RT Journal Article T1 Expression and function of the LIM-homeodomain transcription factor Islet-1 in the developing and mature vertebrate retina A1 Bejarano Escobar, Ruth A1 Álvarez Hernán, Guadalupe A1 Morona Arribas, Ruth A1 González Gallegos, Agustín A1 Martín Partido, Gervasio A1 Francisco Morcillo, Javier AB The LIM-homeodomain transcription factor Islet-1 (Isl1) has been widely used as a marker of different subtypes of neurons in the developing and mature retina of vertebrates. During retinal neurogenesis, early Isl1 expression is detected in the nuclei of neuroblasts that give rise to ganglion, amacrine, bipolar, and horizontal cells. In the mature retina, Isl1 expression is restricted to the nuclei of ganglion cells, cholinergicamacrine cells, ON-bipolar cells, and subpopulations of horizontal cells. Recent studies have explored the functional mechanisms of Isl1 during specification and differentiation of these retinal cell types. Thus, conditional inactivation of Isl1 in the developing mouse retina disrupts retinal function, and also results in optic nerve hypoplasia, marked reductions in mature ganglion, amacrine, and bipolar cells, and a substantial increase in horizontal cells. Furthermore, conditional knockout shows delayed ganglion cell axon growth, ganglion cell axon guidance error, and ganglion cell nerve fiber defasciculation. These data together suggest a possible role for Isl1 in the early differentiation and maintenance of different vertebrate retinal cell types. This review examines whether the expression pattern of Isl1 during vertebrate retinal development is conserved across vertebrate species, and discusses current understanding of the developmental functions of Isl1 in retinogenesis. PB Science Direct SN 0014-4835 YR 2015 FD 2015 LK https://hdl.handle.net/20.500.14352/35417 UL https://hdl.handle.net/20.500.14352/35417 LA eng NO Ministerio de Ciencia y Tecnología NO Junta de Extremadura DS Docta Complutense RD 10 abr 2025