Developmental haemopoiesis Flashcards
Where is the first site of haemopoiesis and how long for?
The yolk sack is the main site at 3 weeks gestation
Where is the next site of gestation?
6wks to 6-7months the liver and spleen are involved and continue till 2 weeks after birth
Where is the main site in normal childhood and adult life?
Bone marrow is the only source
Which genes are critical for primitive haemopoiesis?
LMO2
SCL/Tal1
GATA1
Where is the site of definitive haemopoiesis?
Aorto-gonado-mesonephros
this occurs at 5 weeks gestation
Which genes are critical for definitive haemopoiesis?
LMO2
SCL/Tal1
GATA1
RUNX1 - essential to definitive but not primitive
Where is the main site of haemopoiesis in fetal life?
the fetal liver - begins at 7-8 weeks
What are the features of HSCs?
Can undergo self renewal
Can undergo multilineage differentiation
non- descript morphology
Can sustain lifelong haemopoiesis if transplanted to another
What is the main site of lymphopoiesis in fetal life?
Bone marrow
What happens with progenitor expression?
When myeloid-primed progenitors are present the LMPP is not expressed
If the lymphomyeloid progenitor is expressed the MPPs are not
Describe the journey of erythropoiesis
The megakaryocyte-erythroid progenitor can differentiate to MK cell or erythroblast
erythropoiesis begins in the yolk sac
What is the regulator of fetal erythropoiesis and where is it produced?
EPO
produced in the liver
What is the regulator of fetal megakaryopoiesis and where is it produced?
TPO
produced in the liver
Where are granulocytes produced?
Bone marrow
monocytes and granulocytes
What are they controlled by?
GM-CSF
G-CSF
