Cerebral Cortex Advance Access published online on November 17, 2007
Cerebral Cortex, doi:10.1093/cercor/bhm191
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Sall1 Regulates Mitral Cell Development and Olfactory Nerve Extension in the Developing Olfactory Bulb
1 Departments of Neurobiology, 2 Biochemistry and Molecular Genetics Graduate Program, University of Pittsburgh, Pittsburgh, PA 15261, USA, 3 Division of Integrative Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, Japan, 4 Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15261, USA
Address correspondence to Dr A. Paula Monaghan, 6065 BST3, 3501 5th Avenue, Pittsburgh, PA 15261, USA. Email: monaghan{at}pitt.edu.
Sall1 is a zinc finger containing transcription factor that is highly expressed during mammalian embryogenesis. In humans, the developmental disorder Townes Brocks Syndrome is associated with mutations in the SALL1 gene. Sall1-deficient animals die at birth due to kidney deficits; however, its function in the nervous system has not been characterized. We examined the role of Sall1 in the developing olfactory system. We demonstrate that Sall1 is expressed by cells in the olfactory epithelium and olfactory bulb (OB). Sall1-deficient OBs are reduced in size and exhibit alterations in neurogenesis and mitral cell production. In addition, the olfactory nerve failed to extend past the ventral–medial region of the OB in Sall1-deficient animals. We observed intrinsic patterns of neurogenesis during olfactory development in control animals. In Sall1-mutant animals, these patterns of neurogenesis were disrupted. These findings suggest a role for Sall1 in regulating neuronal differentiation and maturation in developing neural structures.
Key Words: neurogenesis • olfactory nerve innervation • proliferation • spalt • Townes Brocks Syndrome