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Updated: Jun 14, 2025
Quantitative Analysis of Protein Expression to Study Lineage Specification in Mouse Preimplantation Embryos
Published on: February 22, 2016
Protocol for immunofluorescence detection and quantification of phosphorylated SMAD proteins in human blastocysts
Todd Fallesen1, A Sophie Brumm2
1Crick Advanced Light Microscopy, The Francis Crick Institute, London, UK.
Abstract:
The transforming growth factor β (TGF-β) signaling superfamily includes NODAL and bone morphogenetic protein (BMP) signaling, which lead to the phosphorylation of different SMAD proteins and regulate key developmental events. Here, we present a protocol for immunofluorescence detection of phosphorylated SMAD proteins combined with other transcription factors in pre-implantation human embryos. We describe steps for segmenting the nuclei in human blastocysts and quantifying their immunofluorescence intensity. This protocol can be adapted to investigate TGF-β superfamily signaling activity in other mammalian embryos or in vitro models of their development. For complete details on the use and execution of this protocol, please refer to Brumm et al.1.
Insights
This study details a protocol for detecting phosphorylated SMAD proteins in human embryos to understand transforming growth factor β (TGF-β) signaling. The method allows quantification of signaling activity during early development.
Area of Science:
- Developmental Biology
- Cell Signaling
- Molecular Biology
Background:
- Transforming growth factor β (TGF-β) signaling is crucial for embryonic development.
- Key pathways include NODAL and bone morphogenetic protein (BMP) signaling.
- These pathways involve the phosphorylation of SMAD proteins.
Purpose of the Study:
- To present a protocol for immunofluorescence detection of phosphorylated SMAD proteins in human embryos.
- To enable combined detection with other transcription factors.
- To quantify TGF-β superfamily signaling activity in pre-implantation embryos.
Main Methods:
- Immunofluorescence detection of phosphorylated SMAD proteins.
- Segmentation of nuclei in human blastocysts.
- Quantification of immunofluorescence intensity.
- Combined detection with transcription factors.
Main Results:
- A detailed protocol for analyzing TGF-β signaling in human embryos is provided.
- The method allows for nuclear segmentation and intensity quantification.
- This technique facilitates the study of signaling pathways in early development.
Conclusions:
- The developed protocol enables robust analysis of TGF-β superfamily signaling in human pre-implantation embryos.
- This method can be adapted for other mammalian embryos and in vitro models.
- It provides a valuable tool for investigating developmental signaling events.
