Histochemical study of the definitive erythropoietic foci in the chicken yolk sac.
It is well known that avian yolk sac is involved in both primitive and definitive erythropoiesis during embryonic development. Definitive erythropoiesis is first detected at about 4-5 days incubation and its maximum activity is reached between day 10 and 15 of incubation, ending between days 18 and 20 of incubation. We confirmed the definitive erythropoietic foci in the chicken yolk sac throughout the 5th to 19th day of incubation by histochemical light and electron microscopy. The definitive erythropoietic foci were observed in the yolk sac endodermal layer from day 5 until day 19, just before hatching. Ultrastructurally, definitive erythropoietic foci were observed extravascularly in the yolk sac endodermal cell layer in direct contact with the vitellolysis zone. These findings provide a basis for clarifying definitive erythropoiesis in vertebrates.
Niimi
Gen
G
Laboratory of Electron Microscopy, School of Medicine, Fujita Health University, Toyoake, Aichi, Japan. g-niimi@fujita-hu.ac.jp
Usuda
Nobuteru
N
Shinzato
Masanori
M
Kaneko
Chiyuki
C
Nagamura
Yoichi
Y
Pereda
Jaime
J
D000818:Animals; D001808:Blood Vessels / Q000196:embryology / Q000648:ultrastructure; D002642:Chick Embryo; D004396:Coloring Agents; D004527:Egg Proteins / Q000378:metabolism; D004707:Endoderm / Q000648:ultrastructure; D004912:Erythrocytes / Q000648:ultrastructure*; D015672:Erythroid Precursor Cells / Q000648:ultrastructure*; D004920:Erythropoiesis; D006651:Histocytochemistry; D008833:Microcirculation / Q000196:embryology / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D018919:Neovascularization, Physiologic; D015017:Yolk Sac / Q000098:blood supply* / Q000196:embryology* / Q000648:ultrastructure
D004396:Coloring Agents; D004527:Egg Proteins