Topic03 - Heart Development Flashcards
The mammalian heart is the first functional organ made during embryonic development. TRUE or FALSE?
TRUE.
All organisms lose the regenerative ability of the heart after birth. TRUE or FALSE?
FALSE. The teleost fish and urodeles have hearts that retain full regenerative ability in adults.
What causes scarring of the heart?
The deposition of extracellular matrix following heart injury
Briefly state the steps involved in heart formation
- Cardiac crescent
- Heart tube
- Looping heart
- Chamber formation
State the inductive signals involved in heart development
TGfb-Nodal, BMP, Wnt
State the key transcription factors involved in heart development
TBX5, GATA4, ISL1, NKX2.5
Briefly state the function of Baf60c
Baf60c is a subunit of the BAF chromatin remodeling complex that helps to coordinate the action of key cardiac TFs.
State the four main families of chromatin remodeling complexes
- SWI/SNF
- CHD
- ISWI
- INO80
Which family does BAF belong to?
SWI/SNF
What does BAF stand for?
Brg1/Brm-associated factor
Most chromatin remodeling complexes contain a subunit with ATPase activity. TRUE or FALSE?
FALSE. All of them have ATPase activity.
State the histone covalent modification-recognition domain of Brg1. Which modification does it recognise?
Brg1 has a bromodomain which recognises acetylated lysine residues.
Which domains recognise histone covalent modifications?
Bromo- and chromo- domains.
State the four different outcomes of SWI/SNF chromatin remodelling
- Repositioning
- Octamer ejection
- Unwrapping
- Dimer ejection
State the result of Brg-1 knockout in embryonic myocardial cells.
These cells will undergo premature differentiation.
How does Brg-1 maintain embryonic cardiomyocyte fate?
Brg1 interacts with other chromatin regulators such as HDACs to repress adult MHC and activate embryonic MHC.
What does MHC stand for?
Myosin heavy chain
State the adult MHC and embryonic MHC genes
MYH6 (adult)
MYH7 (embryonic)
What is Tbx5?
Tbx5 is a key cardiac transcription factor important for normal heart development.
What is the difference between direct reprogramming and indirect reprogramming?
Direct reprogramming involves trans-differentiation, while indirect reprogramming involves a pluripotent intermediate.
State the factors required for direct reprogramming to heart tissue.
Baf60c, Gata4, Tbx
Baf60c and Brg1 are subunits of the BAF complex. TRUE or FALSE?
TRUE.
Define cardiac hypertrophy
The enlargement or thickening of heart muscle, a decrease in the size of the chambers of the heart, and a reduce capacity of the heart to pump blood to the tissues and organs around the body.
Why does cardiac hypertrophy occur?
- Physiologically induced, via exercise.
2. Pathologically induced, which results in the re-expression of foetal heart gene programs (MYH7)
