Entry Name Oocyte meiosis - Equus caballus (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 Ortholog table Other DBs Organism Equus caballus (horse) [GN:
ecb ]
Gene 100068411 CPEB1; cytoplasmic polyadenylation element-binding protein 1 isoform X1 [KO:K02602 ]
100058918 CPEB4; cytoplasmic polyadenylation element-binding protein 4 isoform X1 [KO:K02602 ]
100061932 CPEB3; cytoplasmic polyadenylation element-binding protein 3 isoform X1 [KO:K02602 ]
100069076 CPEB2; LOW QUALITY PROTEIN: cytoplasmic polyadenylation element-binding protein 2 [KO:K02602 ]
100068871 PKMYT1; membrane-associated tyrosine- and threonine-specific cdc2-inhibitory kinase isoform X1 [KO:K06633 ] [EC:2.7.11.1 ]
100069972 FBXW11; F-box/WD repeat-containing protein 11 isoform X3 [KO:K03362 ]
100070200 BTRC; F-box/WD repeat-containing protein 1A isoform X1 [KO:K03362 ]
100051869 ANAPC1; anaphase-promoting complex subunit 1 isoform X1 [KO:K03348 ]
100054552 CDC27; cell division cycle protein 27 homolog isoform X6 [KO:K03350 ]
100067388 ANAPC4; anaphase-promoting complex subunit 4 isoform X1 [KO:K03351 ]
100069285 CDC16; cell division cycle protein 16 homolog isoform X1 [KO:K03353 ]
100058376 ANAPC7; anaphase-promoting complex subunit 7 isoform X1 [KO:K03354 ]
100062837 ANAPC10; anaphase-promoting complex subunit 10 isoform X1 [KO:K03357 ]
100053266 CDC26; anaphase-promoting complex subunit CDC26 isoform X1 [KO:K03359 ]
100066106 ANAPC15; anaphase-promoting complex subunit 15 isoform X2 [KO:K25228 ]
100072806 ANAPC16; anaphase-promoting complex subunit 16 isoform X2 [KO:K25229 ]
100054815 REC8; meiotic recombination protein REC8 homolog isoform X1 [KO:K13054 ]
100052492 SMC1B; structural maintenance of chromosomes protein 1B isoform X1 [KO:K06636 ]
100061736 SMC1A; structural maintenance of chromosomes protein 1A isoform X1 [KO:K06636 ]
100059335 SMC3; structural maintenance of chromosomes protein 3 [KO:K06669 ]
100072353 MAD2L1; mitotic spindle assembly checkpoint protein MAD2A isoform X1 [KO:K02537 ]
100051122 MAD2L2; mitotic spindle assembly checkpoint protein MAD2B isoform X1 [KO:K13728 ]
100058904 MAD1L1; mitotic spindle assembly checkpoint protein MAD1 isoform X1 [KO:K06679 ]
100051948 PPP2R5E; serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit epsilon isoform isoform X1 [KO:K11584 ]
100054880 PPP2R5D; serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit delta isoform [KO:K11584 ]
100054977 PPP2R5C; serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit gamma isoform isoform X6 [KO:K11584 ]
100054440 PPP2R5A; serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit alpha isoform [KO:K11584 ]
100050735 PPP2R5B; serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit beta isoform isoform X1 [KO:K11584 ]
100062627 PPP2R1A; serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A alpha isoform [KO:K03456 ]
100070408 PPP2R1B; serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A beta isoform isoform X1 [KO:K03456 ]
100067798 PLCZ1; 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase zeta-1 isoform X1 [KO:K05861 ] [EC:3.1.4.11 ]
111767502 1-phosphatidylinositol 4,5-bisphosphate phosphodiesterase zeta-1-like isoform X1 [KO:K05861 ] [EC:3.1.4.11 ]
100052808 ITPR1; inositol 1,4,5-trisphosphate receptor type 1 isoform X1 [KO:K04958 ]
100064557 ITPR2; inositol 1,4,5-trisphosphate receptor type 2 isoform X1 [KO:K04959 ]
100053019 ITPR3; inositol 1,4,5-trisphosphate receptor type 3 isoform X1 [KO:K04960 ]
100064482 CALML6; LOW QUALITY PROTEIN: calmodulin-like protein 6 [KO:K02183 ]
100057357 PPP3CC; serine/threonine-protein phosphatase 2B catalytic subunit gamma isoform isoform X1 [KO:K04348 ] [EC:3.1.3.16 ]
100067434 PPP3CA; serine/threonine-protein phosphatase 2B catalytic subunit alpha isoform isoform X4 [KO:K04348 ] [EC:3.1.3.16 ]
100072862 PPP3CB; serine/threonine-protein phosphatase 2B catalytic subunit beta isoform isoform X1 [KO:K04348 ] [EC:3.1.3.16 ]
100064138 CAMK2G; calcium/calmodulin-dependent protein kinase type II subunit gamma isoform X13 [KO:K04515 ] [EC:2.7.11.17 ]
100071654 CAMK2A; calcium/calmodulin-dependent protein kinase type II subunit alpha isoform X1 [KO:K04515 ] [EC:2.7.11.17 ]
100072618 CAMK2D; calcium/calmodulin-dependent protein kinase type II subunit delta isoform X6 [KO:K04515 ] [EC:2.7.11.17 ]
100146368 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 ecb04914 Progesterone-mediated oocyte maturation
KO pathway LinkDB All DBs
