Details for: CL4033028

Cell ID: CL4033028

Cell Name: diffuse bipolar 2 cell

Description: An OFF diffuse bipolar cell that predominantly connects to ON parasol cells and lateral amacrine cells. This cell contains a large number of synaptic ribbons and a small axon arbor area.

Synonyms: DB2 cell

Selected Context(s): Overall

Gene Significance Landscape

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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 diffuse bipolar 2 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 diffuse bipolar 2 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 diffuse bipolar 2 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 diffuse bipolar 2 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.
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Select a context for the target cell.
Target Cell for CSI:  diffuse bipolar 2 cell (CL4033028)

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Node size also reflects Target Cell CSI magnitude.
Node Color (Target Cell CSI in specific network):
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 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 [diffuse bipolar 2 cell](/details-cell/CL4033028) (DB2) is an OFF-type bipolar neuron within the retina, characterized by its role in relaying signals through synaptic connections with ON parasol cells and lateral amacrine cells. Based on its gene significance profile, this cell type is defined by an exceptionally strong and specific transcriptional and epigenetic regulatory program. High Cell Significance Index (CSI) scores for multiple chromatin-modifying enzymes ([KMT2E](/details-gene/55904), [KMT2C](/details-gene/58508)) and transcription coregulators ([CAMTA1](/details-gene/23261)) suggest that its distinct identity and function are actively maintained by a complex regulatory network. This program supports the expression of key synaptic machinery components, such as [RIMS1](/details-gene/22999) and [NRXN3](/details-gene/9369), which are crucial for its specialized role in the visual processing circuit. ## Key Characteristics and Function **Overall**, the gene expression landscape of the [diffuse bipolar 2 cell](/details-cell/CL4033028) points to a highly specialized, terminally differentiated neuron with a sophisticated system for maintaining its unique functional state. The top marker genes can be organized into several key functional clusters. * **Epigenetic and Transcriptional Regulation:** A prominent feature of this cell is the high significance of genes involved in chromatin organization and transcription. This includes histone methyltransferases like [KMT2E](/details-gene/55904) and [KMT2C](/details-gene/58508), histone demethylase [JMJD1C](/details-gene/221037), and chromatin remodeling complex member [ARID1B](/details-gene/57492). These are complemented by the high specificity of transcription coregulators such as [CAMTA1](/details-gene/23261) and the DNA-binding transcription factor [ZNF292](/details-gene/23036). This molecular signature suggests that the cell's specific phenotype is established and preserved through a stable, yet actively maintained, epigenetic landscape that dictates a precise transcriptional output. * **Synaptic Architecture and Neurotransmission:** The cell's function as a neuron is underscored by the high significance of genes critical for synaptic structure and signal transmission. [RIMS1](/details-gene/22999) and [PPFIA2](/details-gene/8499) are key scaffolding proteins of the presynaptic active zone, crucial for neurotransmitter release. [NRXN3](/details-gene/9369), a neurexin, is a cell adhesion molecule vital for synapse formation and specification. The presence of GABA receptor subunits ([GABBR2](/details-gene/9568), [GABRR3](/details-gene/200959)) indicates responsiveness to inhibitory inputs, consistent with its integration into complex retinal circuits. Furthermore, the voltage-gated potassium channel [KCNMA1](/details-gene/3778) is a key determinant of neuronal excitability. * **Post-Transcriptional and Signaling Control:** The high CSI for [TNRC6B](/details-gene/23112), a core component of P-bodies, points to the importance of post-transcriptional gene silencing, likely via microRNAs, in fine-tuning protein expression levels. Additionally, the tumor suppressor [PTEN](/details-gene/5728), a phosphatase that negatively regulates the PI3K/AKT signaling pathway, is a top marker. Its prominent role suggests stringent control over cell growth, survival, and metabolic pathways, which is critical for maintaining homeostasis in a long-lived post-mitotic neuron. * **Cellular Identity Profile:** The anti-marker profile provides crucial negative context. The significant negative CSI scores for a large number of core mitochondrial genes involved in the respiratory chain (e.g., [ND1](/details-gene/4535), [ND2](/details-gene/4536), [ND5](/details-gene/4540), [COX1](/details-gene/4512), [COX3](/details-gene/4514)) is particularly noteworthy. This does not imply an absence of mitochondria but