Figure 4

LD show dynamic behaviour during development. (A) Extended focus projections and (B) optical sections of an embryo imaged from the morula to blastocyst stage. LD move actively within the embryo in the course of development, and gradually become fewer in number and larger. (C) 3D Opacity rendering of LD showing them merging to form larger LD. (D, D') Two different 3D views of several LD, showing that larger LD appear to be aggregates of several smaller LD. Corresponding LD are numbered in the two views, and the orientation is shown at bottom left. One can see that LD aggregates appear irregular because they are composed of several bodies. Banding and stretching of LD along the Z axis in (D') are rendering artefacts. (D'') Optical section of the LD in (D), showing that larger LD are aggregates of smaller LD. LD numbers correspond to those in (D). (E) Tracks of representative LD (magenta lines) over a one hour period. LD do not appear to move in a coordinated manner across the embryo. Their tracks are convoluted to varying extents. Scale bar in (A) = 20 μm and applies to (A and B). Scale bar in (D'') = 10 μm and in (E) = 20 μm