Sex combs on midleg, Su(z)302
Polycomb group - a member of a protein complex, termed PRC1 (Polycomb repressive complex 1) - Preincubation of nucleosomal arrays with PRC1 blocks the ability of these arrays to be remodeled by SWI/SNF - coordinates PcG complexes and polymerizes to produce broad domains of PcG silencing
Gene model reviewed during 5.53
Scm associates with the PRC1 core complex containing PSC, PC, PH and Sce/RING1. Forms homotypic and heterotypic interactions. Interacts with the SAM domain of ph-p via its SAM domain in vitro. Interacts with corto in vitro.
The SAM domain is essential for function.
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\Scm using the Feature Mapper tool.
Comment: reference states >12 hr AEL
GBrowse - Visual display of RNA-Seq signalsView Dmel\Scm 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.
Scm is required for normal neuroblast survival and proliferation in postembryonic central nervous system development.
Silencing activity depends upon a protein interaction domain in tethered Scm protein.
Pc-G proteins can silence gene expression at a large number of chromosomal locations, affecting both enhancer-activated and basal w transcription. Repression is observed even with separation distances of up to 3.0kb between target promoters and binding sites for tethered Pc-G proteins.
Pc, Scm, Psc, ph-p and ph-d contribute to the PRC1 (Polycomb repressive complex 1). PRC1 directly antagonizes ATP-dependent remodeling of nucleosomal arrays in a purified system and may directly modulate (and be modified by) SWI/SNF (brm/mor) activity.
Silencing activity of the iab-7PRE in the bithorax complex is dependent upon proteins from the Polycomb group.
Scm encodes a zinc finger protein with similarity to the polyhomeotic proteins.
In an effort to subdivide the Pc-group genes functionally, the phenotypes of adult flies heterozygous for every pairwise combination of Pc-group mutation were examined. Asx, Pc, Pcl, Psc, Scm and Sce have similar functions in some imaginal tissues. Most duplications of Pc-group genes neither exhibit anterior transformations nor suppress the extra sex comb phenotype of Pc-group mutations, suggesting that not all Pc-group genes behave as predicted by the mass action model.
The bithorax complex genes are regulated by the Pc group of genes, acting via 'Pc group response elements' (PREs), that can work even when removed from the normal bithorax complex context. The Pc group products apparently provide stable memory or imprinting of boundaries which are specified by gap and pair-rule regulators.
Embryos mutant for two or more Pc group genes (Pc, Scm, Pcl, Psc, Asx, E(Pc), E(z), ph-d, pho and esc) show strong ectopic en expression, but only weak derepression occurs if embryo is mutant at only one of the Pc group genes. This effect is independent of the function of en itself, and wg.
Mutations of genes in the polycomb group (esc, E(z), Pc, ph-p, ph-d, Scm, Pcl, Sce, Asx, Psc, pho and Antp) cause abnormal segmental development due to the ectopic expression of abd-A and Abd-B. Embryos lacking both maternal and zygotic Scm product were generated to determine abd-A and Abd-B expression patterns.
The Pc group genes are negative regulators of homeotic genes.
Dominant suppressor of z1 eye colour: yellow eye colour darken to an orange tan, and is also associated with homeotic transformations.
Scm is one of the 18 loci identified in a screen for dominant modifiers of Pc and/or Antp phenotypes. Alleles of Pc, Pcl, Scm, Dll, brm, kto, Scr and trx show clear dominant enhancement or suppression of AntpScx, whereas alleles of vtd, Vha55, Su(Pc)37D, urd, mor, skd and osa do not.
Pole cell transplantation techniques demonstrate that Scm is maternally expressed and is required for normal BXC expression during embryogenesis.