Understanding
mitotic nuclear remodeling from the comparative and synthetic
biology perspectives constitutes the main thrust of our
current research.
Mitotic
division ensures faithful inheritance of genetic material in
proliferating eukaryotic cells and errors in this process
often lead to developmental defects and disease. Cellular
genome is compartmentalized inside the nucleus delimited by
the double-membrane nuclear envelope. The nuclear envelope
must be dynamically restructured during mitosis to allow
chromosome segregation and formation of the daughter nuclei.
Eukaryotic
cells perform this necessary task using a strikingly diverse
set of cell type- and organism-specific approaches, ranging
from fully “open” to fully “closed” mitosis depending on
whether and when the nuclear envelope breaks down or remains
intact. The recent focus on a relatively small cohort of model
systems has provided only limited insights into the extent and
the molecular basis of mitotic variability. By making use of
an “experiment of Nature”, comparative and synthetic analyses
of related eukaryotes utilizing distinct approaches to mitotic
division may add a new, evolutionary dimension to this
important field and provide a discovery tool capable of
challenging established paradigms and revealing fundamentally
novel biological principles.
We
use two fission yeast species, Schizosaccharomyces
pombe and Schizosaccharomyces
japonicus that employ strikingly divergent mitotic
strategies to address the following questions:
How
is the nuclear envelope area controlled during mitotic
division?
How
do cells break and reform the nuclear membrane?
What
are the rules for generating functional diversity in nuclear
envelope management?
Aside
from the nuclear envelope biology, the two fission yeasts
exhibit intriguing differences in several integral biological
processes including cytokinesis, cell size control, chromatin
organization, and polarized growth. We also use S.
japonicus and S.
pombe to understand the interplay between cellular
division site placement and cortical patterning. We have been
developing new avenues of research aimed at understanding the
mechanisms underlying differences in overall cell size and cell
size homeostasis in the two sister species and the scaling of
chromosome compaction during mitosis.