The heart

Question 1

How many babies a day are born with congenital heart disease

Answer 1

12 in the UK

Question 2

Which organisms have 4 chambered hearts

Answer 2

Humans
Mice
Chicks

Question 3

Which organism have 3 chambered hearts

Answer 3

Xenopus

Question 4

Which organism have 2 chambered hearts

Answer 4

Zebrafish

Question 5

Which organism has a tubular heart

Answer 5

Drosophila

Question 6

The structure that heart progenitors form

Answer 6

Bilateral population around the mid line meaning the structure of cells on each side is mirrored

Question 7

What is the general overview of cardiogenisis

Answer 7

Bilateral population of cells form

They migrate to midline and fuse to form the heart tube

Asymmetric bending due to heart looping morphogenesis

Chamber formation

maturation- formation of structures required to function

Question 8

What are heart fields

Answer 8

Two populations of cells that form the bilateral population at the earliest stage of cardiogenisis

Question 9

How are the two heart fields positioned at early stages

Answer 9

The first field stage is anteriorly and dorsally positioned ‘behind’ the second heart field

Question 10

What does the first heart field form

Answer 10

Left ventricle and both atriums

Question 11

What does the second heart field form

Answer 11

Right ventricle
Both atriums
Outflow tract

Question 12

How and where do cells in the heart fields originate from

Answer 12

specified using morphogen gradients

Mesodermal tissue in primitive streak

Question 13

How did we find out where these cells originated from

Answer 13

Using cell fate mapping in MICE

Question 14

What do chambers of the heart need to be

Answer 14

Contractile

Question 15

What needs to be specific about chambers

Answer 15

The direction of contractions

Question 16

When does patterning of heart structures begin

Answer 16

At the tube stage

Question 17

What signals pattern chambers

Answer 17

Notch - Tbx20

Question 18

What signals pattern the Atrioventricular canal

Answer 18

Bmp - Tbx2

Question 19

How do signals patterning the heart work

Answer 19

Through a complex interplay of activating and inhibitory molecules

Question 20

What does Tbx2 do to elicit valve formation

Answer 20

It represses chamber programming

Question 21

What does Tbx20 do to causes chamber identity

Answer 21

It represses valve programming

Question 22

Diseases caused by Tbx2

Answer 22

Patent ductus arteriosus

Question 23

Diseases caused by Tbx20

Answer 23

Atrial septal defects
Double outlet right ventricle

Question 24

what does the second heart field express that is important for looping

Answer 24

Islet1

Question 25

What do cells expressing Islet1

Answer 25

They are recruited to migrate into the heart. This movement and gain of cells causes looping

Question 26

Where is Islet1 expressed around the forming heart

Answer 26

In mesoderm adjacent to the heart

Question 27

How was islet1 migration visualised

Answer 27

using LacZ lineage tracing

Question 28

What diseases are caused by Islet1 defects

Answer 28

congenital heart disease double outlet right ventricle

Question 29

How is left-right asymmetric establish in the heart

Answer 29

Nodal expression in only the left lateral plate of the embryo

Question 30

Which organism was used to investigate left-right asymmetry

Answer 30

Zebrafish Nodal = Spaw

Question 31

How is left-right asymmetry set Spaw action set up

Answer 31

Spaw only propagates itself in left lateral plate due to lefty1 expression in the notochord

Question 32

How is left1 induced in the notochord

Answer 32

Bmp signalling from the node

Question 33

How does Spaw act in the left side

Answer 33

Targets left side genes in the cardiac disk which then undergoes rotation and involution

Question 34

What happens when nodal flow is lost

Answer 34

Randomisation of lateralised gene expression Fish - mis-direction of heart looping

Question 35

What human diseases are caused by Wrong Asymmetry

Answer 35

Situs inversus - Asymptomatic Situs Ambiguous - BAD