Podcast
Questions and Answers
What role does VEGF play in endothelial cell behavior?
What role does VEGF play in endothelial cell behavior?
Where do adult hematopoietic stem cells originate?
Where do adult hematopoietic stem cells originate?
What is the main function of stem cell factor (SCF) in the bone marrow?
What is the main function of stem cell factor (SCF) in the bone marrow?
What cellular feature do endothelial tip cells use to sprout new vessels in response to VEGF?
What cellular feature do endothelial tip cells use to sprout new vessels in response to VEGF?
Signup and view all the answers
What can abnormal levels of VEGF lead to?
What can abnormal levels of VEGF lead to?
Signup and view all the answers
What is essential for the differentiation of both heart and blood cells?
What is essential for the differentiation of both heart and blood cells?
Signup and view all the answers
How do Wnt signals contribute to the formation of blood vessels?
How do Wnt signals contribute to the formation of blood vessels?
Signup and view all the answers
What happens in the absence of Wnts during kidney development?
What happens in the absence of Wnts during kidney development?
Signup and view all the answers
Which molecules are released by the endoderm to inhibit Wnt signals?
Which molecules are released by the endoderm to inhibit Wnt signals?
Signup and view all the answers
What guides the migration of cardiac progenitors during heart formation?
What guides the migration of cardiac progenitors during heart formation?
Signup and view all the answers
What is the effect of blocking BMP with Noggin and Chordin?
What is the effect of blocking BMP with Noggin and Chordin?
Signup and view all the answers
Which phenomenon occurs in a chick embryo with cardia bifida?
Which phenomenon occurs in a chick embryo with cardia bifida?
Signup and view all the answers
Which structure is formed first in the embryonic development timeline?
Which structure is formed first in the embryonic development timeline?
Signup and view all the answers
Which structure represents the initial form of kidney tubules in development?
Which structure represents the initial form of kidney tubules in development?
Signup and view all the answers
What causes the outgrowth of the ureteric bud from nephric duct cells?
What causes the outgrowth of the ureteric bud from nephric duct cells?
Signup and view all the answers
What is the final structure formed during kidney development?
What is the final structure formed during kidney development?
Signup and view all the answers
Which component is essential for the branching of the ureteric bud?
Which component is essential for the branching of the ureteric bud?
Signup and view all the answers
Which type of mesoderm is responsible for forming the heart and blood vessels?
Which type of mesoderm is responsible for forming the heart and blood vessels?
Signup and view all the answers
What key process occurs after the formation of the pronephros?
What key process occurs after the formation of the pronephros?
Signup and view all the answers
During the development of kidneys, the metanephric mesenchyme interacts with which structure?
During the development of kidneys, the metanephric mesenchyme interacts with which structure?
Signup and view all the answers
What effect does GDNF have on kidney development when measured in vitro?
What effect does GDNF have on kidney development when measured in vitro?
Signup and view all the answers
What role does retinoic acid play in cardiac development?
What role does retinoic acid play in cardiac development?
Signup and view all the answers
What significant change occurs during cardiac looping?
What significant change occurs during cardiac looping?
Signup and view all the answers
What developmental process extends vasculogenesis?
What developmental process extends vasculogenesis?
Signup and view all the answers
Where does extraembryonic vasculogenesis occur?
Where does extraembryonic vasculogenesis occur?
Signup and view all the answers
What factors guide both vasculogenesis and angiogenesis?
What factors guide both vasculogenesis and angiogenesis?
Signup and view all the answers
Which gene is associated with valve formation during cardiac development?
Which gene is associated with valve formation during cardiac development?
Signup and view all the answers
During heart maturation, what happens at the first breath?
During heart maturation, what happens at the first breath?
Signup and view all the answers
What is the primary function of VEGF in the context of vascular development?
What is the primary function of VEGF in the context of vascular development?
Signup and view all the answers
Study Notes
Developmental Biology - Lesson 25
- Chapter 20 covers intermediate and lateral plate mesoderm, specifically focusing on heart, blood, and kidneys development.
Mesodermal Lineages
- Mesodermal lineages are determined by BMP4 levels, with lower levels centrally/medially and higher levels laterally.
Intermediate Mesoderm
- This gives rise to the kidney.
Lateral Plate Mesoderm
- This develops into heart, blood vessels, and blood.
Kidney Development
- Pronephros: Initial kidney tubules form.
- Mesonephros: Pronephros undergoes apoptosis, forming a second set of kidney tubules.
- Metanephros: Mesonephros undergoes apoptosis, and final kidney tubules form through reciprocal interactions between metanephrogenic mesenchyme and the ureteric bud.
