Embryonic induction is the process of interaction between the parts of the embryo, in which one part influences the fate of another. This concept refers to experimental embryology.
The article is devoted to one of the most important and difficult 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. For the first time, this process was studied using the example of the lens in amphibians in the embryonic state. History has preserved many examples and experiments on this topic, which are based on Spemann's theory.
Hypothesis
As mentioned earlier, embryonic induction is a process of interaction between the 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 20sof the last century conducted a series of experiments, which we will discuss in more detail later.
Hans Spemann experiment
As a result of his experiments, Dr. Spemann revealed a pattern that development occurs in a strict dependence of some organs on others. The experiment was carried out on tritons. Spemann transplanted a portion of the blastopore lip from the back of one embryo into the abdominal cavity of another. As a result, at the place where the organ was transplanted, the formation of a new embryo began. Normally, a neural tube never forms in the abdominal cavity.
Based on experience, the doctor concluded that there are organizers that influence the further development of the body. However, the organizers can only start if the cages are competent. What does it mean? Competence is understood as the ability of the germinal material to change its presumptive fate under the influence of various kinds of influences. When studying inductive interactions in various species of chordates, scientists came to the conclusion that there are many individual features in the areas and terms of competence of various organisms. That is, the organizers act if the cell is able to accept the inductor, but in all organisms this or that process occurs in different ways.
Let's conclude: the development of an organism is a chain process, without one cell it is impossible to form another. Embryonic induction gradually determines the formation and differentiation of organs. Also, this process is the basis for the formation of the external appearance of a developing individual.
Hilda Mangold Research
Hans Spemann hadgraduate student - Hilda Mangold. With amazing dexterity, she was able to perform 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 onto an embryo of another species. Moreover, for transplantation, she chose the areas of the embryo where the formation of cells took place, from which germ layers were subsequently to be formed. The embryo with a piece of another embryo transplanted onto it continued to develop successfully. And the 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 them, Mangold proved that there is an embryonic induction. This is possible because a small site has these unique properties, it has been called an organizer.
Types of induction
There are two types: heteronomous induction and homonomous induction. What is it and what is the difference? The first type is a process in which a transplanted cell is forced to rebuild itself to a common rhythm, that is, it gives rise to some kind of new organ. The second provokes a change in surrounding cells. Encourages the material to develop in the same direction.
Basic Cellular Processes
For more clarity, see the table below. We suggest using her example to study the main cellular processes of embryonic induction.
| Forms of cellular interactions | Education of normalstructures | Consequences of violations |
| movement | formation of the neural tube during the movement of primary germ cells | disturbances in the formation of the neural tube, violation of the structure |
| selective breeding | rudiments of organs | lack of organs |
| selective death | separation of fingers, death of epithelial cells during the fusion of palatine buds, nasal processes, etc. | cleft palate, cleft lip, face, spinal hernias |
| adhesion | formation of the neural tube from the neural plate, etc. | disturbances in the formation of the neural tube, violation of the structure |
| thickening | formation of limbs | missing or having extra limbs |
The manifestation of this phenomenon was found at various stages of the development of the organism. Embryonic induction is currently being actively studied.
