Lecture 32. Multicellular Organisms 1 Flashcards
What determines the four essential processes of development?
Selective gene expression
What are the four essential processes of development?
Cell proliferation, cell specialisation, interaction of cells with surrounding environment, cell movement and migration
What are the shared sequence of events in all animals?
Egg – Cleavage – Gastrulation – Germ layers
What do conserved genes between species show?
Common ancestry
What proteins are important for multicellular development?
Cell adhesion and signalling transmembrane
proteins
What are two types of anchoring junctions that connect with the intracellular cytoskeleton?
Cell-cell and cell-matrix
Adherens junctions
Actin filaments via cadherin proteins
Desmosome junctions
Intermediate filaments via cadherin proteins
Actin-linked cell matrix adhesion
Actin filaments via integrin proteins
Hemidesmosomes
Intermediate filaments via integrin proteins
Transcription factors
DNA regulatory proteins
Enhancers
Non-coding regulatory DNA
What leads to variation in body plan/shape/structure?
Transcription factors and enhancers
How were pivotal genes and protein products identified?
Natural or induced mutations of normal phenotype
The first developmental genes were first identified as?
Spontaneous mutations which produce an abnormal phenotype
How was cell lineage and cell-cell interactions deciphered?
Experimental embryology
What is the embryo divided up into?
A small number of broad regions
What will the broad regions in the embryo become?
The future germ layers (mesoderm, ectoderm and endoderm)
What is ‘fate’?
What a cell will normally develop into
What are the two stages of commitment?
Specification and determination
What is ‘specification’?
A cell is specified when it can be cultured in a neutral environment and differentiate according to it’s fate
What is ‘determination’?
It can differentiate according to its fate even if in a different environment. (Fully determined- no matter what)
Induction
Where a signal from one group of cells influences the developmental fate of another
Inductive interaction
Determines pattern formation i.e. what drives cells with the same potential to follow a different path of development
