yolk sac

Summary

Summary: The first of four extra-embryonic membranes to form during EMBRYOGENESIS. In REPTILES and BIRDS, it arises from endoderm and mesoderm to incorporate the EGG YOLK into the DIGESTIVE TRACT for nourishing the embryo. In placental MAMMALS, its nutritional function is vestigial; however, it is the source of INTESTINAL MUCOSA; BLOOD CELLS; and GERM CELLS. It is sometimes called the vitelline sac, which should not be confused with the VITELLINE MEMBRANE of the egg.

Top Publications

  1. Lucitti J, Jones E, Huang C, Chen J, Fraser S, Dickinson M. Vascular remodeling of the mouse yolk sac requires hemodynamic force. Development. 2007;134:3317-26 pubmed
    ..Recent work has shown that vessel remodeling in the mouse yolk sac is secondarily effected when cardiac function is reduced or absent...
  2. Tasaki T, Kim S, Zakrzewska A, Lee B, Kang M, Yoo Y, et al. UBR box N-recognin-4 (UBR4), an N-recognin of the N-end rule pathway, and its role in yolk sac vascular development and autophagy. Proc Natl Acad Sci U S A. 2013;110:3800-5 pubmed publisher
    ..die during embryogenesis and exhibit pleiotropic abnormalities, including impaired vascular development in the yolk sac (YS)...
  3. Mohanty S, Kim J, Ganesan L, Phillips G, Hua K, Jarjoura D, et al. IgG is transported across the mouse yolk sac independently of FcgammaRIIb. J Reprod Immunol. 2010;84:133-44 pubmed publisher
    While generally accepted that FcRn of the human syncytiotrophoblast and the mouse yolk sac endoderm is the major IgG transporter, the finding of a different Fc receptor FcgammaRIIb (RIIb) in the human placental endothelium has suggested ..
  4. Kanashiro C, Santos T, Miglino M, Mess A, Carter A. Growth and development of the placenta in the capybara (Hydrochaeris hydrochaeris). Reprod Biol Endocrinol. 2009;7:57 pubmed publisher
    ..We paid attention to the development of the lobulated arrangement of the placenta, the growth of the labyrinth in the course of gestation, the differentiation of the subplacenta, and the pattern of invasion by extraplacental trophoblast...
  5. Ginhoux F, Greter M, Leboeuf M, Nandi S, See P, Gokhan S, et al. Fate mapping analysis reveals that adult microglia derive from primitive macrophages. Science. 2010;330:841-5 pubmed publisher
    ..These results identify microglia as an ontogenically distinct population in the mononuclear phagocyte system and have implications for the use of embryonically derived microglial progenitors for the treatment of various brain disorders...
  6. Giroux S, Alves Leiva C, Lecluse Y, Martin P, Albagli O, Godin I. Gene transfer to pre-hematopoietic and committed hematopoietic precursors in the early mouse yolk sac: a comparative study between in situ electroporation and retroviral transduction. BMC Dev Biol. 2007;7:79 pubmed
    ..precursors harbour the features of hematopoietic stem cells (HSC), precursors formed earlier in the yolk sac (YS) display limited differentiation and self-renewal potentials...
  7. Yadgary L, Cahaner A, Kedar O, Uni Z. Yolk sac nutrient composition and fat uptake in late-term embryos in eggs from young and old broiler breeder hens. Poult Sci. 2010;89:2441-52 pubmed publisher
    ..Eggs were sampled at embryonic d 0 (fresh eggs), 13, 15, 17, 19, and 21 (hatch). Egg, embryo, yolk content, and yolk sac membrane were weighed, and the yolk sac (YS; i.e., yolk content + yolk sac membrane) composition was analyzed...
  8. Ueno H, Weissman I. The origin and fate of yolk sac hematopoiesis: application of chimera analyses to developmental studies. Int J Dev Biol. 2010;54:1019-31 pubmed publisher
    During mammalian development, as exemplified by mice, hematopoietic cells first appear in the yolk sac blood islands, then in the dorsal aorta of the aorta-gonad-mesonephros (AGM) region and the placenta, eventually seeding into liver, ..
  9. Schulz C, Gomez Perdiguero E, Chorro L, Szabo Rogers H, Cagnard N, Kierdorf K, et al. A lineage of myeloid cells independent of Myb and hematopoietic stem cells. Science. 2012;336:86-90 pubmed publisher
    ..Myb was required for development of HSCs and all CD11b(high) monocytes and macrophages, but was dispensable for yolk sac (YS) macrophages and for the development of YS-derived F4/80(bright) macrophages in several tissues, such as ..

