Three large studies unravel the network underlying the genetic elements that control how cells transform and evolve from precursors to mature cells, as reported online in this week's Nature Genetics.
The complete development of functional organs relies on compatibility between immature cells that are still growing and mature cells that have acquired a specific function. Understanding the switch between growth and specified functions has been elusive, until now.
Three independent groups led by Yoshihide Hayashizaki, John Mattick, and Piero Carninci, part of the FANTOM4 project, have utilized in-depth sequencing technologies to evaluate genome-wide changes in gene expression that occur during cell development. One finding from the Carninci group is the genome-wide expression of repetitive mobile elements. These authors identified over 250,000 previously unknown gene expression start sites as well as the functional consequences of the repetitive elements on the global expression of neighboring genes. Another interesting finding from the Mattick group is the identification of a novel class of evolutionarily conserved short RNAs that are located at the start sites of active genes. Together, with the pioneering work from the Hayashizaki group, these studies collectively provide a comprehensive look at the dynamic regulatory framework that supports the switch from immature growing cells to mature functioning cells.