lncRNAs
Long non-coding RNAs (lncRNAs) are RNA transcripts longer than 200 nucleotides that do not encode proteins. They are transcribed by RNA polymerase II and are typically capped at the 5' end, spliced, and polyadenylated. LncRNAs show diverse genomic organization and can be classified as intergenic (lincRNAs), sense or antisense transcripts overlapping protein-coding genes, intronic, or bidirectional relative to nearby promoters. They are found in the nucleus and cytoplasm and often exhibit cell type- and condition-specific expression.
Most lncRNAs have low primary sequence conservation across species, but some retain conserved structural motifs and
Functionally, lncRNAs participate in regulating gene expression at transcriptional and post-transcriptional levels. Mechanisms include guiding chromatin-modifying
Notable examples include Xist, which mediates X-chromosome inactivation; HOTAIR, which can recruit PRC2 to regulate a
Studying lncRNAs relies on high-throughput sequencing, transcript annotation, and functional perturbation using RNA interference, antisense oligonucleotides,