Das, T., Payer, B., Cayouette, M., and Harris, W.A. (2003) In vivo time-lapse imaging of cell divisions during neurogenesis in the developing zebrafish retina. Neuron. 37(4):597-609.
Asymmetric cell division has been proposed to be a mechanism for generating cell fate diversity. Evidence in both vertebrates and invertebrates has suggested that division of neuroblasts along the apico-basal axis allows for unequal segregation of cell fate determinants and consequently distinct cell fates for the resulting
daughter cells. Here, Das et al. used in vivo two-photon imaging to reconstruct cell divisions in the zebrafish retina and show that, surprisingly, there are no apico-basal cell divisions in the zebrafish retina during the period of neurogenesis. Rather, the period of neurogenesis correlates with an unexpected shift in orientation of cell division from central-peripheral to circumferential. Further, in mutants that exhibit delayed timing of neurogenesis and differentiation, this shift is also delayed, suggesting a role for this shift in initiating neurogenesis in the zebrafish retina.