More Information

Publications62

  1. Tesar D, Cheung E, Bjorkman P. The chicken yolk sac IgY receptor, a mammalian mannose receptor family member, transcytoses IgY across polarized epithelial cells. Mol Biol Cell. 2008;19:1587-93 pubmed publisher
    ..In birds, maternal IgY in egg yolk is transferred across the yolk sac to passively immunize chicks during gestation and early independent life...
  2. Mohanty S, Anderson C, Robinson J. The expression of caveolin-1 and the distribution of caveolae in the murine placenta and yolk sac: parallels to the human placenta. Placenta. 2010;31:144-50 pubmed publisher
    ..expression pattern of caveolin-1 and the distribution of caveolae in the murine placental labyrinth and visceral yolk sac have been determined...
  3. Holtz M, Misra R. Endothelial-specific ablation of serum response factor causes hemorrhaging, yolk sac vascular failure, and embryonic lethality. BMC Dev Biol. 2008;8:65 pubmed publisher
    ..Resulting embryos were harvested at specific ages for observation of physical condition and analysis of genotype...
  4. Koike S, Keino Masu K, Ohto T, Sugiyama F, Takahashi S, Masu M. Autotaxin/lysophospholipase D-mediated lysophosphatidic acid signaling is required to form distinctive large lysosomes in the visceral endoderm cells of the mouse yolk sac. J Biol Chem. 2009;284:33561-70 pubmed publisher
    ..5 because of angiogenic defects in the yolk sac. However, what cellular defects occur in Enpp2(-/-) embryos and what intracellular signaling pathways are ..
  5. Landry J, Kinston S, Knezevic K, de Bruijn M, Wilson N, Nottingham W, et al. Runx genes are direct targets of Scl/Tal1 in the yolk sac and fetal liver. Blood. 2008;111:3005-14 pubmed publisher
    ..To this end, we generated an Scl(-/-) yolk sac cell line to identify candidate Scl target genes by global expression profiling after reintroduction of a TAT-Scl ..
  6. Miglino M, Franciolli A, De Oliveira M, Ambrosio C, Bonatelli M, Machado M, et al. Development of the inverted visceral yolk sac in three species of caviids (Rodentia, Caviomorpha, Caviidae). Placenta. 2008;29:748-52 pubmed publisher
    ..We attempt to identify diversity within the visceral yolk sac and its association with the chorioallantoic placenta in three species of caviids, two of them possessing a ..
  7. Qiu C, Olivier E, Velho M, Bouhassira E. Globin switches in yolk sac-like primitive and fetal-like definitive red blood cells produced from human embryonic stem cells. Blood. 2008;111:2400-8 pubmed
    ..be expanded in serum-free liquid culture into large numbers of megaloblastic nucleated erythroblasts resembling yolk sac-derived cells...
  8. Wenceslau C, Miglino M, Martins D, Ambrosio C, Lizier N, Pignatari G, et al. Mesenchymal progenitor cells from canine fetal tissues: yolk sac, liver, and bone marrow. Tissue Eng Part A. 2011;17:2165-76 pubmed publisher
    ..fetal development, mesenchymal progenitor (MP) cells are co-localized in major hematopoietic territories, such as yolk sac (YS), bone marrow (BM), liver (LV), and others...
  9. Samokhvalov I, Samokhvalova N, Nishikawa S. Cell tracing shows the contribution of the yolk sac to adult haematopoiesis. Nature. 2007;446:1056-61 pubmed
    ..major vitelline and umbilical vessels, and placenta; however, whether they arise locally or from immigrant yolk sac precursor cells remains unclear...
  10. Franco de Oliveira M, Favaron P, Ambrosio C, Miglino M, Mess A. Chorioallantoic and yolk sac placentation in Thrichomys laurentinus (Echimyidae) and the evolution of hystricognath rodents. J Exp Zool B Mol Dev Evol. 2012;318:13-25 pubmed publisher
    ..organization of the labyrinth and the trophospongium as well as the establishment of the complete inverted yolk sac placenta...
  11. Chen Z, Wu J, Yang C, Fan P, Balazs L, Jiao Y, et al. DiGeorge syndrome critical region 8 (DGCR8) protein-mediated microRNA biogenesis is essential for vascular smooth muscle cell development in mice. J Biol Chem. 2012;287:19018-28 pubmed publisher
    ..Blood vessels were absent in the yolk sac of DGCR8 KOs after E12.5...
