Govt. Exams
Entrance Exams
Base editors convert one nucleotide to another without creating double-strand breaks, but optimizing specificity to edit only intended bases while avoiding unintended modifications remains a significant hurdle.
Pooled CRISPR screening uses large libraries of guide RNAs to simultaneously test thousands of genetic perturbations, allowing identification of genes associated with specific phenotypes through NGS readout.
RNAi uses small interfering RNAs (siRNAs) that guide the RNA-Induced Silencing Complex (RISC) to degrade specific target mRNAs, effectively silencing gene expression post-transcriptionally.
Germline (heritable) editing raises profound ethical, religious, and social concerns about modifying the human genome permanently. Most countries, including India, have strict regulations or moratoriums on germline editing applications.
The spread of herbicide or insect resistance genes to wild relatives creates organisms that are difficult to control and can disrupt ecosystems. This is the primary biosafety concern in several regulatory assessments, particularly for herbicide-resistant crops.
Ex vivo gene therapy involves editing cells outside the body, allowing for rigorous selection of successfully modified cells and quality control before reimplantation. This reduces risks associated with unsuccessful edits.
Comprehensive environmental impact assessment requires multi-generational studies examining effects on biodiversity, soil health, water systems, and non-target organisms. Short-term yield data alone is insufficient for determining ecological safety.
Epigenetic editing modifies gene expression without altering the DNA sequence itself, making changes potentially reversible. Prime editing offers precise edits with fewer off-targets. Base editing directly converts one DNA base to another. Epigenetic approaches offer the most control and reversibility.
Bacterial expression requires prokaryotic regulatory elements such as bacterial promoters and Shine-Dalgarno sequences for proper transcription and translation. The human gene alone won't be recognized by bacterial machinery.
When foreign DNA integrates into the genome, it can disrupt endogenous genes or be influenced by local chromatin context (position effect), causing unintended phenotypic changes beyond the transgene's direct effect.
