Figure 2

RFP expression in CAG::mRFP1 preimplantation stage embryos. Single CAG::mRFP1 Tg/+ zygote including the second polar body (A–E). A single x-y section taken from a z-stack, bright field image (A), overlay single confocal section of red fluorescence and bright field (B), red fluorescence channel only (left panel in C). Representative x-y sections taken from the same z-stack that was used to render volumes shown D and E. Rendered z-stack (3D reconstruction) of the whole zygote and second polar body (PB) shown in the previous panels and rotated through 180 degrees counter-clockwise (D). Rendered z-stack (3D reconstruction) of a computationally bisected zygote shown in the previous panels and rotated through 180 degrees counter-clockwise (E). Note that the zygote is not spherical, it has a clear short and long axis (lines with arrows), and the fertilization cone resulting from the site of sperm entry is also clearly evident as a protrusion (asterix). Non-transgenic, CAG::EGFP Tg/+, CAG::mRFP1 Tg/+ embryos recovered at E3.0 and representing compacted morulae through to blastocyst stages (F–I). Bright filed (F), red fluorescence channel (G), green fluorescence channel (H) and green and red fluorescence channel overlay (I). Single CAG::mRFP1 Tg/+ blastocyst (J–M). A single x-y section taken from a z-stack, bright field image (J), overlay single confocal section of red fluorescence and bright field (K), red fluorescence channel only (left panel in L). Representative x-y sections taken from the same z-stack that was used to render the volume shown in M. Rendered z-stack (3D reconstruction) of a computationally bisected blastocyst and rotated through 180 degrees counter-clockwise (M). Note that individual cells of the trophectoderm can be distinguished. The RGB colored vector on the bottom left of the 3D reconstruction rotations depicts the x-axis in green, y-axis in red and z-axis in blue.