  12. Sakaguchi T, Kikuchi Y, Kuroiwa A, Takeda H, Stainier D. The yolk syncytial layer regulates myocardial migration by influencing extracellular matrix assembly in zebrafish. Development. 2006;133:4063-72 pubmed
    ..Based on these data, we propose that the extra-embryonic YSL regulates myocardial migration, at least in part by influencing fibronectin expression and subsequent assembly of the extracellular matrix in embryonic tissues...
  13. Yadgary L, Kedar O, Adepeju O, Uni Z. Changes in yolk sac membrane absorptive area and fat digestion during chick embryonic development. Poult Sci. 2013;92:1634-40 pubmed publisher
    The capacity of yolk sac (YS) utilization by the chick embryo may be affected by structural changes in the YS membrane (YSM) and by the mechanisms within its cells for digestion, absorption, and transfer of nutrients...
  14. Nagase M, Nagase T, Koshima I, Fujita T. Critical time window of hedgehog-dependent angiogenesis in murine yolk sac. Microvasc Res. 2006;71:85-90 pubmed
    Hedgehog family was reported to be involved in murine yolk sac angiogenesis...
  15. Woollett L. Maternal cholesterol in fetal development: transport of cholesterol from the maternal to the fetal circulation. Am J Clin Nutr. 2005;82:1155-61 pubmed
    ..of cholesterol from the basolateral side of the placental cells and the secretion of cholesterol from endodermal yolk sac cells to the fetal circulation can be regulated...
  16. Shibata M, GARCIA GARCIA M. The mouse KRAB zinc-finger protein CHATO is required in embryonic-derived tissues to control yolk sac and placenta morphogenesis. Dev Biol. 2011;349:331-41 pubmed publisher
    b>Yolk sac and placenta are required to sustain embryonic development in mammals, yet our understanding of the genes and processes that control morphogenesis of these extraembryonic tissues is still limited...
  17. Kim J, Mohanty S, Ganesan L, Hua K, Jarjoura D, Hayton W, et al. FcRn in the yolk sac endoderm of mouse is required for IgG transport to fetus. J Immunol. 2009;182:2583-9 pubmed publisher
    ..may give us a useful model to understand FcRn function in the human placenta, we have studied FcRn in the mouse yolk sac placenta in detail...
  18. Wang B, He L, Dong H, Dalton T, Nebert D. Generation of a Slc39a8 hypomorph mouse: markedly decreased ZIP8 Zn²?/(HCO??)? transporter expression. Biochem Biophys Res Commun. 2011;410:289-94 pubmed publisher
    ..Slc39a8(neo/neo) homozygotes exhibit dramatically decreased ZIP8 expression in embryo, fetus, and visceral yolk sac - in comparison to their littermate wild-type controls...
  19. Burke K, Jauniaux E, Burton G, Cindrova Davies T. Expression and immunolocalisation of the endocytic receptors megalin and cubilin in the human yolk sac and placenta across gestation. Placenta. 2013;34:1105-9 pubmed publisher
    ..They play an essential role in transport of nutrients through the visceral yolk sac of rodents during embryogenesis...
  20. Udan R, Vadakkan T, Dickinson M. Dynamic responses of endothelial cells to changes in blood flow during vascular remodeling of the mouse yolk sac. Development. 2013;140:4041-50 pubmed publisher
    ..The dynamic and specific endothelial cell behaviors captured in this study reveal how sensitive endothelial cells are to changes in blood flow and how such responses drive vascular remodeling. ..
  21. Mess A. Chorioallantoic and yolk sac placentation in the dassie rat Petromus typicus and its significance for the evolution of hystricognath rodents. Placenta. 2007;28:1229-33 pubmed
    ..mostly with species native to South America, but the current paper presents novel findings on chorioallantoic and yolk sac placentation in an Old World hystricognath and discusses its significance for the evolution of the group...
  22. Carvalho R, Itoh F, Goumans M, Lebrin F, Kato M, Takahashi S, et al. Compensatory signalling induced in the yolk sac vasculature by deletion of TGFbeta receptors in mice. J Cell Sci. 2007;120:4269-77 pubmed
    ..Absence of either receptor in ECs resulted in vascular defects in the yolk sac, as seen in mice lacking receptors in all cells, causing embryonic lethality at embryonic day (E)10.5...
