Details for: CL0000190

Cell ID: CL0000190

Cell Name: fast muscle cell

Description: A muscle cell that can develop high tension rapidly. It is usually innervated by a single alpha neuron.

Synonyms: glycolytic muscle fiber

Selected Context(s): Overall

Gene Significance Landscape

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Score:
Display
Genes

Contexts:

Cell Significance Index (CSI) is uniquely calculated to reveal cell-specific gene markers. More info here

Significant Genes List

Genes with the highest and lowest Percentile Rank Scores (PRS) for fast muscle cell within the selected context(s).

Gene ID: A unique numerical identifier for this specific gene.
Symbol: Shortened abbreviation or name that represents this gene.
Ensembl Gene ID: A unique identifier assigned by Ensembl for genomic data mapping.
CSI Score: A combined effect size and statistical significance measure for fast muscle cell. Higher scores indicate a stronger, more significant difference in expression.
(Previously described as "Fold Change", but now represents Cliff's Delta × –log10(p).)

Gene ID: A unique numerical identifier for this specific gene.
Symbol: Shortened abbreviation or name that represents this gene.
Ensembl Gene ID: A unique identifier assigned by Ensembl for genomic data mapping.
CSI Score: A combined effect size and statistical significance measure for fast muscle cell. Higher scores indicate a stronger, more significant difference in expression.
Average CSI: csi sum / gene count
Cell network configuration

This network visualizes key genes for fast muscle cell. It primarily includes:
1. Top genes highly significant for this cell (Num. Top Cell Genes - based on the 'Min. CSI' setting).
2. Any additional specific 'Context Genes' you add below.
The final network is a combined view. Choose an Interaction Source (pathways or protein interactions) and optionally compare CSI scores with a Baseline Cell Type.

Maximum number of selected genes.
Select a context for the baseline cell.
Select a context for the target cell.
Target Cell for CSI:  fast muscle cell (CL0000190)

 Legend
Nodes (Genes):
 Query Gene
Node size also reflects Target Cell CSI magnitude.
Node Color (Target Cell CSI in specific network):
 Very High
 High
 Medium
 Low
 Very Low
 N/A or Not Sig.
Edges (Interactions):
 STRING (Protein-Protein)
 ONTOLOGY (Shared Pathway)
 Colors vary by pathway category; default arrow applies.

