Mechanisms of differentiation and evolution in chordates 

Lucia Manni, Fabio Gasparini, Chiara Anselmi, Virginia Vanni

Tunicates (or Urochordates) are the chordate subphylum considered the sister group of vertebrates. We rear and use two tunicate species, the solitary ascidian Ciona robusta and the colonial ascidian Botryllus schlosseri, for comparative studies aimed to understand their mechanisms of differentiation and evolution.
In B. schlosseri, we compare the mechanisms underlying development via sexual and asexual reproduction, and in regeneration. This permits to investigate if: similar mechanisms are used in different developmental pathways, homologies can be recognized among structures at various levels of organization, and conserved mechanisms have been co-opted during the evolution of different developmental pathways. In both C. robusta and B. schlosseri we are defining the ontology of anatomy and development.

Main scientific issues:

• origin, differentiation and evolution of placodes and their derivatives;
• Evolution of angiogenesis;
• transcriptome dynamics in B. schlosseri asexual life cycle;
• Ontology and speciation.

Database: http://botryllus.cribi.unipd.it

Web-based platform where the results obtained from the trancriptome analysis of 3 different stages of the blastogenetic cycle of B. schlosseri are stored and available for further, free gene expression analysis.

Group website: https://sites.google.com/site/ascidianbiologylab/

Collaborators:

Sebastian M Shimeld (Oxford University, UK)
Thomas Stach (Humboldt-Universität zu Berlin, DE)
Carmela Gissi (University of Bari, IT)
Roberta Pennati (University of Milan, IT)
Kohji Hotta (University of Keio, JP)
Ayelet Voskoboynik (University of Stanford, USA)
Delphine Dauga (Bioself Communication, FR)

Publications:

• Rosental B, Kowarsky M, Seita J, Corey DM, Ishizuka KJ, Palmeri KJ, Chen S, Sinha R, Okamoto J, Mantalas G, Manni L, Raveh T, Clarke DN, Newman AM, Neff NF, Nolan GP, Quake SR, Weissman IL, Voskoboynik A (2018) Evolutionary origin of the mammalian hematopoietic system found in a colonial chordate. Nature IN PRESS. bioRxiv preprint first posted online Dec. 26, 2017. doi: doi.org/10.1101/206318
•   Manni L, Anselmi C, Cima F, Gasparini F, Voskoboynik A, Martini M, Peronato A, Burighel P, Zaniolo G, Ballarin L (2018) Sixty years of experimental studies on the blastogenesis of the colonial tunicate Botryllus schlosseri. Dev Biol IN PRESS. doi.org/10.1016/j.ydbio.2018.09.009
• Gasparini F, Skobo T, Benato F, Gioacchini G, Voskoboynik A, Carnevali O, Manni L, Dalla Valle L (2016) Characterization of Ambra1 in asexual cycle of a non-vertebrate chordate, the colonial tunicate Botryllus schlosseri, and phylogenetic analysis of the protein group in Bilateria. Mol Phylogenet Evol 95:46-57. doi.org/10.1016/j.ympev.2015.11.001
• Brunetti R, Gissi C, Pennati R, Caicci F, Gasparini F, Manni L (2015) Morphological evidence that the molecularly determined Ciona intestinalis type A and type B are different species: Ciona robusta and Ciona intestinalis. J Zool Syst Evol Res 53(3):186-193. doi.org/10.1111/jzs.12101
• Gasparini F, Degasperi V, Shimeld SM, Burighel P, Manni L (2013). Evolutionary conservation of the placodal transcriptional network during sexual and asexual development in chordates. Dev Dynam 242(6):752-766. doi: 10.1002/dvdy.23957. doi.org/10.1002/dvdy.23957

Video:https://www.canal-u.tv/video/tele2sciences/la_dissection_de_l_ascidie.45817