exon skipping is the removal of introns and joining of exons in eukaryotic rna.
exon skipping is the removal of introns and joining of exons in eukaryotic rna.
the removal of introns and joining of exons in eukaryotic rna?
exon skipping
exon shuffling was first introduced in 1978 when walter gilbert discovered that the existence of introns could play a major role in the evolution of proteins. it was noted that recombination within introns could help assort exons independently and that repetitive segments in the middle of introns could create hotspots for recombination to shuffle the exonic sequences. however, the presence of these introns in eukaryotes and absence in prokaryotes created a debate about the time in which these introns appeared. two theories arose: the "introns early" theory and the "introns late" theory. supporters of the "introns early theory" believed that introns and rna splicing were the relics of the rna world and therefore both prokaryotes and eukaryotes had introns in the beginning. however, prokaryotes eliminated their introns in order to obtain a higher efficiency, while eukaryotes retained the introns and the genetic plasticity of the ancestors. on the other hand, supporters of the "introns late" theory believe that prokaryotic genes resemble the ancestral genes and introns were inserted later in the genes of eukaryotes. what is clear now is that the eukaryotic exon-intron structure is not static, introns are continually inserted and removed from genes and the evolution of introns evolves parallel to exon shuffling.
exon shuffling
mature messenger rna









































mature messenger rna, often abbreviated as mature mrna is a eukaryotic rna transcript that has been spliced and processed and is ready for translation in the course of protein synthesis. unlike the eukaryotic rna immediately after transcription known as precursor messenger rna, mature mrna consists exclusively of exons and has all introns removed. 









































mature mrna is also called "mature transcript", "mature rna" or "mrna".









































the production of a mature mrna molecule occurs in 3 steps:
mature messenger rna