Lehrstuhl für Zell- und Entwicklungsbiologie

ALSHEIMER LAB

Our current research is mainly focused on the function of nucleocytoplasmic network systems in nuclear shaping and meiotic chromosome dynamics. We are also interested in general regulation of chromosome synapsis and in evolutionary aspects of meiosis

Research synopsis

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 center 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.

Besides this, we are also engaged in analyzing general mechanisms of meiotic chromosome pairing and synapsis. We for example try to understand the specific function of telomere driven bouquet formation. We also study the molecular composition of synaptonemal complexes (SCs) and the regulation of SC assembly and disassembly. Furthermore, we are interested in evolutionary aspects of meiosis, i.e. the evolution of the synaptonemal complex in metazoans.

Recent publications

Link, J., Benavente, R., and Alsheimer, M. (2016). Analysis of Meiotic Telomere Behavior in the Mouse. Methods Mol. Biol. 1411, 195-208. (doi: 10.1007/978-1-4939-3530-7_12)

Fraune, J., Brochier-Armanet, C., Alsheimer, M., Volff J.N., Schücker, K., and Benavente, R. (2016). Evolutionary history of the mammalian synaptonemal complex. Chromosoma 125, 355-360. (DOI: 10.1007/s00412-016-0583-8.

Gómez, R., Felipe-Medina, N., Ruiz-Torres, M., Berenguer, I., Viera, A., Pérez, S., Barbero, J.L., Llano, E., Fukuda, T., Alsheimer, M., Pendás, A. M., Losada, A., and Suja, J.A. (2016). Sororin loads to the synaptonemal complex central region independently of meiotic cohesin complexes. EMBO Rep 17, 695-707. (doi: 10.15252/embr.201541060)

Pasch, E., Link, J., Beck, C., Scheuerle, S., and Alsheimer, M. (2015). The LINC complex component Sun4 plays a crucial role in sperm head formation and fertility. Biol. Open 4, 1792-1802.

Link, J., Jahn, D., and Alsheimer, M. (2015). Structural and functional adaptations of the mammalian nuclear envelope to meet the meiotic requirements. Nucleus 6, 93-101.

Viera, A., Alsheimer, M., Gómez, R., Berenguer, I., Ortega, S., Symonds, C.E., Santamaría, D., Benavente, R., and Suja, J.A. (2015). CDK2 regulates nuclear envelope protein dynamics and telomere attachment in mouse meiotic prophase. J. Cell Sci. 128, 88-99.

Fraune, J., Alsheimer, M., Redolfi, J., Brochier-Armanet, C., and Benavente, R. (2014). Protein SYCP2 Is an Ancient Component of the Metazoan Synaptonemal Complex. Cytogenet. Genome Res. 144, 299-305.

de la Fuente, R., Manterola, M., Viera, A., Parra, M.T., Alsheimer, M., Rufas, J.S., and Page, J. (2014). Chromatin organization and remodeling of interstitial telomeric sites during meiosis in the Mongolian Gerbil (Meriones unguiculatus). Genetics 197, 1137-1151.

Daniel, K., Tränkner, D., Wojtasz, L., Shibuya, H., Watanabe, Y., Alsheimer, M., and Tóth, A. (2014). Mouse CCDC79 (TERB1) is a meiosis-specific telomere associated protein. BMC Cell Biology 15, 17.

Link, J., Leubner, M., Schmitt, J., Göb, E., Benavente, R., Jeang, K.-T., Xu, R., and Alsheimer, M. (2014). Analysis of meiosis in SUN1 deficient mice reveals a distinct role of SUN2 in mammalian meiotic LINC complex formation and function. PLoS Genet. 10, e1004099.

RESEARCH TOPICS

LINC Complexes in Nuclear Shaping

A hallmark of sperm formation is the highly regulated species-specific shaping of the cell nucleus. We try to understand how germ cell nuclei actually change their specific shape from round to elongate.

The nuclear envelope in meiotic chromosome dynamics

Meiosis essentially requires an unambiguous assignment of the homologous chromosomes to ensure their proper segregation. We try to understand the specific function of the nuclear envelope during this core process of meiosis.

Evolution of the synaptonemal complex (SC)

Meiosis is highly conserved in eukaryotic evolution. But whether this is also true for the synaptonemal complex, a unique and vitally important supporting structure, was in dispute. In the past years we could provide evidence that at least in metazoans the SC has an common origin.

PEOPLE

Silke Braune

Isabell Köblitz

Hanna Thoma

Kontakt

Lehrstuhl für Zoologie I - Zell- und Entwicklungsbiologie
Am Hubland
97074 Würzburg

Tel.: +49 931 31-84250
Fax: +49 931 31-84252
E-Mail

Suche Ansprechpartner

Hubland Süd, Geb. B1 Hubland Nord, Geb. 32 Julius-von-Sachs-Platz 2 Fabrikschleichach Hubland Süd, Geb. B2 Campus Medizin