Chromosome segregation during meiosis
The reduction of chromosome number during meiosis is achieved by two successive rounds of chromosome segregation, called meiosis I and meiosis II. While meiosis II is similar to mitosis in that sister kinetochores are bi-oriented and segregate to opposite poles, recombined homologous chromosomes segregate during the first meiotic division. Formation of chiasmata, mono-orientation of sister kinetochores and protection of centromeric cohesion are three major features of meiosis I chromosomes which ensure the reductional nature of chromosome segregation. In our studies we use the fission yeast Schizosaccharomyces pombe, which is an excellent model organism, to identify new proteins required for proper segregation of chromosomes during meiosis. In order to decipher molecular functions of identified proteins, we combine genetic, biochemical and cell biology techniques.
Chromosome segregation during mitosis.
Accurate chromosome segregation in mitosis depends on the establishment of correct (amphitelic) kinetochore orientation. Merotelic kinetochore orientation is an error which occurs when a single kinetochore is attached to microtubules emanating from opposite spindle poles. Recent studies showing that merotelic kinetochore attachment represents a major mechanism of aneuploidy in mitotic cells and is the primary mechanism of chromosomal instability in cancer cells underline the importance of studying merotely. We focus on fission yeast proteins required to prevent and correct merotelic attachments in order to understand how cells ensure high fidelity of chromosome segregation.
Together with Daniela Cimini (Virginia Polytech) and Iva Tolic (Ruder Boskovic Institute), we use merotelic kinetochores as an experimental model for studying the mechanical properties of the kinetochore in vivo (HFSP young investigator grant).
Our work is supported by:
APVV (Slovak Research and Development Agency)
VEGA (scientific grant agency of the Ministry of Education of the Slovak Republic
We would like to acknowledge previous support from:
FWF, HFSP and EU-FP7