Dr. Marta Olszewska defended her M.Sc., Eng. thesis in ‘Biotechnology’ at Poznan University of Life Sciences in 2006. Since 2004 in Department of Reproductive Biology and Stem Cells. She received her Ph.D. in the field of medical biology in 2014 (Institute of Human Genetics, Polish Academy of Sciences, Poznan), and now works as Assistant Professor. Her scientific interests concern: cytogenetics of male infertility, including chromosome aberrations in human spermatozoa, searching for mutations responsible for decreased sperm count (incl. mouse models) and also epigenetics of male germ cells.
Head of the Research Team of Sperm Genetics
Team Members:
mgr Zuzanna Graczyk – PhD Student
mgr inż. Jagoda Kostyk – Biologist
Zuzanna Myślicka – M.Sc. Student
Julia Pospieszna, M.Sc. Eng. – past member
Spermatozoa characterizes unique nuclear packaging of the chromatin; thus, the chromosomes’ positions are also specific. It is known that in men with various disturbances of fertility the nuclear organization is changed. There are also evidences that epigenetic changes are prone both to: genetics, as well as for environmental factors. What is interesting, relative interaction between them may work as a cause or a reason of disturbances in male fertility.
The research tasks of the Team are based on a comprehensive experimental approach to spermatozoa of males with oligozoospermia, as well as of chromosomal aberrations carriers, taking into account the characteristics of both: the genetic and epigenetic content of the sperm cell important for the course of spermatogenesis. Simultaneous evaluation of all the above-mentioned parameters may be a stimulus to develop new tests assessing both the structural and regulatory layer of the sperm genetic material.
Currently, the Team implements the research tasks following epigenetic and cytogenetic aspects of human spermatozoa from males with reproductive failures following the research projects:
- ‘Cytogenetic and molecular analyses of positioning of human sperm chromosomes, including: sperm chromatin integrity, epigenetic marks, karyotyping and sperm fractioning’ SONATA BIS NSC, no. 2020/38/E/NZ2/00134
The main purpose of the Project is to determine how the positions of the chromosomes within human sperm nucleus may be altered depending on: the state of fertility, karyotype, chromatin integrity status, epigenetic variations within DNA or histones, and between members of the same family, incl. various fractions of sperm cells. The novelty of the Project is that all analyses will be done sequentially on the same individual sperm cells, what means that the positioning of the chromosomes will be prepared in particular single spermatozoa, cell by cell, with known and documented: genotype, chromatin integrity state, and epigenetic marks level/change. Tests will be performed in males with normal karyotype (control, fertile vs. infertile from the same family, i.e. brothers), and with chromosomal abnormalities but phenotypically normal (i.e. carriers of chromosomal translocations). All tests will be performed on various sperm fractions: sperm with good motility, mature chromatin, and defined fertilization potential.
Carriership of balanced chromosomal rearrangements (CR) can be called: a ‘hidden biological bomb’, because aberrations frequently do not affect carriers’ phenotype, contrary to its negative influence on spermatogenesis. CR carriers may be at risk for abnormal pregnancy and/or offspring with developmental disabilities, because of the production of genetically unbalanced gametes during improper meiotic segregation. It is important, especially in the context of IVF techniques, where only visual evaluation of sperm motility and morphology is performed when selecting sperm cell for IVF procedure.
- ‘Analysis of DNA methylation pattern in spermatozoa of infertile men with oligozoospermia’ SONATA NSC, no. 2015/17/D/NZ5/03442
The purpose of the Project is to delineate methylation pattern for selected genes in DNA from spermatozoa of infertile men with diagnosed oligozoospermia (low sperm count in ejaculate). It is assumed that spermatozoa of oligozoospermic males may have changed methylation patterns of genes that are crucial for spermatogenesis, what may influence their fertility status. Moreover, in spermatozoa of oligozoospermic males also other genomic elements may be disrupted, including: sperm chromatin integrity (deprotamination and DNA fragmentation) and higher sperm aneuploidy level. Diagnostics of oligozoospermia has been developed to some level. However, standard sperm analysis and hormonal evaluation is not sufficient for delineation of the reasons and mechanisms that may underlie infertility at the molecular level. It is important especially in intricated cases. We anticipate that undertaken evaluation will show us the effect of changed/disrupted methylation pattern of selected genes that possibly may be linked with oligozoospermia. The purpose of the Project is carrying out via complex characterization of spermatozoa from infertile males with oligozoospermia, including: (i) methylation pattern analysis of sperm DNA in promotor sequences for selected genes (gene panel and/or whole methylome sequencing), (ii) global methylation analysis of sperm DNA, followed by analysis of methylation and acetylation of selected histones’ residues, followed by their immunolocalization within human sperm nuclei, (iii) sperm chromatin integrity analysis, (iv) analysis of aneuploidy level for selected chromosomes in spermatozoa.
Realized grant projects:
- National Science Centre, SONATA BIS nr 2020/38/E/NZ2/00134 (2021-2026) Cytogenetic and molecular analyses of positioning of human sperm chromosomes, including: sperm chromatin integrity, epigenetic marks, karyotyping and sperm fractioning (principal investigator)
- National Science Centre, OPUS nr 2020/37/B/NZ5/00549 (2021-2025) Systematic genomic search for novel genes/variants in consanguineous families including males with reproductive failure (main investigator)
- National Science Centre, SONATA no. 2015/17/D/NZ5/03442 (2016-2019) Analysis of DNA methylation pattern in spermatozoa of infertile men with oligozoospermia (principal investigator)
- National Science Centre, OPUS no. 2015/17/B/NZ2/01157 (2016-2019) Searching for novel genes essential for human oligo- and azoospermia – mouse ‘knockout’ model (main investigator)
- National Science Centre, OPUS no. 2011/01/B/NZ2/04819 (2011-2014) Complex cytogenetic and molecular analysis of male germline cells from chromosome translocation (CT) carriers with reproduction failure (main investigator)
- Ministry of Science and Higher Education, no. NN401376339 (2010-2013) Topology of the chromosomes in spermatozoa from men with disturbed spermatogenesis (main investigator)
- National Centre of Research and Development, no. R1306606 (2009-2012) Partners’ infertility – identification of the reasons on molecular level, as a basis for preventic alghoritms creation (investigator)
- Ministry of Science and Higher Education, no. NN401 097937 (2009-2013) Positioning of the chromosomes in differentiating myogenic stem cell (investigator)
- Ministry of Science and Higher Education, no. N40703432/1371 (2007-2009) Analysis of RCT carriers’ pedigrees including paternal sperm karyotypes; evaluation of Polish and Ukrainian RCT carriers with reproductive failure (investigator)
Co-author of 45 conference communications
Member of scientific organizations:
European Cytogeneticists Association (ECA)
Polish Society of Andrology (PTA)
Polish Society of Human Genetics (PTGC)
Society for Biology of Reproduction (TBR)
Polish Laboratory Animal Science Association (PolLASA)
F1000
