Departament de Genètica 


Jaume Baguñà
Cristian Cañestro
Jordi Garcia
Pere Martínez
Marta Riutort
Iñaki Ruiz-Trillo
Joan Antoni Vela




1) Multigenic and phylogenomic approaches to the origin and diversification of the bilaterian superclade Lophotrochozoa

Constructing robust phylogenies is central to understand the origin and radiation of any animal clade. We focus in the superclade Lophotrochozoa, an asemblage of 15 bilaterian phyla ranging from the well-known annelids, molluscs and platyhelminthes to a bunch of minor lesser-known phyla. After a decade of intensive gene sequencing (namely the 18S ribosomal gene), the origin, radiation and relationships of lophotrochozoan phyla are still very poorly known. Prominent among them is the unsettled position of the Platyhelminthes (flatworms), Gastrotricha, Gnathostomulida and Xenoturbella.

We follow a dual approach: 1) to sequence genes known to be good phylogenetic markers (e.g. 18S and 28S rDNA, myosin II, ATPase, tropomyosin, etc,...) using a taxon wide sampling, and 2) a phylogenomic approach based on EST collections from the basalmost taxa of each phylum. Various tree reconstruction methods are used. Using both approaches some robust groups of phyla are already emerging and morphological synapomorphies being tested.

Prof. Jaume Baguñà
Dr. Marta Riutort

Ph.D. students
Jordi Paps

Prof. Gonzalo Giribet (Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MS, USA)
Dr. Ulf Jondelius (Dept. of Systematic Zoology, Univ. of Uppsala, Uppsala, Suecia)
Prof. Mark. Q. Martindale (Kewalo Marine Lab, Univ. of Hawaii, Honolulu, HI, USA)
Dr. Kevin J. Peterson (Darmouth College, Medical School; Hannover, USA)
Prof. Hervé Philippe (Dpt. de Biochimie, Univ. Montréal, Montréal, Quebec, Canada)

2) The origin of Bilaterian animals. A multigene and functional approach

The transition from radially symmetrical organisms with a single body axis and two germ layers to bilateral organisms with two body axes and a third germ layer, is the biggest unsolved riddle in Animal Evolution. A major stumbling block is how the bilaterian ancestor looked like: morphologically simple or structurally complex. In the last 6-8 years, increasing evidence suggests that Acoel Platyhelminthes might well be the extant organisms closest to such ancestor.

The acoels Convoluta pulchra and Symsagitiffera roscoffensis are currently used to understand how such transition took place. We follow two strategies: 1) isolation and characterization of the Hox and ParaHox gene clusters by homology screening and testing its genomic clustering and colinearity using BAC libraries; 2) from homology screens and large EST sequence collections, pick up genes involved in body axes and mesodermal patterning and analyze its embryonic expresión and function by in situ hybridization and RNA interference.

Dr. Pere Martínez(Investigador Senior ICREA)
Prof. Jaume Baguñà

Eduardo Moreno
Marta Chiodin
Amandine Bery (Marie-Curie)
Alexander Alsen (Marie-Curie)
Drs. Xavier Bailly and Patrick Cormier (Station Biologique Roscoff, France)
Prof. Mark. Q. Martindale (Kewalo Marine Lab, University of Hawaii, Honolulu, HI, EUA)

3) Molecular taxonomy and phylogeography of freshwater and land planarians

Freshwater and land planarians (Platyhelminthes; Tricladida) have always been considered separate monophyletic groups. Molecular analyses, instead, suggest they are paraphyletic: land planarians cluster with the freshwater family Dugesiidae, whereas the other freshwater families, Planariidae and Dendrocoelidae, form a separate clade. To corroborate it, we are analyzing a worldwide taxon sample using nuclear and mitochondrial genes. These studies should also give clues to whether freshwater to land transition was unique or multiple.

Using a similar set of genes we also test whether the asexual (fissiparous) forms of the freshwater genera Dugesia and Schmidtea in the Mediterranean, geographically more widespread than their sexual counterparts, have an ancient or a recent origin. First, we are establishing the phylogenetic relationships among the different species and populations of both genera; second, we compare its intrapopulational genetic variability. From it, we hope to unravel when and how asexual forms originated and why they are more widespread.

Dr. Marta Riutort
Prof. Jaume Baguñà

PhD students
Eva Lázaro
Marta Álvarez

Dr. Ronald Sluys (Zoological Museum, Amsterdam University, The Nederlands)
Dr. Maria Pala, Dr. Salvatore Cassu (Università di Sassari, Sardinia, Italy)