scholarly journals Localization and synthesis of alpha-fetoprotein in chorioallantoic membrane from chick embryo.

1991 ◽  
Vol 39 (12) ◽  
pp. 1679-1684 ◽  
Author(s):  
L Sanchez Palazon ◽  
A Rodriguez-Burgos
Keyword(s):  
Chick Embryo ◽  
Embryonic Development ◽  
Organ Culture ◽  
Immunohistochemical Study ◽  
Chorioallantoic Membrane ◽  
Yolk Sac ◽  
Alpha Fetoprotein ◽  
Short List ◽  
Blood Contamination

Alpha-fetoprotein (AFP) is a major globulin of the embryonic serum of mammals, birds, and other vertebrates. It is synthesized chiefly by the liver and/or the yolk sac. The aim of this work was to confirm the occurrence of AFP in the chorioallantoic membrane (CAM) from 14-day chick embryo. AFP had previously been detected by immunoelectrophoresis in CAM extracts under the suspicion that it could be a mere artifact resulting from blood contamination. The immunohistochemical study of the CAM carried out for this purpose revealed the protein to be solely located in the mesodermal layer. The joint use of organ culture and immunoperoxidase techniques has enabled us to find evidence for the synthesis of AFP in the cells of this layer. These results confirm the occurrence of such a significant carrier globulin to embryonic development in one more tissue that can be added to the short list of AFP-producing tissues.

scholarly journals SOME OBSERVATIONS ON THE INTRACELLULAR LOCALIZATION OF THE VIRUS OF HERPES SIMPLEX IN THE CHICK EMBRYO LIVER

1954 ◽  
Vol 100 (5) ◽  
pp. 473-484 ◽  
Author(s):  
Alan Gray ◽  
T. F. McNair Scott
Keyword(s):  
Herpes Simplex ◽  
Chick Embryo ◽  
Intracellular Localization ◽  
Chorioallantoic Membrane ◽  
Growth Cycle ◽  
Yolk Sac ◽  
Nuclear Fraction ◽  
Free Virus ◽  
Isolated Nuclei ◽  
Embryo Liver

The growth cycle of the virus of herpes simplex in chick embryo liver has been shown to follow the same pattern as in the chorioallantoic membrane and the rabbit's corneal cells. However, there is considerable variability in the time taken for the yolk sac-inoculated virus to get from the yolk sac into the liver. A brief description has been given of various fractionation procedures employed for obtaining isolated nuclei. It has been shown that free virus is not selectively adsorbed to isolated nuclei. Evidence has been presented to show that in the herpes-infected chick embryo liver, large proportions of the total virus can at times be found associated with the nuclear fraction. The percentage of the total virus in the nuclear fraction varies inversely with the titer of virus in the whole liver, and the number of hours after inoculation of the virus; only a negligible amount (as compared with that in the total) being associated with the nuclear fraction when a period of over 12 hours has elapsed after reappearance of virus. Furthermore, demonstration of virus in the isolated nuclei following extraction with hypertonic NaCl provides additional evidence that this virus is intimately associated with the nuclei.

The influence of the area opaca on the development of the young chick embryo

Development ◽  
1967 ◽  
Vol 17 (1) ◽  
pp. 195-212
Author(s):  
Ruth Bellairs ◽  
D. R. Bromham ◽  
C. C. Wylie
Keyword(s):  
Chick Embryo ◽  
Chorioallantoic Membrane ◽  
Yolk Sac ◽  
Vitelline Membrane ◽  
Young Chick ◽  
Chick Blastoderm ◽  
Inner Surface ◽  
Peripheral Cells ◽  
Area Pellucida

The area opaca of the chick blastoderm is generally regarded as being merely the primordium of the yolk sac. Thus it might be expected that during the early stages of development its role would be essentially to grow and to differentiate, rather than to exert any influence on the development of the area pellucida. Such a view would be supported by the fact that pieces of the area pellucida can differentiate in the absence of the area opaca if they are isolated on the chorioallantoic membrane (Rawles, 1936) or in vitro (de Haan, 1964). There are, however, reasons for enquiring whether the area opaca does exert some influence on the area pellucida. The first is that New (1959) has demonstrated that the blastoderm is normally under tension, and that this tension is produced by the peripheral cells of the area opaca which adhere to the inner surface of the vitelline membrane.

