E-MTAB-6219
DNA-seq of a library of mutated minigene reporters.
We developed a high-throughput mutagenesis screen to comprehensively identify the cis-regulatory elements that control a target splicing event from the MST1R gene that codes for the RON receptor tyrosine kinase. Skipping of alternative exon 11 results in a constitutively active isoform that promotes epithelial to mesenchymal transition and thereby contributes to the invasive phenotype of tumors. First, we created a library of mutated minigenes via mutagenic PCR. Importantly, the reverse primer introduced a random barcode sequence which labels the associated mutations. Next, the plasmid library was transfected as a pool and depending on the mutations, the transcripts exhibit changes in alternative splicing. The minigene library and the splicing outcome were analyzed by next-generation sequencing and subsequent integration of the datasets resulted in a map of splicing regulatory sites. The DNA-seq experiment was performed to map the mutations and the associated barcodes in order to identify all minigene variants in the library.  For sequencing, we generated five overlapping amplicons of the minigene library using four different forward primers: 5'CAAGCAGAAGACGGCATACGAGATCGGTCTCGGCATTCCTGCTGAACCGCTCTTCCGATCTNNNNNNNNNNCTATAGGGAGACCCAAGCTT 3', 5'CAAGCAGAAGACGGCATACGAGATCGGTCTCGGCATTCCTGCTGAACCGCTCTTCCGATCTNNNNNNNNNNGTTCCACTGAAGCCTGAG 3', 5'CAAGCAGAAGACGGCATACGAGATCGGTCTCGGCATTCCTGCTGAACCGCTCTTCCGATCTNNNNNNNNNNAGCTGCCAGCACGAGTTC 3', 5'CAAGCAGAAGACGGCATACGAGATCGGTCTCGGCATTCCTGCTGAACCGCTCTTCCGATCTNNNNNNNNNNGAATCTGAGTGCCCGAGG 3', and 5'CAAGCAGAAGACGGCATACGAGATCGGTCTCGGCATTCCTGCTGAACCGCTCTTCCGATCTNNNNNNNNNNctactggctggtcctcatga 3', and 5'AATGATACGGCGACCACCGAGATCTACACTCTTTCCCTACACGACGCTCTTCCGATCTNNNNNNNNNNATAGAATAGGGCCCTCTAGA 3' as a common reverse primer. After amplification, the PCR products were cleaned using the GeneRead size selection Kit (QIAGEN) according to manufacturer's instructions. The purified products were first analysed with the TapeStation 2200 capillary gel electrophoresis instrument (Agilent) and then fluorimetrically quantified using a Qubit fluorimeter (Thermo Scientific). Sequencing was carried out on the Illumina MiSeq platform using paired-end reads of 300 nt length and a 10% PhiX spike-in to increase sequence complexity.
We developed a high-throughput mutagenesis screen to comprehensively identify the cis-regulatory elements that control a target splicing event from the MST1R gene that codes for the RON receptor tyrosine kinase. Skipping of alternative exon 11 results in a constitutively active isoform that promotes epithelial to mesenchymal transition and thereby contributes to the invasive phenotype of tumors. First, we created a library of mutated minigenes via mutagenic PCR. Importantly, the reverse primer introduced a random barcode sequence which labels the associated mutations. Next, the plasmid library was transfected as a pool and depending on the mutations, the transcripts exhibit changes in alternative splicing. The minigene library and the splicing outcome were analyzed by next-generation sequencing and subsequent integration of the datasets resulted in a map of splicing regulatory sites. The DNA-seq experiment was performed to map the mutations and the associated barcodes in order to identify all minigene variants in the library.  For sequencing, we generated five overlapping amplicons of the minigene library using four different forward primers: 5'CAAGCAGAAGACGGCATACGAGATCGGTCTCGGCATTCCTGCTGAACCGCTCTTCCGATCTNNNNNNNNNNCTATAGGGAGACCCAAGCTT 3', 5'CAAGCAGAAGACGGCATACGAGATCGGTCTCGGCATTCCTGCTGAACCGCTCTTCCGATCTNNNNNNNNNNGTTCCACTGAAGCCTGAG 3', 5'CAAGCAGAAGACGGCATACGAGATCGGTCTCGGCATTCCTGCTGAACCGCTCTTCCGATCTNNNNNNNNNNAGCTGCCAGCACGAGTTC 3', 5'CAAGCAGAAGACGGCATACGAGATCGGTCTCGGCATTCCTGCTGAACCGCTCTTCCGATCTNNNNNNNNNNGAATCTGAGTGCCCGAGG 3', and 5'CAAGCAGAAGACGGCATACGAGATCGGTCTCGGCATTCCTGCTGAACCGCTCTTCCGATCTNNNNNNNNNNctactggctggtcctcatga 3', and 5'AATGATACGGCGACCACCGAGATCTACACTCTTTCCCTACACGACGCTCTTCCGATCTNNNNNNNNNNATAGAATAGGGCCCTCTAGA 3' as a common reverse primer. After amplification, the PCR products were cleaned using the GeneRead size selection Kit (QIAGEN) according to manufacturer's instructions. The purified products were first analysed with the TapeStation 2200 capillary gel electrophoresis instrument (Agilent) and then fluorimetrically quantified using a Qubit fluorimeter (Thermo Scientific). Sequencing was carried out on the Illumina MiSeq platform using paired-end reads of 300 nt length and a 10% PhiX spike-in to increase sequence complexity.