The Mangold and Spemann experiment Flashcards
Spemann-Mangold organiser experiment
This was a study conducted in the early 20th century by german embryologists Hans Spemann and Hilde Mangold. This experiment aimed to investigate the role of a specific region of cells, called the organiser, in determining the fate and pattern of embryonic development in Xenopus laevis embryos
Experimental Setup
Spemann and Mangold performed a series of transplantation experiments on Xenopus embryos. They took a small group of cells from the dorsal lip of the blatopore ( a region that later became the embryos dorsal side) of one embryo (the donor) and transplanted it into a different region of another embryo (the host)
Observation of the transplanted cells
The transplanted cells from the donor embryo developed into a new dorsal lip in the host embryo. This newly formed tissue became known as the Spemman-Mangold organiser. The important observation was that the organiser had the ability to induce the neighbouring cells in the host embryo, such as the notochord and neural tube.
Secondary axis formation
The induction of the host embryo by the transplanted organiser resulted in the formation of a secondary axis, essentiallt duplicating the body plan. The host embryos developed with two complete sets of structures, each with its own nervous system and axial structures.
Conclusions
The experiment demonstrated that the Spemann-Mangold organiser possessed a unique property of being able to organise and induce neighboring cells to develop into specific structures. The induction of the secondary axis provided strong evidence that the fate and the patterning of cells during embryonic development could be influenced by specific regions or signal from neighboring cells.
Importance and contribution (Organiser and embryonic development)
The experiment identified the existence of a specific group of cells, the organiser, that played a critical role in determining the fate and pattern of embryonic development. This challenged the prevailing notion that embryonic development was soley predetermined by the genetic information inherited from the parent.
Importance and Contribution (Inductive properties)
The experiment demonstrated that the organiser had the ability to induce nearby cells to adopt specific fates and development were not fixed in their destiny but could be influenced and directed by their microenvironment.
Importance and Contribution (Plasticity of embryonic development)
The conclusions of the experiment contributed to the debate about the deterministic or plastic nature of embryonic development. It provided evidence in support of the idea that embryonic cells possess a certain degree of plasticity and that their fate is influenced by interactions with neighboring cells and signals from the surrounding environment.
