Localization and synthesis of alphafoetoprotein in post-implantation mouse embryos

Development ◽  
1978 ◽  
Vol 43 (1) ◽  
pp. 289-313
Author(s):  
M. Dziadek ◽  
E. Adamson

The localization and synthesis of alphafoetoprotein (AFP) during mouse embryogenesis were studied by immunoperoxidase and by immunoprecipitation after radioactive labelling, using an antiserum prepared against AFP. AFP is first detectable in embryos on the 7th day of gestation (7th day embryos). In 7th and 8th day embryos AFP is confined to visceral (proximal) endoderm cells around the embryonic region of the egg cylinder. Visceral extra-embryonic and parietal (distal) endoderm cells do not contain AFP. By the 9th day of gestation AFP is also present in the extra-embryonic ectoderm, mesoderm and embryonic ectoderm cells around the three cavities of the embryo. These tissues do not synthesize AFP when cultured in isolation, but can adsorb AFP when it is added to the medium. On the 12th day of gestation AFP synthesis is confined to the endoderm layer of the visceral yolk sac. It is concluded that the ability to synthesize AFP is a property which is restricted to the visceral endoderm during early post-implantation development. The presence of AFP in other tissues of the embryo appears to be due to adsorption.

Development ◽  
1978 ◽  
Vol 48 (1) ◽  
pp. 239-247
Author(s):  
J. Rossant ◽  
R. L. Gardner ◽  
H. L. Alexandre

Chimaeric conceptuses have been produced by injection of 5½- and 6½-day extra-embryonic ectoderm and 5½-day embryonic and extra-embryonic endoderm into 3½-day mouse blastocysts. Extra-embryonic ectoderm cells contributed only to the ectoplacental cone and/or trophoblast giant cell fractions, reflecting the probable trophectoderm origin of these cells. Proximal (visceral) endoderm cells overlying both the embryonic and extra-embryonic ectoderm contributed cells only to the endoderm of the visceral yolk sac, indicating that the definitive embryonic endoderm has not formed by 5½ days p.c.


Development ◽  
1984 ◽  
Vol 81 (1) ◽  
pp. 143-152
Author(s):  
Wei-Kang Shi ◽  
John K. Heath

Apolipoprotein expression was examined in the postimplantation mouse embryo. Antibodies directed against murine Apolipoprotein AI and human low-density lipoprotein (LDL) particles specifically immunoprecipitated metabolically labelled radioactive apolipoproteins from the culture supernatant of 10·5 days post coitum (days p.c.) yolk sac visceral endoderm cultured in vitro. No evidence for apolipoprotein expression by other embryonic or extraembryonic tissues at this stage was obtained. Immunohistochemical staining at sectioned 10·5 days p.c. embryos with anti-Apolipoprotein AI antibodies revealed specific localization of immunoreactive material in the yolk sac visceral endoderm. We conclude that the yolk sac visceral endoderm is a source of lipoproteins during postimplantation embryonic development.


Development ◽  
1980 ◽  
Vol 55 (1) ◽  
pp. 33-51
Author(s):  
R. E. Poelmann

The shape of the embryonic ectoderm of early post-implantation mouse embryos changes greatly in the period of 6·2–7·3 days post coitum. The subcellular morphology of the embryonic ectoderm remains unchanged, except in the primitive-streak region. Cell kinetics differ between ectodermal regions. These differences may be related to the changes in the shape of the ectoderm. The increase in cell number in the lateral ectoderm (the prospective surface ectoderm) exceeds that in the frontal ectoderm (the future neurectoderm). This is not due to differences in the duration of the cell cycle. It can be explained, however, by the occurrence of different relative numbers of dividing and non-dividing cells. These numbers vary between the two regions. The percentage of non-dividing cells in the frontal ectoderm may reach 45, whereas in the lateral ectoderm this percentage is not higher than 15. Autoradiography in tritiated thymidine-treated embryos combined with the mitotic indices gave us all of the parameters necessary to present a model capable of clarifying the growth of the ectoderm during gastrulation, as well as the changes in the shape of the ectoderm.


