Differential incorporation of docosahexaenoic and arachidonic acids by the yolk sac membrane of the avian embryo

2003 ◽  
Vol 136 (2) ◽  
pp. 357-367 ◽  
Author(s):  
Brian K. Speake ◽  
Elizabeth A. Deans ◽  
Kate A. Powell
Keyword(s):  
Yolk Sac ◽  
Avian Embryo ◽  
Arachidonic Acids

Demonstration of a phagocytic cell system belonging to the hemopoietic lineage and originating from the yolk sac in the early avian embryo

Development ◽  
1992 ◽  
Vol 115 (1) ◽  
pp. 157-168 ◽  
Author(s):  
M.A. Cuadros ◽  
P. Coltey ◽  
M. Carmen Nieto ◽  
C. Martin
Keyword(s):  
Acid Phosphatase ◽  
Developmental Stages ◽  
Cell Lineage ◽  
Cell System ◽  
Yolk Sac ◽  
Double Labelling ◽  
Avian Embryo ◽  
Phagocytic Cell ◽  
Phagocytic Capacity ◽  
Hemopoietic Cells

It is well established that hemopoietic cells arising from the yolk sac invade the avian embryo. To study the fate and role of these cells during the first 2.5-4.5 days of incubation, we constructed yolk sac chimeras (a chick embryo grafted on a quail yolk sac and vice versa) and immunostained them with antibodies specific to cells of quail hemangioblastic lineage (MB1 and QH1). This approach revealed that endothelial cells of the embryonic vessels are of intraembryonic origin. In contrast, numerous hemopoietic cells of yolk sac origin were seen in embryos ranging from 2.5 to 4.5 days of incubation. These cells were already present within the vessels and in the mesenchyme at the earliest developmental stages analyzed. Two hemopoietic cell types of yolk sac origin were distinguishable, undifferentiated cells and macrophage-like cells. The number of the latter cells increased progressively as development proceeded, and they showed marked acid phosphatase activity and phagocytic capacity, as revealed by the presence of numerous phagocytic inclusions in their cytoplasm. The macrophage-like cells were mostly distributed in the mesenchyme and also appeared within some organ primordia such as the neural tube, the liver anlage and the nephric rudiment. Comparison of the results in the two types of chimeras and the findings obtained with acid phosphatase/MB1 double labelling showed that some hemopoietic macrophage-like cells of intraembryonic origin were also present at the stages considered. These results support the existence in the early avian embryo of a phagocytic cell system of blood cell lineage, derived chiefly from the yolk sac. Cells belonging to this system perform phagocytosis in cell death and may also be involved in other morphogenetic processes.

Fatty acid esterification in the yolk sac membrane of the avian embryo

2004 ◽  
Vol 174 (2) ◽  
pp. 163-168 ◽  
Author(s):  
K. A. Powell ◽  
E. A. Deans ◽  
B. K. Speake
Keyword(s):  
Fatty Acid ◽  
Yolk Sac ◽  
Avian Embryo ◽  
Acid Esterification ◽  
Fatty Acid Esterification

On the origin of haemopoietic stem cells in the avian embryo: an experimental approach

Development ◽  
1975 ◽  
Vol 33 (3) ◽  
pp. 607-619
Author(s):  
par Françoise Dieterlen-Lievre
Keyword(s):  
Stem Cells ◽  
Blood Cell ◽  
Experimental Approach ◽  
Developmental Stages ◽  
Yolk Sac ◽  
Avian Embryo ◽  
Cell Nuclei ◽  
Haemopoietic Stem Cells ◽  
Cell Series ◽  
Haemopoietic Cells

It is currently accepted that stem cells of the definitive blood cell lines originate from the yolk-sac blood islands. Experiments were devised to examine the validity of this theory in the avian embryo. These involved grafting two-day-old quail embryos on to chick yolk-sacs of comparable developmental stages, i.e. before or shortly after the establishment of vascularization.The conclusions of the experiments are based on the possibility of distinguishing chick cell nuclei from those of the quail. In the developing haemopoietic organs (spleen and thymus) of quail embryos grafted on to the chick and subsequently incubated for 6–11 days, all cells, whether belonging to the granulopoietic, erythropoietic or lymphopoietic series, are of quail type. Thus these organs have not been colonized by chick stem cells. On the other hand, coelomic graft experiments show that the development of these organs is indeed dependent on an extrinsic colonization by haemopoietic cells; quail spleen or thymus rudiment, developing in the coelom of a chick, is populated by chick cells. Thus no incompatibility which would prevent heterospecific colonization exists in this system. It is concluded that haemopoietic stem cells of the definitive blood cell series originate from some source other than the yolk-sac, and that this source must be intra-embryonic.

