Final answer:
Knockout genes are deactivated to study gene function, taking advantage of techniques like reverse genetics and reporter genes such as GFP. This process helps geneticists understand the influence of genes on phenotypes. Additionally, epigenetics explores how identical genotypes can express differently, influencing traits and disease outcomes.
Step-by-step explanation:
"Knockout genes" are genes that have been genetically altered or deactivated in an organism (a "knockdown organism") to study the role of the missing gene. Researchers employ various techniques such as RNA interference (RNAi) that effectively diminishes the mRNA transcription levels from specific genes. Additionally, reverse genetics is used to determine the function of genes by starting with a known DNA sequence and observing the resulting phenotype when this gene is altered. Reporter genes, like lacZ and the gene encoding green fluorescent protein (GFP), are often used in connection with the genes of interest to monitor their expression and understand gene function.
Geneticists turn genes off to understand what functions those genes control by observing the differences between normal and knockout organisms. This enables them to ask questions about gene function, expression patterns, and the resultant phenotypes. The study of the epigenome and epigenetic modifications allows scientists to research how identical genotypes can result in different phenotypes due to differences in gene expression influenced by the environment. Research on conditions like cancer has shown how genetic markers and epigenetic factors play a crucial role in disease progression and potential treatments.