Constitutive and alternative splicing are two mechanisms by which eukaryotic cells process pre-mRNA transcripts to produce mature mRNA molecules. These processes play a crucial role in gene expression and regulation, as they determine which parts of the pre-mRNA are included or excluded in the final mRNA molecule. Here are the key differences between constitutive and alternative splicing and their effects on gene expression in eukaryotic cells:1. Constitutive splicing:- In constitutive splicing, all introns non-coding regions are removed from the pre-mRNA, and all exons coding regions are joined together in a linear sequence. This process occurs in a consistent manner for a given gene, producing a single mRNA molecule with a fixed set of exons.- Constitutive splicing does not contribute to protein diversity, as it generates only one type of mRNA molecule from a single pre-mRNA transcript. However, it is essential for the proper functioning of genes, as it removes introns that would otherwise disrupt the coding sequence of the mRNA.2. Alternative splicing:- Alternative splicing is a regulated process that allows the generation of multiple mRNA molecules from a single pre-mRNA transcript by selectively including or excluding specific exons or parts of exons. This process can occur through various mechanisms, such as exon skipping, mutually exclusive exons, alternative 5' or 3' splice sites, and intron retention.- Alternative splicing greatly contributes to protein diversity in eukaryotic cells, as it enables the production of different protein isoforms from a single gene. These protein isoforms can have distinct functions, cellular localizations, or interactions with other molecules, allowing for fine-tuned regulation of gene expression and cellular processes.- The regulation of alternative splicing is achieved through the action of various trans-acting factors, such as splicing factors and RNA-binding proteins, which recognize specific cis-acting elements within the pre-mRNA sequence. These factors can either promote or inhibit the inclusion of specific exons, depending on the cellular context and environmental signals.In summary, the key differences between constitutive and alternative splicing lie in their mechanisms and outcomes. Constitutive splicing is a consistent process that removes all introns and joins all exons, producing a single mRNA molecule for a given gene. In contrast, alternative splicing is a regulated process that generates multiple mRNA molecules with different exon compositions from a single pre-mRNA transcript, contributing to protein diversity and allowing for the fine-tuned regulation of gene expression in eukaryotic cells.