RNA editing has become a generic term for a wide array of post-transcriptional processes that change the mature RNA sequence relative to the corresponding encoding genomic DNA matrix. This phenomenon, which is almost limited to eukaryotes with some exceptions, is characterized by nucleotide insertion, deletion, or substitution in various types of RNAs including mRNAs, tRNAs, miRNAs, and rRNAs , and is likely to contribute to RNA diversity. Until recently, this mechanism was considered relatively rare in vertebrates, mainly restricted to brain-specific substrates and repetitive regions of the genome, and limited to extensively validated ADAR-mediated adenosine to inosine (A-to-I) substitutions and APOBEC-mediated cytosine to uracil (C-to-U) changes.
The ultimate goal of quantitative trait loci (QTL) mapping approaches is to gain a better understanding of biological mechanisms involved in these phenotypes to offer molecular tools for medical diagnosis or animal selection. Over the past three decades, several thousand QTL have been mapped for different traits in many species. In this context, whereas genome-wide association study is developing as the reference QTL mapping method for human populations, most of the QTL referenced today in experimental or livestock species were mapped by linkage analysis approaches through F2 genetic crosses.