Final answer:
Alternative splicing significantly contributes to enzyme diversity by allowing a single gene to produce multiple protein isoforms. This mechanism does not increase the genome size but increases proteomic complexity, allowing for tissue-specific expression and evolutionary adaptation of new protein functions.
Step-by-step explanation:
Does Alternative Splicing Contribute to Enzyme Diversity?
Alternative splicing plays a significant role in contributing to the diversity of enzymes in cells. Through this process, a single gene can give rise to multiple unique proteins, including various enzymes, each with a potentially different function or role within the cell. Alternative splicing allows for various combinations of exons to be joined or for certain introns to be retained, leading to the production of different mRNA transcripts from the same gene. This incredibly efficient process can lead to an 'economy of genes,' whereby a diverse array of proteins can be produced without the need for a corresponding increase in the number of genes within the genome.
Research suggests that more than 95% of multi-exon genes in humans undergo alternative splicing, underlining its importance as an evolutionary mechanism for increasing protein diversity without expanding the genome size. Additionally, alternative splicing enables the expression of different gene isoforms in various tissues and at different developmental stages, contributing to the complex regulation of protein function.
Evolutionarily, alternative RNA splicing can also give rise to protein variants with new functions, without the loss of the original functional protein, facilitating adaptations and the evolution of new functions. Furthermore, gene duplication has often worked alongside alternative splicing to provide a scaffold for evolutionary innovation, by allowing duplicated genes to evolve new functions while the original genes continue to perform their essential roles.