Primary cilia are microtubule-based organelles that extend from the surface of mammalian cells and are specialized to respond to Hedgehog ligands and other signals. Abnormalities in primary cilia cause obesity, cystic kidney disease, and birth defects that affect development of the brain, skeleton and heart. Although primary cilia are widely distributed in embryonic and adult tissues, recent studies showed that the formation of primary cilia is regulated by lineage- and stage- dependent processes. The mechanisms that control cell-type specific primary cilia are not known. The goal of this project is to define the mechanisms that regulate primary cilia formation in specific tissues of the mouse embryo, with the long-term goal of developing therapies to restore or ablate cilia to treat human disease. Studies carried out in cells derived from mouse embryos will define the roles of specific proteins in the regulatory network that controls cilia initiation. The functions of specific proteins in that network, including RSG1, other RGK proteins and KIF24, will be validated in mutant mouse embryos. Studies will be carried out to determine why four specific cell types in the mouse embryo lack primary cilia: the extraembryonic endoderm (which contributes to the yolk sac of the fetus), the trophectoderm (an essential component of the placenta), the mature intestinal epithelium, and primordial germ cells. Developmental signals that regulate the dynamic gain or loss of primary cilia in the intestine and primordial germ cells will be identified. As it is clear that many regulators of tissue-specific formation of primary cilia have yet to be identified, screens will be carried out to identify genes that can promote formation of primary cilia in mouse extraembryonic endoderm stem cells, which never bear primary cilia.

Public Health Relevance

Primary cilia are microtubule-based organelles that extend from the surface of many mammalian cells to sense chemical and mechanical stimuli. Abnormalities in primary cilia can cause obesity, cystic kidney disease, as well as birth defects that affect development of the brain, skeleton and heart, and primary cilia are lost in many tumors. Recent work has shown that the presence of primary cilia is dynamically regulated during development. The proposed work will define mechanisms that control primary cilia formation during development, which will pave the way for therapies to treat cilia-associated disease and tumors.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM126124-04
Application #
10063527
Study Section
Development - 1 Study Section (DEV1)
Program Officer
Ainsztein, Alexandra M
Project Start
2018-01-01
Project End
2021-11-30
Budget Start
2020-12-01
Budget End
2021-11-30
Support Year
4
Fiscal Year
2021
Total Cost
Indirect Cost
Name
Sloan-Kettering Institute for Cancer Research
Department
Type
DUNS #
064931884
City
New York
State
NY
Country
United States
Zip Code
10065
Agbu, Stephanie O; Liang, Yinwen; Liu, Aimin et al. (2018) The small GTPase RSG1 controls a final step in primary cilia initiation. J Cell Biol 217:413-427