PT  - JOURNAL ARTICLE
AU  - Moshiri, Ala
AU  - Reh, Thomas A.
TI  - Persistent Progenitors at the Retinal Margin of <em>ptc</em>+/- Mice
AID  - 10.1523/JNEUROSCI.2980-03.2004
DP  - 2004 Jan 07
TA  - The Journal of Neuroscience
PG  - 229--237
VI  - 24
IP  - 1
4099  - http://www.jneurosci.org/content/24/1/229.short
4100  - http://www.jneurosci.org/content/24/1/229.full
SO  - J. Neurosci.2004 Jan 07; 24
AB  - The hedgehog signaling pathway is a key regulator of neural development, affecting both proliferation and differentiation of neural progenitors. Sonic hedgehog (Shh) is a mitogenic factor for retinal progenitors in vitro. To determine whether this signaling system is important in vivo for regulating retinal progenitor proliferation, we analyzed mice with a single functional allele of the Shh receptor patched (ptc). We found that ptc+/- mice had increased numbers of neural progenitors at every stage of retinal development that we examined. In addition, these mice had persistent progenitors at the retinal margin for up to 3 months of age, reminiscent of the ciliary marginal zone of lower vertebrates. To test whether the progenitors at the retinal margin of ptc+/- mice could be induced to regenerate retinal neurons in response to damage, we bred ptc+/- mice onto a retinal degeneration background (pro23his rhodopsin transgenic) and labeled newly generated cells with combined immunohistochemistry for bromodeoxyuridine and retinal neuron and photoreceptor-specific markers. We found newly generated neurons and photoreceptors at the retinal margin in ptc+/-;pro23his mice. We propose that the Shh pathway may act as a regulator of both prenatal and postnatal retinal growth.