scholarly journals Antibodies to early pregnancy factor retard embryonic development in mice in vivo

Reproduction ◽  
1991 ◽  
Vol 92 (2) ◽  
pp. 443-451 ◽  
Author(s):  
S. Athanasas-Platsis ◽  
H. Morton ◽  
G. F. Dunglison ◽  
P. L. Kaye
Keyword(s):  
Embryonic Development ◽  
Early Pregnancy ◽  
Early Pregnancy Factor

Early pregnancy factor has immunosuppressive and growth factor properties

1992 ◽  
Vol 4 (4) ◽  
pp. 411 ◽  
Author(s):  
H Morton ◽  
AC Cavanagh ◽  
S Athanasas-Platsis ◽  
KA Quinn ◽  
BE Rolfe
Keyword(s):  
Growth Factor ◽  
Early Pregnancy ◽  
Passive Immunization ◽  
Immunological Response ◽  
Reversed Phase ◽  
Tumour Cells ◽  
Delayed Type Hypersensitivity ◽  
Early Pregnancy Factor

Early pregnancy factor (EPF) was first described as a pregnancy-associated substance, although recent studies suggest a more general link with cell development. It is a product of actively dividing cells and its apparent functional importance to them suggests its potential as a regulator of cell proliferation. The recent discovery of EPF in platelets has provided a comparatively rich and readily available source of EPF. The purification procedures employed to isolate EPF from this source have also been applied to pregnancy serum and urine, medium conditioned by oestrous mouse ovaries (stimulated with prolactin and embryo-conditioned medium), medium conditioned by tumour cells, and serum from rats 24 h after partial hepatectomy (PH). In all instances, biological activity followed the same pattern throughout. Furthermore, the final active reversed-phase high-performance liquid chromatography fraction from all sources was bound specifically by immobilized anti-EPF monoclonal antibodies (MAbs), indicating that the active fractions produced from these diverse sources are very closely related, if not identical. Some differences have been observed in the behaviour of EPF in various conditions. EPF is produced by proliferating tumour cells and by liver cells post-PH, and passive immunization studies with anti-EPF MAbs have shown that these cells need EPF for survival. In contrast, EPF has not been detected as a product of the pre-embryo, and addition of anti-EPF MAbs to embryo cultures does not adversely affect development from the 2-cell to the blastocyst stage. Although the pre-embryo is not dependent on EPF for its development in vitro, neutralization of EPF in vivo by anti-EPF MAbs retards its development. Thus, EPF appears to play an indirect role in maintaining the pre-embryo. By virtue of its ability to suppress the delayed-type hypersensitivity reaction, it has been suggested that EPF might act as an immunological response modifier of the maternal immune system. Alternatively, the effect of EPF on lymphocytes may be to reduce the expression of all or some cytokines and this could inhibit development. Whether or not EPF acts more directly as an autocrine growth factor from around the time of implantation, when the embryo first begins synthesis of EPF, is not known and remains to be investigated.

Early Pregnancy Factor is Required at Two Important Stages of Embryonic Development in the Mouse

2000 ◽  
Vol 43 (4) ◽  
pp. 223-233 ◽  
Author(s):  
S. ATHANASAS-PLATSIS ◽  
A.C. CAVANAGH ◽  
H. MORTON ◽  
C.M. CORCORAN ◽  
P.L. KAYE
Keyword(s):  
Embryonic Development ◽  
Early Pregnancy ◽  
Early Pregnancy Factor

scholarly journals Influence of Anti-Bovine Early Pregnancy Factor Antibody on Embryonic Development and Implantation in Rats.

1995 ◽  
Vol 41 (2) ◽  
pp. 159-163 ◽  
Author(s):  
Iwao HONTA ◽  
Kazuei ITO ◽  
Jutaro TAKAHASHI ◽  
Yasuhisa YASUDA
Keyword(s):  
Embryonic Development ◽  
Early Pregnancy ◽  
Early Pregnancy Factor

LIPID METABOLISM OF THE RAT UTERUS AFTER MATING

1971 ◽  
Vol 51 (4) ◽  
pp. 637-644 ◽  
Author(s):  
J. R. BEALL ◽  
N. T. WERTHESSEN
Keyword(s):  
Fatty Acid ◽  
Lipid Metabolism ◽  
Free Fatty Acid ◽  
Embryonic Development ◽  
Early Pregnancy ◽  
Sterol Ester ◽  
Sterol Fraction ◽  
Uterine Tissue ◽  
Rat Uterus

