Dscam, Down syndrome cell adhesion molecule, l(2)43Bc, Drosophila Down syndrome cell adhesion molecule, Neu1
95 alternative exons are arranged in four clusters.The exon 4, 6, 9, and 17 clusters contain 12, 48, 33, and 2 variable exons, respectively. The exons within each cluster are alternatively spliced in a mutually exclusive manner such that Dscam mRNAs contain only one variable exon from each cluster.
Dscam can potentially encode 38,016 different mRNAs by virtue of alternative splicing. The Dscam gene contains 115 exons, 20 of which are constitutively spliced and 95 of which are alternatively spliced FBrf0139679
Annotated transcripts do not represent all possible combinations of alternative exons.
All variable Dscam exons from GB:AF260530 have been annotated in at least one transcript. Where possible, they have been annotated in a combination found in an mRNA characterized in FBrf0128634 or FBrf0156018. Remaining variable exons 6.11, 6.17, 6.29, 6.31, 6.38, 6.40, 6.41, 9.10, 9.28, and 9.29 have been arbitrarily joined with other variable exons.
Low-frequency RNA-Seq exon junction(s) not annotated.
Gene model reviewed during 5.47
Variant in sequenced strain: frameshift at 2R:7342645 affects one of the 33 alternative exons for exon 9.
None of the polypeptides share 100% sequence identity.
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Dscam1 using the Feature Mapper tool.
Isoform-specific expression patterns are observed. Alternative exon 4 variants of Dscam1 are expressed at different frequencies in the mushroom body. In class IV dendritic arborizing neurons, the splicing of Dscam1 exon 4 is probabilistic, not deterministic. The frequency of inclusion of particular exon 4 variants is different between cell types, and changes over time.
GBrowse - Visual display of RNA-Seq signalsView Dmel\Dscam1 in GBrowse 2
Please Note FlyBase no longer curates genomic clone accessions so this list may not be complete
Please Note This section lists cDNAs and ESTs that fall within the genomic extent of the gene model, which may include cDNAs and ESTs of genes within introns, or of overlapping genes. Please see GBrowse for alignment of the cDNAs and ESTs to the gene model.
For each fully sequenced cDNA the DGRC maintains various forms of the cDNA (e.g tagged or untagged) in several different host vectors for subsequent cloning and expression in Drosophila and Drosophila cell lines.
Dscam diversity is essential for neural circuit assembly in the brain. It is crucial for neighbouring neurons to express distinct Dscam isoforms, but the specific identity of the isoforms expressed in an individual neuron is unimportant. Dscam diversity appears to provide each neuron with a unique identity by which it can distinguish its own processes from those of other neurons, and this self-recognition is essential for wiring the brain.
Dendrite self avoidance in da sensory neurons requires cell-recognition molecules encoded by the Dscam locus. Interactions between identical Dscam isoforms on the cell surface underlie self-recognition, while the cytoplasmic tail is required to convert this recognition to dendrite repulsion.
Alternative splicing of Dscam can potentially generate 19,008 distinct extracellular domains containing different combinations of three variable immunoglobulin domains. 95% (more than 18,000) of these isoforms exhibit striking isoform-specific homophilic binding in a high-throughput ELISA-based binding assay. Each of the three variable domains binds to the same variable domain in an opposing isoform.
Hemocyte-specific loss of Dscam function impairs the efficiency of phagocytic uptake of bacteria.
Dscam plays an early role in promoting selective fasciculation of young axons in the peduncle of the developing mushroom body.
dsRNA made from templates generated with primers directed against this gene tested in RNAi screen for effects on Kc167 and S2R+ cell morphology.
Dscam has a role in mediating formation and guidance of axonal branches in the mushroom body.