Editing Alternative splicing (section)

{{Short description|Process by which a gene can code for multiple proteins}}
[[File:DNA alternative splicing.gif|450px|right|thumb|Alternative splicing produces three protein [[isoform]]s. Protein A includes all of the exons, whereas Proteins B and C result from [[exon skipping]].]]

'''Alternative splicing''', '''alternative RNA splicing''', or '''differential splicing''', is an alternative [[RNA splicing|splicing]] process during gene expression that allows a single gene to produce different splice variants. For example, some exons of a gene may be included within or excluded from the final [[RNA]] product of the gene.<ref name=Black/> This means the exons are joined in different combinations, leading to different splice variants. In the case of protein-coding genes, the proteins translated from these splice variants may contain differences in their amino acid sequence and in their biological functions (see Figure).

Biologically relevant alternative splicing occurs as a normal phenomenon in [[eukaryote]]s, where it increases the number of proteins that can be encoded by the genome.<ref name=Black/> In humans, it is widely believed that ~95% of multi-exonic genes are alternatively spliced to produce functional alternative products from the same gene<ref name=Pan2008/> but many scientists believe that most of the observed splice variants are due to splicing errors and the actual number of biologically relevant alternatively spliced genes is much lower.<ref>{{ cite journal | vauthors = Bhuiyan SA, Ly S, Phan M, Huntington B, Hogan E, Liu CC, Liu J, Pavlidis P | date = 2018 | title = Systematic evaluation of isoform function in literature reports of alternative splicing | journal = BMC Genomics | volume = 19 | issue = 1 | pages = 637 | doi = 10.1186/s12864-018-5013-2| pmid = 30153812 | pmc = 6114036 | s2cid = 52113302 | doi-access = free }}</ref><ref>{{ cite journal | vauthors = Tress ML, Abascal F, Valencia A | date = 2017 | title = Alternative splicing may not be the key to proteome complexity | journal = Trends in Biochemical Sciences | volume = 42 | issue = 2 | pages = 98–110 | doi = 10.1016/j.tibs.2016.08.008| pmid = 27712956 | pmc = 6526280 }}</ref>