Embryonic induction is the process of interaction of the parts of the embryo, in which one area affects the fate of another. This concept refers to experimental embryology.
The article is devoted to one of the most important and complex questions of this science: "What does embryonic induction mean?"
A bit of history
The phenomenon of embryonic induction was discovered in 1901 by such German scientists as Hans Spemann and Hilda Mangold. This process was first studied on the example of the lens in amphibians in an embryonic state. History has preserved many examples and experiments on this topic, which are based on the theory of Spemann.
Hypothesis
As mentioned earlier, embryonic induction is the process of interaction of parts of the embryo. So, according to the hypothesis, there are a number of cells that act on other cells as organizers that provoke changes in development. In order to more clearly illustrate this process, scientists in the 20s of the last century conducted a series of experiments, which we will discuss in more detail below.
Hans Spemann experiment
As a result of his experiments, Dr. Spemann revealed the pattern that development occurs in the strict dependence of some organs on others. The experiment was carried out on newts. Speman transplanted from the back of one embryo into the abdominal cavity of another part of the blastopore lip. As a result of this, at the place where the organ was transplanted, the formation of a new embryo began. Normally, the neural tube never forms on the abdominal cavity.
Based on experience, the doctor concluded that there are organizers that affect the further development of the body. However, the organizers can give a start only if the cells have the competence. What does it mean? Competency refers to the ability of the germinal material to change its presumptive fate under the influence of various kinds of influences. When studying induction interactions in various species of chordates, scientists came to the conclusion that in the areas and terms of competence of various organisms there are many individual characteristics. That is, the organizers act if the cell is able to take an inducer, but in all organisms this or that process occurs in different ways.
We conclude: the development of the body is a chain process, without one cell the formation of another is impossible. Embryonic induction gradually determines the shaping and differentiation of organs. Also, this process is the basis for the formation of the appearance of a developing individual.
Research Hilda Mangold
Hans Spemann had a graduate student - Hilda Mangold. Possessing amazing dexterity, she was able to conduct a series of complex experiments with microscopic newt embryos (1.5 mm in diameter). Separating a small piece of tissue from one embryo, she transplanted it to another type of embryo. Moreover, for transplantation, she chose the areas of the embryo where the formation of cells occurred, from which subsequently the germ layers were to be formed . The embryo, with a piece of another embryo transplanted onto it, successfully continued to develop. A grafted piece of tissue gave rise to a new body, endowed with a back, spine, abdomen and head.
What was the significance of the experiments? In the course of these, Mangold proved that there is embryonic induction. This is possible because a small site has these unique properties, it was called the organizer.
Types of induction
There are two types: heteronomic induction and homonomic induction. What is it and what is the difference? The first type is a process in which a transplanted cell is forced to rebuild to the general rhythm, that is, it generates some new organ. The second provokes a change in surrounding cells. Encourages material to develop in the same direction.
Basic cellular processes
For clarity, the table below. We suggest using her example to study the basic cellular processes of embryonic induction.
Cell processes| Forms of cell interactions | The formation of normal structures | Consequences of Violations |
| displacement | neural tube formation during movement of primary germ cells | disorders in the formation of the neural tube, violation of the structure |
| selective breeding | primordial organs | lack of organs |
| electoral death | finger separation, death of epithelial cells during the fusion of the palatine primordia, nasal processes, etc. | cleft palate, cleft lip, face, spinal hernia |
| adhesion | neural tube formation from the neural plate, etc. | disorders in the formation of the neural tube, violation of the structure |
| thickening | limb formation | lack of limbs or the presence of additional |
The manifestation of this phenomenon was found at various stages of the development of the organism. Embryonic induction is currently being actively studied.