Real-time analysis of the role of Ca 2 in flagellar movement and motility in single sea urchin sperm
Por:
Wood C.D., Nisihigaki T., Furuta T., Baba S.A., Darszon A.
Publicada:
1 ene 2005
Resumen:
Eggs of many marine and mammalian species attract sperm by releasing chemoattractants that modify the bending properties of flagella to redirect sperm paths toward the egg. This process, called chemotaxis, is dependent on extracellular Ca2+. We used stroboscopic fluorescence imaging to measure intracellular Ca2+ concentration([Ca2+]i) in the flagella of swimming sea urchin sperm. Uncaging of cyclic GMP induced Ca 2+ entry via atleast two distinct pathways, and we identified a nimodipine-sensitive pathway, compartmentalized in the flagella, as a key regulator of flagellar bending and directed motility changes. We found that, contrary to current models, the degree of flagellar bending does not vary in proportion to the overall [Ca2+]i. Instead we propose a new model whereby flagella bending is increased by Ca2+ flux through the nimodipine-sensitive pathway, and is unaffected by [Ca2+]i increases through alternative pathways. © The Rockefeller University Press.
Filiaciones:
Wood C.D.:
Department of Developmental Genetics and Molecular Physiology, Institute of Biotechnology, National Autonomous University of Mexico (UNAM), Cuernavaca, Morelos 62210, Mexico
Nisihigaki T.:
Department of Developmental Genetics and Molecular Physiology, Institute of Biotechnology, National Autonomous University of Mexico (UNAM), Cuernavaca, Morelos 62210, Mexico
Furuta T.:
PRESTO, JST and Department of Biomolecular Science, Toho University, Funabashi 274-8510, Japan
Baba S.A.:
Department of Biology, Ochanomizu University, Tokyo 112-8610, Japan
Darszon A.:
Department of Developmental Genetics and Molecular Physiology, Institute of Biotechnology, National Autonomous University of Mexico (UNAM), Cuernavaca, Morelos 62210, Mexico
Bronze
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