However, if these ncRNAs are functional and important in developmental and physiological processes, why have so few been identified in genetic screens to date? Here I outline the emerging evidence for ncRNA involvement in key molecular genetic phenomena and in specific functions and phenotypes. I also outline the expectational, perceptual, and practical factors that may collectively account for the low genetic visibility of individual ncRNAs. Awareness of these factors and the possibility that the structure of the genomic programming of complex organisms is different from our current understanding may lead to the increased recognition of ncRNAs in genetic analyses, assisted by the emerging fusion of genetics, genomics, and systems biology.
