title: In-vitro development of the rat parietal yolk sac.
abstract: Rat embryos were cultured with the parietal yolk sac and other membranes intact. The development of the parietal yolk sac after 24 h in vitro was assessed by (1) the increase in size, (2) the morphology of the cellular components, and (3) the development of the embryo within the yolk sac. Development in vitro most resembled that in vivo when the embryos and membranes were explanted and cultured in rat serum diluted 1 : 1 with Hanks' or Waymouth's medium. High levels of oxygen were also beneficial. Culture in undiluted serum or under low oxygen concentrations resulted in very poor expansion of the yolk sac, abnormal trophoblastic giant cell morphology and stunted embryonic development.
mesh_terms: D000818:Animals; D003470:Culture Media; D046508:Culture Techniques / Q000379:methods; D004622:Embryo, Mammalian / Q000033:anatomy & histology*; D005260:Female; D008297:Male; D010100:Oxygen; D011247:Pregnancy; D051381:Rats; D015017:Yolk Sac / Q000033:anatomy & histology*
chemical_list: D003470:Culture Media; D010100:Oxygen