Difference Between Primary and Secondary Embryonic Induction

The key difference between primary and secondary embryonic induction is that primary embryonic induction is the tissue interactions in early embryogenesis that generates the neural tube while secondary embryonic induction is the development of various tissues and organs in most animal embryos.

Embryonic induction is an embryonic process. In this process, one group of cells induces the development of another group of cells. Likewise, different inducing tissues induce the development of various tissues and organs during the embryonic development in most animal embryos. In short, in embryonic induction, the presence of one tissue influences the development of other tissues in the very young embryo. Therefore, the absence of an inducing tissue results in improper development of the other tissues. There are two types of embryonic induction as primary and secondary embryonic induction. Primary embryonic induction refers to the events taking place during the early embryogenesis. Secondary embryonic induction refers to the tissue interactions that result in various cell types.

CONTENTS

1. Overview and Key Difference
2. What is Primary Embryonic Induction
3. What is Secondary Embryonic Induction
4. Similarities Between Primary and Secondary Embryonic Induction
5. Side by Side Comparison – Primary vs Secondary Embryonic Induction in Tabular Form
6. Summary

What is Primary Embryonic Induction?

Primary embryonic induction is the first induction event that takes place during early embryogenesis. Firstly, tissues interact to generate the neural tube. Neural tube eventually forms the central nervous system. The cells of the neural crest induce the surface ectoderm cells in order to proliferate and invaginate to form the neural tube.

What is Secondary Embryonic Induction?

Secondary embryonic induction is the development of various tissues and organs in animal embryos. Therefore, in secondary induction, tissues interact in order to govern cell differentiation and morphogenesis during embryonic development. Many cell types originate as a result of secondary induction. Development of eye and ear is an example of secondary embryonic induction. Moreover, as a result of secondary embryonic induction, tooth, hair, lens and many organs are formed. Secondary embryonic induction starts once the basic embryonic plan has been established. A chain of secondary induction processes takes place differentiating many specialized cell types.

What are the Similarities Between Primary and Secondary Embryonic Induction?

• Both, primary and secondary embryonic induction play an important role in the development of tissues and organs in most animal embryos.
• The molecular nature of “primary” and “secondary” inductions is similar.

What is the Difference Between Primary and Secondary Embryonic Induction?

Primary embryonic induction is the tissue interactions in early embryogenesis that generate the neural tube. Secondary embryonic induction is the embryonic induction that directs the development of various tissues and organs in most animal embryos. So, this is the key difference between primary and secondary embryonic induction.

Summary – Primary vs Secondary Embryonic Induction

During embryogenesis, the process of one group of cells influences or induces the direction of differentiation of the neighbouring group of cells is known as embryonic induction. It is the most important mechanism in vertebrate development. When the chordamesoderm contacts the dorsal ectoderm, induction of neural ectoderm takes place. It is known as primary embryonic induction. In primary embryonic induction, the surface ectoderm cells develop into the neural tube. Neural tube eventually forms the central nervous system. Secondary embryonic induction is the development of many tissues and organs due to embryonic induction. Thus, this summarizes the difference between primary and secondary embryonic induction.

Reference:

1. “Embryonic induction.” Nature News, Nature Publishing Group, Available here.
2. Balinsky, Boris Ivan. “Embryonic Induction.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 23 Sept. 2011, Available here.

Image Courtesy:

1. “1301 Neural Tube Dev” By OpenStax –  (CC BY 4.0) via Commons Wikimedia