Entry Name Oocyte meiosis - Equus przewalskii (Przewalski's horse)
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 Other DBs Organism Equus przewalskii (Przewalski's horse) [GN:
epz ]
Gene 103540579 MAD2L1; mitotic spindle assembly checkpoint protein MAD2A [KO:K02537 ]
103541395 ANAPC5; anaphase-promoting complex subunit 5 isoform X1 [KO:K03352 ]
103541493 ANAPC7; anaphase-promoting complex subunit 7 isoform X1 [KO:K03354 ]
103542811 FBXW11; F-box/WD repeat-containing protein 11 isoform X1 [KO:K03362 ]
103543523 PPP2CA; serine/threonine-protein phosphatase 2A catalytic subunit alpha isoform [KO:K04382 ] [EC:3.1.3.16 ]
103546230 CPEB1; cytoplasmic polyadenylation element-binding protein 1 isoform X4 [KO:K02602 ]
103546630 ITPR2; inositol 1,4,5-trisphosphate-gated calcium channel ITPR2 isoform X1 [KO:K04959 ]
103546883 ANAPC4; anaphase-promoting complex subunit 4 isoform X1 [KO:K03351 ]
103547898 ANAPC10; anaphase-promoting complex subunit 10 isoform X1 [KO:K03357 ]
103548163 PPP2R5D; serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit delta isoform [KO:K11584 ]
103549121 CAMK2A; calcium/calmodulin-dependent protein kinase type II subunit alpha isoform X1 [KO:K04515 ] [EC:2.7.11.17 ]
103549334 ANAPC15; anaphase-promoting complex subunit 15 isoform X1 [KO:K25228 ]
103549452 PPP3CB; serine/threonine-protein phosphatase 2B catalytic subunit beta isoform isoform X1 [KO:K04348 ] [EC:3.1.3.16 ]
103549465 CAMK2G; calcium/calmodulin-dependent protein kinase type II subunit gamma isoform X1 [KO:K04515 ] [EC:2.7.11.17 ]
103549616 CAMK2D; calcium/calmodulin-dependent protein kinase type II subunit delta isoform X1 [KO:K04515 ] [EC:2.7.11.17 ]
103549644 CDC16; cell division cycle protein 16 homolog isoform X1 [KO:K03353 ]
103550297 ITPR1; inositol 1,4,5-trisphosphate-gated calcium channel ITPR1 isoform X1 [KO:K04958 ]
103551012 ANAPC1; anaphase-promoting complex subunit 1 isoform X1 [KO:K03348 ]
103551399 BTRC; F-box/WD repeat-containing protein 1A isoform X1 [KO:K03362 ]
103551624 PKMYT1; membrane-associated tyrosine- and threonine-specific cdc2-inhibitory kinase isoform X1 [KO:K06633 ] [EC:2.7.11.1 ]
103551751 MAD1L1; mitotic spindle assembly checkpoint protein MAD1 isoform X1 [KO:K06679 ]
103552187 MAD2L2; mitotic spindle assembly checkpoint protein MAD2B isoform X2 [KO:K13728 ]
103552437 PPP2R5E; serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit epsilon isoform isoform X1 [KO:K11584 ]
103552513 CPEB2; LOW QUALITY PROTEIN: cytoplasmic polyadenylation element-binding protein 2 [KO:K02602 ]
103552773 PPP3CC; serine/threonine-protein phosphatase 2B catalytic subunit gamma isoform isoform X5 [KO:K04348 ] [EC:3.1.3.16 ]
103554315 PPP2R5A; serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit alpha isoform [KO:K11584 ]
103554373 CPEB4; cytoplasmic polyadenylation element-binding protein 4 isoform X1 [KO:K02602 ]
103554952 CAMK2B; calcium/calmodulin-dependent protein kinase type II subunit beta isoform X1 [KO:K04515 ] [EC:2.7.11.17 ]
103555607 PPP2R1B; serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A beta isoform isoform X1 [KO:K03456 ]
103555928 PLCZ1; 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase zeta-1 isoform X1 [KO:K05861 ] [EC:3.1.4.11 ]
103556448 PPP2R5C; serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit gamma isoform isoform X4 [KO:K11584 ]
103559057 CPEB3; cytoplasmic polyadenylation element-binding protein 3 isoform X1 [KO:K02602 ]
103559135 PPP2R5B; serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit beta isoform isoform X1 [KO:K11584 ]
103560745 CDC27; cell division cycle protein 27 homolog isoform X1 [KO:K03350 ]
103563872 ANAPC16; anaphase-promoting complex subunit 16 isoform X1 [KO:K25229 ]
103564028 REC8; meiotic recombination protein REC8 homolog isoform X1 [KO:K13054 ]
103564670 PPP2R1A; serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A alpha isoform [KO:K03456 ]
103564711 SMC3; structural maintenance of chromosomes protein 3 isoform X1 [KO:K06669 ]
103564724 ITPR3; inositol 1,4,5-trisphosphate-gated calcium channel ITPR3 isoform X1 [KO:K04960 ]
103565650 CDC26; anaphase-promoting complex subunit CDC26 isoform X1 [KO:K03359 ]
103566700 SMC1B; structural maintenance of chromosomes protein 1B isoform X1 [KO:K06636 ]
103567415 CALML6; LOW QUALITY PROTEIN: calmodulin-like protein 6 [KO:K02183 ]
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 epz04914 Progesterone-mediated oocyte maturation
KO pathway
