Homologous recombination and CRISPR-Cas can both be directed toward a selected genomic site, but they provide different routes for changing it. Homologous recombination supports replacement using a designed DNA template, whereas CRISPR-Cas directs a DNA cut and can be followed by repair that joins the resulting ends or incorporates that template. The choice therefore affects how the intended alteration is produced.
Cellular DNA repair determines the final result after the targeted change is initiated. Repair may join the DNA ends, or it may incorporate a designed template, so the resulting sequence depends on which repair outcome occurs. This step matters because the experiment is interpreted through whether the altered cells or organisms show the expected loss of normal gene-product function.
Comparing mutant cells or organisms with unmodified controls is essential for linking an observed phenotype to the deletion. Differences in development, physiology, or disease-related pathways become informative when the unmodified group provides the comparison point. This design turns a sequence-level alteration into evidence about the gene's contribution to a biological process.
An experiment begins by selecting the genomic sequence to alter. Researchers then create the change through homologous recombination or CRISPR-Cas, allowing cellular repair to join DNA ends or use a designed template. Finally, they compare altered cells or organisms with unmodified controls and assess effects on development, physiology, or disease-related pathways.
Researchers can assess effects across several biological levels, including development, physiology, and disease-related pathways. The key interpretation comes from comparing altered cells or organisms with unmodified controls, then determining which outcomes differ between them. This makes the model useful for connecting a gene's disruption with observable biological changes rather than examining the DNA sequence alone.
Functional genomics uses these models to connect a gene disruption with measurable biological consequences, helping researchers assign function and analyze pathways. The same evidence can be considered in disease-related contexts: if altering a gene changes a relevant pathway, researchers can evaluate that gene as a potential therapeutic target. This makes deletion models useful for both biological discovery and target assessment.