Roles of the cilium-associated gene CCDC11 in left–right patterning and in laterality disorders in humans
Published: 2 June 2017
Michal Gur1, Enbal Ben-Tal Cohen1, Olga Genin1, Abraham Fainsod2, Zeev Perles3 and Yuval Cinnamon*,1
1Agricultural Research Organization, The Volcani Center, Department of Poultry and Aquaculture Science, Rishon LeTsiyon, 2Department of Developmental Biology and Cancer Research, Institute for Medical Research, Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem and 3Pediatric Cardiology Department, Division of Pediatrics, Hadassah – Hebrew University Medical Center, Jerusalem, Israel
Axial determination occurs during early stages of embryogenesis. Flaws in laterality patterning result in abnormal positioning of visceral organs, as manifested in heterotaxy syndrome, or complete left–right inversion as in situs inversus totalis. These malformations are often associated with ciliopathies, as seen in primary ciliary dyskinesia. We have recently described a novel mutation in the Coiled-Coil Domain-Containing 11 (CCDC11) gene associated with laterality disorders in a consanguineous family of Arab–Muslim origin with two affected siblings presenting with diverse phenotypes, one with heterotaxy syndrome and the other with non-primary ciliary dyskinesia situs inversus totalis. This study further characterizes the roles of CCDC11 and the implications of the identified mutation on left-right axial patterning in patient-derived cells and in the frog embryo as a model organism. We analyzed patient-derived cells and manipulated Ccdc11 levels in Xenopus laevis frog embryos. Cilia length in patient cells was longer than in controls, and CCDC11 was localized to the centriole and the actin cytoskeleton. Mutated truncated protein accumulated and was also localized to the centriole and actin cytoskeleton. In frog embryos, Ccdc11 was regulated downstream of FoxJ1, and overexpression of the full-length or truncated protein, or downregulation of the gene resulted in severe disruption of embryonic left–right axial patterning. Taken together, our initial description of the deleterious mutation in CCDC11 in patients, the current results and more recent supportive studies highlight the important role of CCDC11 in axial patterning.
CCDC11, cilia, laterality disorder, human mutation, Xenopus laevis embryo