What is Alternative splicing?
[[File:Pre-mRNA to mRNA.svg|320px|right|Exons and introns in pre-mRNA: forming mature mRNA by splicing. The UTRs are non-coding parts of exons at the ends of the mRNA.]] [[File:Splicing overview.jpg|right|thumb|220px|Alternative splicing produces two protein [[isoform]]s.]] '''Alternative splicing''' allows DNA to code for more than one protein. It varies the [[exon]] make-up of the [[messenger RNA]]. In alternative splicing the [[exon]]s of the pre-[[messenger RNA]] produced by [[transcription (genetics)|transcription]] are reconnected in different ways during [[RNA splicing]]. This produces different mature messenger RNAs from the same gene. They get [[Translation (genetics)|translated]] into different [[protein]]s. Thus, a single gene may code for multiple proteins.<ref name=Black>{{cite journal|last = Black|first = Douglas L.|title = Mechanisms of alternative pre-messenger RNA splicing|journal = Annual Reviews of Biochemistry|volume = 72|issue = 1|pages = 291–336|year = 2003|doi = 10.1146/annurev.biochem.72.121801.161720|pmid = 12626338 | s2cid=23576288 |url = http://www.escholarship.org/uc/item/2hg605wm}}</ref> Alternative splicing is normal in [[eukaryote]]s. It greatly increases the diversity of proteins that can be encoded by the [[genome]].<ref name=Black/> In humans, ~95% of multiexonic [[Gene|genes]] are alternatively spliced.<ref>multiexonic: those genes where the coding sections (exons) are separated by non-coding sections (introns)</ref><ref name=Pan>{{cite journal|last = Pan|first = Q | display-authors = etal|title = Deep surveying of alternative splicing complexity in the human transcriptome by high-throughput sequencing|journal = Nature Genetics|volume = 40|pages = 1413–1415|year = 2008|pmid = 18978789|issue = 12|doi = 10.1038/ng.259|s2cid = 9228930 }}</ref><ref name=Matlin>{{cite journal|title = Understanding alternative splicing: towards a cellular code|journal = Nature Reviews|volume = 6|pages = 386–398|year = 2005|pmid = 15956978|issue = 5|doi = 10.1038/nrm1645|s2cid = 14883495|last1 = Ma