Karlstrom to discuss forebrain and pituitary development in zebrafish

Professor Rolf O. Karlstrom of the Biology Department will speak on "Ventral Forebrain and Pituitary Development: A view from the zebrafish" on Wednesday, Oct. 31 at 4 p.m. in 222 Morrill Science Center II as part of the Neuroscience and Behavior Program's colloquium series.

Karlstrom's team is using a variety of genetic and experimental approaches to determine how Hedgehog/Gli (Hh/Gli) mediated cell-cell signaling induces and patterns the zebrafish forebrain. They are analyzing several mutations that affect both Hh/Gli signaling and cell differentiation in the forebrain. The researchers showed that the detour (dtr) and you-too (yot) loci encode zebrafish Gli1 and Gli2 (respectively), hedgehog responsive transcription factors that are required for formation of a wide variety of embryonic tissues, including the ventral forebrain. Mutations in gli2 result in forebrain and axon guidance defects. Forebrain defects in dtr(gli1) and yot(gli2) include  mis-specification of ventral diencephalic cell types,  specific loss of of a subset of endocrine secreting cells in the pituitary gland, and in yot(gli2) the transdifferentiation of the pituitary into an ectopic lens.