Expression of glucose-phosphate isomerase in relation to growth of the mouse oocyte in vivo and in vitro

1985 ◽  
Vol 11 (3) ◽  
pp. 271-281 ◽  
Author(s):  
Mia Buehr ◽  
Anne McLaren
Keyword(s):  
Mouse Oocyte ◽  
Glucose Phosphate Isomerase ◽  
Glucose Phosphate

scholarly journals A model study of the fructose diphosphatase–phosphofructokinase substrate cycle

1973 ◽  
Vol 134 (2) ◽  
pp. 581-586 ◽  
Author(s):  
David P. Bloxham ◽  
Michael G. Clark ◽  
Paul C. Holland ◽  
Henry A. Lardy
Keyword(s):  
Triose Phosphate Isomerase ◽  
Theoretical Treatment ◽  
Glucose Phosphate Isomerase ◽  
Triose Phosphate ◽  
Glucose Phosphate ◽  
Model Study

A fructose diphosphatase–phosphofructokinase substrate cycle has been reconstructed in vitro to provide a system that recycles fructose 6-phosphate and hydrolyses ATP to ADP and Pi. The concerted actions of glucose phosphate isomerase, phosphofructokinase, aldolase and triose phosphate isomerase catalysed the loss of 3H from [5-3H,U-14C]glucose 6-phosphate. This was used as the basis of a method for the estimation of the fructose diphosphatase–phosphofructokinase substrate cycle. For the reconstructed cycle, the rate of decrease of the 3H/14C ratio in [5-3H,U-14C]hexose 6-phosphate was proportional to the rate of fructose 6-phosphate substrate cycling. A detailed theoretical treatment of this relationship is developed, which enables the rate of substrate cycling to be determined in vivo.

Investigation of the determinative state of the mouse inner cell mass

Development ◽  
1975 ◽  
Vol 33 (4) ◽  
pp. 979-990
Author(s):  
J. Rossant
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
In Utero ◽  
Glucose Phosphate Isomerase ◽  
Trophoblast Cells ◽  
Electrophoretic Variants ◽  
Glucose Phosphate

Inner cell masses (ICMs) were dissected from 3½- and 4½-day blastocysts and cultured in contact with 2½-day morulae. Blastocysts and morulae were homozygous for different electrophoretic variants of the enzyme glucose phosphate isomerase (GPI). Aggregation of ICMs and morulae was observed, and such aggregates were able to form blastocysts in vitro and morphologically normal foetuses in utero. GPI analysis of these conceptuses revealed that most were chimaeric. However, donor ICM-type isozyme was only detected in the embryonic and extra-embryonic fractions of the chimaeras and never in the trophoblastic fraction. Thus, ICM cells appear unable to form trophoblast derivatives even when exposed to ‘outside’ conditions as experienced by developing trophoblast cells. This is evidence that ICM cells, although not overtly differentiated, are determined by 3½ days.

scholarly journals The Novel Transcription Factor SgrR Coordinates the Response to Glucose-Phosphate Stress

2007 ◽  
Vol 189 (6) ◽  
pp. 2238-2248 ◽  
Author(s):  
Carin K. Vanderpool ◽  
Susan Gottesman
Keyword(s):  
Binding Site ◽  
Binding Domain ◽  
Alternative Mechanism ◽  
Gene Encoding ◽  
Bacterial Transcription ◽  
Glucose Phosphate ◽  
Plasmid Library ◽  
Promoter Dna

ABSTRACT SgrR is the first characterized member of a family of bacterial transcription factors containing an N-terminal DNA binding domain and a C-terminal solute binding domain. Previously, we reported genetic evidence that SgrR activates the divergently transcribed gene sgrS, which encodes a small RNA required for recovery from glucose-phosphate stress. In this study, we examined the regulation of sgrR expression and found that SgrR negatively autoregulates its own transcription in the presence and absence of stress. An SgrR binding site in the sgrR-sgrS intergenic region is required in vivo for both SgrR-dependent activation of sgrS and autorepression of sgrR. Purified SgrR binds specifically to sgrS promoter DNA in vitro; a mutation in the site required for in vivo activation and autorepression abrogates in vitro SgrR binding. A plasmid library screen identified clones that alter expression of a P sgrS -lacZ fusion; some act by titrating endogenous SgrR. The yfdZ gene, encoding a putative aminotransferase, was identified in this screen; the yfdZ promoter contains an SgrR binding site, and transcriptional fusions indicate that yfdZ is activated by SgrR. Clones containing mlc, which encodes a glucose-specific repressor protein, also downregulate P sgrS -lacZ. The mlc clones do not appear to titrate the SgrR protein, indicating that Mlc affects sgrS expression by an alternative mechanism.

