Current Lab Members

Alfonso Martinez Arias (group leader)
ICREA research professor, EMBO member

Stephen Babin (PhD student)
Stephen is French and Irish. After graduating with an MSc in Neuroscience from École Normale Supérieure de Paris, he joined the lab in early 2022 and is investigating the regulation of cell-to-cell heterogeneity and the coordination of cell behavior during early mammalian development using mouse gastruloids and a combination of single-cell imaging approaches.

Tina Balayo (research assistant)
Originally from Vigo, Spain, Tina has extensive experience with embryonic stem cells, having worked in several labs in Cambridge, the Canary Islands, and now Barcelona. She also has experience in training PhD students and postdocs, notably at Institut Pasteur, where she taught at the Advances in Stem Cell Biology international workshop.

Sara Bonavia (postdoctoral fellow)
Sara was born in Italy. A physicist by training, she completed her PhD at Université de Paris, where she used microfluidics to study the establishment of the antero-posterior axis in the mouse embryo. In the lab, she is interested in deciphering how cell numbers and epithelial architecture affect axis formation and patterning during early development using mouse gastruloids.

André Dias (postdoctoral fellow)
André completed his PhD at Instituto Gulbenkian de Ciência in Oeiras, Portugal, his home country. There, he studied the role of axial progenitors in shaping the vertebrate body plan.

Raquel Flores Peirats (research assistant)
Raquel is from Barcelona. She has been working at UPF for over twenty-two years and is currently involved in three different labs: the Genetics, Stembryo Engineering, and Endocrine Regulatory Genomics labs, where she has gained extensive experience in pluripotent stem cells and human genomics. She is also proactive in teaching tasks and student mentoring at different levels.

Joshua Frenster (postdoctoral fellow)
Joshi grew up in Germany. He went on to pursue his MSc and PhD at New York University School of Medicine in the Placantonakis lab, studying the role of adhesion GPCR signalling in glioblastoma. He is now investigating the mechanisms of cell competition and apoptosis in early mammalian development using mouse gastruloids as a model system.

Ulla-Maj Fiuza (postdoctoral fellow)
Ulla is Portuguese/Finnish. After obtaining her PhD from the University of Cambridge, she studied ascidian embryonic development in the labs of Patrick Lemaire (CNRS-CRBM-UM) and Lars Hufnagel (EMBL-Heidelberg; EIPOD fellow). She joined the lab to investigate the role of cell numbers and epithelial architecture in axis formation and patterning during early mammalian development, using mouse gastruloids.

Veronika Mantziou (PhD student)
Originally from Greece, Veronika graduated with an MPhil in Genetics from the University of Cambridge. She then joined the lab in 2019 as a PhD student to study cell fate specification events in early human development, using human gastruloids and a combination of imaging methods. She recently transferred to Barcelona, where the lab moved.

Soyeon Park (PhD student)
Soyeon is Korean/Canadian and graduated with an MSc in Clinical Embryology from Oxford University. She is now using mouse gastruloids as a model to study the role of Wnt canonical and non-canonical signalling in the patterning of early mammalian tissue, using a combination of transcriptomic and imaging approaches.

Pau Pascual Mas (computer scientist)
A Barcelona native, Pau recently joined the lab after graduating with an MSc in Genetics and Genomics from Universitat de Barcelona. He is performing computational analysis of next generation sequencing data in mouse and human gastruloids.

Marta Santana Feliu (research assistant)

Gaëlle Robertson (research assistant)
Originally from South Africa, Gaëlle graduated from Stellenbosch University with an MSc in Genetics. She joined both the Martinez Arias and Guëll labs at UPF in 2021. In the Guëll lab, she is part of a project that aims on building programmable lentiviruses. In our lab, she is developing tools to perform live imaging of signalling events in gastruloids.


  • Ms Aikaterini Geladaki (now PhD student, University of Cambridge)
  • Dr Ben Steventon (now group leader, University of Cambridge)
  • Dr Cassie Yu Bian
  • Dr Chris Cooke (now senior scientist, Abcam Cambridge)
  • Dr Christian Schröter (now group leader, MPI Dortmund)
  • Dr Christoph Budjan (now research fellow, Harvard Medical School)
  • Dr David Turner (now group leader, University of Liverpool)
  • Dr Fernando Faunes (now research scientist, UNAB Santiago)
  • Dr Fiona Hamey (now senior software scientist, Exploristics Oxford)
  • Ms Flora Gaudillière (now MSc student, ENS Lyon)
  • Mr Giles Harper-Donnelly (now PhD student, University of Cambridge)
  • Dr Helena Pérez Valle
  • Dr Hsiao Yu Fang (now scientific program manager, NIH Washington D.C)
  • Dr Jamie Trott (now co-founder, Deep River Development Cambridge)
  • Dr Joaquín de Navascués (now lecturer, University of Essex)
  • Mr Jonathan Mackenzie
  • Ms Luz Alonso Crisostomo (now research scientist, AstraZeneca Cambridge)
  • Ms Meagan Hennessy (now PhD student, UCLA)
  • Ms Meenakshi Chakraborty (now PhD student, Stanford University)
  • Dr Meritxell Vinyoles Vergés
  • Dr Naomi Moris (now group leader, the Francis Crick Institute London)
  • Dr Pau Rué (now director of data, Typeform Barcelona)
  • Dr Pedro Machado
  • Dr Penny Hayward (now principal scientist, PhoreMost Ltd Cambridge)
  • Dr Peter Baillie-Benson (now senior scientist, The Francis Crick Institute)
  • Ms Rebecca Broome (now scientist, Cancer Research UK)
  • Dr Sabitri Ghimire (now research associate, University of Cambridge)
  • Dr Shlomit Edri (now postdoc, Israel Institute of Technology)
  • Dr Silvia Muñoz Descalzo (now group leader, ULPGC)
  • Ms Stefania Borchia (now digital marketing manager, Ubisense Cambridge)
  • Mr Stefano Vianello (now PhD student, EPFL)
  • Ms Sung Ly
  • Dr Tatiana Subkhankulova (now research fellow, UCL)
  • Dr Vikas Trivedi (now group leader, EMBL Barcelona)
  • Dr Wade Suen (now business analyst, Dante Labs Cambridge)
  • Dr Xioyan Ma