Visitors: Nicolas Magain

Nicolas Magain

I started to study biology in 2005, I got a bachelor degree in biological sciences in 2008 then a master degree in ecology and organisms biology in 2010, in the University of Liege. My master thesis was a study on the Peltigerales in Reunion Island, including taxonomic and phylogenetic analyses, with a special focus on Lobariaceae.

I started a PhD thesis in the University of Liege in 2010, with Prof. Emmanuel Serusiaux as main advisor. I am working on Peltigera, especially on the Peltigera neopolydactyla-dolichorhiza complex. Indeed, Peltigera neopolydactyla and Peltigera dolichorhiza have a similar morphology, and if we combine their geographical range, they form an almost cosmopolitan repartition, growing in boreal and temperate regions from northern Norway to southern Chile, as well as in tropical mountains. However, observed morphotype and chemotype variation within this complex suggested the presence of multiple undescribed species. I wanted to figure out if it was actually a single cosmopolitan species or an assemblage of many unrecognized, locally distributed species.

My first goal is to realize a multi-locus phylogeny of all representatives of P. neopolydactyla-dolichorhiza complex with the broadest geographic sampling possible, and to combine different approaches, including phylogenetic inferences, population genetic methods and species delimitation statistical methods to determine if my complex is actually composed of one or several species and in the latter case, how many species it contains and if the complex is mono-, para- or polyphyletic.

In order to reach this goal, I joined Lutzoni lab as a visitor/research scholar in August 2011, to participate to the NSF-funded project on Peltigera. I am currently working with Prof. Franois Lutzoni and Dr. Jolanta Miadlikowska and my contribution to the project will be a multi-locus phylogeny of Peltigera section Polydactylon, which contains Peltigera neopolydactyla and Peltigera dolichorhiza but also several other species, including P. polydactylon, P. scabrosa, P. scabrosella, P. occidentalis and P. hymenina. After that, I will apply different statistical treatments to this multi-locus data to infer the boundaries of species in the group.

Preliminary results show that P. neopolydactyla-dolichorhiza is a complex of several species, and even that what is usually identified as P. neopolydactyla and P. dolichorhiza is actually a polyphyletic group, in need of taxonomic revision. Moreover, P. polydactylon and P. scabrosa appear to be assemblages of several species too, and in many cases, what was considered as a single species on different continents appears to be different species with a similar morphology, which calls into question the concept of cosmopolitan species in this section.

Once the taxonomic and phylogenetic aspects will be achieved, my second goal will be to study the population structure on the newly well-defined species, at different scales from worldwide to local, to assess gene flow, dispersion, isolation etc. using tools as microsatellites or Intergenic Spacers.

My third goal will be to sequence some loci of Nostoc, the photobiont of Peltigera neopolydactyla and Peltigera dolichorhiza, in order to realize a co-phylogeny with the mycobiont, to assess the specificity of the symbiosis.

Outside these goals, my main interests are taxonomy and phylogeny of Peltigerales, with a special focus on Lobariaceae and Peltigerinae in general, as well as evolution, population genetics and biogeography of lichen-forming fungi, and speciation in general.