Entry Name Oocyte meiosis - Electrophorus electricus (electric eel)
Description During meiosis, a single round of DNA replication is followed by two rounds of chromosome segregation, called meiosis I and meiosis II. At meiosis I, homologous chromosomes recombine and then segregate to opposite poles, while the sister chromatids segregate from each other at meoisis II. In vertebrates, immature oocytes are arrested at the PI (prophase of meiosis I). The resumption of meiosis is stimulated by progesterone, which carries the oocyte through two consecutive M-phases (MI and MII) to a second arrest at MII. The key activity driving meiotic progression is the MPF (maturation-promoting factor), a heterodimer of CDC2 (cell division cycle 2 kinase) and cyclin B. In PI-arrested oocytes, MPF is initially inactive and is activated by the dual-specificity CDC25C phosphatase as the result of new synthesis of Mos induced by progesterone. MPF activation mediates the transition from the PI arrest to MI. The subsequent decrease in MPF levels, required to exit from MI into interkinesis, is induced by a negative feedback loop, where CDC2 brings about the activation of the APC (anaphase-promoting complex), which mediates destruction of cyclin B. Re-activation of MPF for MII requires re-accumulation of high levels of cyclin B as well as the inactivation of the APC by newly synthesized Emi2 and other components of the CSF (cytostatic factor), such as cyclin E or high levels of Mos. CSF antagonizes the ubiquitin ligase activity of the APC, preventing cyclin B destruction and meiotic exit until fertilization occurs. Fertilization triggers a transient increase in cytosolic free Ca2+, which leads to CSF inactivation and cyclin B destruction through the APC. Then eggs are released from MII into the first embryonic cell cycle.
Class Cellular Processes; Cell growth and deathBRITE hierarchy
Pathway map Ortholog table Other DBs Organism Electrophorus electricus (electric eel) [GN:
eee ]
Gene 113579902 cpeb3; cytoplasmic polyadenylation element-binding protein 3 isoform X1 [KO:K02602 ]
113581734 cytoplasmic polyadenylation element-binding protein 4 isoform X1 [KO:K02602 ]
113589313 cytoplasmic polyadenylation element-binding protein 2-like isoform X1 [KO:K02602 ]
113571583 cytoplasmic polyadenylation element-binding protein 1-like [KO:K02602 ]
113574105 cpeb1; cytoplasmic polyadenylation element-binding protein 1 isoform X1 [KO:K02602 ]
113587627 cytoplasmic polyadenylation element-binding protein 4-like isoform X1 [KO:K02602 ]
113576838 pkmyt1; membrane-associated tyrosine- and threonine-specific cdc2-inhibitory kinase [KO:K06633 ] [EC:2.7.11.1 ]
113587992 anapc1; anaphase-promoting complex subunit 1 isoform X1 [KO:K03348 ]
113578840 anapc11; anaphase-promoting complex subunit 11 isoform X1 [KO:K03358 ]
113581589 anapc15; anaphase-promoting complex subunit 15 isoform X1 [KO:K25228 ]
113572783 anapc16; anaphase-promoting complex subunit 16 isoform X1 [KO:K25229 ]
113586891 smc1a; structural maintenance of chromosomes protein 1A [KO:K06636 ]
113589241 structural maintenance of chromosomes protein 1B-like isoform X1 [KO:K06636 ]
113580689 smc3; structural maintenance of chromosomes protein 3 [KO:K06669 ]
113579285 mad2l1; mitotic spindle assembly checkpoint protein MAD2A [KO:K02537 ]
113575830 mad2l2; mitotic spindle assembly checkpoint protein MAD2B [KO:K13728 ]
113574943 mad1l1; mitotic spindle assembly checkpoint protein MAD1 [KO:K06679 ]
113587267 ppp2r5c; serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit gamma isoform isoform X1 [KO:K11584 ]
113569689 serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit gamma isoform-like isoform X1 [KO:K11584 ]
113572986 serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit epsilon isoform-like [KO:K11584 ]
113572732 ppp2r5d; serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit delta isoform [KO:K11584 ]
