RESEARCH INTERESTS
The Riggs lab has sought to understand how the cell is organized throughout the cell cycle and focused on the partitioning and inheritance or organelles and other cytoplasmic material. Much of the focus has been on our understanding of genetic organization and partitioning during cell division but our knowledge of organelle dynamics during mitosis and the inheritance to the daughter cells is limited. The focus of the Riggs lab is to increase our understanding of organelle inheritance and any regulatory pathways and the role of organelles in directing the generation of cell diversity.
RESEARCH INTERESTS
ORGANELLE INHERITANCE
Organelle inheritance
The term mitosis was coined in the early 1880 from the Greek word for thread. This was due to the observation of the condensed mitotic chromosomes. Over the next 100 years, there has been a concerted effort to understand many aspects of mitosis, including the identification of the microtubule based mitotic spindle, kinetochore connections, and regulatory pathways including the spindle assembly checkpoint. However, when we look at our knowledge surrounding cell division and inheritance, it has largely been focused on the genetic material aka chromosomes. Our understanding of mitotic cellular organization and inheritance of cytoplasmic material including organelles is extremely limited. Specifically, there is no identified pathway or mechanism surrounding inheritance of organelles like the golgi apparatus, endoplasmic reticulum, or endosomes. Importantly, connections have been made between organelle organization and movement in mitosis and several diseases including neurodegenerative conditions. The Riggs lab is interested in understanding how organelles are inherited and partitioned during mitosis. Specifically, we use a combination of genetic and imaging approaches to examine distribution of organelles during cell division using the model system, Drosophila melanogaster. The fruit fly offers many scientific approaches and tools towards investigating organelle inheritance including in vivo imaging techniques and many orthologous genes found in humans.
Projects include
Our investigation of the mitotic endoplasmic reticulum and its reorganization and remodeling during mitosis,
Endosome movement and domain maturation during cell division,
Mitochondrial membrane domains and their connection with the ER for partitioning and inheritance
GENERATION OF CELL DIVERSITY
During early development, after fertilization, cells will rapidly divide to form into an early morula stage (prior to cell differentiation). A major question explored during development is how cells initiate their selection and segregate into tissues and organ systems. On the cellular level, factors are asymmetrically segregated during division that either drive a self renewing state or a state of differentiation. Many of these factors or cell fate determinants, initially identified in Drosophila, are highly homologous in multicellular organisms. Additionally, errors in distribution and function of these determinants lead to a host of defects and disorders associated with several diseases. Unanswered questions in the field include how these cell fate determinants are distributed and transported during mitosis, how they are maintained and partitioned to daughter cells at cytokinesis.
Projects include
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Asymmetric partitioning and distribution of the endoplasmic reticulum during mitosis in pro-neuronal cells prior to cell fate selection in the early Drosophila embryo
Role of microRNAs in the regulation and distribution of cell fate determinants in neural development