https://novaprd-lb.newcastle.edu.au/vital/access/manager/Index ${session.getAttribute("locale")} 5 Loss of GGN leads to pre-implantation embryonic lethality and compromised male meiotic DNA double strand break repair in the mouse https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:14941 Wed 11 Apr 2018 17:19:33 AEST ]]> Degradation of APCcdc²⁰ and APCcdh¹ substrates during the second meiotic division in mouse eggs https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6544 Wed 11 Apr 2018 16:31:09 AEST ]]> Application of two-photon flash photolysis to reveal intercellular communication and intracellular Ca²⁺ movements https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6553 Wed 11 Apr 2018 16:21:07 AEST ]]> Repetitive sperm-induced Ca²⁺ transients in mouse oocytes are cell cycle dependent https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6546 Wed 11 Apr 2018 16:15:33 AEST ]]> Cell cycle-dependent repetitive Ca²⁺ waves induced by a cytosolic sperm extract in mature ascidian eggs mimic those observed at fertilization https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6551 Wed 11 Apr 2018 15:20:31 AEST ]]> A cell cycle-associated change in Ca²⁺ releasing activity leads to the generation of Ca²⁺ transients in mouse embryos during the first mitotic division https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6547 Wed 11 Apr 2018 15:10:36 AEST ]]> Mouse Emi2 is required to enter meiosis II by reestablishing cyclin B1 during interkinesis https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6545 Wed 11 Apr 2018 14:52:54 AEST ]]> DNA double strand breaks but not interstrand crosslinks prevent progress through meiosis in fully grown mouse oocytes https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:15099 Wed 11 Apr 2018 14:49:33 AEST ]]> A novel mechanism controls the Ca²⁺ oscillations triggered by activation of ascidian eggs and has an absolute requirement for Cdk1 activity https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6552 Wed 11 Apr 2018 13:43:05 AEST ]]> Premature dyad separation in meiosis II is the major segregation error with maternal age in mouse oocytes https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:21342 Wed 11 Apr 2018 12:17:52 AEST ]]> Calmodulin-dependent protein kinase II, and not protein kinase C, is sufficient for triggering cell-cycle resumption in mammalian eggs https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6543 Wed 11 Apr 2018 12:03:05 AEST ]]> Timing of anaphase-promoting complex activation in mouse oocytes is predicted by microtubule-kinetochore attachment but not by bivalent alignment or tension https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:24259 Wed 11 Apr 2018 11:39:29 AEST ]]> APC FZR1 prevents nondisjunction in mouse oocytes by controlling meiotic spindle assembly timing https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:18262 Wed 11 Apr 2018 11:37:00 AEST ]]> The APC activator fizzy-related-1 (FZR1) is needed for preimplantation mouse embryo development https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:21729 Fzr1 knockout mouse embryos show normal preimplantation development but die due to a lack of endoreduplication needed for placentation. However, interpretation of the role of FZR1 during this period is hindered by the presence of maternal stores. In this study, therefore, we used an oocyte-specific knockout to examine FZR1 function in early mouse embryo development. Maternal FZR1 was not crucial for completion of meiosis, and furthermore viable pups were born to Fzr1 knockout females mated with normal males. However, in early embryos the absence of both maternal and paternal FZR1 led to a dramatic loss in genome integrity, such that the majority of embryos arrested having undergone only a single mitotic division and contained many γ-H2AX foci, consistent with fragmented DNA. A prominent feature of such embryos was the establishment of two independent spindles following pronuclear fusion and thus a failure of the chromosomes to mix (syngamy). These generated binucleate 2-cell embryos. In the 10% of embryos that progressed to the 4-cell stage, division was so slow that compaction occurred prematurely. No embryo development to the blastocyst stage was ever observed. We conclude that Fzr1 is a surprisingly essential gene involved in the establishment of a single spindle from the two pronuclei in 1-cell embryos as well as being involved in the maintenance of genomic integrity during the mitotic divisions of early mammalian embryos.]]