SUMMARY In this study of lipid metabolism of the rat uterus during early pregnancy, lipids were extracted after incubation with [1,2-14C]acetate or after its administration in vivo. The results indicated that the synthesis and concentration of triglyceride increased with time after mating. Triglyceride accumulated in uterine tissue before implantation and was depleted in tissue from implantation areas by day 7. Synthesis of fatty acid increased with time after mating, as did the concentration of various lipids other than cholesterol in the free sterol fraction. Supporting the concept that lipids are necessary during early embryonic development, the results suggest that the rat utilizes endometrial fatty acid esterified to triglyceride. No trends related to time were seen in the rate of synthesis nor in the concentration of sterol ester or free fatty acid; hence, specific concentrations of these lipids are probably not necessary for embryonic development during early pregnancy.

scholarly journals Recent Possibilities for the Diagnosis of Early Pregnancy and Embryonic Mortality in Dairy Cows

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1666
Author(s):  
Ottó Szenci
Keyword(s):  
Blood Flow ◽  
Dairy Cows ◽  
Early Pregnancy ◽  
Fetal Mortality ◽  
Reproductive Efficiency ◽  
Interferon Tau ◽  
Early Pregnancy Factor ◽  
Pelvic Inlet ◽  
On Farm ◽  
Protein Assays

One of the most recent techniques for the on-farm diagnosis of early pregnancy (EP) in cattle is B-mode ultrasonography. Under field conditions, acceptable results may be achieved with ultrasonography from Days 25 to 30 post-AI. The reliability of the test greatly depends on the frequency of the transducer used, the skill of the examiner, the criterion used for a positive pregnancy diagnosis (PD), and the position of the uterus in the pelvic inlet. Non-pregnant animals can be selected accurately by evaluating blood flow in the corpus luteum around Day 20 after AI, meaning we can substantially improve the reproductive efficiency of our herd. Pregnancy protein assays (PSPB, PAG-1, and PSP60 RIA, commercial ELISA or rapid visual ELISA tests) may provide an alternative method to ultrasonography for determining early pregnancy or late embryonic/early fetal mortality (LEM/EFM) in dairy cows. Although the early pregnancy factor is the earliest specific indicator of fertilization, at present, its detection is entirely dependent on the use of the rosette inhibition test; therefore, its use in the field needs further developments. Recently found biomarkers like interferon-tau stimulated genes or microRNAs may help us diagnose early pregnancy in dairy cows; however, these tests need further developments before their general use in the farms becomes possible.

scholarly journals Cellular dynamics of EMT: lessons from live in vivo imaging of embryonic development

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Jeffrey D. Amack
Keyword(s):  
Extracellular Matrix ◽  
Embryonic Development ◽  
In Vivo Imaging ◽  
Cytoskeletal Proteins ◽  
Cell Junctions ◽  
Model Organisms ◽  
Cellular Dynamics ◽  
Mesenchymal Transition ◽  
Cell Cell

AbstractEpithelial-mesenchymal transition (EMT) refers to a process in which epithelial cells lose apical-basal polarity and loosen cell–cell junctions to take on mesenchymal cell morphologies and invasive properties that facilitate migration through extracellular matrix. EMT—and the reverse mesenchymal-epithelial transition (MET)—are evolutionarily conserved processes that are used throughout embryonic development to drive tissue morphogenesis. During adult life, EMT is activated to close wounds after injury, but also can be used by cancers to promote metastasis. EMT is controlled by several mechanisms that depend on context. In response to cell–cell signaling and/or interactions with the local environment, cells undergoing EMT make rapid changes in kinase and adaptor proteins, adhesion and extracellular matrix molecules, and gene expression. Many of these changes modulate localization, activity, or expression of cytoskeletal proteins that mediate cell shape changes and cell motility. Since cellular changes during EMT are highly dynamic and context-dependent, it is ideal to analyze this process in situ in living organisms. Embryonic development of model organisms is amenable to live time-lapse microscopy, which provides an opportunity to watch EMT as it happens. Here, with a focus on functions of the actin cytoskeleton, I review recent examples of how live in vivo imaging of embryonic development has led to new insights into mechanisms of EMT. At the same time, I highlight specific developmental processes in model embryos—gastrulation in fly and mouse embryos, and neural crest cell development in zebrafish and frog embryos—that provide in vivo platforms for visualizing cellular dynamics during EMT. In addition, I introduce Kupffer’s vesicle in the zebrafish embryo as a new model system to investigate EMT and MET. I discuss how these systems have provided insights into the dynamics of adherens junction remodeling, planar cell polarity signaling, cadherin functions, and cytoskeletal organization during EMT, which are not only important for understanding development, but also cancer progression. These findings shed light on mechanisms of actin cytoskeletal dynamics during EMT, and feature live in vivo imaging strategies that can be exploited in future work to identify new mechanisms of EMT and MET.

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