Exon extension splicing

Exon Extension Splicing SVHO 2proteinsfrom single transcript t ag Tag Prevent Induce transformation apoptosis. & cell proliferation 5'SST 5SST 3'SST exon2 DNA GODI ) stop codon stopcodon A 2 1 2 mRNA, 1 exonextension and inclusion ofstopcodon. tag Tag Alternative splicing mediated bysteric hindrance startintron 2 5' 3' 2 3 4 or 1 2 4

combination of major & miron spuce HIC minor major AU AC GU AC GU AGIT 5'ss 3'ss major minor mojor SEP and SRP injuresce the inclusion & exclusion of exonscintions celltype 2 Cell type 1 Splicing site Represer 1 site repressor splicing roachienary fill spliced unspliced Splice site 1c Splicing encharce a 00 (activator 5 Unspliced. 3' spliced

Sex Petermination_Drosophilla Sex Letbal Male embryo - lack sxlprotein Produce transcript female embryo -has SXL protein noprotein more SXL transclipt protein splicing silencer Binding Protein Watson 444 Sonalebas SXL Produce more SXL 1 2 o Produce transformer (Tra) splicing enchances protein of DSX 1 To IH Or 24 Stop coden : : Translationsthere SXL protein or 0 2 34 Or 13 1 Tra protein (SEBP) or 1 2 3 Fresheaded by Tracomits Q 34 DSX Double Sex 3 4 5 6 Tra + Tra2 + Profer (An) 3 5 6 3 DSX OF

CPG methylated Inactive Demyethylated - -Active Transcription can proceed in right/ wrong direction 99% right wrong direction PAS-PAS-PAS- Pol areas than I % wrong PAS- - IT Keep somany Po III whylow. US inviscinity. PAS site is not neal 5' go 8 splicesite (Ue Right direction bindingsite) Term: - 5'PAS 5'PAS PAS- fc keepth RNA I SS SS polymerase in the viscinilyof Promoter since, the transcription in wrongdirection interminated immediately.