Fig. 3

Fig. 3

Vsx1+ progenitors in the unlaminated and laminated region exhibit distinct cell biological behaviors

A. Concurrent visualization of nucleokinesis in a vsx1⁺ progenitor in the laminated retina (Q26; UAS:memYFP, upper panels) and the cell cycle stage (mOrange2‐PCNA mRNA, lower panels) by in vivo time‐lapse confocal imaging. Progenitor soma is pseudo‐colored cyan in YFP channel and outlined in cyan in mOrange channel. Scale bar: 10 μm.

B. Nuclear movement of vsx1⁺ progenitors in the unlaminated region (vsx1:GFP) of the retina prior to mitosis at the apical surface (orange circle). Seven cells, five fish. Black line represents the average position of all vsx1⁺ progenitors prior to mitosis in unlaminated regions.

C. Nuclear trajectories of vsx1⁺ progenitors in the laminated region that undergo mitosis at the INL/OPL interface (cyan circle, left panel) and post‐mitotic BCs in their vicinity (right panel). In the time interval during which trajectories were tracked, all 12 vsx1⁺ progenitors move to the INL/OPL interface prior to mitosis; 8 of 12 post‐mitotic surrounding BCs do so (five fish). Black lines represent the average position of all vsx1⁺ progenitors prior to mitosis in laminated regions (left panel) or of the post‐mitotic BCs (right panel).

D. Centrosomes (centrin4‐YFP mRNA, grayscale) of a vsx1⁺ progenitor (magenta mask, Q19) and post‐mitotic BCs in the laminated region concurrently translocate to the OPL and remain clustered there. The centrosome of the highlighted vsx1⁺ progenitor is pseudo‐colored green. Scale bar: 10 μm.

E. Continuation of the time‐lapse from (D) (centrosomes not depicted). The vsx1⁺ progenitor (magenta mask) shows transient lateral arborizations in the synaptic layers as wide as its soma (see brackets at −210′, −165′). A further example can be seen in (A) (see brackets at −67′).