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Genetic pathway adaptation and eye development in the Iberian Mole
Author(s) -
Collinson Jon Martin
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.419.1
Subject(s) - lens (geology) , biology , mole , pax6 , fossorial , crystallin , phenotype , microbiology and biotechnology , anatomy , gene , genetics , zoology , biochemistry , paleontology , transcription factor
We have studied eye development in the Iberian mole Talpa occidentalis , and present the first molecular embryological study of the eyes of any fossorial mammal. Although permanently closed, the eye potentially retains function, with transparent cornea and lens, and a fully differentiated retina that projects to an optic chiasm. In other model vertebrates, genetic pathways controlling lens development robustly compartmentalise the lens into a simple, undifferentiated, proliferative anterior epithelium, and quiescent, anuclear, terminally differentiated posterior lens fibres. These pathways are not as robust in the mole, and lead to loss of the anterior epithelial phenotype and only partial differentiation of the lens fibres, which continue to express 'epithelial' genes. FOXE3‐positive lens fibres continue to proliferate within the posterior compartment of the embryonic lens, and the undifferentiated status of the anterior epithelial cells was compromised: most of them undergo apoptosis. Furthermore, beta‐crystallin and PROX1 expression patterns are abnormal and our data suggest that genes encoding beta‐crystallins are not directly regulated by PAX6, c‐MAF and PROX1 in the Iberian mole, as they are in other model vertebrates. Paradigms of genetic regulatory networks developed in other vertebrates therefore appear not to hold true for the Iberian mole.