  23. Griffin C, Brennan J, Magnuson T. The chromatin-remodeling enzyme BRG1 plays an essential role in primitive erythropoiesis and vascular development. Development. 2008;135:493-500 pubmed
    ..Additionally, vascular remodeling of the extraembryonic yolk sac is abnormal in Brg1(fl/fl):Tie2-Cre(+) embryos...
  24. Yang P, Zhao Z, Reece E. Blockade of c-Jun N-terminal kinase activation abrogates hyperglycemia-induced yolk sac vasculopathy in vitro. Am J Obstet Gynecol. 2008;198:321.e1-7 pubmed publisher
    Maternal hyperglycemia has an impact on both the function and morphology of the rodent visceral yolk sac; the objective of the present study was to determine whether hyperglycemia in vitro affects yolk sac vasculogenesis...
  25. Ager E, Suzuki S, Pask A, Shaw G, Ishino F, Renfree M. Insulin is imprinted in the placenta of the marsupial, Macropus eugenii. Dev Biol. 2007;309:317-28 pubmed
    Therian mammals (marsupials and eutherians) rely on a placenta for embryo survival. All mammals have a yolk sac, but while both chorio-allantoic and chorio-vitelline (yolk sac) placentation can occur, most marsupials only develop a yolk ..
  26. Corbel C, Salaün J, Belo Diabangouaya P, Dieterlen Lievre F. Hematopoietic potential of the pre-fusion allantois. Dev Biol. 2007;301:478-88 pubmed
    ..These results provide evidence that the allantois has hematopoietic potential per se. Whether this potential also involves the ability to produce HSC is still to be determined...
  27. McKeown C, Nowak R, Moyer J, Sussman M, Fowler V. Tropomodulin1 is required in the heart but not the yolk sac for mouse embryonic development. Circ Res. 2008;103:1241-8 pubmed publisher
    ..of mouse Tmod1 leads to defects in cardiac development, fragility of primitive erythroid cells, and an absence of yolk sac vasculogenesis, followed by embryonic lethality at embryonic day 9.5...
  28. Venkatesh D, Park K, Harrington A, Miceli Libby L, Yoon J, Liaw L. Cardiovascular and hematopoietic defects associated with Notch1 activation in embryonic Tie2-expressing populations. Circ Res. 2008;103:423-31 pubmed publisher
    ..N1ICD(+) embryos showed midgestation lethality with defects in angiogenic remodeling of embryonic and yolk sac vasculature, cardiac development, smooth muscle cell investment of vessels, and hematopoietic differentiation...
  29. Nagai H, Sheng G. Definitive erythropoiesis in chicken yolk sac. Dev Dyn. 2008;237:3332-41 pubmed publisher
    ..wave of erythropoiesis in amniotic animals generates all primitive erythrocytes and takes place exclusively in yolk sac mesoderm...
  30. Oliveira M, Carter A, Bonatelli M, Ambrosio C, Miglino M. Placentation in the rock cavy, Kerodon rupestris (Wied). Placenta. 2006;27:87-97 pubmed
    ..The yolk sac epithelium exhibited coated pits, endocytotic vesicles and larger vacuoles, consistent with a role in protein ..
  31. Zohn I, Sarkar A. The visceral yolk sac endoderm provides for absorption of nutrients to the embryo during neurulation. Birth Defects Res A Clin Mol Teratol. 2010;88:593-600 pubmed publisher
    ..by histotrophic mechanisms and absorbed by endocytosis in the endoderm-derived cell layer of the visceral yolk sac (VYS)...
  32. Katsuno T, Umeda K, Matsui T, Hata M, Tamura A, Itoh M, et al. Deficiency of zonula occludens-1 causes embryonic lethal phenotype associated with defected yolk sac angiogenesis and apoptosis of embryonic cells. Mol Biol Cell. 2008;19:2465-75 pubmed publisher
    ..5. In the yolk sac, the ZO-1 deficiency induced defects in vascular development, with impaired formation of vascular trees, along ..
  33. Stevenson R, Rogers R, Chandler J, Gauderer M, Hunter A. Escape of the yolk sac: a hypothesis to explain the embryogenesis of gastroschisis. Clin Genet. 2009;75:326-33 pubmed publisher
    ..Our proposal is that the determining defect in gastroschisis is failure of the yolk sac and related vitelline structures to be incorporated into the umbilical stalk...
