TY - JOUR
T1 - Oct4 is required for lineage priming in the developing inner cell mass of the mouse blastocyst
AU - Le Bin, Gloryn Chia
AU - Muñoz-Descalzo, Silvia
AU - Kurowski, Agata
AU - Leitch, Harry
AU - Lou, Xinghua
AU - Mansfield, William
AU - Etienne-Dumeau, Charles
AU - Grabole, Nils
AU - Mulas, Carla
AU - Niwa, Hitoshi
AU - Hadjantonakis, Anna Katerina
AU - Nichols, Jennifer
PY - 2014/3/1
Y1 - 2014/3/1
N2 - The transcription factor Oct4 is required in vitro for establishment and maintenance of embryonic stem cells and for reprogramming somatic cells to pluripotency. In vivo, it prevents the ectopic differentiation of early embryos into trophoblast. Here, we further explore the role of Oct4 in blastocyst formation and specification of epiblast versus primitive endoderm lineages using conditional genetic deletion. Experiments involving mouse embryos deficient for both maternal and zygotic Oct4 suggest that it is dispensable for zygote formation, early cleavage and activation of Nanog expression. Nanog protein is significantly elevated in the presumptive inner cell mass of Oct4 null embryos, suggesting an unexpected role for Oct4 in attenuating the level of Nanog, which might be significant for priming differentiation during epiblast maturation. Induced deletion of Oct4 during the morula to blastocyst transition disrupts the ability of inner cell mass cells to adopt lineage-specific identity and acquire the molecular profile characteristic of either epiblast or primitive endoderm. Sox17, a marker of primitive endoderm, is not detected following prolonged culture of such embryos, but can be rescued by provision of exogenous FGF4. Interestingly, functional primitive endoderm can be rescued in Oct4-deficient embryos in embryonic stem cell complementation assays, but only if the host embryos are at the preblastocyst stage. We conclude that cell fate decisions within the inner cell mass are dependent upon Oct4 and that Oct4 is not cellautonomously required for the differentiation of primitive endoderm derivatives, as long as an appropriate developmental environment is established.
AB - The transcription factor Oct4 is required in vitro for establishment and maintenance of embryonic stem cells and for reprogramming somatic cells to pluripotency. In vivo, it prevents the ectopic differentiation of early embryos into trophoblast. Here, we further explore the role of Oct4 in blastocyst formation and specification of epiblast versus primitive endoderm lineages using conditional genetic deletion. Experiments involving mouse embryos deficient for both maternal and zygotic Oct4 suggest that it is dispensable for zygote formation, early cleavage and activation of Nanog expression. Nanog protein is significantly elevated in the presumptive inner cell mass of Oct4 null embryos, suggesting an unexpected role for Oct4 in attenuating the level of Nanog, which might be significant for priming differentiation during epiblast maturation. Induced deletion of Oct4 during the morula to blastocyst transition disrupts the ability of inner cell mass cells to adopt lineage-specific identity and acquire the molecular profile characteristic of either epiblast or primitive endoderm. Sox17, a marker of primitive endoderm, is not detected following prolonged culture of such embryos, but can be rescued by provision of exogenous FGF4. Interestingly, functional primitive endoderm can be rescued in Oct4-deficient embryos in embryonic stem cell complementation assays, but only if the host embryos are at the preblastocyst stage. We conclude that cell fate decisions within the inner cell mass are dependent upon Oct4 and that Oct4 is not cellautonomously required for the differentiation of primitive endoderm derivatives, as long as an appropriate developmental environment is established.
KW - Blastocyst
KW - Chimaera
KW - Nanog
KW - Oct4 (pou5f1)
KW - Primitive endoderm
KW - Sox17
UR - http://www.scopus.com/inward/record.url?scp=84894067021&partnerID=8YFLogxK
U2 - 10.1242/dev.096875
DO - 10.1242/dev.096875
M3 - Article
C2 - 24504341
AN - SCOPUS:84894067021
SN - 0950-1991
VL - 141
SP - 1001
EP - 1010
JO - Development (Cambridge)
JF - Development (Cambridge)
IS - 5
ER -