Development ◽  
1992 ◽  
Vol 115 (1) ◽  
pp. 277-288 ◽  
Author(s):  
J.J. Lee ◽  
G. Radice ◽  
C.P. Perkins ◽  
F. Costantini

The H beta 58 transgenic mouse line carries a recessive insertional mutation that results in developmental abnormalities beginning at day 7.5 p.c. and embryonic arrest at about day 9.5. In this paper, we describe the characterization of a novel gene encoded at the H beta 58 locus, whose disruption appears to be responsible for the mutant phenotype. The wild-type H beta 58 gene encodes a single 2.7 kb mRNA during embryonic and fetal development, and in many adult somatic tissues. In the mutant locus, this transcription unit is split by the transgene insertion, and one of its coding exons is deleted. Consistent with the physical disruption of the gene, the level of the H beta 58 mRNA in heterozygous mutant mouse tissues was half the normal level, indicating that the mutant allele fails to encode a stable mRNA. In situ hybridization studies revealed that expression of the wild-type H beta 58 gene begins in the oocyte, and continues throughout pre- and post-implantation embryogenesis, despite the fact that homozygous mutant embryos develop successfully through the egg cylinder stage (day 6.5 p.c.). In the early post-implantation embryo, expression of the normal H beta 58 gene is relatively low in the embryonic ectoderm, the tissue displaying the earliest phenotypic effects of the mutation, and highest in the visceral endoderm. We therefore propose that the effects of the mutation on the embryonic ectoderm may be exerted indirectly, via the visceral endoderm. Sequence analysis of H beta 58 cDNA clones revealed no homology between the 38 × 10(3) M(r) H beta 58 protein and other known proteins. However, the H beta 58 gene displayed extremely strong conservation between mammals and birds (greater than 96% amino acid identity), although it appeared less conserved in amphibians and invertebrates.


1994 ◽  
Vol 8 (20) ◽  
pp. 2466-2477 ◽  
Author(s):  
W S Chen ◽  
K Manova ◽  
D C Weinstein ◽  
S A Duncan ◽  
A S Plump ◽  
...  

Development ◽  
1981 ◽  
Vol 61 (1) ◽  
pp. 117-131
Author(s):  
M. G. Stinnakre ◽  
M. J. Evans ◽  
K. R. Willison ◽  
P. L. Stern

The expression of Forssman antigen on the surface of cells of post-implantation mouse embryos between 5 and 7½ days old and of cells of the gonads from 10½ days has been followed using the monoclonal antiserum M1/22.25. In the early post-implantation embryo a lineage-related distribution is found. The inner cell mass of the blastocyst was previously shown to be Forssman antigen positive and its derivative tissues the epiblast of the 5-day embryo and the primary embryonic endoderm are also positive. The endoderm cells remain positive both over the embryonic and extraembryonic portions of the embryo but the epiblast becomes Forssman antigen negative as it differentiates into embryonic ectoderm. The extraembryonic ectoderm which is derived from the Forssman negative trophectoderm remains negative throughout. The primordial germ cells are Forssman antigen positive from their first appearance in the germinal ridge until day 14 when they become negative but after that time it is other cells not related by direct lineage which become Forssman antigen positive. These are tentatively identified as Sertoli cells precursors as it is the Sertoli cells which are the antigen-positive population in the adult testis.


2017 ◽  
Vol 130 (20) ◽  
pp. 3568-3577 ◽  
Author(s):  
Miho Oka ◽  
Keisuke Hashimoto ◽  
Yoshifumi Yamaguchi ◽  
Shin-ichiro Saitoh ◽  
Yuki Sugiura ◽  
...  

2000 ◽  
Vol 148 (3) ◽  
pp. 567-578 ◽  
Author(s):  
Joerg Huelsken ◽  
Regina Vogel ◽  
Volker Brinkmann ◽  
Bettina Erdmann ◽  
Carmen Birchmeier ◽  
...  

The anterior-posterior axis of the mouse embryo is defined before formation of the primitive streak, and axis specification and subsequent anterior development involves signaling from both embryonic ectoderm and visceral endoderm. Τhe Wnt signaling pathway is essential for various developmental processes, but a role in anterior-posterior axis formation in the mouse has not been previously established. β-Catenin is a central player in the Wnt pathway and in cadherin-mediated cell adhesion. We generated β-catenin–deficient mouse embryos and observed a defect in anterior-posterior axis formation at embryonic day 5.5, as visualized by the absence of Hex and Hesx1 and the mislocation of cerberus-like and Lim1 expression. Subsequently, no mesoderm and head structures are generated. Intercellular adhesion is maintained since plakoglobin substitutes for β-catenin. Our data demonstrate that β-catenin function is essential in anterior-posterior axis formation in the mouse, and experiments with chimeric embryos show that this function is required in the embryonic ectoderm.


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