> Wed 11 Apr 2018 11:35:19 AEST ]]> How eggs arrest at metaphase II: MPF stabilisation plus APC/C inhibition equals Cytostatic Factor https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6549 Wed 11 Apr 2018 10:43:58 AEST ]]> The passage of Ca²⁺ and fluorescent markers between the sperm and egg after fusion in the mouse https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6548 Wed 11 Apr 2018 10:37:33 AEST ]]> Exploring the mechanism of action of the sperm-triggered calcium-wave pacemaker in ascidian zygotes https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6550 Wed 11 Apr 2018 10:31:25 AEST ]]> A cytosolic sperm protein factor mobilizes Ca²⁺ from intracellular stores by activating multiple Ca²⁺ release mechanisms independently of low molecular weight messengers https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6596 Wed 11 Apr 2018 09:57:51 AEST ]]> Start and stop signals of oocyte meiotic maturation https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:18182 Tue 23 Jun 2015 18:36:00 AEST ]]> Time-lapse epifluorescence imaging of expressed cRNA to cyclin B1 for studying meiosis i in mouse oocytes https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:24275 Thu 17 Nov 2016 17:26:48 AEDT ]]> Calmodulin-dependent protein kinase gamma 3 (CamKIIγ3) mediates the cell cycle resumption of metaphase II eggs in mouse https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:7337 Sat 24 Mar 2018 08:35:13 AEDT ]]> The Aurora kinase inhibitor ZM447439 accelerates first meiosis in mouse oocytes by overriding the spindle assembly checkpoint https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:11469 Sat 24 Mar 2018 08:11:09 AEDT ]]> Spatial regulation of APC<sup>Cdh1</sup>-induced cyclin B1 degradation maintains G2 arrest in mouse oocytes https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:11246 Cdh1) activity, which ubiquitylates and so targets cyclin B1 for degradation. Thus, APCCdh1 activity prevents precocious meiotic entry by promoting cyclin B1 degradation. However, it remains unresolved how cyclin B1 levels are suppressed sufficiently to maintain arrest but not so low that they make oocytes hormonally insensitive. Here, we examined spatial control of this process by determining the intracellular location of the proteins involved and using nuclear-targeted cyclin B1. We found that raising nuclear cyclin B1 concentrations, an event normally observed in the minutes before nuclear envelope breakdown, was a very effective method of inducing the G2/M transition. Oocytes expressed only the α-isoform of Cdh1, which was predominantly nuclear, as were Cdc27 and Psmd11, core components of the APC and the 26S proteasome, respectively. Furthermore, APCCdh1 activity appeared higher in the nucleus, as nuclear-targeted cyclin B1 was degraded at twice the rate of wild-type cyclin B1. We propose a simple spatial model of G2 arrest in which nuclear APCCdh1-proteasomal activity guards against any cyclin B1 accumulation mediated by nuclear import.]]> Sat 24 Mar 2018 08:10:55 AEDT ]]> Essential role of protein phosphatase 2A in metaphase II arrest and activation of mouse eggs shown by okadaic acid, dominant negative protein phosphatase 2A, and FTY720 https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:18116 2+-mediated activation of the anaphase-promoting complex/cyclosome (APC/C). Although the loss in activity of the M-phase kinase CDK1 is known to be an essential downstream event of this process, the contribution of phosphatases to arrest and meiotic resumption is less apparent, especially in mammals. Therefore, we explored the role of protein phosphatase 2A (PP2A) in mouse eggs using pharmacological inhibition and activation as well as a functionally dominant-negative catalytic PP2A subunit (dn-PP2Ac-L199P) coupled with live cell imaging. We observed that PP2A inhibition using okadaic acid induced events normally observed at fertilization: degradation of the APC/C substrates cyclin B1 and securin resulting from loss of the APC/C inhibitor Emi2. Although sister chromatids separated, chromatin remained condensed, and polar body extrusion was blocked as a result of a rapid spindle disruption, which could be ameliorated by non-degradable cyclin B1, suggesting that spindle integrity was affected by CDK1 loss. Similar cell cycle effects to okadaic acid were also observed using dominant-negative PP2Ac. Preincubation of eggs with the PP2A activator FTY720 could block many of the actions of okadaic acid, including Emi2, cyclin B1, and securin degradation and sister chromatid separation. Therefore, in conclusion, we used okadaic acid, dn-PP2Ac-L199P, and FTY720 on mouse eggs to demonstrate that PP2A is needed to for both continued metaphase arrest and successful exit from meiosis.]]