Contractile Purse String Formation
Contractile Purse String Formation - Related Videos
08:30
Investigating von Willebrand Factor Pathophysiology Using a Flow Chamber Model of von Willebrand Factor-platelet String Formation
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Cited by 6 •
2017
In this paper, we describe a method to assess endothelial von Willebrand factor release and the subsequent platelet capture under fluid shear stress in response to inflammatory stimuli using an in vitro flow chamber system.
09:49
Procedures for Rat in situ Skeletal Muscle Contractile Properties
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Cited by 18 •
2011
This video demonstrates the surgical preparation and procedures needed to study the contractile responses of the rat medial gastrocnemius muscle preparation in situ. This preparation allows measurement of skeletal muscle contractile properties under physiological conditions. The animal is anesthetized and the muscle is separated from surrounding tissue at its distal end. The Achilles tendon is attached to a force transducer, allowing measurement of the muscle’s contractile response at 37...
08:08
Measurement of Cytosolic Ca2+ in Isolated Contractile Lymphatics
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Cited by 24 •
2011
We introduce an approach to evaluate the cytosolic Ca2+ concentration in isolated lymphatics to study Ca2+-dependent and Ca2+-sensitizing mechanisms of lymphatic smooth muscle contraction.
07:03
Intrauterine Telemetry to Measure Mouse Contractile Pressure In Vivo
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Cited by 16 •
2015
This manuscript provides a protocol for implanting telemeters in the mouse for the purpose of measuring intrauterine pressures during pregnancy.
02:15
The Contractile Ring
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2023
Contractile rings are composed of microfilaments and are responsible for separating the daughter cells during cytokinesis. Contractile ring assembly proceeds along with other cell cycle events; however, very few mechanistic details are known about the timing and coordination of the contractile rings with the cell cycle. A small GTPase, RhoA, controls the function and assembly of the contractile ring. RhoA belongs to the Ras superfamily of proteins. The activation of formins by RhoA promotes...
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RhoA signaling coordinates actomyosin assembly by engaging associated regulators that promote F-actin formation and myosin II activation. This coordination creates a force-producing system rather than an unorganized actin population. Its developmental importance lies in connecting molecular signaling with mechanical behavior, allowing cytoskeletal activity to contribute directly to epithelial closure, tissue reshaping, and changes in tissue curvature.
Cell-cell junctions provide the attachments that allow tension generated by actin and myosin to influence neighboring membranes. Without this coupling, contractile activity would be less effectively transmitted across the epithelial boundary. Junctional connection therefore converts local cytoskeletal force production into coordinated inward movement, helping groups of cells close gaps or change their arrangement during tissue development.
Myosin II activation enables the F-actin cable to generate tension and constrict the boundary. That tension draws adjacent membranes inward, so the structure can produce a measurable change in tissue geometry rather than merely mark the boundary. In developmental settings, this force generation supports epithelial closure, coordinated cell rearrangements, and alterations in tissue curvature.
In epithelial wound closure, the cable helps draw the wound edges inward and reduce the open boundary. During morphogenesis, related force production contributes to broader tissue remodeling, including coordinated cell rearrangements and changes in curvature. The shared mechanism links actomyosin contraction to tissue-scale movement, while the biological outcome depends on whether the tissue is repairing damage or acquiring developmental form.
A useful approach combines live imaging with genetic perturbation of purse-string components. Live imaging follows the timing and organization of cytoskeletal or boundary movements, while perturbation tests whether specific components are required for those behaviors. Together, these methods connect molecular regulators and force-producing structures with observed epithelial closure, rearrangement, or tissue-shape changes.
These approaches can show how changes in purse-string components affect actomyosin organization, boundary constriction, and tissue remodeling. Comparing normal dynamics with perturbed conditions helps researchers link a component to force production and developmental patterning rather than simply observing its location. The resulting evidence informs models of mechanical regulation in multicellular systems and tissue repair.