scholarly journals THE EFFECTS OF 5-BROMODEOXYURIDINE ON YOLK SAC ERYTHROPOIESIS IN THE CHICK EMBRYO

1971 ◽  
Vol 48 (3) ◽  
pp. 523-532 ◽  
Author(s):  
Yasusada Miura ◽  
Fred H. Wilt
Keyword(s):  
Chick Embryo ◽  
Organ Culture ◽  
Cell Formation ◽  
Primitive Streak ◽  
Yolk Sac ◽  
Red Cell ◽  
Thymidine Analog ◽  
A Cell ◽  
Cell Clump ◽  
Regulatory Event

The effects of the thymidine analog, 5-bromodeoxyuridine (BUdR), on the formation of red cells in the yolk sac of the chick embryo were examined. The prospective area opaca vasculosa from a definitive primitive streak embryo was excised, disaggregated, and deposited into a cell clump, and the cell clump was placed in organ culture. Hemoglobin synthesis is detectable after about 16 hr in culture. The formation of erythropoietic foci and incorporation of 55Fe into heme were used to measure the extent of erythropoiesis. Exposure to 40 µg/ml of BUdR within 6 hr after explantation almost completely eliminated red cell formation; subsequent transfer to thymidine medium showed that the inhibition was reversible, and there was no histological evidence of analog toxicity. Between 6 and 12 hr after initiation of organ culture, the tissue became completely refractory to BUdR. DNA synthesis, as monitored by thymidine-3H and BUdR-3H pulses, was extensive both during and after the period of BUdR sensitivity. Hence, during both BUdR sensitive and insensitive periods the analog was incorporated into DNA of cells which had not yet synthesized hemoglobin. It is proposed that between 6 and 12 hr a crucial regulatory event for terminal differentiation is perturbed by the presence of BUdR in the chromosomes.

scholarly journals THE INFLUENCE OF CORTISONE ON EXPERIMENTAL VIRAL INFECTION

1966 ◽  
Vol 123 (2) ◽  
pp. 309-325 ◽  
Author(s):  
K. Marilyn Smart ◽  
Edwin D. Kilbourne
Keyword(s):  
Chick Embryo ◽  
Inflammatory Response ◽  
Chorioallantoic Membrane ◽  
Allantoic Fluid ◽  
Influenza Viruses ◽  
Present System ◽  
Interferon Production ◽  
Hydrocortisone Administration ◽  
Experimental Viral Infection

A comparative study was undertaken of the pathogenesis of infection of the allantoic sac of the chick embryo with three influenza viruses of differing virulence, and of the influence of hydrocortisone on the course of infection. Judged on the basis of earlier onset and greater degree of inflammatory response and diminished survival time of infected embryos, Mel. and Lee viruses were markedly more virulent than PR8, despite the earlier appearance of virus in PR8-infected embryos. Interferon appeared first and in greater quantity in the allantoic fluid of Lee-infected embryos and latest with PR8 infection. Thus, there was no correlation of avirulence and better interferon production with the viruses under study in the present system. Furthermore, evidence obtained suggested that Lee virus ("virulent") was most susceptible to interferon action, and also that viral synthesis in the chorioallantoic membrane with PR8 ("avirulent") persisted after the appearance of interferon. The injection of hydrocortisone within 2 hr of the initiation of infection delayed the synthesis of all three viruses; had no significant effect upon the inflammatory response; and transiently inhibited the synthesis of interferon, while prolonging the survival of Lee- and Mel.-infected embryos. Late administration of hydrocortisone suppresses both the inflammatory response and the production of interferon. Only in the case of Lee virus infection did hydrocortisone administration lead to augmentation of final yields of virus with the low infection multiplicity employed in the present experiments. It is postulated that Lee virus is a better inducer of interferon because its infectivity in vivo is more rapidly inactivated. As a consequence synthesis of Lee virus is more under the control of endogenous interferon than is the case with PR8 or Mel. virus. Therefore, inhibition of interferon synthesis with hydrocortisone has a greater influence on final yields of Lee virus.

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