While there exist some long non-coding RNAs (lncRNAs) that are structurally similar
to mRNAs (capped, spliced, poly a tail), not all of the lncRNAs exhibit these features.
Structurally, lncRNAs are classified under the regulatory non-coding RNAs category
these lncRNA molecules operate as signals, decoys, guides, and scaffolds. In eukaryotes,
lncRNAs are transcribed by RNA Polymerase II and RNA Polymerase III at several loci
of the genome. Unlike other protein-coding mRNAs, lncRNAs exhibit functional uniqueness
by participating in and modulating the various cellular processes such as, histone
modification, DNA methylation, and cellular transcription (Wei et al., 2017). LncRNA
alters chromatin structure and DNA accessibility, thereby regulating patterns of gene
expression (Wang et al., 2011b). Disordered lncRNA with quantitative or qualitative
alterations lead to the progression of numerous diseases including blood associated
diseases. LncRNAs not only regulate lineage commitment such as cardiovascular lineage
but also contribute for the hematopoietic stem cell development with a significant
role in myeloid and lymphoid lineage commitment. However, the key molecular functions
of lncRNAs in hematopoiesis are still unclear, particularly, their functional role
during megakaryocyte development from hematopoietic stem cells (HSCs) is largely unexplored.
This review summarizes the current status of knowledge on lncRNAs classification,
biogenesis and its role in blood cells.