22.2 Nuclear splice junctions are interchangeable but are read in pairs GT-AG rule describes the presence of these constant dinucleotides at the first two and last two positions of introns of nuclear genes Splice sites are the sequences immediately surrounding the exon-intron boundaries 消当
GT-AG rule describes the presence of these constant dinucleotides at the first two and last two positions of introns of nuclear genes. Splice sites are the sequences immediately surrounding the exon-intron boundaries. 22.2 Nuclear splice junctions are interchangeable but are read in pairs
22.2 Nuclear splice junctions are interchangeable but are read in pairs Left (5)ste Right(③)ste Exoe64⑤7310010462g4l63 12PyN C65A10F10JN EXon Intron Figure 22. 3 The ends of nuclear introns are defined by the gt-ag rule 消当
Figure 22.3 The ends of nuclear introns are defined by the GT-AG rule 22.2 Nuclear splice junctions are interchangeable but are read in pairs
22.2 Nuclear splice junctions are interchangeable but are read in pairs Correct splicing removes 3 introns by pairwise reoognit ion of the juncions Figure 22.4 Splicing Junctions are Pairing of wrong junctions would remove exons as well as introns, but aberrant products are not found recognIz red only in the correct pairwise GGU combinations 请莘大
Figure 22.4 Splicing junctions are recognized only in the correct pairwise combinations. 22.2 Nuclear splice junctions are interchangeable but are read in pairs
22.2 Nuclear splice junctions are interchangeable but are The vector cont ains two exons that are spliced together in the transcrip promotery 5' splice junction! 3 splice junction Figure 2.20 A special exon int ron exon splicing vector is used for exon trapping. If an A genomic fragment is inserted into the intron, any exon in the exon is present in the fragment will be found in the RNA Genomic fragment genomic fragment, its intron exon intron sequence will be Insert into recovered in the cloning site cytoplasmic RNA, but if the genomic fragment consists exon exon intron solely of an intron Transcrip splicing 消当
Figure 2.20 A special splicing vector is used for exon trapping. If an exon is present in the genomic fragment, its sequence will be recovered in the cytoplasmic RNA, but if the genomic fragment consists solely of an intron, 22.2 Nuclear splice junctions are interchangeable but are read in pairs
Gene =5.6 kb 22.2 Nuclear splice junctions 1■2■345l67 are interchangeable but are read in pairs ↓ 1.1kb Figure 22.5 Northern pRimary transcript(5.5 kb blotting of nuclear RNA with an ovomucoid pI robe identifies discrete Lacks introns 5&6 precursors to mRNA. The contents of the more Lacks introns 4.5.6.&7 prominent bands are Contains only intron 3 indicated. Photograph kindly provided by bert OMalley mRNA(1. 1 kb) 消当
Figure 22.5 Northern blotting of nuclear RNA with an ovomucoid probe identifies discrete precursors to mRNA. The contents of the more prominent bands are indicated. Photograph kindly provided by Bert O'Malley. 22.2 Nuclear splice junctions are interchangeable but are read in pairs