title: Quantitative Analysis of Protein Expression to Study Lineage Specification in Mouse Preimplantation Embryos.
abstract: This protocol presents a method to perform quantitative, single-cell in situ analyses of protein expression to study lineage specification in mouse preimplantation embryos. The procedures necessary for embryo collection, immunofluorescence, imaging on a confocal microscope, and image segmentation and analysis are described. This method allows quantitation of the expression of multiple nuclear markers and the spatial (XYZ) coordinates of all cells in the embryo. It takes advantage of MINS, an image segmentation software tool specifically developed for the analysis of confocal images of preimplantation embryos and embryonic stem cell (ESC) colonies. MINS carries out unsupervised nuclear segmentation across the X, Y and Z dimensions, and produces information on cell position in three-dimensional space, as well as nuclear fluorescence levels for all channels with minimal user input. While this protocol has been optimized for the analysis of images of preimplantation stage mouse embryos, it can easily be adapted to the analysis of any other samples exhibiting a good signal-to-noise ratio and where high nuclear density poses a hurdle to image segmentation (e.g., expression analysis of embryonic stem cell (ESC) colonies, differentiating cells in culture, embryos of other species or stages, etc.).
authors.affiliation: Developmental Biology Program, Sloan Kettering Institute.
authors.forename: Nestor
authors.initials: N
authors.lastname: Saiz
authors.affiliation: Developmental Biology Program, Sloan Kettering Institute.
authors.forename: Minjung
authors.initials: M
authors.lastname: Kang
authors.affiliation: Developmental Biology Program, Sloan Kettering Institute.
authors.forename: Nadine
authors.initials: N
authors.lastname: Schrode
authors.affiliation: Developmental Biology Program, Sloan Kettering Institute.
authors.forename: Xinghua
authors.initials: X
authors.lastname: Lou
authors.affiliation: Developmental Biology Program, Sloan Kettering Institute; hadjanta@mskcc.org.
authors.forename: Anna-Katerina
authors.initials: AK
authors.lastname: Hadjantonakis
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology*; D053595:Embryonic Stem Cells / Q000378:metabolism / Q000502:physiology*; D005455:Fluorescent Antibody Technique; D051379:Mice; D008853:Microscopy / Q000379:methods; D011499:Protein Processing, Post-Translational / Q000502:physiology*; D011506:Proteins / Q000378:metabolism*; D040901:Proteomics / Q000379:methods; D012984:Software
chemical_list: D011506:Proteins