Non-coding RNA - significance in animal embryos
Despite an increase in intricacy of organs and systems as evolution has progressed, genomics has revealed that the number of protein-coding genes show little variation across the metazoan group. This is in stark contrast to ncRNAs that are highly correlated with developmental complexity. The NCRNASDEVNET (Non-coding RNAs and their role in developmental networks) project has looked at fruit fly Drosophila melanogaster development to identify key roles for ncRNAs. The researchers investigated the mesoderm, the germ layer containing all the major organs including muscles, blood, heart and lungs. Using deep sequencing of the entire transcriptome of the mesoderm at three key times in early development, the researchers compiled a list of newly discovered ncRNAs that incorporate around 140 genes. Most of these genes were differentially expressed depending on the tissue and time of development. Different classes of ncRNA were evident, including long intergenic ncRNAs, stable RNAs originated from enhancers, antisense RNAs and antisense promoter-overlapping ncRNAs. The research also looked into validating the ncRNAs as well as defining a function for the genes. Fluorescent antisense probes revealed that one new transcript is expressed very early in embryos in a pattern that determines the antero-posterior polarity, a critical developmental stage. Future research will test the functions of the ncRNAs by deletion or inhibiting their expression in flies. Currently work is ongoing to produce knockdown mutants for a selection of the ncRNAs. NCRNASDEVNET results will bolster the mounting interest in RNA-centred research with valuable information and help to elucidate evolutionary theory in multicellular animals. Understanding regulatory networks behind development is essential for the study of developmental diseases – improving diagnosis and targeted treatment.
Keywords
Non-coding RNA, metazoans, developmental complexity, mesoderm, disease, treatment
