text: A repeat polymorphism of cytosines and adenines (CA) was found to be near BCYRN1 and was used as a reference for mapping the gene. Linkage mapping and radiation hybrid mapping localized the BCYRN1 gene to chromosome 2p16.
  As a long non-coding cytoplasmic RNA, BC200 RNA is a part of the largest group of non-coding transcripts in the human genome, which is more prevalent than protein coding genes. The 5' region (left arm) of monomeric Alu short interspersed repetitive elements (SINEs) allows for BC200 RNA transposition and has been evolutionarily conserved in other primates. Of this group of SINEs, BC200 is one of few that are transcriptionally active. In humans, it is found in neuropil areas which are composed of predominantly unmyelinated dendrites, axons, and glial cells.
  Similarly, the functional analog of BC200 RNA in rodents (BC1 RNA) is expressed largely in somatodendritic domains of the nervous system, making it an ideal model for experimentation.  One large difference is in origin; BC200 emerged from retrotransposed Alu domain, while BC1 originated from retrotransposed tRNA. Although they evolved separately, both are not usually expressed in non-neural somatic cells, with the exception of tumors.