Jordan McCarthy · PhD researcher · ETH Zürich
I study how RNA quality control changes as yeast cells age. In the Barral laboratory at ETH Zürich, I combine single-cell microscopy with experiments that collect aging cells for molecular analysis.
01 The questions
My PhD research in the Barral laboratory at ETH Zürich asks how nuclear RNA quality control changes during aging and stress. A mother yeast cell produces successive daughters. The number it produces over its lifetime is its replicative lifespan. This gives us a way to connect molecular changes to a cell’s life history, and to test mechanisms in a well-understood organism.
RNA carries genetic instructions from DNA toward the machinery that makes proteins. Many newly made RNA messages contain segments called introns, which are normally removed by a process called splicing. Cells also control which messages can leave the nucleus.
I study how this processing and quality control change with age. The immediate aim is to understand mechanisms of aging in budding yeast. Whether a finding applies to human aging is a separate experimental question.
How are incompletely processed transcripts retained in the nucleus, and what allows them to escape? The distinction between processing an RNA and controlling its export is central to the question.
RNA surveillance / Nuclear retentionThe nuclear pore connects the nucleus with the rest of the cell. I study how changes in this architecture relate to RNA quality control as a cell grows older.
Nuclear architecture / AgingA molecular change is not yet an explanation. The aim is to distinguish correlation from cause, and connect altered RNA handling to a measurable consequence for the cell.
Mechanism / Single-cell biology02 How I do the work
One approach follows the life of an individual cell. The other collects aging cells in sufficient numbers to measure their molecules. Together, they let us study aging at two different scales.
The life of one cell
Microfluidic traps keep mother cells in view while fresh medium flows through the chip. Repeated imaging lets us follow divisions and changes within cells, instead of comparing isolated snapshots.
The question: How does a cell change as it produces successive daughters, and what changes its replicative lifespan?
The molecules of a population
The Miniature-chemostat Aging Device, or MAD, retains magnetically labelled yeast cells while their daughters are washed away. This provides aging cell populations for RNA measurements and other molecular analyses.
The question: Which molecular features differ between younger and older cell populations?
I learned the MAD approach with the Caudron laboratory in Montpellier and worked with the ETH workshop on our laboratory implementation. With thanks to Remo Zangger and Daniel Smith for the setup, and to Sung Sik Lee for the aging-chip platform. MAD was introduced by Hendrickson and colleagues, eLife (2018).
The microscopy frame and apparatus photographs are from slides 39, 48 and 49 of my 26 September 2025 lab presentation. The presentation date is not the acquisition date. These images illustrate the methods rather than a quantitative experimental comparison.
03 Selected work
eLife · · Research article
Our 2025 study connects displacement of the nuclear basket to pre-mRNA leakage and chromosome loss in aging yeast. Removing introns from three chromosome-segregation genes suppressed that chromosome-loss phenotype.
The finding connects a structural change at the nuclear pore to a specific, intron-dependent failure of cell function.
Peer-reviewed / Version of record
Formal analysis, validation, investigation, and writing – review and editing, as recorded in the published author-contribution statement. This was a collaborative study; the full author list appears above.
04 About
I trained at the University of Massachusetts Amherst and the Technion before joining the Barral laboratory at ETH Zürich. My work brings together biochemistry, genetics and cell biology to understand how RNA quality control changes as cells age.
ETH Zürich
PhD researcher · Barral laboratory · Institute of Biochemistry
Technion – Israel Institute of Technology
Biology
University of Massachusetts Amherst
Biochemistry & Molecular Biology + Microbiology; Spanish
05 In conversation
For a research or methods conversation, tell me your biological question, the organism you work on, and the measurement that is difficult today. For a seminar invitation, include the audience and proposed date.