Govt. Exams
Entrance Exams
Homologous recombination has very low frequency in mammalian cells compared to yeast, requiring enrichment strategies and selection markers. This limitation has been overcome by CRISPR technology.
Whole-genome sequencing provides unbiased coverage of the entire genome, allowing discovery of unexpected mutations, copy number variations, and structural rearrangements not detected by targeted approaches.
TALENs consist of a modular DNA-binding domain (which recognizes specific sequences) fused to the FokI nuclease domain, allowing precise DNA cleavage at target sites.
dCas9-KRAB recruits repressor complexes causing DNA methylation and histone deacetylation, establishing stable heterochromatin without genetic changes, useful for therapeutic gene silencing.
Cytidine deaminase (APOBEC) converts cytosine to uracil (paired with G) leading to C-G→T-A transition. TadA adenosine deaminase converts adenosine to inosine (read as G), causing A-T→G-C.
scCRISPR-seq enables simultaneous analysis of CRISPR perturbations and transcriptome responses at single-cell level, revealing cellular heterogeneity in gene-edited populations.
AAVs are 25 nm particles with limited packaging (~4.7 kb) but excellent CNS tropism, low immunogenicity, and non-integrating nature, making them safer for neurological applications.
High-fidelity Cas9 variants (eSpCas9, SpCas9-HF1) with stringent guide RNA design using prediction tools significantly reduce off-target cleavage in therapeutic applications.
Each zinc finger domain recognizes approximately 3 bp. Three domains recognize 9 bp, which provides adequate specificity for most genomic targets.
Prime editing fuses Cas9 nickase with reverse transcriptase, allowing creation of diverse genetic modifications from a single RNA template without creating double-strand breaks, offering superior precision and safety.
