Shanghai scientists have discovered distinct roles of a mysterious biomolecule in different species, shedding light on the terra incognita of the genomic revolution.

Long noncoding RNAs, or lncRNAs, are what we call the “dark matters” of genomes. Pervasively transcribed in eukaryotic genomes, lncRNAs play important roles in gene expression. And yet their roles remain largely unknown.

The latest research found that lncRNA in orthologous genes, genes in different species that can be traced back to a common ancestor, likely have different functions. It suggested how lncRNAs work in different species and evolve with the species evolution.

The research, led by Chen Lingling from the Center for Excellence in Molecular Cell Science of the Chinese Academy of Sciences, was published in the scientific journal Cell.

FAST, an abundant lncRNA, exists in cytoplasm in human embryonic stem cells. It takes part in regulating cell signaling pathways, key to how the body functions, and supports self-renewal of stem cells.

While in embryonic stem cells of mice, FAST also exists but in nucleus. It neither works in cell signaling pathway or cell self-renewal.

Further research shows PPIE, a protein that suppresses production of lncRNAs in nucleus, determines the maturation and different roles of lncRNAs in different species.

Large amounts of PPIE are found in embryonic stem cells of mice and many immature FAST are left behind in the nucleus. In human embryonic stem cells, there is less PPIE, so more FAST are processed.