Department of Cell Nucleus Plasticity

Head:

Helena Fulková, Ph.D.

E-mail: helena.fulkova@iem.cas.cz
Phone: +420 241 062 232
+420 241 062 588
Twitter: @FulkaLab

The group is focused on studying the cell nucleus plasticity namely during early mammalian embryogenesis. The process of differentiation and de-differentiation is accompanied by dramatic changes of the nucleus morphology and epigenetic remodelling of chromatin. The aim of our group is to characterize these changes and to define the role of specific sub-nuclear organelles in the process.

Deputy Head:

Zuzana Smékalová, MSc.
zuzana.smekalova@iem.cas.cz
Phone: +420 241 062 232

Poctdoctoral researchers:

Pavel Čabart, PhD
pavel.cabart@iem.cas.cz

Oksana Shcherbak, PhD
oksana.shcherbak@iem.cas.cz

Tereza Znachorová, MSc.
tereza.znachorova@iem.cas.cz

PhD student:

Nataliia Dudko, MSc.
nataliia.dudko@iem.cas.cz

Important results:

2021:

1. In order for the embryo to develop successfully, the sperm germ cell must be remodelled and form a functional pronucleus. This process can be perturbed by the presence of DNA damage of the paternal genome. Moreover, the egg does not always possess the capacity to remodel the sperm after fertilization. Even though, mild DNA damage does not have to lead to a developmental arrest, it is impossible to assess the extent of the damage by current methods and therefore, whether the sperm will, or will not, support further development. These questions can be addressed by the interspecific ICSI (intracytoplasmic sperm injection).
Publications:

Rychtarova, J., Langerova, A., Fulka, H., Loi, P., Benc, M., Fulka, J, Jr.: (2021) Interspecific ICSI for the Assessment of Sperm DNA Damage: Technology Report. Animals. 2021; 11(5):1250. https://doi.org/10.3390/ani11051250

Chapter in: Palermo, G., & Nagy, Z. (Eds.). (2021). Manual of Intracytoplasmic Sperm Injection in Human Assisted Reproduction: With Other Advanced Micromanipulation Techniques to Edit the Genetic and Cytoplasmic Content of the Oocyte. Cambridge: Cambridge University Press. https://doi.org/10.1017/9781108887595

2. In collaboration with the Institute of Molecular Genetics and the RIKEN Bioresource Research Center we have finished the phenotypic analysis of a genetically modified hamster (Mesocricetus auratus). Using this model, we have analysed the effect of small RNAs from the piRNA family on gametogenesis in both sexes.

Publication:

Loubalova, Z., Fulka, H., Horvat, F., Pasulka, J., Malik, R., Hirose, M., Ogura, A., Svoboda, P.: (2021) Formation of spermatogonia and fertile oocytes in golden hamsters requires piRNAs. Nature Cell Biology. 2021; 23(9): 992-1001. doi: 10.1038/s41556-021-00746-2 – In collaboration with IMG a RIKEN BRC, Japan

2020:

1. Acrosin is essential for fertilisation

For a successful fertilisation, the sperm must penetrate through the glycoprotein coat surrounding the oocyte, the zona pellucida. It is assumed that this step is governed by partial lysis of the zona pellucida by hydrolytic enzymes present in the sperm acrosome, with acrosin being the most abundant enzyme. However, evidence for this has been lacking. In collaboration with our Japanese colleagues we have prepared a knockout golden hamster (Mesocricetus auratus) model, which helped to clarify the role of acrosin in this process.

Article:
Hirose, M., Honda, A., Fulka, H. et al.: (2020) Acrosin is essential for sperm penetration through the zona pellucida in hamsters, Proceedings of the National Academy of Sciences of the United States of America, 117,5,2513-2518

2. The soluble germinal vesicle component is responsible for the somatic cell remodelling after its transfer

Somatic cell nucleus transfer experiments show that the oocyte is capable of remodelling the transferred nucleus to such an extent that a new individual can be born. However, what oocyte components are responsible for the process is not entirely clear. Using the selective enucleation we have shown that it is the soluble nuclear fraction, which has the biggest effect on the transferred nucleus. The selective enucleation will allow us to study the replication dependent and independent processes of nuclear reprogramming. The article was selected as an “Outstanding paper 2019” and got a cover of the October 2019 issue of Journal of Reproduction and Development.

