Prenatal retinal neurospheres lose VSX2 expression over time in culture.

<p>KI67+ hRPCs in the outer neuroblastic layer of 96 day human prenatal retina co-express the neural stem cell markers (<b>A</b>) NESTIN and (<b>B</b>) SOX2. Short term prenatal retinal neurosphere cultures also contain abundant (<b>C</b>) KI67+/NESTIN+ and (<b>D</b>) KI67+/SOX2+ hRPCs. Nearly all VSX2+ hRPCs in short term prenatal retinal neurosphere cultures co-label with (<b>E</b>) NESTIN and (<b>F</b>) SOX2. Prenatal retinal neurosphere cultures (n = 5) from 79–108 day gestation tissue were sampled at 1 week, 1 month, and 2 months. After 2 months, very little VSX2 immunostaining is detected, although (<b>G</b>) NESTIN and (<b>H</b>) SOX2 remain highly expressed. The percentage of VSX2, KI67, NESTIN, and SOX2 immunopositive cells were quantified (<b>I</b>) in short term cultures and (<b>J</b>) over a 2 month period. Nuclei were visualized with DAPI and cell count data is expressed as % immunopositive cells. Scale bars: 50 μm (panels A,B); 20 μm (panels C-H).