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Lens and retina formation require expression of Pitx3 in Xenopus pre‐lens ectoderm
Author(s) -
Khosrowshahian Farhad,
Wolanski Marian,
Chang Wing Y.,
Fujiki Kazuhiro,
Jacobs Larry,
Crawford Michael J.
Publication year - 2005
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/dvdy.20540
Subject(s) - eye development , ectoderm , biology , lens (geology) , anophthalmia , microbiology and biotechnology , retina , morpholino , microphthalmia , mesoderm , neuroectoderm , xenopus , anatomy , embryogenesis , neuroscience , zebrafish , embryo , genetics , embryonic stem cell , transcription factor , paleontology , gene
Pitx3 is expressed in tissues fated to contribute to eye development, namely, neurula stage ectoderm and prechordal mesoderm, then presumptive lens ectoderm, placode, and finally lens. Pitx3 overexpression alters lens, optic cup, optic nerve, and diencephalon development. Many of the induced anomalies are attributable to midline deficits; however, as assessed by molecular markers, ectopic Pitx3 appears to temporarily enlarge the lens field. These changes are usually insufficient to generate either ectopic lenses to enlarge the eye that eventually differentiates. Conversely, use of a repressor chimera or of antisense morpholinos alters early expression of marker genes, and later inhibits lens development, thereby abrogating retinal induction. Reciprocal grafting experiments using wild‐type and morpholino‐treated tissues demonstrate that Pitx3 expression in the presumptive lens ectoderm is required for lens formation. Contradictory to recent assertions that retina can form in the absence of a lens, the expression of Pitx3 in the presumptive lens ectoderm is critical for retina development. Developmental Dynamics 234:577–589, 2005. © 2005 Wiley‐Liss, Inc.