitro were used for analysis of RAS transcripts (RT-PCR) and localisation of the receptors AGTR1 and AGTR2 (immunofluorescent labelling). We also investigated the effects of Ang II, Olmesartan (AGTR1 antagonist) and PD123319 (AGTR2 antagonist) on oocyte cleavage, embryo expansion and hatching. Pre-implanted embryos possessed AGTR1 and AGTR2 but not the other RAS components. Both receptors were present in the trophectoderm and in the inner cell mass of the blastocyst. AGTR1 was mainly localised in granular-like structures in the cytoplasm, suggesting its internalisation into clathrin-coated vesicles, and AGTR2 was found mainly in the nuclear membrane and in the mitotic spindle of dividing trophoblastic cells. Treating embryos with PD123319 increased the proportion of hatched embryos compared with the control. These results, the first on RAS in the early embryo, suggest that the pre-implanted embryo responds to Ang II from the mother rather than from the embryo itself. This may be a route by which the maternal RAS influences blastocyst hatching and early embryonic development.

Sign in / Sign up

Export Citation Format

Share Document