News from CRG
A neutral genetic mutation—a fluke in the evolutionary process that had no apparent biological purpose—that appeared over 700 million years ago could help explain the origin of complex organs and structures in human beings and other vertebrates, according to an article published in Nature Communications by a team led by CRG group leader Manuel Irimia and other scientists in Barcelona and Italy.
Specifically, this mutation, which likely occurred very early in evolution after the separation of our group from that of sea anemones, affected a gene of the Fgfr (fibroblast growth factor receptors) family. Curiously, this genetic change triggered, millions of years later, the connection between two gene regulatory networks (those controlled by ESRP and by Fgfr), which became key for the origin of many vertebrate organs and structures (lungs, forelimbs and inner ear).
Evolutionary developmental biology (evo-devo) focuses on comparing the embryonic development of multiple living beings to understand how their adult forms have changed giving rise to new species. “We found that the family of regulatory proteins called ESRP, which control alternative splicing, were part of an ancient genetic machinery, shared by animals as diverse as fish, sea urchins and ourselves, that controls the integration of certain cells into the linings of developing organs, a fundamental step in the formation of some organs" explains Irimia. The article shows how the same regulatory genes have been used to generate different organs and biological structures in living beings during the evolutionary process, and it also describes the apparently meaningless mutation that took place over 700 million years ago and became the molecular driver for complex morphological developments.
“Clearly, the most exceptional result of the work is the proof of how important serendipity is for evolution, and how versatile biological evolution is. It is surprising to find that a single gene (ESRP), through its ancestral biological role (cell adherence and motility) has been used throughout the animal scale for very different purposes: from the immune system of an echinoderm to the lips, lungs or inner ears of humans,” states professor Jordi Garcia-Fernàndez, of the University of Barcelona and the IBUB - MM/PRBB
Evolutionary recruitment of flexible Esrp-dependent splicing programs into diverse embryonic morphogenetic processes. Burguera et al. Nature Communications 8, Article number: 1799 (2017) doi:10.1038/s41467-017-01961-y