%0 Journal Article
%T Origin and evolution of the Notch signalling pathway: an overview from eukaryotic genomes
%A Eve Gazave
%A Pascal Lap¨¦bie
%A Gemma S Richards
%A Fr¨¦d¨¦ric Brunet
%A Alexander V Ereskovsky
%A Bernard M Degnan
%A Carole Borchiellini
%A Michel Vervoort
%A Emmanuelle Renard
%J BMC Evolutionary Biology
%D 2009
%I BioMed Central
%R 10.1186/1471-2148-9-249
%X We searched for 22 components of the Notch pathway in 35 different species that represent 8 major clades of eukaryotes, performed phylogenetic analyses and compared the domain compositions of the two fundamental molecules: the receptor Notch and its ligands Delta/Jagged. We confirm that a Notch pathway, with true receptors and ligands is specific to the Metazoa. This study also sheds light on the deep ancestry of a number of genes involved in this pathway, while other members are revealed to have a more recent origin. The origin of several components can be accounted for by the shuffling of pre-existing protein domains, or via lateral gene transfer. In addition, certain domains have appeared de novo more recently, and can be considered metazoan synapomorphies.The Notch signalling pathway emerged in Metazoa via a diversity of molecular mechanisms, incorporating both novel and ancient protein domains during eukaryote evolution. Thus, a functional Notch signalling pathway was probably present in Urmetazoa.The emergence of multicellularity, considered to be one of the major evolutionary events concerning life on Earth, occurred several times independently during the evolution of Eukaryota in the Proterozoic geological period [1]. Multicellular organisms are not only a superimposition of the fundamental unit of life, namely the cell; the emergence of multicellularity further implies that cells must communicate, coordinate and organise. In Embryophyta and Metazoa, higher levels of differentiation and organization of cells resulted in the emergence of organs and their organisation into complex body plans. Reaching this critical step required the elaboration of sophisticated intercellular communication mechanisms [2,3]. Cell-cell interactions through signal transduction pathways are therefore crucial for the development and the evolution of multicellular organisms. The modifications of these signal transduction pathways explain the macroevolution process observed. In metazo
%U http://www.biomedcentral.com/1471-2148/9/249