Chordin Like Protein 1 (CHRDL1)

In the visual system, the establishment of the anteroposterior and dorsoventral axes in the retina and tectum during development is important for topographic retinotectal projection.

Ventroptin, an antagonist of bone morphogenic protein-4, which is mainly expressed in the ventral retina, not only with a ventral high-dorsal low gradient but also with a nasal high-temporal low gradient at later stages. Misexpression of ventroptin altered expression patterns of several topographic genes in the retina and projection of the retinal axons to the tectum along both axes. Thus, the topographic retinotectal projection appears to be specified by the double-gradient molecule ventroptin along the 2 axes. The chick ventroptin protein contains a putative signal peptide and 3 cysteine-rich repeats.