Meiosis is the specialized cell division that is essential for the generation of haploid germ cells. It not only
compensates for the doubling of chromosome number after fertilization but also generates genetic diversity by
reciprocal exchange of paternal and maternal chromosomes. Defects in the meiotic cell divisions are the leading
cause of miscarriages and birth defects. We use the genetic model system C. elegans to identify genes that are
essential for proper meiotic prophase cell cycle progression and faithful meiotic chromosome segregation. The
characterization of the encoded factors and their interaction partners will be the aim of this project.
Recently, we isolated a novel meiotic gene, chis-1 (chiasma stability) (Jantsch et al, submitted) with a particularly
interesting, dual phenotype showing both defects in meiotic cell cycle progression but also a defect in the
maintenance of chiasmata thus leading to both a reduced number of germ cells and unfaithful chromosome
segregation in gametes.
Two complementing principle strategies will be chosen to identify CHIS-1 interacting partners. On the one hand, a
biochemical approach will be taken with the aim to co-purify CHIS-1 interaction partners. On the other hand,
advantage of the excellent genetics of C. elegans will be taken, by performing a genetic screen with the aim to
isolate extragenic suppressors of the chis-1 phenotype.
Once we will have identified novel meiotic genes in C. elegans we will undertake bioinformatics screens to identify
homolgues in other eukaryotes and humans.
Ultimately this project will contribute to a better understanding of genetic risk factors for compromised fertility and
birth defects due to chromosomal mal-segregation.