Related Experiment Video
Updated: Jul 17, 2026
16:27
Biophysical Assays to Probe the Mechanical Properties of the Interphase Cell Nucleus: Substrate Strain Application and Microneedle Manipulation
Published on: September 14, 2011
Thick and thin filaments in postmitotic, mononucleated myoblasts
Science (New York, N.Y.)
|May 30, 1975
Summary
Cytochalasin B separates muscle cells, enabling postmitotic myoblasts to synthesize muscle proteins and form filament arrays. These structures allow spontaneous cell contraction, even without full sarcomere development.
Area of Science:
- Cell Biology
- Muscle Development
- Biochemistry
Background:
- Primary muscle cultures contain both replicating and postmitotic cells.
- Understanding muscle cell differentiation requires isolating specific cell types.
Purpose of the Study:
- To investigate the behavior of postmitotic myogenic cells after separation from replicating cells.
- To examine the synthesis and assembly of muscle proteins in isolated myoblasts.
Main Methods:
- Addition of cytochalasin B to primary muscle cultures.
- Physical separation of postmitotic myogenic cells.
- Microscopic analysis of myoblast structure and protein assembly.
Main Results:
- Cytochalasin B effectively separated postmitotic myoblasts from other cell types.
- Mononucleated myoblasts synthesized myosin and actin, forming thick and thin filaments.
- Myofilaments assembled into ordered arrays, despite atypical sarcomere structure.
- These myoblasts exhibited spontaneous contraction.
Conclusions:
- Postmitotic myoblasts can synthesize and assemble contractile proteins independently.
- Ordered myofilament assembly occurs even in the absence of complete sarcomere formation.
- Cytochalasin B is a useful tool for studying early muscle cell differentiation.
More Related Videos
Related Concept Videos
01:32The Nucleus
The nucleus is a membrane-bound organelle that acts as a control center in a eukaryotic cell. It contains chromosomal DNA, which controls gene expression and precisely regulates the production of proteins within the cell. In contrast, the DNA inside the mitochondria and chloroplast only carries out functions that are specific to those organelles.
Arrangement of DNA within Nucleus
The regulation of gene expression inside the nucleus is dependent on many factors, including the DNA structure. The...
Arrangement of DNA within Nucleus
The regulation of gene expression inside the nucleus is dependent on many factors, including the DNA structure. The...
02:55The Nucleolus
The nucleolus is the most prominent substructure of the nucleus. When it was first discovered, it was considered to be an isolated organelle that forms fibrils and granules. In 1931, the relationship between the nucleolus and chromosomes was first described by Heitz. He observed that the appearance and size of nucleolus varies depending on the stage of the cell cycle. He also noticed constricted regions on different chromosomes clustered together at definite cell cycle stages. These regions,...
01:10The Role of Actin and Myosin in Non-muscle Cells
Actin and myosin or actomyosin filaments also play a significant role in cells other than those involved in muscle contraction (which occurs within the sarcomere of muscle cells). The mechanism of non-muscle cell contractile bundles was first observed in Dictyostelium and Acanthamoeba. In non-muscle cells, two bundles are commonly found: stress fibers and actomyosin adherence belts. These contractile bundles are smaller and less organized than the ones found in muscle cells. They are held...
01:25The Nucleus
The nucleus is a membrane-bound organelle that acts as a control center in a eukaryotic cell. It contains chromosomal DNA, which controls gene expression and precisely regulates the production of proteins within the cell. In contrast, the DNA inside the mitochondria and chloroplast only carries out functions that are specific to those organelles.
Arrangement of DNA within Nucleus
The regulation of gene expression inside the nucleus is dependent on many factors, including the DNA structure. The...
Arrangement of DNA within Nucleus
The regulation of gene expression inside the nucleus is dependent on many factors, including the DNA structure. The...
00:55Fibrous Proteins
Fibrous proteins are either long and narrow proteins or assemble to form long and thin structures. They contain repetitive units and usually consist of either alpha helices or beta sheets and, in rare cases, a mix of both. The amino acids in the primary structure often consist of repeating amino acid sequences. The role of fibrous proteins is primarily structural. Many are located in the extracellular matrix and are present in connective tissues to impart strength and joint mobility. They are...
01:13Structure and Organization of Smooth Muscles
Smooth muscle tissue is a type of muscle tissue that can be found lining various vital organs in the human body, including the lungs, blood vessels, digestive tract, and respiratory tract. This type of tissue is responsible for regulating the movements of these organs, playing crucial roles in the functioning of various systems, including the vascular, digestive, respiratory, and urinary systems.
Structure of smooth muscle cell
Smooth muscle cells are spindle-shaped with tapering ends and a...
Structure of smooth muscle cell
Smooth muscle cells are spindle-shaped with tapering ends and a...