Description
Intragenic microRNAs (miRNAs), including both intronic and exonic miRNAs, accounting approximately 50% of total mammalian miRNAs. Previous studies showed that intragenic miRNAs are often co-expressed with their host genes, and thus it was believed that intragenic miRNAs and their host genes are derived from the same primary transcripts. However, we provide evidence to show here that the observations from previous studies might be biased due to the small number and the predominance of "broadly conserved" intronic miRNAs they studied.