Sponges reveal new information on our common ancestor
Sars scientists with groundbreaking research in Nature
A discovery by researchers Sofia A. V. Fortunato; a BIO MSc and PhD graduate, Marcin Adamski, Sven Leininger, Jing Liu and Maja Adamska at the Sars - International Centre for Marine Molecular Biology and their collaborators from the University of St. Andrews have provided new insights into the nature of the last common ancestor of animals.
The team led by Adamska has sequenced the genomes of two previously unstudied calcisponges found in Norwegian waters. Their results show that the repertoire of genes that regulate embryonic development in calcisponges differ significantly from those previously found in siliceous sponges by that they have ParaHox genes.
ParaHox genes are important in embryonic development, and when they're expressed in a cell they "tell" the cell its identity, so it “knows” whether it belongs in brain, gut etc., and position, if it should be in the head, tail or somewhere else in the organism. As ParaHox genes previously only had been found in higher organisms, it was assumed that they evolved after the sponge lineage separated from the lineage eventually leading to higher animals. Thus with the results of the Sars group, this chapter in the history of our ancestors will need rewriting.
The Sars researchers have also investigated the function of the identified genes by looking at their expression (activity) during sponge development. Their results indicate that the calcisponge ParaHox genes have an important role in the development of the sponges’ equivalent of a gut, the same function these genes also have in higher organisms. This adds extra weight to the historical importance of ParaHox genes as far back as our common ancestor who inhabited the oceans over 600 million years ago.
These findings show the importance of investigating organisms that are often neglected, to be able to say more about our historical and evolutionary lineage.
Read more about the researchers work and discovery in the 30th October issue of Nature.