Contact Info

Jean-Ju Chung, PhD
Lab Location
E07Sterling Hall of Medicine, B-Wing
333 Cedar Street

New Haven, CT 06510
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Office Location
E36CSterling Hall of Medicine, B-Wing
333 Cedar Street

New Haven, CT 06510
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Mailing Address
Yale School of Medicine, SHM-B147
333 Cedar street

New Haven, CT 06510

Curriculum Vitae

Ion Channels & Reproductive Physiology Lab @ Yale

An Exotic Cell with the Sac to Spill

Mammalian sperm, a highly specialized cell, has a well defined cap (acrosome) that covers of the sperm head and elaborate cytoskeletal structures in the tail. Shown here is an x-y projection of three dimensional structured illumination microscopy (3D-SIM) image of a sperm head with the connecting sperm tail from transgenic mice expressing EGFP in the head (green) and DsRed in mitochondrial sheath (red). Lectins (cyan) are used to probe the unique distribution of glycoproteins over the acrosome edge in the head and the flagella membrane.

Linear Ca2+ Signaling Domains in Flagella

Precisely localized, scaffolded Ca2+ channel complexes are essential for proper Ca2+ signaling. In the sperm principal piece, which lacks ER and mitochondria, highly organized Ca2+ channels and signaling molecules in the plasma membrane are responsible for localizing Ca2+ signals (Chung et al, 2014, Cell 157:808-822). The sperm-specific calcium channel, CatSper, transduces Ca2+ signals that mediate hyperactivated motility in the mouse spermatozoa. Three dimensional-photoactivated localization microscopy (3D-PALM) reveals that CatSper channels are organized in four linear domains along the flagellum. Shown here is an x-y projection of two sperm tails, with each color representing the relative distance from the focal plane along the z-axis. This compartmentalized organization may help tune the Ca2+ signaling, thus enable faster engagement of effectors. Because sperm rotate about their longitudinal axis as they rheotax (Miki and Clapham, 2013, Curr. Biol. 23: 443-452), the multilinear arrangement of CatSper may conserve space and enhance detection of finite signals.