113580786 ppp2r5a; serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit alpha isoform [KO:K11584 ]
113575526 ppp2r5e; serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit epsilon isoform [KO:K11584 ]
113579837 ppp2r5b; serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit beta isoform isoform X1 [KO:K11584 ]
113579598 serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A beta isoform-like [KO:K03456 ]
113591355 serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A beta isoform [KO:K03456 ]
113578036 ppp2ca; serine/threonine-protein phosphatase 2A catalytic subunit alpha isoform [KO:K04382 ] [EC:3.1.3.16 ]
113586037 serine/threonine-protein phosphatase 2A catalytic subunit alpha isoform-like isoform X1 [KO:K04382 ] [EC:3.1.3.16 ]
113575990 LOW QUALITY PROTEIN: inositol 1,4,5-trisphosphate receptor type 1-like [KO:K04958 ]
113581750 serine/threonine-protein phosphatase 2B catalytic subunit alpha isoform-like isoform X1 [KO:K04348 ] [EC:3.1.3.16 ]
113577345 ppp3ca; serine/threonine-protein phosphatase 2B catalytic subunit alpha isoform isoform X1 [KO:K04348 ] [EC:3.1.3.16 ]
113587439 camk2a; calcium/calmodulin-dependent protein kinase type II subunit alpha isoform X1 [KO:K04515 ] [EC:2.7.11.17 ]
113572944 LOW QUALITY PROTEIN: calcium/calmodulin-dependent protein kinase type II subunit beta-like [KO:K04515 ] [EC:2.7.11.17 ]
113583472 camk2b; calcium/calmodulin-dependent protein kinase type II subunit beta isoform X1 [KO:K04515 ] [EC:2.7.11.17 ]
Compound C01245 D-myo-Inositol 1,4,5-trisphosphate
Reference Authors Haccard O, Jessus C
Title Oocyte maturation, Mos and cyclins--a matter of synthesis: two functionally redundant ways to induce meiotic maturation.
Journal Reference Authors Crane R, Gadea B, Littlepage L, Wu H, Ruderman JV
Title Aurora A, meiosis and mitosis.
Journal Reference Authors Perdiguero E, Nebreda AR
Title Regulation of Cdc25C activity during the meiotic G2/M transition.
Journal Reference Authors Perry JA, Kornbluth S
Title Cdc25 and Wee1: analogous opposites?
Journal Reference Authors Jessus C, Ozon R
Title How does Xenopus oocyte acquire its competence to undergo meiotic maturation?
Journal Reference Authors Revenkova E, Jessberger R
Title Shaping meiotic prophase chromosomes: cohesins and synaptonemal complex proteins.
Journal Reference Authors Belloc E, Pique M, Mendez R
Title Sequential waves of polyadenylation and deadenylation define a translation circuit that drives meiotic progression.
Journal Reference Authors Pesin JA, Orr-Weaver TL
Title Regulation of APC/C activators in mitosis and meiosis.
Journal Reference Authors Tang W, Wu JQ, Guo Y, Hansen DV, Perry JA, Freel CD, Nutt L, Jackson PK, Kornbluth S
Title Cdc2 and Mos regulate Emi2 stability to promote the meiosis I-meiosis II transition.
Journal Reference Authors Wu JQ, Kornbluth S
Title Across the meiotic divide - CSF activity in the post-Emi2/XErp1 era.
Journal Reference Authors Schmidt A, Rauh NR, Nigg EA, Mayer TU
Title Cytostatic factor: an activity that puts the cell cycle on hold.
Journal Reference Authors Vogt E, Kirsch-Volders M, Parry J, Eichenlaub-Ritter U
Title Spindle formation, chromosome segregation and the spindle checkpoint in mammalian oocytes and susceptibility to meiotic error.
Journal Reference Authors Perry AC, Verlhac MH
Title Second meiotic arrest and exit in frogs and mice.
Journal Reference Authors Tunquist BJ, Eyers PA, Chen LG, Lewellyn AL, Maller JL
Title Spindle checkpoint proteins Mad1 and Mad2 are required for cytostatic factor-mediated metaphase arrest.
Journal Reference Authors Hutchins JR, Dikovskaya D, Clarke PR.
Title Regulation of Cdc2/cyclin B activation in Xenopus egg extracts via inhibitory phosphorylation of Cdc25C phosphatase by Ca(2+)/calmodulin-dependent protein [corrected] kinase II.
Journal Related eee04914 Progesterone-mediated oocyte maturation
KO pathway LinkDB All DBs