suggests a metabolic phenotype with a comparatively lower reliance on oxidative phosphorylation than the average cell type in its environment. Similarly, the negative association with ubiquitous housekeeping genes like [FTH1](/details-gene/2495) (ferritin), [UBB](/details-gene/7314) (ubiquitin), and [CFL1](/details-gene/1072) (cofilin) reinforces the concept of a highly specialized cell that may down-regulate general cellular programs to prioritize its unique neuronal functions. ## Clinical Significance and Contextual Roles While the provided data represents an **Overall** context, the specific marker genes of the [diffuse bipolar 2 cell](/details-cell/CL4033028) have significant clinical implications, particularly in neurodevelopmental and retinal diseases. The high significance of [RIMS1](/details-gene/22999) is of direct clinical relevance, as mutations in this gene are implicated in autosomal dominant cone-rod dystrophy (CORD7) ([Link](https://doi.org/10.1016/s0888-7543(03)00010-7)), a degenerative disease of the retina. This finding suggests that the [diffuse bipolar 2 cell](/details-cell/CL4033028) may be a vulnerable cell type in this condition, and its dysfunction could contribute to the disease phenotype. Furthermore, several of the top epigenetic regulators are linked to human diseases. Mutations in [PTEN](/details-gene/5728) are well-documented as a cause of various cancers ([Link](https://doi.org/10.1038/ng0497-356), [Link](https://doi.org/10.1126/science.275.5308.1943)). Although this cell is post-mitotic, dysregulation of [PTEN](/details-gene/5728) could impact neuronal survival and circuit stability. Similarly, genes like [KMT2C](/details-gene/58508), [ARID1B](/details-gene/57492), and [KANSL1](/details-gene/284058) are associated with neurodevelopmental syndromes (e.g., Kleefstra syndrome, Coffin-Siris syndrome, and Koolen-de Vries syndrome, respectively). Their specific enrichment in this cell type highlights a potential cellular locus for investigating the retinal or visual processing deficits that may occur in these disorders. The unique molecular signature of the [diffuse bipolar 2 cell](/details-cell/CL4033028) may thus render it susceptible to a range of genetic perturbations affecting neuronal development, function, and survival. ## Potential Mechanisms and Research Directions 1. **Hypothesis:** The distinct identity and synaptic specificity of the [diffuse bipolar 2 cell](/details-cell/CL4033028) are actively enforced by a combinatorial code of chromatin-modifying enzymes, including [KMT2E](/details-gene/55904), [KMT2C](/details-gene/58508), and [ARID1B](/details-gene/57492). This epigenetic machinery establishes and maintains a unique chromatin accessibility landscape that ensures high-level expression of synaptic genes like [RIMS1](/details-gene/22999) and [NRXN3](/details-gene/9369) while silencing genes associated with other neuronal or glial fates. * **Surprising Findings:** The striking prominence of a large suite of chromatin regulators, many of which are more commonly studied in the context of pluripotency and cancer, as the top identity markers for a terminally differentiated retinal neuron is unexpected. This suggests that the maintenance of a stable neuronal phenotype is a highly active process requiring continuous epigenetic oversight. * **Testable Questions:** Does cell-type-specific conditional knockout of [KMT2C](/details-gene/58508) or [ARID1B](/details-gene/57492) in developing or adult retinal bipolar cells lead to a measurable loss of DB2 cell identity, aberrant synaptic rewiring, and specific deficits in the OFF visual pathway as measured by electroretinography? 2. **Hypothesis:** The [diffuse bipolar 2 cell](/details-cell/CL4033028) operates with a distinct, low-energy metabolic profile characterized by a reduced reliance on oxidative phosphorylation, as indicated by the significantly lower expression of core mitochondrial respiratory chain genes ([ND1](/details-gene/4535), [COX1](/details-gene/4512), etc.). This specialized metabolic state may be an adaptation to its specific signaling load but could also represent a key vulnerability, rendering it exceptionally sensitive to ischemic or metabolic insults characteristic of diseases like diabetic retinopathy or glaucoma. * **Surprising Findings:** For a neuron, which is typically viewed as a cell with high energy demands, the strong negative significance of numerous essential mitochondrial genes is counterintuitive. It challenges the assumption of a uniformly high rate of oxidative phosphorylation across all retinal interneurons and suggests significant metabolic heterogeneity within the retinal circuitry. * **Testable Questions:** Using single-cell metabolic profiling or in vivo imaging with metabolic sensors, can we confirm that [diffuse bipolar 2 cells](/details-cell/CL4033028) exhibit a lower rate of oxygen consumption and a greater reliance on glycolysis compared to adjacent retinal neurons, such as amacrine or ganglion cells, under both basal and stimulated conditions?