Scientists are mourning the tragic deaths of two developmental biologists who were killed in a train crash in Spain on 28 October.

Marta Shahbazi Alonso, a 41-year-old stem-cell and developmental biologist at the prestigious MRC Laboratory of Molecular Biology (LMB) in Cambridge, UK, and Tamara González Costa, a 31-year-old postdoc at the Institute of Molecular Biotechnology (IMBA) in Vienna, died in a high-speed train collision near the town of Urda in central Spain. The crash, which killed 69 people and injured more than 100 others, is one of the worst rail disasters in Europe’s modern history.

The scientists, who were both originally from Spain, were heading to the 19th meeting of the Spanish Society for Developmental Biology (SEBD) in El Rompido. Shahbazi Alonso, a celebrated embryologist, was travelling to the conference to receive an award recognizing her contributions to the study of human embryo development.

Shahbazi Alonso and González Costa were “two brilliant scientists, with so much talent and so much road ahead, who dedicated their lives to expanding the frontiers of knowledge”, wrote Eva Ortega-Paino, secretary-general for research at Spain’s Ministry of Science and Innovation, on LinkedIn in Spanish. “The grief and emptiness I feel are immeasurable, and nothing comparable to the pain their families suffer today.”

Early-life models

Researchers describe Shahbazi Alonso as an outstanding scientist who made pioneering contributions to extending the time that human embryo models can grow in lab cultures — a notoriously difficult task.

Shahbazi Alonso joined the University of Cambridge in 2014 as a postdoc in the laboratory of leading stem-cell and developmental biologist Magdalena Żernicka-Goetz. “One of the things that I will never forget, and will always stay with me, is her enthusiasm,” says Żernicka-Goetz, who also runs a lab at the California Institute of Technology in Pasadena. “She loved science for the sake of science.”

In 2016, Shahbazi Alonso, working in Żernicka-Goetz’s team, developed¹ a method to grow human embryos in the lab up to 14 days post-fertilization, up from seven days after fertilization in previous efforts. The work allowed scientists to study this crucial stage of human development in unprecedented detail, and provided an alternative to mouse models.

“For the very first time, we can identify features of human embryo life at the time when these many pregnancies fail, and be able to understand what has to happen … for the embryo to survive,” says Żernicka-Goetz.

It was “a real breakthrough”, says Vincent Pasque, a stem cell and developmental biologist at the Catholic University of Leuven in Belgium who knew Shahbazi Alonso.

Shahbazi Alonso's research with Żernicka-Goetz also identified² ‘molecular checkpoints‘ that coordinate cell development and tissue formation in early embryos.

“Marta was not just an exceptional scientist and a rising star in her field; she was a vibrant, deeply valued member of our institute’s family and part of the future of the LMB,” said Jan Löwe, the LMB’s director, in a press statement on 2 November. “We are devastated by her passing, and our hearts go out to her family, her children and everyone who had the privilege of working alongside her at the LMB and elsewhere.”

Role model

Colleagues also speak warmly of Shahbazi Alonso, a mother of two, as someone who skillfully balanced the dual challenges of a demanding scientific career and parenthood. “She was a perfect scientist and a perfect mum,” says friend and collaborator Roser Vento-Tormo, a geneticist at the Wellcome Sanger Institute in Cambridge. Shahbazi Alonso was a passionate scientist, loved by her students and colleagues, and a generous person, she says. “When I was pregnant and I needed to know everything about being a mum, she really shared everything with me” — from food recipes to local schools, she adds.

In 2020, Shahbazi Alonso set up her own research group at the LMB where she continued work on embryo development. “She was a role model for many people around the world, including me,” says Pasque. “The way she combined motherhood and doing science was absolutely stellar.”

“I actually use Marta as a model to my students,” says Żernicka-Goetz, “not just scientific knowledge but also the attitude towards work [and] the focus on science”.

Vento-Tormo says that Shahbazi Alonso’s latest work has made major contributions to understanding aneuploidies — conditions that cause an embryo cell to have extra or missing chromosomes and is associated with pregnancy loss and failure of implantation. Some of this research “will come to light in the following months”.

“She was preparing her tenure file,” says Pasque. “This is a real tragedy for our community.”