Rasa completed her PhD early in 2022 under the academic supervision of Sarah Teichmann, and is a phenomenal candidate for this prestigious award owing to a series of outstanding discoveries in human developmental biology. She is an exceptional young scientist with scientific and personal maturity well beyond her career stage and without doubt a future leader in the field.

Rasa received an Integrated BSc and MSc degree in molecular and cell biology from the University of Glasgow. During this time, she actively sought research opportunities and received fellowships for diverse research projects, including working with model organisms to understand intestinal stem cell biology and pain pathways in the central nervous system. Rasa’s active and impactful contribution to diverse research projects, her scientific intuition and independence set her apart early on, and earned her a place in the highly competitive 4-year Wellcome Sanger PhD programme in 2017.

Around that time, our understanding of how the tremendous cellular diversity of the human intestinal tract was generated during development was still in its infancy. Rasa saw how emerging single cell and spatial technologies applied to human tissues – sampled across the lifespan and across the spatial zones of the gut – could fill this gap in an unbiased manner. To achieve her aims, Rasa immediately immersed herself into the genomics field and rapidly built programming and data analysis skills, highlighting an impressive aptitude for research at the interface of wet and dry lab science. Over the course of her PhD, she obtained, processed and analysed human tissue samples from up to 11 intestinal regions and different developmental stages to generate among the first, most comprehensive and finest quality single cell dissections of the developing human intestinal tract. This fantastic achievement was reported in two high impact first author publications (Elmentaite et al., Dev Cell, 2020, 103 citations; Elmentaite et al., Nature, 2021, 117 citations).

Rasa‘s discoveries have changed our understanding of human gut development, with important clinical implications. She charted enteric progenitors as they colonise intestinal tissues and give rise first to specific subsets of enteric neurons, and later to diverse types of supporting glia. She located expression of genes associated with Hirschsprung’s disease (e.g. RET) to specific neural lineages, providing insights into the disease development at early embryonic stages. This has potential implications for treatment and therapy development.

One of her most impressive achievements was, for the first time, to describe the three key cell types that orchestrate lymph node and gut-associated lymphoid tissue formation in human development. This cell circuitry in second trimester human development consists of “lymphoid tissue initiator” and “organizer” cells of lymphoid, mesenchymal and endothelial origin, which signal to recruit other immune cells to orchestrate aggregation at specific gut sites. She revealed a re-initiation of this cellular program during inflammation in paediatric Crohn’s disease, to recruit and retain immune cells to the site of damage. Rasa’s discovery that developmental programmes are adopted in inflammatory bowel disease is one with wide impact for all inflammatory conditions, with potential to inform the design of next generation cell-centred therapeutics.

Rasa’s highly collaborative spirit led to valuable contributions to twelve research projects in human single cell and developmental biology. These include a comparison of cell identity in vivo versus in vitro in intestinal organoids (Beumer et al., Cell, 2020), a collaboration on the developmental origins of neuroblastoma cancers (Kildisciute et al., Science Advances, 2021), and two papers mapping the immune system across organs in development and adult stages (Dominguez-Conde, Xu et al. Science 2022; Suo, Dann, et al. Science 2022). She also led a major effort in reviewing cell lineages that are common across tissues for a review invitation in Nature Reviews Genetics (Elmentaite et al., 2022). This impressive output demonstrates Rasa’s general intellectual curiosity and ability to look beyond her own research programme to wider issues in developmental biology.

As described above, Rasa’s list of achievements during her PhD is nothing short of spectacular and has transformed our understanding of gut development and disease. She is a most worthy winner of the Beddington Medal.

• Sarah Teichmann