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Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells.

Landry J, Sharov AA, Piao Y, Sharova LV, Xiao H, Southon E, Matta J, Tessarollo L, Zhang YE, Ko MS, Kuehn MR, Yamaguchi TP, Wu C - PLoS Genet. (2008)

Bottom Line: Differentiation of Bptf(-/-) embryonic stem cell lines into embryoid bodies revealed its requirement for development of mesoderm, endoderm, and ectoderm tissue lineages, and uncovered many genes whose activation or repression are Bptf-dependent.We also provide functional and physical links between the Bptf-containing NURF complex and the Smad transcription factors.We conclude that Bptf likely regulates genes and signaling pathways essential for the development of key tissues of the early mouse embryo.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Biochemistry and Molecular Cell Biology, National Cancer Institute, National Institutes of Heath, Bethesda, MD, USA. landrjos@mail.nih.gov

ABSTRACT
We have characterized the biological functions of the chromatin remodeling protein Bptf (Bromodomain PHD-finger Transcription Factor), the largest subunit of NURF (Nucleosome Remodeling Factor) in a mammal. Bptf mutants manifest growth defects at the post-implantation stage and are reabsorbed by E8.5. Histological analyses of lineage markers show that Bptf(-/-) embryos implant but fail to establish a functional distal visceral endoderm. Microarray analysis at early stages of differentiation has identified Bptf-dependent gene targets including homeobox transcriptions factors and genes essential for the development of ectoderm, mesoderm, and both definitive and visceral endoderm. Differentiation of Bptf(-/-) embryonic stem cell lines into embryoid bodies revealed its requirement for development of mesoderm, endoderm, and ectoderm tissue lineages, and uncovered many genes whose activation or repression are Bptf-dependent. We also provide functional and physical links between the Bptf-containing NURF complex and the Smad transcription factors. These results suggest that Bptf may co-regulate some gene targets of this pathway, which is essential for establishment of the visceral endoderm. We conclude that Bptf likely regulates genes and signaling pathways essential for the development of key tissues of the early mouse embryo.

Show MeSH
Bptf mutants are defective in the expression of distal visceral endoderm markers.(A) Wild type embryos were stained in whole mount for Bptf mRNA by in situ RNA hybridization at E4.5, E5.5, and E6.5. Bptf is expressed in the inner cell mass and primitive endoderm at E4.5 and in the embryonic and extra-embryonic tissues in E5.5 and E6.5 embryos. Abbreviations: ve, visceral endoderm; ee, embryonic ectoderm; xe, extra-embryonic ectoderm; DVE, distal visceral endoderm. (B) Whole mount in situ RNA hybridization analysis of wild type and mutant E4.5 and E5.5 embryos for Nanog, Gata6, Lefty1, Cer1, Hex1, and Nodal expression. At E4.5, Bptf mutant embryos show expression of Nanog, Gata6, Lefty1, and Hex1, suggesting that the primitive endoderm and inner cell mass is present in Bptf mutants. Mutant E5.5 embryos are defective in the expression of DVE markers Cer1 and Hex1, suggesting that mutants cannot form the DVE. Interestingly, the general visceral endoderm marker GATA6 is not expressed in the VE but rather in the embryonic ectoderm at E5.5.
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pgen-1000241-g002: Bptf mutants are defective in the expression of distal visceral endoderm markers.(A) Wild type embryos were stained in whole mount for Bptf mRNA by in situ RNA hybridization at E4.5, E5.5, and E6.5. Bptf is expressed in the inner cell mass and primitive endoderm at E4.5 and in the embryonic and extra-embryonic tissues in E5.5 and E6.5 embryos. Abbreviations: ve, visceral endoderm; ee, embryonic ectoderm; xe, extra-embryonic ectoderm; DVE, distal visceral endoderm. (B) Whole mount in situ RNA hybridization analysis of wild type and mutant E4.5 and E5.5 embryos for Nanog, Gata6, Lefty1, Cer1, Hex1, and Nodal expression. At E4.5, Bptf mutant embryos show expression of Nanog, Gata6, Lefty1, and Hex1, suggesting that the primitive endoderm and inner cell mass is present in Bptf mutants. Mutant E5.5 embryos are defective in the expression of DVE markers Cer1 and Hex1, suggesting that mutants cannot form the DVE. Interestingly, the general visceral endoderm marker GATA6 is not expressed in the VE but rather in the embryonic ectoderm at E5.5.