Observations on rat and mouse oocyte maturation in vivo and in vitro: morphology and physiology

1974 ◽  
Vol 4 (1) ◽  
pp. 15-24 ◽  
Author(s):  
G.H. Zeilmaker ◽  
J.P.W. Vermeiden ◽  
C.M.P.M. Verhamme ◽  
A.C.W. van Vliet
Keyword(s):  
Oocyte Maturation ◽  
Mouse Oocyte

scholarly journals Glycolytic enzymes in mammalian spermatozoa. Activities and stabilities of hexokinase and phosphofructokinase in various fractions from sperm homogenates

1971 ◽  
Vol 124 (4) ◽  
pp. 741-750 ◽  
Author(s):  
R. A. P. Harrison
Keyword(s):  
Thiol Group ◽  
Published Data ◽  
Glucose Phosphate Isomerase ◽  
Cytoplasmic Material ◽  
Phosphate Ions ◽  
Glucose Phosphate ◽  
Homogenization Methods ◽  
Ram Sperm ◽  
Mammalian Spermatozoa

1. Methods of homogenizing suspensions of washed mammalian spermatozoa were studied. The most useful methods were those using sonication and those using a French press. 2. Hexokinase, phosphofructokinase, glucose phosphate isomerase and adenosine triphosphatase activities in ram, bull and boar spermatozoa were investigated by using these two homogenization methods. Glucose phosphate isomerase, representative of soluble cytoplasmic material, was very readily extracted and remained entirely in the supernatant after centrifugation at 145000g for 60min. In contrast, the other three activities were less easily extracted and were sedimented in various proportions under the described conditions of centrifugation. 3. Attempts to obtain subcellular fractions from sperm homogenates by ‘classical’ methods failed, owing apparently to the inhomogeneity of subcellular particles in the homogenates. It is concluded that, after removal of sperm heads, the only meaningful fractionation is a separation of spermatozoal material which sediments at 145000g during 60min from that which does not. 4. The stabilities of hexokinase and phosphofructokinase activities in bull, boar and ram sperm homogenates were investigated. Hexokinases showed very little dependence on the various environments tested, whereas the optimum conditions for phosphofructokinase stability were: a minimum of sonication, the presence of phosphate ions and of a thiol-group protectant, and a pH7.5. Activities of hexokinase, phosphofructokinase and glucose phosphate isomerase per sperm cell were compared with published data on rates of fructolysis by spermatozoa; the potential catalytic activities were shown to be considerably in excess of these rates. However, phosphofructokinase may be the rate-limiting enzyme of glycolysis in vivo in bull and ram spermatozoa.

scholarly journals Nuclear transfer from teratocarcinoma cells into mouse oocytes and eggs

Development ◽  
1990 ◽  
Vol 108 (2) ◽  
pp. 337-348
Author(s):  
J.A. Modlinski ◽  
D. Gerhauser ◽  
B. Lioi ◽  
H. Winking ◽  
K. Illmensee
Keyword(s):  
Embryonal Carcinoma ◽  
Preimplantation Embryos ◽  
Time Intervals ◽  
Electrophoretic Variants ◽  
Glucose Phosphate ◽  
Teratocarcinoma Cells ◽  
Nuclear Transplant ◽  
Ec Cells

