How is transcribed mRNA processed in eukaryotes?

Eukaryotic mRNAs undergo multiple processing steps before they are transferred from the nucleus to the cytoplasm, where they can be translated into a protein.

When an RNA transcript is first produced in a eukaryotic cell, it is considered a pre-mRNA molecule. 

To process pre-mRNA into mRNA, a 5' cap is added to the beginning of the RNA transcript, and a 3' poly-A tail (tail of A nucleotides) is added to the end of the RNA transcript. 

The introns or non-coding sections of the RNA transcript are then removed, and the exons or coding sections are spliced together, creating mature mRNA that can travel out of the nucleus and be used to synthesize proteins. RNA-stabilizing proteins coat the mRNA transcript to prevent it from damage and degradation while being exported out of the nucleus.