Nuclear Structure and Dynamics
The defining characteristic of eukaryotes is the sequestration of the genetic material by the nuclear envelope (NE). The NE is composed of two nuclear membranes, nuclear pore complexes and the nuclear lamina, a proteinaceous meshwork that is in intimate contact with the nuclear side of the inner nuclear membrane. Besides its primary role in separating nuclear and cytoplasmic activities, the NE constitutes a most central component of intracellular architecture. It is vitally involved in many fundamental nuclear functions such as dynamic chromatin organization, transcription and replication. Several components of the NE were identified to function as key players in signalling pathways and recent studies evidenced that the NE has a pivotal role in nuclear migration, anchoring and positioning. Furthermore, the NE was demonstrated to be a most crucial determinant for maintaining nuclear morphology and shape and for general nuclear integrity and, beyond, the NE was shown to serve as a kind of rail for telomere driven chromosomal rearrangement during meiotic prophase I. Thus, from the current point of view the nuclear envelope represents more than just a simple barrier, rather it constitutes a multifunctional platform at the very centre of fundamental cellular processes. Research in our lab covers several aspects regarding the function of the nuclear envelope and its components during dynamic reorganization of nuclei. One main focus is set on the role of the nuclear envelope in the evolutionary highly conserved meiotic chromosome dynamics and its impact on genome haploidization. In a second core project we try to figure out the molecular mechanisms underlying the well-directed nuclear shaping during sperm head formation.