dNOS, NO synthase
Ca++/Calmodulin sensitive enzyme - ectopic expression of NOS at the late stages of larval development results in a decrease in cell proliferation and a reduction in the size of the adult fly's structures - regulates growth coordination during imaginal disc regeneration
Multiple transcript isoforms producing truncated protein isoforms have been postulated (FBrf0145604); since there is little supporting data, only one truncated isoform has been retained in the most recent annotation.
Gene model reviewed during 5.51
Low-frequency RNA-Seq exon junction(s) not annotated.
Gene model reviewed during 5.52
5.0 (northern blot)
None of the polypeptides share 100% sequence identity.
1350 (aa); 150 (kD observed); 152 (kD predicted)
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Nos using the Feature Mapper tool.
Nos-RA (dNOS1) and Nos-RF (dNOS4) are co-expressed at all developmental stages. Expression levels of both transcripts are comparable in embryos, but expression of Nos-RF is lower in larvae and adults than is expression of Nos-RA.
Nos protein expression is upregulated in the ring gland very late in larval development; expression is detected mostly in the corpus cardiacum at "blue gut" stage, but detectable thoughout the entire ring gland at "cleared gut" stage.
Nos protein is expressed in white prepupae in a small set of cells in the optic lobe, directly adjacent to the termini of the retinal axons. By pupal stage P6 (24 hr APF), Nos protein is expressed at a low level in the lamina, and at a high level in the medulla. This pattern continues through pharate adult stage P8 (50 hr APF), then decreases by pharate adult stage P9 (72 hr APF). No expression is observed in the optic lobe at pharate adult stage P15 (96 hr APF).
Histochemical staining for the NADPH-diaphorase activity of Nos protein was used to detect Nos protein in all imaginal discs, imaginal rings, histoblasts and the larval brain. Protein is first detected early in third instar larvae. Staining becomes more intense as development proceeds and in late third instar larvae and early pupal stages a very specific and reproducible pattern of staining is seen in each disc. Nos protein reaches its highest levels in imaginal discs at the time when the cell cycle slows down and then gradually decreases through early pupal development. The pattern of staining in leg discs is described in detail.
GBrowse - Visual display of RNA-Seq signalsView Dmel\Nos 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.
Alternative transcription start sites and alternative splice sites are used to generate a large number of different mRNAs from the Nos gene. Some of these mRNAs encode truncated Nos polypeptides that can form heterodimers with full-length Nos protein (NOS1) and strongly inhibit its enzymatic activity when co-expressed in cultured mammalian cells.
Nos is expressed in imaginal discs during larval development. Inhibition of Nos activity (by injection of specific Nos inhibitors) at the late stages of larval development results in excessive cell proliferation and increased size of structures of the adult body, changes are most profound in and most often affected the leg segments. Excessive proliferation of various cell types in the eye is masked by programmed cell death in the larvae and pupae.