Summary
One group of cells signals a neighbouring group to change its developmental path.
In depth
Examples: notochord induces the neural plate; the optic vesicle induces the lens; the Spemann organiser induces a second axis. Competence of responding cells matters.
Induction involves signals, receptors and competence. Reciprocal induction occurs between tissues in organ development. Permissive induction allows a pre-determined fate, instructive induction changes it.
Remember: the same signal can have different effects on different tissues.
Induction occurs when one tissue (the inducer) signals another (the responder) to change fate. Hans Spemann and Hilde Mangold demonstrated it in 1924 when a transplanted dorsal lip of the blastopore induced a second body axis.
Classic examples include the optic vesicle inducing the lens, and the notochord inducing the neural plate and floor plate. The responder needs competence, the ability to respond, and the signal may be secreted proteins or direct contact. Inductions are often sequential and reciprocal, building complex organs.
Example: kidney tubules form when the ureteric bud induces mesenchyme to condense.
Frequently asked questions
What is Induction?
One group of cells signals a neighbouring group to change its developmental path.
Which area of biology covers Induction, and how advanced is it?
Induction is one of the 54 topics in Developmental Biology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Spemann Organiser, Morphogens, Organogenesis.
Why does Induction matter?
It explains how complexity arises from simple interactions.
Can you give an example of Induction?
Hans Spemann and Hilde Mangold's 1924 transplant won the 1935 Nobel Prize.
What should I learn before Induction?
Work through the Beginner topics in Developmental Biology first, such as Fertilisation, Zygote, Embryo, then return to Induction. Intermediate topics assume the Beginner vocabulary.
What topics are related to Induction?
The closest topics to Induction are Spemann Organiser, Morphogens, Organogenesis, Developmental Gene Regulatory Networks. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Induction?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Induction. To practise the whole of Developmental Biology, use the Developmental Biology quiz.
How is Induction different from Spemann Organiser?
Induction: One group of cells signals a neighbouring group to change its developmental path. Spemann Organiser: A signalling region in the amphibian gastrula that induces a second body axis when transplanted. Read both side by side and note what each one explains.
How should I study Induction step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Spemann Organiser and explain the difference aloud. Finally, take the Developmental Biology quiz and come back to this page for any question you miss.