Alternative splicing and one gene one polypeptide hypothesis

Alternative splicing is a regulated process during gene expression that results in a single gene coding for multiple proteins. in this process, particular exons of a gene may be included within, or excluded from, the final, processed messenger RNA (mRNA) produced from that gene. Consequently the proteins translated from alternatively spliced mRNAs will contain differences in their amino acid sequence and, often, in their biological functions. Notably, alternative splicing allows the human genome to direct the synthesis of many more proteins than would be expected from its 20,000 protein-coding genes. It has been proposed that for eukaryotes alternative splicing was a very important step towards higher efficiency, because information can be stored much more economically. Several proteins can be encoded by a single gene, rather than requiring a separate gene for each, and thus allowing a more varied proteome from a genome of limited size. So the previous one gene one polypeptide hypothesis in no more valid, now one gene many polypeptide hypothesis is valid.