Comparative study of glial fibrillary acidic protein (GFAP)-like immunoreactivity in the retina of some representative vertebrates.

: A polyclonal glial fibrillary acidic protein (GFAP) antiserum was used to study the distribution of GFAP-like immunoreactivity in the retina of adult vertebrates (teleosts, amphibians, reptiles, birds and mammals). GFAP-positive Muller cells were demonstrated in all the species studied, although with different degrees and patterns of immunoreactivity. In nonmammalian vertebrates, Muller cells were the only immunoreactive retinal elements. The staining was located throughout the retina of the species examined, with the exception of the rabbit, which exhibited regional variability in the expression of GFAP. The data indicate that GFAP expression in retinal Muller cells is a common feature of a wide variety of adult vertebrate species.