Fig 8. A model for glia overmigration when retinal progenitors fitness is compromised by loss of dMyc.

Decreased levels of dMyc in retinal progenitors induce JNK activation and Mmp1 expression in eye disc cells. In a non-autonomous manner glia overmigrates anteriorly to the MF where it displays increased proliferation in response to autonomous pMad activation. JNK activation in the eye disc per se is sufficient to produce Mmp1 and induce glia overmigration but not to stimulate glia proliferation.