> Sat 24 Mar 2018 08:04:35 AEDT ]]> Chromosomal, metabolic, environmental, and hormonal origins of aneuploidy in mammalian oocytes https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:17343 Sat 24 Mar 2018 08:01:41 AEDT ]]> The APC/C activator FZR1 is essential for meiotic prophase I in mice https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:21158 FZR1 activity in the male germline led to both a mitotic and a meiotic testicular defect resulting in infertility due to the absence of mature spermatozoa. Spermatogonia in the prepubertal testes of such mice had abnormal proliferation and delayed entry into meiosis. Although early recombination events were initiated, male germ cells failed to progress beyond zygotene and underwent apoptosis. Loss of APC/CFZR1 activity was associated with raised cyclin B1 levels, suggesting that CDK1 may trigger apoptosis. By contrast, female FZR1Δ mice were subfertile, with premature onset of ovarian failure by 5 months of age. Germ cell loss occurred embryonically in the ovary, around the time of the zygotene-pachytene transition, similar to that observed in males. In addition, the transition of primordial follicles into the growing follicle pool in the neonatal ovary was abnormal, such that the primordial follicles were prematurely depleted. We conclude that APC/CFZR1 is an essential regulator of spermatogonial proliferation and early meiotic prophase I in both male and female germ cells and is therefore important in establishing the reproductive health of adult male and female mammals.]]> Sat 24 Mar 2018 08:00:18 AEDT ]]> Melatonin prevents postovulatory oocyte aging in the mouse and extends the window for optimal fertilization in vitro https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:20252 Sat 24 Mar 2018 07:59:55 AEDT ]]> Increased zona pellucida thickness and meiotic spindle disruption in oocytes from cigarette smoking mice https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:17909 Sat 24 Mar 2018 07:56:41 AEDT ]]> Reduced ability to recover from spindle disruption and loss of kinetochore spindle assembly checkpoint proteins in oocytes from aged mice https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:20695 Sat 24 Mar 2018 07:55:41 AEDT ]]> Non-canonical function of spindle assembly checkpoint proteins after APC activation reduces aneuploidy in mouse oocytes https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:21277 Sat 24 Mar 2018 07:54:41 AEDT ]]> Reduced chromosome cohesion measured by interkinetochore distance is associated with aneuploidy even in oocytes from young mice https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:20166 Sat 24 Mar 2018 07:51:44 AEDT ]]> Securin and not CDK1/cyclin B1 regulates sister chromatid disjunction during meiosis II in mouse eggs https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:5601 Sat 24 Mar 2018 07:49:25 AEDT ]]> Injections of porcine sperm extracts trigger fertilization-like calcium oscillations in oocytes of a marine worm https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6580 Sat 24 Mar 2018 07:49:18 AEDT ]]> A mammalian sperm cytosolic phospholipase C activity generates inositol trisphosphate and causes Ca²⁺ release in sea urchin egg homogenates https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6582 Sat 24 Mar 2018 07:49:18 AEDT ]]> Ca²⁺-promoted cyclin B1 degradation in mouse oocytes requires the establishment of a metaphase arrest https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6569 Sat 24 Mar 2018 07:49:17 AEDT ]]> SIAH1 targets the alternative splicing factor T-STAR for degradation by the proteasome https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6573 Sat 24 Mar 2018 07:49:17 AEDT ]]> Ca²⁺oscillations and the cell cycle at fertilisation of mammalian and ascidian eggs https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6579 Sat 24 Mar 2018 07:49:17 AEDT ]]> The soluble sperm factor that causes Ca²⁺ release from sea-urchin (Lytechinus pictus) egg homogenates also triggers Ca²⁺ oscillations after injection into mouse eggs https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6581 Sat 24 Mar 2018 07:49:17 AEDT ]]> Maintenance of sister chromatid attachment in mouse eggs through maturation-promoting factor activity https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6574 Sat 24 Mar 2018 07:49:16 AEDT ]]> Ca²⁺ oscillations promote APC/C-dependent cyclin B1 degradation during metaphase arrest and completion of meiosis in fertilizing mouse eggs https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6570 Sat 24 Mar 2018 07:49:16 AEDT ]]> Potential role of a sperm-derived phospholipase C in triggering the egg-activating Ca²⁺ signal at fertilization https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6575 Sat 24 Mar 2018 07:49:16 AEDT ]]> Simultaneous measurement of intracellular nitric oxide and free calcium levels