scholarly journals Aorta-associated CD34+ hematopoietic cells in the early human embryo

Blood ◽  
1996 ◽  
Vol 87 (1) ◽  
pp. 67-72 ◽  
Author(s):  
M Tavian ◽  
L Coulombel ◽  
D Luton ◽  
HS Clemente ◽  
F Dieterlen-Lievre ◽  
...  
Keyword(s):  
Stem Cells ◽  
Human Embryo ◽  
Hematopoietic Cells ◽  
Yolk Sac ◽  
Blood System ◽  
In Vitro Assays ◽  
Avian Embryo ◽  
Hematopoietic Stem

Abstract Hematopoiesis is established from circulating blood stem cells that seed the embryonic rudiments of blood-forming tissues, a basic notion in developmental hematology. However, the assumption that these stem cells originate from the extraembryonic mesoderm, where primitive hematopoiesis is initiated by intrinsic precursors, has been reconsidered after analysis of blood cell development in avian embryo chimeras: yolk-sac-derived stem cells do not contribute significantly to the definitive blood system, whose first forerunners develop independently along the ventral aspect of the embryonic aorta. Recently, the homologous intraembryonic tissues of the mouse have been submitted to sensitive in vivo and in vitro assays, which showed that they also harbor multipotential hematopoietic stem cells. We have now identified a dense population of hematogenous cells, marked by the surface expression of the CD34 glycoprotein, associated with the ventral endothelium of the aorta in the 5-week human embryo. Therefore, we extend to the human species the growing evidence that intraembryonic hematopoietic cells developing independently of the yolk sac might be the real stem of the whole blood system.

scholarly journals Aorta-associated CD34+ hematopoietic cells in the early human embryo

Blood ◽  
1996 ◽  
Vol 87 (1) ◽  
pp. 67-72 ◽  
Author(s):  
M Tavian ◽  
L Coulombel ◽  
D Luton ◽  
HS Clemente ◽  
F Dieterlen-Lievre ◽  
...  
Keyword(s):  
Stem Cells ◽  
Human Embryo ◽  
Hematopoietic Cells ◽  
Yolk Sac ◽  
Blood System ◽  
In Vitro Assays ◽  
Avian Embryo ◽  
Hematopoietic Stem

Hematopoiesis is established from circulating blood stem cells that seed the embryonic rudiments of blood-forming tissues, a basic notion in developmental hematology. However, the assumption that these stem cells originate from the extraembryonic mesoderm, where primitive hematopoiesis is initiated by intrinsic precursors, has been reconsidered after analysis of blood cell development in avian embryo chimeras: yolk-sac-derived stem cells do not contribute significantly to the definitive blood system, whose first forerunners develop independently along the ventral aspect of the embryonic aorta. Recently, the homologous intraembryonic tissues of the mouse have been submitted to sensitive in vivo and in vitro assays, which showed that they also harbor multipotential hematopoietic stem cells. We have now identified a dense population of hematogenous cells, marked by the surface expression of the CD34 glycoprotein, associated with the ventral endothelium of the aorta in the 5-week human embryo. Therefore, we extend to the human species the growing evidence that intraembryonic hematopoietic cells developing independently of the yolk sac might be the real stem of the whole blood system.

Visualization of Antibody Transport in Rat Visceral Yolk-Sac Placenta

1982 ◽  
Vol 40 ◽  
pp. 246-247
Author(s):  
William P. Jollie
Keyword(s):  
Phosphate Buffer ◽  
Yolk Sac ◽  
Female Rats ◽  
Thin Sections ◽  
Visceral Yolk Sac ◽  
Antibody Complex ◽  
Cytochemical Reaction ◽  
Hind Foot ◽  
Antigen Antibody ◽  
Yolk Sac Placenta

