Strip1 regulates retinal ganglion cell survival by suppressing Jun-mediated apoptosis to promote retinal neural circuit formation

For journal club, we read a paper from Dr. Mai Ahmed who recently published her PhD work in eLife, titled “Strip1 regulates retinal ganglion cell survival by suppressing Jun-mediated apoptosis to promote retinal neural circuit formation”. This research came from Dr. Ichiro Masai’s lab at the Okinawa Institute of Science and Technology Graduate University (OIST).

Dr. Ahmed et al. sought to investigate how the complex organization of the retina properly develops by utilizing diverse approaches with zebrafish including mutagenesis screening, morpholino knockdowns, confocal imaging, transplantation, RNA-seq, and more. She found that in strip1 mutants, the inner plexiform layer (IPL) is severely disrupted due to cell death of retinal ganglion cells (RGCs). With this loss, cells from other layers (including amacrine and bipolar cells) improperly enter the RGC layer and disrupt the IPL. So how does strip1 normally ensure RGC survival? Dr. Ahmed first showed that strip1 acts cell autonomously on RGCs along with an interacting partner strn3:  together, these proteins suppress the action of the proapoptotic protein Jun in RGCs. Yet when RGC survival is rescued by Bcl2 overexpression in strip1 mutants, an ectopic IPL-like forms with little RGC innervation, revealing an additional patterning function of strip1 in RGCs.
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Dr. Ahmed has shared a wonderful story of retinal development that is well-worth the read. We look forward to seeing more of her work as a Junior Research Fellow at OIST.