First person – Federica Giannini Free

Federica Giannini

How would you explain the main findings of your paper in lay terms?

The nucleus is a large cellular compartment that is fundamental to life. In oocytes (female gamete cells), it contains chromosomes that are later transferred to the embryo after fertilization. Indeed, disassembly of the nucleus and freeing of these chromosomes is one of the earliest processes that transitions an oocyte into a fertilizable egg. In our study, we found that the oocyte nucleus contains prominent structural filaments assembled from actin protein subunits. This was highly unexpected, because actin is generally thought not to exist as nuclear filaments in most cell types. Perhaps even more surprisingly, our advanced microscopy experiments demonstrated that the number of these nuclear actin filaments declines dramatically with increasing female reproductive age. Because it is widely accepted that oocyte quality also declines almost exponentially with advancing reproductive age, we explored how nuclear actin filaments are formed in mammalian oocytes. By combining our powerful imaging tools with experimental manipulations of actin's properties, we showed that the building blocks of nuclear actin filaments are imported from outside the nucleus. Other experimental results in our study suggested that the oocyte nucleus may serve as a sink for hiding the cell's excess actin subunits, whose accumulation could prevent the formation of healthy eggs. We are very intrigued by the possibility that age-related loss of nuclear actin filaments may impact female infertility, and we are now working on understanding the function of these fascinating structures in oocyte biology.

When doing the research, did you have a particular result or ‘eureka’ moment that has stuck with you?

For me, a major exciting point was discovering that oocyte nuclear F-actin structures deteriorate with increasing female age. Our team investigates the causes of the so-called maternal age effect, trying to find out the molecular causes of embryo defects and pregnancy failure in reproductively older women. The finding that nuclear actin amount and complexity significantly decrease in ageing oocytes could be good progress towards a comprehensive understanding of female infertility.

Why did you choose Journal of Cell Science for your paper?

I have always liked both the style of the journal and the variety of cell biology research one can find here. The First Person section of the journal has also been a great opportunity for me to know the people behind the science and helped me find inspiration in their career backgrounds and research.

Have you had any significant mentors who have helped you beyond supervision in the lab? How was their guidance special?

I started working on this project when I joined the Mogessie lab during my Erasmus internship, and I had the opportunity to be supervised first by my PI Binyam Mogessie and then by Kathleen Scheffler, the most experienced postdoc in the lab. I gained a lot from their experience in the field as well as from their scientific passion and commitment. Kathleen passed on to me her enthusiasm for science. She was always ready to solve my doubts and to guide me through the beautiful and challenging journey that this project was.

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?

Since I was a child, I was fascinated by cartoons of cellular organelles in schoolbooks. It was not surprising for people who knew me when I decided to enrol for a degree in biology and when I took advantage of an Erasmus scholarship to join the Mogessie lab in Bristol. This choice was the defining moment of my career so far, because I fell in love with the world of cell biology and I am extremely fascinated by the oocyte as a biological system. I always like to think about my scientific career as continuously evolving and that the best is hopefully yet to come.

Who are your role models in science? Why?

I have always looked up to the great Italian neuroembryologist Rita Levi-Montalcini, who was awarded the Nobel Prize in Physiology or Medicine in 1986 for her discovery of nerve growth factors. I was, and I still am, fascinated by her commitment to science and by how she managed to face all her life challenges. It was not easy for her to pursue her career not only as a woman but also as a Jewish person under a fascist government, but eventually she managed to do what she loved and succeeded. I read once that when she was not able to work in the lab due to the racial laws she never gave up and decided to keep going with experiments in her house. Therefore, every time I struggle, or when something goes wrong with my experiments, I always think about what she was capable of, and I'm reminded not to give up.

What's next for you?

The Mogessie lab is moving to Yale University in a few months. I am very excited to continue my PhD research within the excellent academic and research environment of Yale. This is also a wonderful opportunity for me to establish new networks with the strong oocyte meiosis community in the USA. Since I started studying biology, I have been determined to pursue a scientific career in academia. I feel this transatlantic journey will be very beneficial after finishing my PhD, as I would love to continue with a postdoctoral research position.

Tell us something interesting about yourself that wouldn't be on your CV

I'm a big tennis fan and I love it because it is a sport that is also mentally challenging. In a certain way, I find it like scientific research; ups and downs are common, and you must learn to be mentally strong and be ready to go for the right shot as well as the right experiment. My all-time favourite player, Roger Federer, with his technically complex and aesthetically pleasant style, has always reminded me of the beauty and complexity that you can find in the biological world.