Muscle Stem Cells and Myogenesis

What is the main function of satellite cells in skeletal muscle?

Initiating muscle contraction
Generating heat
Maintaining muscle homeostasis (correct)
Supporting muscle attachment to bones

Where do satellite cells reside in skeletal muscle?

In the perimysium
In the sarcolemma
Between the basal lamina and the sarcolemma (correct)
Within the myofibers

What role do satellite cells play in muscle repair?

Encourage muscle contraction
Facilitate inflammation
Aid in muscle regrowth (correct)
Stabilize muscle structure

During which period are satellite cells most proliferative after tissue injury?

Between 5-10 days (B) Signup and view all the answers

What other cell types are involved in mediating muscle regeneration?

Immune cells and fibro/adipogenic progenitors (C) Signup and view all the answers

What is the significance of the basal lamina in muscle structure?

Individually wrapping myofibers (C) Signup and view all the answers

What is the primary function of myofibers?

Actively contracting in response to signals (D) Signup and view all the answers

What distinguishes satellite cells from other muscle cells?

Ability to regenerate tissue (C) Signup and view all the answers

What is the source of muscle progenitor cells required for postnatal muscle growth?

Satellite cells (A) Signup and view all the answers

Why was it important to wait until mice were adults before assessing the role of satellite cells in muscle homeostasis?

To avoid labeling growing cells (B) Signup and view all the answers

What is the result of asymmetric cell division in satellite stem cells?

A Pax7+/Myf5- satellite stem cell daughter and a Pax7+/Myf5+ committed daughter cell (D) Signup and view all the answers

What is the purpose of negative lineage-specific markers in FACS?

To remove non-satellite cells from the sample (A) Signup and view all the answers

What is the advantage of single myofiber isolation?

It maintains the cell on the myofiber, preserving the niche (A) Signup and view all the answers

What is the purpose of inducing muscle injury in some experiments?

To study satellite cell activation (B) Signup and view all the answers

What is the advantage of bio-engineering approaches in studying satellite cells?

They provide a more accurate representation of the in vivo environment (C) Signup and view all the answers

What is the purpose of transplantation/engraftment assays?

To assess muscle stem cell regenerative capacity (B) Signup and view all the answers

What is the role of Pax7 in identifying satellite cells?

It is a nuclear marker used to identify quiescent satellite cells (A) Signup and view all the answers

What is the purpose of using toxins in some experiments?

To lyse the membrane and cause an inflammatory response (A) Signup and view all the answers

What is the advantage of using VCAM as a surface marker?

It is a general marker used to identify satellite cells (D) Signup and view all the answers

What is the role of extrinsic and intrinsic signals in regulating satellite stem cell division?

They regulate asymmetric satellite stem cell division (B) Signup and view all the answers

What is the purpose of using siRNAs/drugs in transplantation/engraftment assays?

To delete specific genes of interest (D) Signup and view all the answers

Which pathway regulates cell fate by interacting with cell surface receptors?

WNT and Notch pathways (C) Signup and view all the answers

What is the main function of CARM1 in cell fate regulation?

Suppressing Myf5 activation (D) Signup and view all the answers

How does p38g regulation affect MyoD expression?

It inhibits MyoD (D) Signup and view all the answers

What is the effect of mutating the S572 residue of CARM1 to an alanine residue?

It increases nuclear localization of CARM1 (C) Signup and view all the answers

What is the role of p38y in satellite stem cell self-renewal?

Preventing Myf5 activation (B) Signup and view all the answers

Which experimental tool is used to identify protein complexes at the single-cell level?

Proximity Ligation Assay (D) Signup and view all the answers

What is the effect of deleting p38-gamma on cell division?

Increase in asymmetric divisions (C) Signup and view all the answers

What is the function of satellite stem cells in muscle homeostasis?

Maintaining muscle regeneration (A) Signup and view all the answers

How do WNT and Notch pathways influence cell fate?

Through cell surface receptors (A) Signup and view all the answers

What is the main role of the myogenic factor expression pathway?

Controlling transcriptional and translational levels (D) Signup and view all the answers

What is the main function of macrophages in the regenerative response?

Switch from M1 to M2 (A) Signup and view all the answers

Which transcription factor is essential for satellite cell function?

Pax7 (D) Signup and view all the answers

What is the role of MYOD in satellite cell activation and proliferation?

Regulating myoblast proliferation (B) Signup and view all the answers

What is the fate of Pax7-null mice (Pax7-/-)?

Die within 2 weeks of birth (B) Signup and view all the answers

Which factor indicates myogenic commitment and regulates myoblast proliferation?

MYF5 (A) Signup and view all the answers

Why is satellite cell quiescence described as a ''reversible state where cells are not actively dividing''?

To prevent spontaneous activation (D) Signup and view all the answers

Which type of cell has more stem-like properties within the satellite cell population?

Pax7+/Myf5- cells (A) Signup and view all the answers

What is the significance of symmetric cell division in satellite stem cells?

Promotes self-renewal (B) Signup and view all the answers

Why do activated satellite cells need high migratory capacity?

To reach the point of injury for repair (A) Signup and view all the answers

What is the role of MRF4 in satellite cell differentiation?

Promoting terminal differentiation (C) Signup and view all the answers