fs(1)1621, fs(1)A1621, liz, splicing necessary factor, SNF/D25
splicing factor - a crucial component of the spliceosome - regulates alternative splicing - a protein component of U1 and U2 small nuclear ribonucleoproteins (snRNPs) - U1 and U2 snRNPs combine with other snRNPs on the pre-mRNA to assemble a spliceosome - involved in Sex-lethal splicing and consequently in sex determination
Gene model reviewed during 5.50
There is only one protein coding transcript and one polypeptide associated with this gene
Belongs to the spliceosome where it is associated with snRNP U1. Interacts with the SMN complex.
Click to get a list of regulatory features (enhancers, TFBS, etc.) and gene disruptions (point mutations, indels, etc.) within or overlapping Dmel\snf using the Feature Mapper tool.
GBrowse - Visual display of RNA-Seq signalsView Dmel\snf in GBrowse 2
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.
Source for identity of: snf CG4528
The gene products of U2A and snf are co-immunoprecipitated by antibodies to either protein, demonstrating that like their yeast and human counterparts they heterodimerize in vivo. A mutation in the U2A binding motif of snf reduces the amount of heterodimer formation but does not abolish it completely. The U2A binding motif from snf is only essential for heterodimer formation in the absence of the C-terminal end of the protein. The RNA binding specificity domain of snf is essential for interaction with U2A. The U2A gene product incorporation into U2 snRNP does not depend on dimerization of the U2A and snf gene products.
SNF is a component of both U1 and U2 snRNPs. In vitro SNF binds U1 snRNA on its own and U2 snRNA in the presence of Drosophila nuclear extract or human U2A' protein.
Zygotic snf function is required for sexual differentiation and a cell vital process during postembryonic development. snf protein cooperates with the female-specific Sxl protein to block utilisation of the male-specific exon of the Sxl pre-mRNA.
Tumorous cells produced by snf mutants are capable of female-specific transcription and RNA processing indicating the ovarian cells retain some female identity. It is proposed that mutations do not cause male transformation of the female germ line but instead either cause an ambiguous sexual identity or block specific stages of oogenesis.
snf is an essential gene and an integral component of the machinery required for splice site recognition.
Mutants display germline hyperplastic phenotype.
The genetic hierarchy regulating female germ-line sex determination includes tra, tra2, dsx, fu, otu, ovo, snf and Sxl. otu+, ovo+ and snf+ activities are required for female-specific Sxl+ pre-mRNA splicing within 2X germ-line cells.
D25 is the Drosophila homologue of U1-A human protein despite its sequence similarity to U2-B human protein.
The snf locus displays a lethal synergistic interaction with Sxl. snf is a positive regulator of Sxl in the germline and soma.
The interaction between snf and Sxl mutations reduces the viability of females heterozygous for Sxl. The mosaicism exhibited by flies heterozygous for snf and Sxl- suggests that the transformation of diplo-X tissues to male morphology is due to the interaction of snf and Sxl in the zygote.
Homozygous females have small ovaries filled with undifferentiated germ cells and very rare oocytes with nurse cells. Females of the genotype Df(1)HC244, SxlM1/snf are fully fertile with normal looking ovaries, snf must act upstream of Sxl. Maternal snf gene product is involved in the activation of zygotic snf+ genes.