ABSTRACT
First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping researchers promote themselves alongside their papers. Ana C. Almeida is co-first author on ‘ An evolutionary perspective on the relationship between kinetochore size and CENP-E dependence for chromosome alignment’, published in JCS. Ana conducted the research described in this article while a PhD student in Helder Maiato's lab at i3S, Porto, Portugal. She is now a postdoctoral researcher in the lab of Ivana Gasic at the Department of Molecular and Cellular Biology, University of Geneva, Switzerland, investigating the physiological and pathophysiological implications of tubulin homeostasis for the microtubule cytoskeleton and three-dimensional cellular organization.
Ana C. Almeida
How would you explain the main findings of your paper in lay terms?
During cell division, chromosomes must correctly align at the equator of the cell to ensure their even distribution into two daughter cells. Chromosome alignment occurs via direct bi-orientation or with the help of a motor protein named CENP-E. Our previous research suggested that larger kinetochores – the attachment sites on chromosomes – align more efficiently and independently of CENP-E. To further test this idea, we examined the presence of CENP-E across different species, comparing those with localized (monocentric) kinetochores to those with extended (holocentric) kinetochores. We find that while CENP-E is present in early ancestors, it is often lost in species with holocentric chromosomes, such as certain insects and worms. Functional experiments in two worm species confirmed that: in Caenorhabditis elegans (which lacks CENP-E), introducing human CENP-E rescued chromosome alignment defects. However, in Pristionchus pacificus (which naturally has CENP-E), removing it has no negative outcomes. These findings reveal that species with larger kinetochores do not rely on CENP-E for proper alignment, underlining a link between kinetochore size and CENP-E dependence for chromosome congression.
Were there any specific challenges associated with this project? If so, how did you overcome them?
One significant challenge was expressing a human gene in C. elegans embryos. We partially overcame this by optimizing codon usage in the CENP-E sequence, adapting it for efficient expression in worms.
Why did you choose Journal of Cell Science for your paper?
This work, while primarily descriptive, offers intriguing insights into kinetochore biology, chromosome congression and evolution. The broad audience and interdisciplinary focus of Journal of Cell Science make it an ideal platform for disseminating these results.
Live-cell imaging of the first embryonic division in C. elegans. Still images of C. elegans embryos expressing GFP::histone H2B (for chromosome visualization) and GFP::γ-tubulin (for spindle pole labelling). The images depict chromosome alignment from prophase to metaphase, highlighting the effect of expressing human CENP-E in a chromokinesin-depleted (siklp-19) embryo. Scale bar: 5 µm.
Live-cell imaging of the first embryonic division in C. elegans. Still images of C. elegans embryos expressing GFP::histone H2B (for chromosome visualization) and GFP::γ-tubulin (for spindle pole labelling). The images depict chromosome alignment from prophase to metaphase, highlighting the effect of expressing human CENP-E in a chromokinesin-depleted (siklp-19) embryo. Scale bar: 5 µm.
Have you had any significant mentors who have helped you beyond supervision in the lab? How was their guidance special?
Helder Maiato has played a crucial role in my development as a scientist. With his true passion for science and his unwavering support, he has provided invaluable guidance and encouragement throughout my PhD. Monica Gotta, whom I met during a sabbatical, has also been an inspiring mentor. She is not only a talented scientist but also a role model, showing me what it means to be a woman in science and helping me navigate my path as a young researcher.
What motivated you to pursue a career in science, and what have been the most interesting moments on the path that led you to where you are now?
One of the defining moments in my scientific journey was my first encounter with microscopy as an undergraduate student. Watching living cells divide under the microscope felt like uncovering a hidden universe. This sparked my interest in the intricate structures involved in cell division – such as the kinetochore and the mitotic spindle – and the broader complexity of cellular architecture. During my PhD, I delved deeper into studying these components using advanced microscopy and gained valuable experience through several collaborative projects. These reinforced the importance of teamwork and science communication – skills that I am eager to continue developing throughout my research career.
What's next for you?
I am continuing my journey as a postdoctoral researcher and EMBO Fellow in Ivana Gasic's lab, where I am investigating how tubulin homeostasis impacts microtubule function. My goal is to build on this expertise and progress towards an independent researcher position.
Tell us something interesting about yourself that wouldn't be on your CV
For 10 years, I sang in one of the most iconic choirs in my hometown of Porto – Coral de Letras da Universidade do Porto.
Ana C. Almeida’s contact details: Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland.
E-mail: [email protected]
