Ines Anna Drinnenberg

While most eukaryotes have monocentric chromosomes where spindle attachment is restricted to a single chromosomal region resembling such classic X-shape like structures under the microscope, many lineages have evolved holocentric chromosomes where spindle microtubules attach along the entire length of the chromosome. Though holocentromeres have been known since more than 70 years the evolutionary transition from monocentromeres to holocentromeres has remained enigmatic ever since. Here, we are focusing on holocentric insects as models to address the following aims:

Determine the molecular architecture of CenH3-deficient holocentromeres

We found that the histone H3 variant, CENH3/CENP-A presumed to be the defining component of centromeres in most eukaryotes has been lost in independently derived holocentric insects. These findings raise the questions how those CenH3-deficient organisms define their centromeres? Using genomics map and characterize the molecular architecture of CenH3-deficient holocentromeres in Lepidoptera (butterflies and moths), thereby also providing insights into the evolutionary transition to their holocentric architectures.

Determine the assembly of CenH3-deficient kinetochores in Lepidoptera

CENH3/CENP-A functions as the cornerstone enabling kinetochore assembly in most eukaryotes. To address how CenH3-deficient kinetochores form we use proteomic and cell biological approaches in lepidopteran cell lines and in vivo models. We have recently identified several conserved kinetochore components including CENP-T that emerged as a key component for CenH3-deficient kinetochore formation in Lepidoptera.

Determine the spatial organization of holocentric chromosomes

Centromeres have a strong impact on spatial genome organization. Using Hi-C we determine how holocentric chromosomes are organized within the nucleus.

Study the evolution to CenH3-deficient holocentromeres across insects

Using comparative genomics we study the evolution of kinetochore components in CenH3-deficient and encoding insects. In addition we aim to evaluate the impact of holocentric architecture on the chromosome segregation machinery by profiling the evolution of factors that drive chromosome segregation.