Factors That Influence Embryonic Development
by Thomas Smith | Feb 18, 2024
- Specific genes expressed in cell during development determine cell type
- Cell can receive external and internal cues that cause regulation of gene expression by turning genes on/off
- External: cells receive signals from extracellular environment
- Adjacent cells: ex: binding of growth factors
- Environment: temperature can trigger cellular response
- Internal: signals come from inside cell
- Cell signals to itself and Cytoplasmic Determinants
- Cleavages don’t divide cells equally → cells acquire variations based on orientation of cleavages
- Cytoplasmic Determinants: eggs cytoplasm contains RNA, protein, and nutrients encoded by mum DNA
- Cytoplasmic determinants not dispersed equally which affect embryonic development
- Cytoplasmic axes and substances unique to each cell may turn genes on or off and set cells down specific path
- Embryonic Induction: signaling molecules from embryonic cells cause transcriptional changes in nearby target cells
- Organizers: cells that exert this influence
- Cell-cell communication can occur by ligands or interaction between cell surfaces → leads to specific gene expression and cell differentiation
- Cells closer receive more than cells farther away
- Apoptosis: some cells produced during development have temporary role and are deliberately destroyed
- Ex: during early stages have webbing but later cells undergo apoptosis
