Molecular evidence for a critical period in mural trophoblast development in bovine blastocysts.
Embryonic and extra-embryonic lineages are separated at the blastocyst stage in the mouse at the onset of implantation but well ahead of implantation in most mammals. To provide information on the development of the trophoblast lineage in late-implanting bovine embryos, we combined the use of molecular markers defining embryonic and extra-embryonic lineages in the mouse with a transcriptomic approach dedicated to the early steps of the elongation process, a characteristic feature of blastocyst development in ruminants. In this study, we present molecular evidence for differences between the cow and the mouse in the programming of trophoblast differentiation. This different programming encompasses: (i) the expression of epiblast specifying genes (Oct-4, Nanog) in bovine trophoblast cells at the onset of elongation, (ii) the transcription of proliferation markers in early elongating blastocysts, (iii) the early detection of trophoblast-specific transcripts related to extra-embryonic tissue's differentiation (Hand1, Ets2, IFN-tau) and (iv) the identification of a new transcript (c12) which displays a reciprocal pattern to that of Oct-4 and Nanog genes in the embryonic cells and for which no equivalent has thus far been found in the mouse. Altogether, these results tended to show that early elongation is a critical transition in bovine trophoblast development.
Degrelle
Séverine A
SA
UMR INRA/ENVA/CNRS Biologie du Développement et de la Reproduction, 78352 Jouy-en-Josas cedex, France.
Campion
Evelyne
E
Cabau
Cédric
C
Piumi
François
F
Reinaud
Pierrette
P
Richard
Christophe
C
Renard
Jean-Paul
JP
Hue
Isabelle
I
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D001755:Blastocyst / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D002417:Cattle; D002454:Cell Differentiation; D019070:Cell Lineage; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D015723:Gene Library; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D007370:Interferon Type I / Q000235:genetics / Q000378:metabolism; D051379:Mice; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3 / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D011257:Pregnancy Proteins / Q000235:genetics / Q000378:metabolism; D050787:Proto-Oncogene Protein c-ets-2 / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity; D014327:Trophoblasts / Q000166:cytology / Q000378:metabolism / Q000502:physiology*
D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D007370:Interferon Type I; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3; D011257:Pregnancy Proteins; D050787:Proto-Oncogene Protein c-ets-2; C494070:Ets2 protein, mouse; C475540:Nanog protein, mouse; C097341:helix-loop-helix protein, eHAND; C020947:interferon tau