Pre-mRNA splicing.
<P>
<Li> Small  nuclear  RNAs  (snRNAs) form a complex called a spliceosome
with small nuclear ribonucleoproteins (snRNPs) and other proteins.
<Li> The  snRNAs  bind  to  specific  nucleotides  in  the introns of a
pre-mRNA.
<Li> The  RNA transcript is cut, releasing the introns and splicing the
exons together, producing mature mRNA.