Final answer:
Alternative RNA splicing, regulated by the spliceosome, allows for the creation of multiple protein products from a single gene by varying the inclusion of exons and introns in the final mRNA. This process is essential for gene regulation and the diversity of proteins in eukaryotic organisms, with up to 70% of human genes undergoing alternative splicing. Mutations in intron sequences can lead to the evolution of new splicing patterns.
Step-by-step explanation:
Alternative RNA splicing is a complex mechanism that plays a crucial role in gene regulation. It involves the removal of introns and the possible rearrangement of exons in a pre-mRNA transcript. The spliceosome complex, composed of both proteins and small nuclear RNAs (snRNAs), precisely catalyzes this process, recognizing specific sequences at the ends of introns. This regulated splicing mechanism allows for a single gene to produce multiple protein products, which can vary between different cells or developmental stages of the same cell. The alternative splicing can generate minor splice variants known as the alternative splicesome, which, while less common, contribute to the diversity of proteomes in eukaryotic organisms. A staggering 70 percent of human genes participate in alternative splicing, underscoring its significance in cellular function and complexity.
Mutations and evolutionary changes, such as transversions in the intron sequences, can lead to new splicing patterns that may result in the production of functional proteins. This hints at how alternative splicing could evolve over time. Moreover, the alternative splicing process can at times be haphazard but primarily remains under strict cellular control, adhering to the original 5'-3' exon order thus maintaining the integrity of the protein coding sequence.