Do the terms exon shuffling and alternative splicing mean the same ?
Exons serve as “modules,” or useful gene segments, that can be shuffled (via gene duplication and transposable elements, for instance) to create genes for new proteins with novel functions. For instance, a module for a membrane-embedding domain could be linked to a module for an oxygen-binding domain, allowing oxygen to be stored on a membrane, or a hormone-binding domain might be joined to a promoter-binding domain, allowing a hormone to control gene transcription. After the gene is copied, or transcribed, to RNA, the introns are removed from this “pre-mRNA,” and the exons are spliced together to form a mature mRNA, consisting of one contiguous protein-coding sequence. In addition, the complete mRNA contains upstream and downstream sequences flanking the coding sequences. These sequences do not encode protein, but help to regulate translation of the mRNA into protein. Variations in the splice pattern lead to alternative transcripts and alternative proteins. Bottom line – Splicing is “
