Rapid evolution of mammalian X-linked testis microRNAs

Background: MicroRNAs (miRNAs), which are small, non-coding RNAs approximately 21-nucleotides in length, have become a major focus of research in molecular biology. Mammalian miRNAs are proposed to regulate approximately 30% of all protein-coding genes. P

We gratefully acknowledge discussions with Rui Zhang for improvement of this manuscript. The study was supported by grants from National Basic Research Program of China (2009CB941703, 2006CB504002), and Chinese Natural Science Funds (30630030)