An interkinetic envelope is assembled during oocyte meiosis
The Institut Jacques Monod is proud to announce that the scientific article “An interkinetic envelope is assembled during oocyte meiosis” published by Layla El Mossadeq et al. (Dumont Lab) is one of the 13 most influential articles of the year that have attracted exceptional interest from readers of The Journal of Cell Biology!
Here is a summary of the scientific article:
“At the end of cell division, the nuclear envelope reassembles around the decondensing chromosomes. Female meiosis culminates in two consecutive cell divisions of the oocyte, meiosis I and II, which are separated by a brief transition phase known as interkinesis. Due to the absence of chromosome decondensation and the suppression of genome replication during interkinesis, it has been widely assumed that the nuclear envelope does not reassemble between meiosis I and II. By analyzing interkinesis in C. elegans oocytes, we instead show that an atypical structure made of two lipid bilayers, which we termed the interkinetic envelope, surrounds the surface of the segregating chromosomes. The interkinetic envelope shares common features with the nuclear envelope but also exhibits specific characteristics that distinguish it, including its lack of continuity with the endoplasmic reticulum, unique protein composition, assembly mechanism, and function in chromosome segregation. These distinct attributes collectively
define the interkinetic envelope as a unique and specialized structure that has been previously overlooked.”
This article was written in collaboration between several teams at the Jacques Monod Institute: the Dumont team, the ImagoSeine platform, the Pintard Lab, and the Jackson/Verbavatz Lab: El Mossadeq, L., L. Bellutti, R. Le Borgne, J.C. Canman, L. Pintard, J.-M. Verbavatz, P. Askjaer, and J.Dumont. 2025. An interkinetic envelope surrounds chromosomes between meiosis I and II in C. elegans oocytes. J. Cell Biol. 224 (3): e202403125. https://doi.org/10.1083/jcb.202403125
The year in Cell Biology 2025
The collection features new advances in plasma membrane repair, autophagy, protein homeostasis, and organelle-dependent cell signaling. It explores mechanisms underlying the phagocytic fate of epithelial cells as well as the interplay between lysosomal exocytosis and focal adhesions. It presents a new meiosis-specific organelle and introduces valuable resources such as a proteome-wide yeast degron library. Additional highlights include discoveries on how sphingolipid metabolism regulates stem cell homeostasis and how mitochondrial dynamics affect astrocyte morphogenesis.
The Journal of Cell Biology reflect on a year of cutting-edge findings, spanning the diverse spectrum of cell biology.