Sheet1 Page 1 RNA splicing-What is it?-Previously, biologists believed that eukaryotic genes were structured like prokaryotic genes-Instead they found large regions of DNA sequence in genes that was not in the mRNA transcript-These were later called *introns* while the coding sequences were called *exons*-In eukaryotes, a gene (DNA) is transcribed (the *primary mRNA transcript*) and then the introns are cut out and the exons ar e-This process, called RNA splicing, is aided by *snRNPs* (called snurps)-They base pair with introns and form a spiceosome-The snRNPs excise the intron and splice the exons together to produce the mature mRNA transcript Some eukaryotic genes contain no introns while others contain up to 50 introns THe introns can vary in length and it is unclear as to the function of introns One consequence of RNA splicing is alternative splicing THis is when different sets of exons (fom the same primary transcript) are included in the mature transcript Prokaryotic genes do not contain introns
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This note was uploaded on 05/06/2008 for the course BIOL 121 taught by Professor Lopez during the Fall '07 term at Lansing.