title: Calcium signaling and meiotic exit at fertilization in Xenopus egg.
abstract: Calcium is a universal messenger that mediates egg activation at fertilization in all sexually reproducing species studied. However, signaling pathways leading to calcium generation and the mechanisms of calcium-induced exit from meiotic arrest vary substantially among species. Here, we review the pathways of calcium signaling and the mechanisms of meiotic exit at fertilization in the eggs of the established developmental model, African clawed frog, Xenopus laevis. We also discuss calcium involvement in the early fertilization-induced events in Xenopus egg, such as membrane depolarization, the increase in intracellular pH, cortical granule exocytosis, cortical contraction, contraction wave, cortical rotation, reformation of the nuclear envelope, sperm chromatin decondensation and sister chromatid segregation.
authors.affiliation: Research Center for Environmental Genomics, Kobe University, Kobe 657-8501, Japan. tokmak@phoenix.kobe-u.ac.jp.
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Tokmakov
authors.affiliation: Department of Biochemistry, St. Petersburg University, St. Petersburg 199034, Russia. stefanov@bio.pu.ru.
authors.forename: Vasily E
authors.initials: VE
authors.lastname: Stefanov
authors.affiliation: Research Center for Environmental Genomics, Kobe University, Kobe 657-8501, Japan. tiwasaki@kobe-u.ac.jp.
authors.forename: Tetsushi
authors.initials: T
authors.lastname: Iwasaki
authors.affiliation: Department of Molecular Biosciences, Kyoto Sangyo University, Kyoto 603-8555, Japan. kksato@cc.kyoto-su.ac.jp.
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Sato
authors.affiliation: Research Center for Environmental Genomics, Kobe University, Kobe 657-8501, Japan. yfukami@kobe-u.ac.jp.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Fukami
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling; D005306:Fertilization; D008540:Meiosis; D014982:Xenopus laevis / Q000502:physiology*; D015053:Zygote / Q000166:cytology / Q000502:physiology*
chemical_list: D002118:Calcium