A technique has been developed for visualizing antibody against horseradish peroxidase (HRP) in rat visceral yolk sac, the placental membrane across which passive immunity previously has been shown to be transferred from mother to young just prior to birth. Female rats were immunized by injecting both hind foot pads with 1 mg HRP emulsified in complete Freund's adjuvant. They were given a booster of 0.5mg HRP in 0.1 ml normal saline i.v. after one week, then bred and autopsied at selected stages of pregnancy, viz., 12, 1 7 and 22 days post coitum, receiving a second booster, injected as above, five days before autopsy. Yolk sacs were removed surgically and fixed immediately in 2% paraformaldehye, 1% glutaraldehye in 0.1 M phosphate buffer with 0.01% CaCl2 at pH 7.4, room temperature, for 3 hr, rinsed 3X in 0.1 M phosphate buffer plus 5% sucrose, then exposed to 1 mg HRP in 1 ml 0.1 M phosphate buffer at pH 7.4 for 1 hr. They were refixed in aldehydes, as above, for 1 5 min (to assure binding of antigen-antibody complex). Following buffer washes, the tissues were incubated in 3 mg diaminobenzidine tetrahydrochloride and 0.01% H2O2 in 0.05 M Tris-HCl buffer for 30 min. After brief buffer washes, they were postfixed in 2% OsO4. in phosphate buffer at pH 7.4, 4°C for 2 hr, dehydrated through a graded series of ethanols, and embedded in Durcupan. Thin sections were observed and photographed without contrast-enhancement with heavy metals. Cytochemical reaction product marked the site of HRP (i.e., antigen) which, in turn, was present only where it was bound with anti-HRP antibody.

DEVELOPMENT OF AN EXPERIMENTAL MODEL OF AVITAMINOSIS F

2020 ◽  
Vol 20 (2) ◽  
pp. 38-40
Author(s):  
A. Levitsky ◽  
A. Lapinska ◽  
I. Selivanskaya
Keyword(s):  
Fatty Acids ◽  
Experimental Model ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Coconut Oil ◽  
The Body ◽  
Regulatory Function ◽  
Omega 3 ◽  
White Rats ◽  
Arachidonic Acids

The article analyzes the role of essential polyunsaturated fatty acids (PUFA), especially omega-3 series in humans and animals. The biosynthesis of essential PUFA in humans and animals is very limited, so they must be consumed with food (feed). Тhe ratio of omega-3 and omega-6 PUFA is very important. Biomembranes of animal cells contain about 30% PUFA with a ratio of ω-6/ ω-3 1-2. As this ratio increases, the physicochemical properties of biomembranes and the functional activity of their receptors change. The regulatory function of essential PUFA is that in the body under the action of oxygenase enzymes (cyclooxygenase, lipoxygenase) are formed extremely active hormone-like substances (eicosanoids and docosanoids), which affect a number of physiological processes: inflammation, immunity, metabolism. Moreover, ω-6 PUFA form eicosanoids, which have pro-inflammatory, immunosuppressive properties, and ω-3 PUFAs form eicosanoids and docosanoids, which have anti-inflammatory and immunostimulatory properties. Deficiency of essential PUFA, and especially ω-3 PUFA, leads to impaired development of the body and its state of health, which are manifestations of avitaminosis F. Prevention and treatment of avitaminosis F is carried out with drugs that contain PUFA. To create new, more effective vitamin F preparations, it is necessary to reproduce the model of vitamin F deficiency. An experimental model of vitamin F deficiency in white rats kept on a fat –free diet with the addition of coconut oil, which is almost completely free of unsaturated fatty acids, and saturated fatty acids make up almost 99 % of all fatty acids was developed. The total content of ω-6 PUFA (sum of linoleic and arachidonic acids), the content of ω-3 PUFA (α-linolenic, eicosapentaenoic and docosahexaenoic acids) in neutral lipids (triglycerides and cholesterol esters) defined. Тhe content of ω-6 PUFA under the influence of coconut oil decreased by 3.3 times, and the content of ω-3 PUFA - by 7.5 times. Тhe influence of coconut oil, the content of ω-6 PUFA decreased by 2.1 times, and the content of ω-3 PUFA - by 2.8 times. The most strongly reduces the content of ω-3 PUFA, namely eicosapentaenoic, coconut oil, starting from 5 %. Consumption of FFD with a content of 15 % coconut oil reduces the content of eicosapentaenoic acid to zero, ie we have an absolute deficiency of one of the most important essential PUFAs, which determined the presence of vitamin F deficiency.

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