  34. Yoshimoto M, Montecino Rodriguez E, Ferkowicz M, Porayette P, Shelley W, Conway S, et al. Embryonic day 9 yolk sac and intra-embryonic hemogenic endothelium independently generate a B-1 and marginal zone progenitor lacking B-2 potential. Proc Natl Acad Sci U S A. 2011;108:1468-73 pubmed publisher
    ..We demonstrate, using Ncx1(-/-) mice that lack systemic blood circulation, that the E9 yolk sac (YS) and the intra-embryonic para-aortic splanchnopleura (P-Sp) tissues independently give rise to AA4...
  35. Yadgary L, Uni Z. Yolk sac carbohydrate levels and gene expression of key gluconeogenic and glycogenic enzymes during chick embryonic development. Poult Sci. 2012;91:444-53 pubmed publisher
    ..mg/g of tissue) and amounts (mg) were determined in the yolks of fertile eggs on the day of set and in the yolk sac (YS) and liver of broiler chick embryos between 11 and 21 embryonic days of age (E)...
  36. Freyer C, Renfree M. The mammalian yolk sac placenta. J Exp Zool B Mol Dev Evol. 2009;312:545-54 pubmed publisher
    There are three fetal membranes in mammals, namely the yolk sac, allantois and amnion, but only the first two form a placenta...
  37. Hoeffel G, Wang Y, Greter M, See P, Teo P, Malleret B, et al. Adult Langerhans cells derive predominantly from embryonic fetal liver monocytes with a minor contribution of yolk sac-derived macrophages. J Exp Med. 2012;209:1167-81 pubmed publisher
    ..Using in vivo lineage tracing, we identify a first wave of yolk sac (YS)-derived primitive myeloid progenitors that seed the skin before the onset of fetal liver hematopoiesis...
  38. Jiang Z, Yu N, Kuang P, Chen M, Shao F, Martin G, et al. Trinucleotide repeat containing 6a (Tnrc6a)-mediated microRNA function is required for development of yolk sac endoderm. J Biol Chem. 2012;287:5979-87 pubmed publisher
    ..Here, we show that Tnrc6a, also known as GW182, is selectively expressed in the yolk sac endoderm and that gene trap disruption of GW182 leads to growth arrest and apoptosis...
  39. Smith B, Mussell J, Fleming P, Barth J, Spyropoulos D, Cooley M, et al. Targeted disruption of cubilin reveals essential developmental roles in the structure and function of endoderm and in somite formation. BMC Dev Biol. 2006;6:30 pubmed
    ..Cubilin is a peripheral membrane protein that interacts with the integral membrane proteins megalin and amnionless to mediate ligand endocytosis by absorptive epithelia such as the extraembryonic visceral endoderm (VE)...
  40. Bosco C, Buffet C, Bello M, Rodrigo R, Gutierrez M, García G. Placentation in the degu (Octodon degus): analogies with extrasubplacental trophoblast and human extravillous trophoblast. Comp Biochem Physiol A Mol Integr Physiol. 2007;146:475-85 pubmed
    ..At day 27, the inverted visceral yolk sac is observed and its columnar epithelium immunostained for CK and hPL...
  41. Kanemura H, Satoh T, Bilasy S, Ueda S, Hirashima M, Kataoka T. Impaired vascular development in the yolk sac and allantois in mice lacking RA-GEF-1. Biochem Biophys Res Commun. 2009;387:754-9 pubmed publisher
    ..of VE-cadherin at cell-cell junctions were significantly impaired in the RA-GEF-1 knockout allantois and yolk sac. Rap1 activation as visualized by an activation-specific probe was also diminished by RA-GEF-1 knockout...
  42. Freyer C, Zeller U, Renfree M. Placental function in two distantly related marsupials. Placenta. 2007;28:249-57 pubmed
    ..During the first phase, the embryo obtains nutrients from uterine secretion transferred into the yolk sac. The amount of uterine secretion declines during the second phase up to the time of shell coat rupture...
  43. Zhu J, Wang H, Yang S, Guo L, Li Z, Wang W, et al. Comparison of toxicity of benzene metabolite hydroquinone in hematopoietic stem cells derived from murine embryonic yolk sac and adult bone marrow. PLoS ONE. 2013;8:e71153 pubmed publisher
    ..the effects of hydroquinone (HQ), a major metabolite of benzene in humans and animals, on mouse embryonic yolk sac hematopoietic stem cells (YS-HSCs) and adult bone marrow hematopoietic stem cells (BM-HSCs)...
