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Title: Spemann and Mangold Blastopore Experiment Post by: ppk on May 6, 2011 In a now classic experiment, Spemann and Mangold took cells from the dorsal lip of the blastopore from one frog embryo (the donor) and transplanted them to an area opposite the dorsal lip in another frog embryo (the host). As a result, the host embryo developed two heads, one at the site of the “new” or transplanted dorsal lip and the other at the site of the host’s original dorsal lip. A thorough examination indicated that the second head was formed from host cells.
Which of the following developmental cues or mechanisms was most likely the trigger (or cause) for the generation of the second head. Explain your answer. a. cytoplasmic determinants that are unequally distributed in the host embryo b. gradients set up in the egg that gave rise to the host embryo c. hox genes (or homeobox genes) present in the embryo receiving the transplant d. cell-cell signalling between the transplanted dorsal lip and the host embryo e. all of the above Title: Re: Spemann and Mangold Blastopore Experiment Post by: duddy on May 7, 2011 d - If the donor cells had not been transplanted to the host, the host would have developed normally. As a result, the altered development must have been triggered by some chemical or cell-cell signal from the transplanted or donor tissue.
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