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Fig. 4. Depletion of Wee2 protein disrupts convergent extension of the paraxial mesoderm during neurulation. (A-C,F) Temporal analysis of Wee2-depleted embryos during neurulation. Embryos were microinjected as in Fig. 2D with CMO (odd panels) or W2MO.1 (even panels), and were allowed to develop until controls reached the indicated stages before being processed for MyoD (A), XNot (B), MA and MHC (C), or Sox3 (F) in situ analysis as indicated. Green arrows indicate a closed blastopore. Lateral limits of paraxial mesoderm (MyoD expression) are indicated by broken red lines. White and yellow arrows indicate lack of anterior neural fold and somitic ridge, respectively. Lateral limits of presumptive neural tissue (Sox3 expression) are indicated by red arrows and vertical lines. (D) The paraxial mesoderm of Wee2-depleted embryos fails to converge towards the midline. Representative CMO and W2MO.1 treated, MyoD stained, stage 18 embryos from 4A were serially sectioned transversely. The anteroposterior positions of the shown sections are indicated by letters in right lower corner of panels as per E. Dorsal is towards the top. Black arrow indicates the forming somitic ridge. (E) Drawing reproduced, with permission, from Nieuwkoop and Faber (Nieuwkoop and Faber, 1994) showing position of cuts in D. |
