Basics of developmental biology

1. BASICS OF DEVELOPMENTAL
BIOLOGY
DR. GHIZAL FATIMA
ASSOCIATE PROFESSOR
ERA UNIVERSITY LUCKNOW

2. INDUCTION
• Refers to cascade of signaling events, during which a
cell or tissue signals to another cell or tissue to
influence its developmental fate.
• Signals that gets generated is called inductive signals
• The inductive signals can be proteing, growth and
differentiation factor
• There are 2 components in every inductive interaction-
• A-Inducer-tissue or cell that produce signal
• B- Responder

3. Competence
• The ability to respond to a specific inductive
signal is called as Competence.
• It occur through expression of appropriate
receptor or component of signaling pathway.
• Best eg. is development of eye

4. Commitment
• The commitment of a cell to specific cell fate
and their capacity to diffentiate into perticular
type of cells.
• Commitment: deciding the fate of a cell
• Cell can attain commitment by:
• 1-cytoplasmic determinant
• 2- Inductive signals
heart

5. Cytoplasmic determinant
• A cell can devide into 2 daughter cell with
different fate.
• This can be achieved by asymmetric
distribution of cytoplasmic factor (RNA,
Protein) that can regulate fate
• They act in early development

6. Cell fate
• The fate of cell to generate in all the different
cell types it forms during normal development
X
HEART LUNGS KIDNEY
FATE

7. Commitment
• Deciding fate of cell
• Cell fate describes the range of cell types a
particular cell forms during normal
development
• Stages of commitment
• 1-specification
• 2-determination

8. Specifation
• It is a labile phase, so it is not fixed
• It can be revert from its fate.
• So in this case commitment is reversible
• It is capable of differentiating autonomously
when placed in a neutral environment.

9. Determination
• Here in this case commitment is fixed.
• It is not going to revert from its fate, so
commitment is irreversible.

10. Differentiation
• Cell differntiation is the process by which cells
becomes funtionally specialized.
• Allowing formation of distinct cell types.
• Structural and functional specificity of cell
depends on proteins it synthesizes.

11. Morphogenesis
• Gaining a particular shape

12. Cell types specification and their
characterstics
• During specification there are 3 major
strategies that embryo can exhibit
• 1-autonomous specification
• 2- conditional specification
• 3-syncytial specification (insects)

13. Autonomous specification
• In most invertibrates
• Knows very early what it is to become without
interacting with other cells
• Prospective potency is equal to prospective
fate
• Produces mosac determinative development

14. Conditional specification
• Characteristic of all invertebrates and few
vertebrates
• It’s a process by which cells achieve there
respective fate by interaction with other cells.
• Here what a cell has to become is specified by
the array of interactions. It has with its
neighbors, which include cell to cell contact.
• Prospective potency is greater than
prospective fate