Joint LIN/Department of Physiology and Biophysics Seminar: Sexually dimorphic patterning of the nervous system by Oliver Hobert, Columbia University

Host: Chieh Chang

Abstract: Differences between males and females of the same species include differences in morphology, physiology and behavior. Within the brain, males and females display a number of anatomical sexual dimorphisms often in the form of neurons that are present exclusively in one, but not the other sex. Much less is known about how the vast majority of neurons that are present in both sexes may differ in anatomy, synaptic connectivity or function between the sexes and how these sexual differences develop. The comparison of the EM-reconstructed connectome of the hermaphroditic and male nervous systems of the nematode Caenorhabditis elegans reveals the existence of sexually dimorphic synaptic connections between sex-shared neurons. We have identified additional, molecular dimorphisms in sex-shared neurons. I will describe our efforts to understand how these dimorphic features of the nervous system are genetically encoded.

Oliver Hobert is a Professor in the Columbia University Department of Biochemistry and Molecular Biophysics and an Investigator of the Howard Hughes Medical Institute, and holds an Interdisciplinary Faculty position in the Department of Systems Biology. His laboratory studies the molecular mechanisms responsible for generating the remarkable diversity of cell types found in the nervous system. Using C. elegans as a model system, they have revealed the regulatory mechanisms that control terminal neuronal identity and demonstrated that these mechanisms are conserved in chordates. They also used this knowledge to reprogram the identity of heterologous cell types to become specific neuron types. The lab’s other interests include the origins of asymmetrical neuronal differentiation along the left/right axis, the molecular mechanisms of neural system plasticity, and the conservation and evolution of neuronal gene expression programs. His lab has also developed a number of tools to analyze whole genome sequence data.