Peculiarity of embryonic erythropoiesis of pigs

Marina Tatoyan, PhD of medicine, work since 2002 in the department of Embryology, Cytology and Histology of the Yerevan State Medical University after M. Heratsi

We managed to clarify the time and localization of the main stages of the pigs' embryonal erythropoiesis. Our study showed that in the pigs' embryogenesis the first are formed an intraembryonic zone of hematopoietic cell localization, which includes the paraaortic mesenchyme and AGM-region. Hematopoietic foci are found from 13-15 days, then gradually decreasing to 25 days and disappear by 35 days of gestation. Extraembryonic yolk sac hematopoiesis also occurs in the early stage of gestation, where similar to the intraembryonic hematopoiesis are formed - blood islands. We have shown that the liver of pig embryos is formed on the 15th day and the hematopoiesis in it begins to develop from the 20th day of gestation. The liver is more leading organ of embryonic erythropoiesis in porcine, compared to another mammalian, the single erythroblastic islands of the liver are also preserved after the birth. After 65 days of pregnancy, hematopoiesis in porcine liver gradually disappeared and replaced by the bone marrow. For the first time erythroblastic islands of the liver and mechanisms of regulation of prenatal erythropoiesis of the pigs have been studies.