Mentions: As a first step in the molecular analysis of Bptf in embryonic development we examined the expression of Bptf using in situ RNA hybridization. We observed expression in the inner cell mass (ICM) and primitive endoderm at E4.5 and all embryonic tissues at E5.5 and E6.5. Interestingly we do not observe Bptf expression in the visceral endoderm at E5.5 and E6.5 (Figure 2A). We also monitored the activity of the β-galactosidase moiety of the Bptf–β-Geo fusion protein in heterozygous mice. Consistent with our in situ analysis a histochemical analysis of whole mounts showed that Bptf–β-Geo is expressed in the embryo proper at E5.5, E6.5 and E7.5 (Figure S8A, S8B, S8C, S8D, S8E, S8F, S8G). Further analysis of histological sections revealed that Bptf–β-Geo expression at E7.5 is primarily confined to the embryonic ectoderm, with reduced levels in mesoderm and no expression in the visceral endoderm (Figure S8A′, Figure S8B′). At subsequent stages, from E7.5 to E13.5, histochemical analysis of whole mounts showed widespread Bptf–β-Geo expression in the developing embryo (Figure S9A, Figure S9B, S9C, S9D, S9E, S9F). This temporal correlation between the earliest stages of Bptf expression and the stages when the mutant phenotype is revealed, suggests that there could be an essential requirement for Bptf as early as E4.5.


Essential role of chromatin remodeling protein Bptf in early mouse embryos and embryonic stem cells.

Landry J, Sharov AA, Piao Y, Sharova LV, Xiao H, Southon E, Matta J, Tessarollo L, Zhang YE, Ko MS, Kuehn MR, Yamaguchi TP, Wu C - PLoS Genet. (2008)

Bptf mutants are defective in the expression of distal visceral endoderm markers.(A) Wild type embryos were stained in whole mount for Bptf mRNA by in situ RNA hybridization at E4.5, E5.5, and E6.5. Bptf is expressed in the inner cell mass and primitive endoderm at E4.5 and in the embryonic and extra-embryonic tissues in E5.5 and E6.5 embryos. Abbreviations: ve, visceral endoderm; ee, embryonic ectoderm; xe, extra-embryonic ectoderm; DVE, distal visceral endoderm. (B) Whole mount in situ RNA hybridization analysis of wild type and mutant E4.5 and E5.5 embryos for Nanog, Gata6, Lefty1, Cer1, Hex1, and Nodal expression. At E4.5, Bptf mutant embryos show expression of Nanog, Gata6, Lefty1, and Hex1, suggesting that the primitive endoderm and inner cell mass is present in Bptf mutants. Mutant E5.5 embryos are defective in the expression of DVE markers Cer1 and Hex1, suggesting that mutants cannot form the DVE. Interestingly, the general visceral endoderm marker GATA6 is not expressed in the VE but rather in the embryonic ectoderm at E5.5.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2570622&req=5