  44. Matsubara A, Iwama A, Yamazaki S, Furuta C, Hirasawa R, Morita Y, et al. Endomucin, a CD34-like sialomucin, marks hematopoietic stem cells throughout development. J Exp Med. 2005;202:1483-92 pubmed
    ..Notably, in the yolk sac, Endomucin expression separated multipotential hematopoietic cells from committed erythroid progenitors in the ..
  45. Ueno H, Weissman I. Clonal analysis of mouse development reveals a polyclonal origin for yolk sac blood islands. Dev Cell. 2006;11:519-33 pubmed
    ..Here we applied this method to the analysis of embryonic yolk sac blood islands...
  46. Jauniaux E, Johns J, Gulbis B, Spasic Boskovic O, Burton G. Transfer of folic acid inside the first-trimester gestational sac and the effect of maternal smoking. Am J Obstet Gynecol. 2007;197:58.e1-6 pubmed
    ..The objective of the study was to investigate the transfer pathways of folic acid inside the first-trimester gestational sac and to evaluate the impact of maternal smoking...
  47. Yoshimoto M, Porayette P, Glosson N, Conway S, Carlesso N, Cardoso A, et al. Autonomous murine T-cell progenitor production in the extra-embryonic yolk sac before HSC emergence. Blood. 2012;119:5706-14 pubmed publisher
    The extra-embryonic yolk sac (YS) is the first hematopoietic site in the mouse embryo and is thought to generate only primitive erythroid and myeloerythroid progenitor cells before definitive HSC emergence within the embryo on E10.5...
  48. Koyano Nakagawa N, Kweon J, Iacovino M, Shi X, Rasmussen T, Borges L, et al. Etv2 is expressed in the yolk sac hematopoietic and endothelial progenitors and regulates Lmo2 gene expression. Stem Cells. 2012;30:1611-23 pubmed publisher
    ..the endothelial and the hematopoietic lineages first appear during gastrulation in the blood island of the yolk sac. We have previously reported that an Ets variant gene 2 (Etv2/ER71) mutant embryo lacks hematopoietic and ..
  49. Rhee S, Guerrero Zayas M, Wallingford M, Ortíz Pineda P, Mager J, Tremblay K. Visceral endoderm expression of Yin-Yang1 (YY1) is required for VEGFA maintenance and yolk sac development. PLoS ONE. 2013;8:e58828 pubmed publisher
    ..role of YY1, a conditional knock-out (cKO) strategy was used to delete YY1 from the visceral endoderm of the yolk sac and the definitive endoderm of the embryo. cKO embryos display profound yolk sac defects at 9...
  50. Ginhoux F, Merad M. [Microglia arise from extra-embryonic yolk sac primitive progenitors]. Med Sci (Paris). 2011;27:719-24 pubmed publisher
    ..These results identify microglia as an ontogenically distinct population in the mononuclear phagocyte system and have implications for the use of embryonically-derived microglial progenitors for the treatment of various brain disorders...
  51. Nakada T, Hoshijima K, Esaki M, Nagayoshi S, Kawakami K, Hirose S. Localization of ammonia transporter Rhcg1 in mitochondrion-rich cells of yolk sac, gill, and kidney of zebrafish and its ionic strength-dependent expression. Am J Physiol Regul Integr Comp Physiol. 2007;293:R1743-53 pubmed
    ..Here we show that zebrafish Rhcg1, a member of the Rh glycoprotein family, is highly expressed in the yolk sac, gill, and renal tubules...
  52. Sugiyama D, Ogawa M, Nakao K, Osumi N, Nishikawa S, Nishikawa S, et al. B cell potential can be obtained from pre-circulatory yolk sac, but with low frequency. Dev Biol. 2007;301:53-61 pubmed
    ..Here, we successfully generated mouse chimeras by grafting yolk sac (YS) on YS of the host embryos before establishing circulation between YS and embryo proper and cultured the ..
  53. Yadgary L, Yair R, Uni Z. The chick embryo yolk sac membrane expresses nutrient transporter and digestive enzyme genes. Poult Sci. 2011;90:410-6 pubmed publisher
    The yolk sac membrane plays a major role in the transport of nutrients from the yolk contents to the chick embryo. We examined whether the yolk sac membrane expresses genes for nutrient digestion, enzymes, and nutrient transporters...