Competence of Tissue.
In 1932 Wallington first given the thought of competence, Reaction of embryonic tissue on the basis of inductive stimuli is called the competence of tissue.
What is Competence?
Competence is a physiological state in which tissue can react against inductive action in a definite period of time.
Example of Competence: During development, ectodermal tissue is competent for sometime according to the neural induction, therefore, it becomes competent for other type of induction such as genes. If, we describe it, genetically, then special type of genes are susceptible for a short period of time to become active or inactive for such type of tissues
Ectoderm is transplanted in another embryo in different experiments of different stages of embryo i.e., from blastula to primitive neurula stage. Ectoderm gradually loses the power of transformation into neural tissue. When ectoderm is transplanted after a very long duration then it develops only in the form of epidermis and not in any tissue or organ.
In 2nd experiment, after separating same parts of ectoderm of gastrula stage were kept in different stages for different period of time and then they are transplanted at different places of neurula where induction was active. Result shows that the capacity of form brain decreases in posterior gastrula stage and in posterior neural stage, the capacity of ectoderm decreases. Whereas the ageing tissue loses its competence for other special type of induction but develops competence for new type of induction.
Thus, the ectoderm which has lost the neural competence will become.com- petent for that induction which form lens, ear vesicle and nasal pits.
During development, one tissues of an embryo interact with an adjacent tissues and induces it to develop under special condition.
These developed tissues in turn interact with their adjacent tissue and induce them to develop in a particular direction and this process continues in successive tissues.
Development of Competence
Capacity of behaviour towards inductive stimuli is not found in the primitive stages of an embryo e.g., competence is not found is primitive cleavage stage or blastula stage. Competence is present only in gastrula stage because RNA transcription occurs only in gastrula stage, m-RNA transcription starts, just before the beginning of gastrulation. Inductive tissue have the capacity to induce others whereas the reactive tissues do action