in chordate eggs demonstrates that nitric oxide has no role at fertilization https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6577 Sat 24 Mar 2018 07:49:16 AEDT ]]> Different Ca²⁺-releasing abilities of sperm extracts compared with tissue extracts and phospholipase C isoforms in sea urchin egg homogenate and mouse eggs https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6571 Sat 24 Mar 2018 07:49:16 AEDT ]]> Sperm-induced Ca²⁺ oscillations in mouse oocytes and eggs can be mimicked by photolysis of caged inositol 1,4,5-trisphosphate: evidence to support a continuous low level production of inositol 1,4,5-trisphosphate during mammalian fertilization https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6576 Sat 24 Mar 2018 07:49:16 AEDT ]]> Turning it on and off: M-phase promoting factor during meiotic maturation and fertilization https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6578 Sat 24 Mar 2018 07:49:15 AEDT ]]> Mammalian sperm contain a Ca²⁺-sensitive phospholipase C activity that can generate InsP₃ from PIP₂ associated with intracellular organelles https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6583 Sat 24 Mar 2018 07:49:15 AEDT ]]> Meiotic and mitotic Ca²⁺ oscillations affect cell composition in resulting blastocysts https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6585 Sat 24 Mar 2018 07:49:10 AEDT ]]> A comparison of sperm- and IP₃-induced Ca²⁺ release in activated and aging mouse oocytes https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6584 Sat 24 Mar 2018 07:49:10 AEDT ]]> Unique protein kinase C profile in mouse oocytes: lack of calcium-dependent conventional isoforms suggested by rtPCR and Western blotting https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6586 Sat 24 Mar 2018 07:49:07 AEDT ]]> Composition of sea urchin egg homogenate determines its potency to inositol trisphosphate and cyclic ADPRibose-induced Ca²⁺ release https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6555 Sat 24 Mar 2018 07:48:22 AEDT ]]> Intracellular calcium in the fertilization and development of mammalian eggs https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6554 Sat 24 Mar 2018 07:48:22 AEDT ]]> The CRY box: a second APCcdh¹-dependent degron in mammalian cdc20 https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6556 Sat 24 Mar 2018 07:48:22 AEDT ]]> Control of homologous chromosome division in the mammalian oocyte https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6539 Sat 24 Mar 2018 07:48:19 AEDT ]]> Prometaphase APCcdh¹ activity prevents non-disjunction in mammalian oocytes https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6537 Sat 24 Mar 2018 07:48:19 AEDT ]]> Ca²⁺ release and the development of Ca²⁺ release mechanisms during oocyte maturation: a prelude to fertilization https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6540 Sat 24 Mar 2018 07:48:19 AEDT ]]> Ionomycin, thapsigargin, ryanodine, and sperm induced Ca²⁺ release increase during meiotic maturation of mouse oocytes https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6541 Sat 24 Mar 2018 07:48:19 AEDT ]]> Meiosis in oocytes: predisposition to aneuploidy and its increased incidence with age https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6538 Sat 24 Mar 2018 07:48:18 AEDT ]]> APCcdh¹ activity in mouse oocytes prevents entry into the first meiotic division https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6563 Sat 24 Mar 2018 07:47:07 AEDT ]]> Calmodulin-dependent protein kinase II triggers mouse egg activation and embryo development in the absence of Ca²⁺ oscillations https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6564 Sat 24 Mar 2018 07:47:07 AEDT ]]> Essential CDK1-inhibitory role for separase during meiosis I in vertebrate oocytes https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6562 Sat 24 Mar 2018 07:47:07 AEDT ]]> Mammalian egg activation: from Ca²⁺ spiking to cell cycle progression https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6565 Sat 24 Mar 2018 07:47:07 AEDT ]]> Ca²⁺ oscillations in the activation of the egg and development of the embryo in mammals https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:6594 Sat 24 Mar 2018 07:46:22 AEDT ]]> Reactive oxygen species and sperm function-in sickness and in health https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:22254 Sat 24 Mar 2018 07:17:34 AEDT ]]> Anaphase-promoting complex control in female mouse meiosis https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:23214 Sat 24 Mar 2018 07:10:28 AEDT ]]> The control of meiotic maturation in mammalian oocytes https://novaprd-lb.newcastle.edu.au/vital/access/manager/Repository/uon:20165 Mon 24 Aug 2015 15:22:23 AEST ]]>