With regard to mature mRNA in eukaryotes

In eukaryotic cells, mature mRNA is formed through a meticulous process that ensures only the coding sequences, known as exons, are retained. Introns, which are non-coding or intervening sequences, are removed during the maturation process. This process, called splicing, occurs in the nucleus and is facilitated by a complex molecular machinery known as the spliceosome.

With regard to mature mRNA in eukaryotes, splicing is crucial because it eliminates introns and joins the exons together in a precise sequence. Exons are the coding regions of a gene that are expressed in the final mRNA molecule and subsequently translated into a protein. Conversely, introns do not contribute to the coding sequence and are removed to ensure the mRNA is functional and ready for translation.

Additionally, with regard to mature mRNA in eukaryotes, further modifications take place to enhance the stability and functionality of the mRNA. A 5' cap is added to the beginning of the transcript, and a poly-A tail is appended to its 3' end. These modifications protect the mRNA from degradation, facilitate its export from the nucleus, and aid in the translation process.

To summarize, with regard to mature mRNA in eukaryotes, exons are the sequences that remain after splicing, while introns are removed. The process of mRNA maturation ensures that only the necessary genetic information is carried forward to synthesize proteins, highlighting the efficiency and specificity of gene expression in eukaryotic cells.