Primary cilia control cellular patterning and dimension of Meibomian glands during morphogenesis but not lipid composition of the meibum

Abstract Meibomian glands (MGs) are modified sebaceous glands which produce the tear film's lipid component. Despite their critical function in maintaining clear vision, the mechanisms underlying MG morphogenesis during development and disease pathogenesis remain obscure. We investigated the role of primary cilia during MG development. Most cells were ciliated during early MG development, followed by cilia disassembly during differentiation. In mature glands, ciliated cells were primarily restricted to the basal layer of the proximal gland central duct. Cilia ablation in keratine14-expressing tissue disrupted the accumulation of proliferative cells at the distal tip of developing MGs but did not affect overall rate of proliferation or apoptosis. Moreover, impaired cellular patterning and elongation processes resulted in hypertrophy of mature MGs with increased meibum volume without altering lipid composition. We demonstrate a novel role of cilia in tissue patterning which may reveal new therapeutic strategies to treat ocular surface disease caused by MG dysfunction.