Reciprocal Induction
- Metanephric mesenchyme induces ureteric bud branching.
- Mesenchyme condenses around ureteric bud tips.
- Mesenchyme aggregates, cavitates, and forms epithelial structures, developing nephrons and collecting ducts.
- These processes involve reciprocal interactions between these tissues.
Kidney Branching
- Tubule branching significantly increases over time (in vitro models).
Molecular Mechanisms of Reciprocal Induction
- Ureteric bud growth relies on GDNF and its receptors.
- GDNF is secreted from metanephric mesenchyme.
- Target cells express Ret (GDNF receptors).
Glial-Derived Neurotrophic Factor (GDNF) Effect
- GDNF signaling from metanephric mesenchyme induces branching of ureteric buds.
- Experimental models using control beads (vs. GDNF-soaked beads) show changes in branching patterns in developing kidneys.
Wnt Signaling in Kidney Development
- Multiple Wnt proteins are involved, especially in ureteric bud-in stalk or tips.
- Without Wnt, kidneys are typically absent.
- Wnts promote mesenchymal condensation around ureteric buds and mesenchyme-to-epithelial transition to form nephrons.
Circulatory System Development
- Formed from lateral plate mesoderm.
- Includes heart, blood vessels, and blood.
- Heart is the first functional organ in the embryo.
- Heart progenitor cells migrate to form cardiogenic fields, leading to development of a functional heart.
Inductive Interactions and Cardiogenic Mesoderm
- Wnt signaling guides lateral plate mesoderm to form blood and blood vessels.
- Wnt inhibitors (Dkk, Crescent, and Cerberus) block Wnt signaling, allowing BMP and FGF8 to develop cardiogenic mesoderm.
- BMP is vital for heart and blood cell differentiation.
- Noggin and Chordin from the notochord prevent heart and blood field formation in the embryo's center.
Heart Primordia Migration
- Cardiac progenitors migrate between ectoderm and endoderm.
- Fibronectin guides cardiac precursors during migration.
- Initially, two separate heart fields exist and then fuse.
Retinoic Acid and Hox Genes
- Posterior portions of heart fields express retinoid acid.
- Retinoic acid gradient regulates Hox gene expression.
- Specific Hox genes promote regional identities within heart fields.
Cardiac Looping and Chamber Formation
- Looping positions the atria anterior to the ventricles, setting up right-left orientation.
- Specific gene expression happens before and after looping, leading to chamber differentiation.
- Endocardial cushions form at atrioventricular canal and outflow tract.
- Genetic factors, like Twist, and cells, like neural crest cells, guide development.
Vasculogenesis and Angiogenesis
- Vasculogenesis forms blood islands (primary capillary networks) with hemangioblasts.
- Angiogenesis expands the vasculature network via remodeling of blood vessels, creating new blood vessels.
- Paracrine signals and receptors guide these processes.
Extraembryonic Vasculogenesis
- Occurs in the yolk sac.
- Forms early vasculature and red blood cells.
- May generate definitive adult blood stem cells (mouse studies)
Intraembryonic Vasculogenesis
- Creates the dorsal aorta, connecting with capillary networks in organs.
- Dorsal aorta scaffold is derived from somite cells.
VEGF Signaling in Angiogenesis
- VEGF (vascular endothelial growth factor) drives capillary network remodeling.
- VEGF induces endothelial migration, expansion of capillary networks, and tip cell response (sprouting of new vessels).
- VEGF balance is crucial for proper vascular development to prevent diseases such as pre-eclampsia.
Hematopoiesis and Stem Cell Formation
- Hematopoiesis is blood cell generation from stem cells.
- Stem cells divide to create stem cells and progenitor cells that become different blood cell types.
- Hematopoietic stem cells are pluripotent, producing all blood cell types.
- HSCs originate in the aorta-gonad-mesonephros region (AGM) and migrate to the bone marrow.
HSC Niche
- HSC survival and function are dependent on the bone marrow niche, which includes perivascular/endothelial cells that produce SCF (stem cell factor).
Hematopoietic Lineage Hierarchy
- Stem cells divide to become multipotent progenitors, then oligopotent progenitors, and eventually lineage-committed progenitors, ending in mature blood cells such as erythrocytes, platelets, eosinophils, monocytes, dendritic cells, NK cells, B cells, and T lymphocytes.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the intricate processes involved in the development of intermediate and lateral plate mesoderm as covered in Chapter 20 of Developmental Biology. This lesson specifically focuses on the formation of the heart, blood vessels, and kidneys, detailing key concepts like mesodermal lineages and reciprocal induction in kidney development.
