morphogenesis • organogensis • chick embryo model • claudins • neural tube closure • development of the left-right axis • gene expression
My research focuses on the study of a family of proteins called claudins that connect cells and regulate cell shape and tissue movements required for neural tube closure and heart development. Mutations in several genes and a variety of environmental factors are known to cause birth defects. Prevention of these defects depends on identifying the molecules involved in embryonic development and understanding what they do. Critical events to determine the shape of the neural tube and heart happen three to four weeks after fertilization. One project in our laboratory is investigating how claudins distinguish the left and right sides of the embryo to appropriately position the heart. In a second project, we have shown that claudins are essential for the neural tube to close and we are now studying how they affect the intracellular mechanisms involved in this process.
Collins MM, Baumholtz AI, Ryan AK. Claudin family members exhibit unique temporal and spatial expression boundaries in the chick embryo. Tissue Barriers 1(3): e24517, 2013.
Collins MM, Baumholtz AI, Ryan AK. Claudin-5 expression in the vasculature of the developing chick embryo. Gene Expression Patterns (in press). ePub 2 Feb 2012.
Gupta IR, Ryan AK. Claudins: Unlocking the code to tight junction function during embryogenesis and in disease. Clinical Genetics 77:314-325, 2010.
Simard A, Di Giorgio L, Amen, M, Amendt BA, Ryan, AK.The Pitx2c N-terminal domain is a critical interaction domain required for asymmetric morphogenesis. Developmental Dynamics 238:2459-2470, 2009.
Simard A, Di Pietro E, Young C, Plaza S, Ryan AK. Alterations in heart looping induced by overexpression of the tight junction protein Claudin-1 are dependent on its C-terminal cytoplasmic tail. Mechanisms of Development 123: 210-227, 2006.