Article:
Fulka, H., Ogura, A., Loi, P., et al.: (2019) Dissecting the role of the germinal vesicle nuclear envelope and soluble content in the process of somatic cell remodelling and reprogramming, Journal of Reproduction and Development, 65,5,433-441
https://www.jstage.jst.go.jp/article/jrd/65/5/65_2019-017/_article

2023

Fulka, H ., Loi, P., Czernik, M., Surani, A., Fulka, J. Jr.: Omne vivum ex ovo: the oocyte reprogramming and remodeling activities. Reproduction 2023. 165 (3). R75–R89. doi: https://doi.org/10.1530/REP-22-0124

2022

Paul, Ch. J., Fulka, H.,: Nuclear Lamins: Key Proteins for Embryonic Development. Biology 2022, 11(2). doi: 10.3390/biology11020198 https://www.mdpi.com/2079-7737/11/2/198/htm

2021

Loubalova, Z., Fulka, H., Horvat, F., Pasulka, J., Malik, R., Hirose, M., Ogura, A., Svoboda, P.: Formation of spermatogonia and fertile oocytes in golden hamsters requires piRNAs. Nature Cell Biology. 2021; 23(9): 992-1001. doi: 10.1038/s41556-021-00746-2 - In collaboration with IMG and RIKEN BRC

Dzijak, R., Galeta, J., Vázquez, A., Kozák, J., Matoušová, M., Fulka, H., Dračínský, M., Vrabel, M.: Structurally Redesigned Bioorthogonal Reagents for Mitochondria-Specific Prodrug Activation. JACS Au. 2021 Jan 25;1(1):23-30. doi: 10.1021/jacsau.0c00053. Epub 2020 Dec 15. PMID: 33554213; PMCID: PMC7851953.

Rychtarova, J., Langerova, A., Fulka, H., Loi, P., Benc, M., Fulka, J, Jr.: Interspecific ICSI for the Assessment of Sperm DNA Damage: Technology Report. Animals. 2021; 11(5):1250. https://doi.org/10.3390/ani11051250

Chapter in a textbook: Palermo, G., & Nagy, Z. (Eds.). Manual of Intracytoplasmic Sperm Injection in Human Assisted Reproduction: With Other Advanced Micromanipulation Techniques to Edit the Genetic and Cytoplasmic Content of the Oocyte. 2021. Cambridge: Cambridge University Press. doi:10.1017/9781108887595 https://doi.org/10.1017/9781108887595

2020

Benc, M., Martinkova, S., Rychtarova, J., Fulka, J., Bartkova, A., Fulka, H., Laurincik, J.: Assessing the effect of interspecies oocyte nucleolar material dosage on embryonic development, Theriogenology, 2020. DOI: 10.1016/j.theriogenology.2020.06.001

Fulka, H. , Rychtarova, J., Loi, P.: The nucleolus-like and precursor bodies of mammalian oocytes and embryos and their possible role in post-fertilization centromere remodelling, Biochemical Society Transactions, 2020. 48,581-593

Hirose, M., Honda, A., Fulka, H. et al.: Acrosin is essential for sperm penetration through the zona pellucida in hamsters, Proceedings of the National Academy of Sciences of the United States of America, 2020. 117,5,2513-2518

GAČR 20-04465S (1. 1. 2020 – 31. 12. 2022)
Understanding the factors critical for successful paternal genome remodelling: Dissecting the role of oocyte components

GAČR 21-42225L (2021-2024)

Genome stability in mammalian oocytes and somatic cells

GAČR as a LEAD agency in cooperation with Swiss National Science Foundation: 22-02610K (2022-2025)

Molecular and functional analysis of the nucleolus in 3D genome organization during early embryo development

prof. Jerzy Dobrucki, PhD, DSc
Department of Cell Biophysics
Jagiellonian University of Krakow
Krakow, Poland

Prof. Pasqualino Loi
Faculty of Veterinary Medicine, Laboratory of Embryology
University of Teramo
Teramo, Italy

Dr. Milan Vrábel
Chemistry of Bioconjugates
Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences
Prague, Czech Republic

Dr. Tomáš Etrych
Biomedical Polymers
Institute of Macromolecular Chemistry CAS
Prague, Czech Republic

Institute of Experimental Medicine CAS