pgen-1000241-g002: Bptf mutants are defective in the expression of distal visceral endoderm markers.(A) Wild type embryos were stained in whole mount for Bptf mRNA by in situ RNA hybridization at E4.5, E5.5, and E6.5. Bptf is expressed in the inner cell mass and primitive endoderm at E4.5 and in the embryonic and extra-embryonic tissues in E5.5 and E6.5 embryos. Abbreviations: ve, visceral endoderm; ee, embryonic ectoderm; xe, extra-embryonic ectoderm; DVE, distal visceral endoderm. (B) Whole mount in situ RNA hybridization analysis of wild type and mutant E4.5 and E5.5 embryos for Nanog, Gata6, Lefty1, Cer1, Hex1, and Nodal expression. At E4.5, Bptf mutant embryos show expression of Nanog, Gata6, Lefty1, and Hex1, suggesting that the primitive endoderm and inner cell mass is present in Bptf mutants. Mutant E5.5 embryos are defective in the expression of DVE markers Cer1 and Hex1, suggesting that mutants cannot form the DVE. Interestingly, the general visceral endoderm marker GATA6 is not expressed in the VE but rather in the embryonic ectoderm at E5.5.
Mentions: As a first step in the molecular analysis of Bptf in embryonic development we examined the expression of Bptf using in situ RNA hybridization. We observed expression in the inner cell mass (ICM) and primitive endoderm at E4.5 and all embryonic tissues at E5.5 and E6.5. Interestingly we do not observe Bptf expression in the visceral endoderm at E5.5 and E6.5 (Figure 2A). We also monitored the activity of the β-galactosidase moiety of the Bptf–β-Geo fusion protein in heterozygous mice. Consistent with our in situ analysis a histochemical analysis of whole mounts showed that Bptf–β-Geo is expressed in the embryo proper at E5.5, E6.5 and E7.5 (Figure S8A, S8B, S8C, S8D, S8E, S8F, S8G). Further analysis of histological sections revealed that Bptf–β-Geo expression at E7.5 is primarily confined to the embryonic ectoderm, with reduced levels in mesoderm and no expression in the visceral endoderm (Figure S8A′, Figure S8B′). At subsequent stages, from E7.5 to E13.5, histochemical analysis of whole mounts showed widespread Bptf–β-Geo expression in the developing embryo (Figure S9A, Figure S9B, S9C, S9D, S9E, S9F). This temporal correlation between the earliest stages of Bptf expression and the stages when the mutant phenotype is revealed, suggests that there could be an essential requirement for Bptf as early as E4.5.

Bottom Line: Differentiation of Bptf(-/-) embryonic stem cell lines into embryoid bodies revealed its requirement for development of mesoderm, endoderm, and ectoderm tissue lineages, and uncovered many genes whose activation or repression are Bptf-dependent.We also provide functional and physical links between the Bptf-containing NURF complex and the Smad transcription factors.We conclude that Bptf likely regulates genes and signaling pathways essential for the development of key tissues of the early mouse embryo.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Biochemistry and Molecular Cell Biology, National Cancer Institute, National Institutes of Heath, Bethesda, MD, USA. landrjos@mail.nih.gov

ABSTRACT
We have characterized the biological functions of the chromatin remodeling protein Bptf (Bromodomain PHD-finger Transcription Factor), the largest subunit of NURF (Nucleosome Remodeling Factor) in a mammal. Bptf mutants manifest growth defects at the post-implantation stage and are reabsorbed by E8.5. Histological analyses of lineage markers show that Bptf(-/-) embryos implant but fail to establish a functional distal visceral endoderm. Microarray analysis at early stages of differentiation has identified Bptf-dependent gene targets including homeobox transcriptions factors and genes essential for the development of ectoderm, mesoderm, and both definitive and visceral endoderm. Differentiation of Bptf(-/-) embryonic stem cell lines into embryoid bodies revealed its requirement for development of mesoderm, endoderm, and ectoderm tissue lineages, and uncovered many genes whose activation or repression are Bptf-dependent. We also provide functional and physical links between the Bptf-containing NURF complex and the Smad transcription factors. These results suggest that Bptf may co-regulate some gene targets of this pathway, which is essential for establishment of the visceral endoderm. We conclude that Bptf likely regulates genes and signaling pathways essential for the development of key tissues of the early mouse embryo.

Show MeSH