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. Anne Rosfelter is first author on ‘ Reduction of cortical pulling at mitotic entry facilitates aster centration’, published in JCS. Anne conducted the research described in this article while a PhD student in Alex McDougall's lab at Laboratoire Biologie du Développement (LBDV), Villefranche-sur-Mer, France. She is now a post-doctoral researcher in the lab of Yu-Chiun Wang at the RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, Japan, investigating the spatial organization of cells and tissue through studying the cytoskeleton.
Anne Rosfelter
How would you explain the main findings of your paper in lay terms?
In some species such as the ascidian P. mammillata (a type of sea squirt), embryogenesis is tightly regulated so that their development is reproducible from the very first division. This requires that the orientation and position of the axis of cell division is well defined, and it is known that the position of the mitotic spindle indicates the axis of division. Thus, we investigated how the spindle centers in the cell prior to the first cell division in P. mammillata, and expected to find a precise mechanism of regulation. Indeed, we found that three different mechanisms are involved in moving the spindle, in a cell-cycle-dependent fashion. Although these mechanisms of microtubule cortical pulling, cytoplasmic pulling and microtubule pushing were previously known, for the first time we found a system in which they act together. Moreover, we found that the centration of the spindle is not immediate. For some time, the spindle stays located against the cell membrane, which seems to resemble the dynamics of spindle movement in human embryogenesis.
Were there any specific challenges associated with this project? If so, how did you overcome them?
There were several challenges, but the main one was probably to try to inhibit dynein. At this very early stage of development, dynein seems to be essential for development, so any perturbation had a drastic outcome, such as the embryo developing into very strange shapes or the spindle/aster disassembling. To overcome this, we decided to use computational modeling to test dynein-related hypotheses. This also allowed us to uncouple cytoplasmic pulling from cortical pulling, which are both potentially partially performed by dynein.
When doing the research, did you have a particular result or ‘eureka’ moment that has stuck with you?
We put all the pieces of this project together progressively, so there was no ‘eureka’ moment. However, one result in particular has stuck with me. When I observed microtubule polymerization pocking on the cell membrane, I was extremely excited to see this in vivo, as this is a concept that was previously discussed and developed, but to my knowledge hadn't been seen in embryos previously.
Confocal image of the plasma membrane, marked by Cell Mask Orange, deformed around microtubules, marked by Ens::3GFP, in presence of latrunculin, which perturbs F-actin. B shows a close up of A, showing membrane in the top panel and microtubules in the bottom panel. Arrowheads indicate one protrusion.
Confocal image of the plasma membrane, marked by Cell Mask Orange, deformed around microtubules, marked by Ens::3GFP, in presence of latrunculin, which perturbs F-actin. B shows a close up of A, showing membrane in the top panel and microtubules in the bottom panel. Arrowheads indicate one protrusion.
Why did you choose Journal of Cell Science for your paper?
JCS is a well-established and recognized journal that often features cytoskeleton and cell cycle research; hence, the Journal scope matches our work well. I also enjoy reading articles from JCS, so I hope that the readers of this journal enjoy my paper too!
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?
I decided to continue my career in science after my Master’s internship, during which I was supervised by Janet Chenevert, who showed me how much she enjoyed doing science for fun and just out of curiosity. Science is demanding, but I realized how lucky I am to have an intellectually fulfilling job and to be surrounded by bright and curious minds.
What's next for you?
My plan is to continue a science career in academia for as long as I enjoy it, so my next step will probably be another postdoc.
Tell us something interesting about yourself that wouldn't be on your CV
Outside the lab I enjoy doing a bit of sports. Somehow, I always end up doing the weirdest sports! Where will curiosity bring me next?
Anne Rosfelter's contact details: RIKEN Center for Biosystems Dynamics Research (BDR) 2-2-3, Minatojima-minamimmachi, Chuo-ku, Kobe 650-0047, Japan.
E-mail: [email protected]
