Figure 4

Use of the XYClone laser for cell ablations in C. fornicata embryos. (A) Diagram showing arrangement of the XYClone laser objective and embryo (small dot) mounted under a raised coverslip supported by glass feet of the appropriate thickness. The approximate thicknesses of commercial numbered coverslips and that of a typical glass slide are provided for reference. See Methods section for explanation on the use of the laser and construction of raised coverslips. (B) Photograph showing XYClone laser objective mounted in the upright configuration on a Zeiss compound microscope. (C,D) Photomicrographs before and after laser ablation of the 1mL and 1mR blastomeres shortly after their birth. (E,F) Photomicrographs before and after laser ablation of the 1mL and 1mR blastomeres shortly after the birth of the 2mL and 2mR cells. A cloud of faintly fluorescent cell debris can be seen dispersing from the embryo. (G,H) Photomicrographs before and after laser ablation of the 2mL blastomere shortly after their birth. (I,J) Photomicrographs before and after laser ablation of the 2mR¹ blastomere. A cloud of fluorescent debris can be seen dispersing from the embryo. (K,L) Photomicrographs before and after laser ablation of the 2mR² blastomere. (M,N) Photomicrographs before and after laser ablation of the 4mL blastomere. A cloud of fluorescent debris can be seen dispersing from the embryo. Gray labels signify the location of missing cells or their dispersing debris. The identities of certain living cells (in white) are shown for reference. Scale bar in N equals 40 μm.