Project: Structures of the Cell Nucleus in Gene Expression

Group 11 Epigenetics of the cell nucleus

Molecular regulation of chromosome dynamics in gametogenesis

Pavel Hozák and Jana Rohožková

Actin binding proteins in nucleus

Vinculin

Outline of the presentation

Molecular regulation of chromosome dynamics in gametogenesis

• Chromosome dynamics during gametogenesis in two eukaryotic models (C. elegans, M. musculus)

• Proteins involved in early meiotic stages during pairing and synapsis of homologous chromosomes

• Identification of new players affecting meiosis during gametogenesis - complications during meiotic divisions still remain incompletely understood

• Vinculin/DEB-1 clearly participates in meiotic prophase progression

Dancing chromosomes are essential for gametogenesis

Preliminary experiments

• Vinculin/DEB-1 clearly participates in meiotic prophase progression

• Depletion of DEB-1 impacts chromosomal pairing stabilization, attachment of chromosomes to cytoskeletal forces, and formation of synaptonemal complex during prophase I

• Resulting in meiosis delay and increased presence of chromosome univalent

• Nuclear functions of vinculin/DEB-1 have not been described, so far

Aim 1/ Mapping of vinculin at meiosis-specific structures in cell nuclei

Aim 2/ Deciphering meiosis-specific roles of vinculin and associated proteins

Conclusion & Planed experiments – C.elegans

• C.elegans deb-1 KO and DEB-1::GFP using CRISPR-Cas9

• Y2H screening, search for DEB-1 interaction partners in C.elegansmeiosis

• Transgenetic C.elegans with DEB-1 point mutations inside interactionsites by TALEN (Head: Talin, α-Actinin α-Catenin; Linker: Arp2/3; Tail: F-actin, PIP2, Paxillin)

• Phenotypisation of DEB-1 deletant and mutant in context ofpreiliminary data

• DEB-1 clearly participates in meiotic prophase progression

• Depletion of DEB-1 impacts chromosomal pairing stabilization,attachment of chromosomes to cytoskeletal forces, and formation ofsynaptonemal complex during prophase I

• Meiosis delay and increased presence of chromosome univalents.

• Our study revealed an unsuspected role of DEB-1 in the progression ofmeiotic prophase, including chromosome dynamics and pairing thathave been shown to be an essential meiotic components.

Conclusion & Planed experiments – M. musculus

• Preparation of conditional Vinculin knock-out in the meioticprophase I (in progressss)

• Phenotypisation of VCL conKO (spermatogenesis and oogenesisprogression, coIP, fertility, …)

• Y2H screening, search for Vinculin interaction partners in mousemeiosis

• VCL is expressed during meiotic prophase I

• It is localized to the meiotic nuclei in a dynamic pattern

• VCL localize to the centromeric but not telomeric region

Acknowledgment

Pavel HozákTomáš VenitJana Fukalová

Prof. Monique Zetka

Prof. Rolf Jessberger