How do cDNA sequences facilitate gene annotation? Describe how the use of full-length cDNAs facilitates discovery of alternative splicing.

Key Concepts

cDNA (complementary DNA)

cDNA is synthesized from messenger RNA (mRNA) through the process of reverse transcription. It represents the coding sequence of a gene without introns, making it a valuable tool for studying gene expression and function. By analyzing cDNA sequences, researchers can identify which genes are actively expressed in a particular cell type or condition, aiding in gene annotation.

Gene Annotation

Gene annotation involves identifying the locations and functions of genes within a genome. This process includes determining the structure of genes, such as exons and introns, and their regulatory elements. cDNA sequences play a crucial role in gene annotation by providing a clear picture of the expressed regions of genes, which helps in accurately mapping and characterizing them.

Alternative Splicing

Alternative splicing is a process by which a single gene can produce multiple mRNA variants by including or excluding certain exons during transcription. This mechanism allows for increased protein diversity and regulation of gene expression. Full-length cDNAs are essential for discovering alternative splicing events, as they capture the complete mRNA transcript, enabling researchers to identify different splice variants and their functional implications.