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## Summary The [fast muscle cell](/details-cell/CL0000190), also known as a glycolytic muscle fiber, is a highly specialized cell type defined by its capacity to develop high tension rapidly. **Overall**, its gene significance profile is dominated by markers essential for muscle contraction, structural integrity, high-capacity energy buffering, and mechanical stress response. Key defining markers include the ankyrin repeat protein [ANKRD2](/details-gene/26287), a component of the titin-based stress-sensing machinery ([Link](https://doi.org/10.1016/j.jmb.2003.09.012)), and muscle-specific creatine kinase ([CKM](/details-gene/1158), vital for rapid ATP regeneration. A striking feature of this cell is the significant negative enrichment for genes encoding core components of the mitochondrial respiratory chain, which underscores its reliance on anaerobic glycolysis for energy production, consistent with its functional role in rapid, short-duration contractions. ## Key Characteristics and Function The functional identity of the [fast muscle cell](/details-cell/CL0000190) is established by several coordinated groups of highly expressed and specific genes. * **Contractile and Cytoskeletal Apparatus:** A large number of top markers are structural components of the sarcomere and its supporting cytoskeleton. These include [NEB](/details-gene/4703) (Nebulin), which specifies thin filament length, and multiple troponin subunits ([TNNC2](/details-gene/7125) and [TNNT3](/details-gene/7140)) that regulate the calcium-dependent actin-myosin interaction. Other significant structural proteins are [MYBPC1](/details-gene/4604) (Myosin Binding Protein C), [TCAP](/details-gene/8557) (Telethonin), and [DES](/details-gene/1674) (Desmin), which collectively ensure the structural integrity and force transduction capabilities of the myofibril. * **Energy Metabolism and Ion Homeostasis:** The cell's capacity for rapid, powerful contractions is supported by genes involved in immediate energy provision and electrical excitability. The high significance of [CKM](/details-gene/1158) highlights the critical role of the phosphocreatine system in buffering ATP levels. [MB](/details-gene/4151) (Myoglobin) expression provides an intracellular oxygen reserve for metabolic bursts. Furthermore, the prominence of [ATP1B1](/details-gene/481), a subunit of the Na+/K+ pump, is essential for maintaining the electrochemical gradients required for repeated membrane depolarization and excitation-contraction coupling, a process in which [TRDN](/details-gene/10345) (Triadin) also plays a key role. * **Regulatory and Stress-Response Network:** The cell phenotype is actively maintained by a suite of regulatory molecules. [ANKRD2](/details-gene/26287) is a notable marker linked to the titin filament, where it is thought to participate in mechanical stress signaling ([Link](https://doi.org/10.1016/j.jmb.2003.09.012)). Additionally, the high significance of the long non-coding RNA [NEAT1](/details-gene/283131) and RNA-binding proteins like [RBFOX1](/details-gene/54715) suggests that post-transcriptional regulation, including alternative splicing, is a critical layer of control in defining the fast-twitch identity. * **Defining Negative Markers:** The anti-marker profile strongly delineates the cell's metabolic specialization. There is a profound and consistent negative significance for a large suite of genes encoding subunits of the mitochondrial electron transport chain, including [ND1](/details-gene/4535), [ND2](/details-gene/4536), [ND4](/details-gene/4538), [ND5](/details-gene/4540), [COX1](/details-gene/4512), [COX2](/details-gene/4513), [COX3](/details-gene/4514), and [CYTB](/details-gene/4519). This molecular signature confirms the cell's identity as a 'glycolytic fiber', which relies on anaerobic metabolism rather than sustained oxidative phosphorylation, typical of slow-twitch fibers. ## Clinical Significance and Contextual Roles While this analysis covers an **Overall** context, the specific gene markers of the [fast muscle cell](/details-cell/CL0000190) have direct implications for human health and disease, particularly in the context of myopathies and neuromuscular disorders. Many of the top structural genes, such as [NEB](/details-gene/4703), [TCAP](/details-gene/8557), and [DES](/details-gene/1674), are well-established disease genes; mutations in them cause various forms of nemaline myopathy, limb-girdle muscular dystrophy, and desminopathy, respectively. The high specificity of these genes in this cell type underscores why these diseases manifest with primary muscle pathology. Intriguingly, the marker gene [CNBP](/details-gene/7555), a zinc-finger RNA-binding protein, is directly implicated in Myotonic Dystrophy Type 2, which is caused by a CCTG repeat expansion in the first intron of the gene ([Link](https://doi.org/10.1126/science.1062125)). Its status as a significant marker highlights the cell-type specific context in which this genetic defect exerts its pathogenicity. Similarly, the protease inhibitor [CST3](/details-gene/1471) is a top marker, and a specific mutation in this gene is known to cause hereditary amyloid angiopathy leading to stroke ([Link](https://doi.org/10.1084/jem.169.5.1771)). Its high expression in [fast muscle cells](/details-cell/CL0000190) is an unexpected finding and may suggest an uncharacterized role for this protein in muscle homeostasis or pathology. ## Potential Mechanisms and Research Directions 1. **Hypothesis:** The distinct metabolic profile of the [fast muscle cell](/details-cell/CL0000190) is not merely a passive consequence of development but is actively maintained by suppressing mitochondrial biogenesis and function. The profound negative signature across nearly all core mitochondrial respiratory genes ([ND1](/details-gene/4535), [COX1](/details-gene/4512), [CYTB](/details-gene/4519), etc.) suggests the presence of dominant repressive mechanisms. * **Surprising Findings:** The uniformity and depth of the negative significance for mitochondrial-encoded genes is particularly striking. This provides a robust "anti-signature" that is as informative for cell identification as the positive markers of the contractile apparatus. * **Testable Questions:** What are the key transcription factors and signaling pathways (e.g., PGC-1alpha, AMPK) that are actively suppressed in [fast muscle cells](/details-cell/CL0000190) compared to slow-twitch fibers to maintain a glycolytic state? 2. **Hypothesis:** A complex network of post-transcriptional regulation, orchestrated by RNA-binding proteins and long non-coding RNAs, is essential for establishing and maintaining the specific isoform expression and protein stoichiometry required for the fast-twitch phenotype. The high significance of the splicing regulator [RBFOX1](/details-gene/54715), the lncRNA [NEAT1](/details-gene/283131), and the RNA-binding protein [CNBP](/details-gene/7555) supports this model. * **Surprising Findings:** The identification of [NEAT1](/details-gene/283131), a core structural component of nuclear paraspeckles often studied in the context of cancer and innate immunity, as a top-ten defining marker of a muscle cell is highly unexpected. This suggests a novel, tissue-specific role for this lncRNA in muscle biology. * **Testable Questions:** Does selective knockdown of [NEAT1](/details-gene/283131) in myocyte cultures programmed towards a fast-twitch lineage result in altered splicing patterns of key contractile genes like [TNNT3](/details-gene/7140) or a shift in metabolic gene expression?