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#Question id: 14838


Sequence of amphibian lens induction postulated by experiments on embryos of the frog Xenopus laevis ; EXCEPT

#Unit 5. Developmental Biology
  1. Unidentified inducers (possibly from the foregut endoderm and cardiac mesoderm) cause the synthesis of the Otx2 transcription factor in the head ectoderm during the late neurula stage.
  2. As the neural folds rise, inducers from the anterior neural plate (including the region that will form the retina) induce Pax6 expression in the anterior ectoderm that can form lens tissue.
  3. As the neural folds rise, inducers from the anterior neural plate (including the region that will form the retina) induce Pax6 expression in the anterior ectoderm that can form lens tissue.
  4. The optic vesicle secretes BMP and FGF family paracrine factors, which induce the synthesis of the Sox transcription factors and initiate observable lens formation