A spontaneous ovarian teratocarcinoma was isolated from a LT/Sv mouse female and converted into an ascites tumor from which embryonal carcinoma (EC) cells were dissociated. Non-enucleated and enucleated, activated oocytes were fused with EC cells and either cultured in vitro or transferred into ligated oviducts of Swiss/A females. The nucleocytoplasmic hybrids cultured in vitro up to 22 h were examined cytologically at various time intervals. EC nuclei showed morphological remodelling in the foreign cytoplasm. EC chromosomes and female pronuclear chromosomes together formed a common metaphase. The nucleocytoplasmic hybrids developed in vivo were analyzed cytologically between the first and third day after oviduct transfer. The majority of embryos developed abnormally and, in a few instances, they had passed several cleavage divisions and reached, at best, a developmental stage resembling a premature morula. Fertilized, enucleated eggs were fused with EC cells or microinjected with EC nuclei. The resulting nucleocytoplasmic hybrids were either cultured in vitro or in vivo up to the fourth day. Enzyme tests were carried out on the nuclear transplant embryos, using electrophoretic variants of glucose phosphate isomerase (GPI) in order to distinguish between EC nuclei (GPI-A) and recipient eggs (GPI-B). The EC-specific GPI could be detected in about one third of the embryos analyzed and, in several instances, also together with the egg-specific GPI. Most of them were arrested during early cleavage divisions. Some embryos cleaved abnormally or mimicked normal embryogenesis. In a few instances, development resulted in embryos that resembled late preimplantation embryos.

scholarly journals Glucosephosphate Isomerase Deficiency: Evidence for In Vivo Instability of an Enzyme Variant With Hemolysis

Blood ◽  
1973 ◽  
Vol 41 (5) ◽  
pp. 691-699 ◽  
Author(s):  
Heidwolf Arnold ◽  
Karl-Georg Blume ◽  
Rupert Engelhardt ◽  
Georg Wilhelm Löhr
Keyword(s):  
Blood Cells ◽  
Cell Populations ◽  
Red Cell ◽  
Glucosephosphate Isomerase ◽  
Metabolic Capacity ◽  
Comparable Amount ◽  
Glucose Phosphate ◽  
Enzyme Variant

Abstract Pathogenesis of hemolysis in glucose-phosphate isomerase (GPI) deficiency was studied. Red cell populations of different ages were obtained by density centrifugation. In comparison to cell populations with comparable amount of reticulocytes, GPI activity decreased faster in the deficient red cells. A method to simulate aging blood cells in vitro was devised. On the first day the rate of glycolysis was normal in the deficient cells, but by the eighth day of the incubation period, the metabolic capacity decreased markedly, and hemolysis was observed. Using mannose as a source of energy, the rate of glycolysis was still normal by the eighth day, which reflects the cause and effect relationship between impairment of energy metabolism and GPI deficiency. It may be concluded that hemolytic anemia in this case of GPI deficiency is caused by the synthesis of a qualitatively changed subunit of the GPI molecule, which is associated with faster inactivation of the enzyme in vivo.

Glucose Phosphate Isomerase Deficiency In 2 Patients With Novel Mutations Presenting As Severe Neurologic Abnormalities and Transfusion Dependent Hemolytic Anemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 947-947 ◽  
Author(s):  
Mammen Puliyel ◽  
Patrick G. Gallagher ◽  
Vasilios Berdoukas ◽  
Bertil Glader ◽  
Thomas Coates
Keyword(s):  
Developmental Delay ◽  
Hemolytic Anemia ◽  
Conflicts Of Interest ◽  
Cerebral Atrophy ◽  
Global Developmental Delay ◽  
Glucose Phosphate Isomerase ◽  
Hematopoietic Stem ◽  
Neurologic Symptoms ◽  
Glucose Phosphate

Abstract Introduction Glucose phosphate isomerase (GPI) deficiency is the third most common red cell enzymopathy. GPI is an enzyme that reversibly catalyzes the conversion of glucose-6-phosphate into fructose 6-phosphate in the second step of glycolysis. Patients afflicted by GPI deficiency have chronic hemolysis and may also suffer from acute hemolytic crises. There are 184 known mutations of the GPI gene and to date, a neurological deficit is found in only five patients and only two of these have been characterized at a molecular level. We report 2 patients with previously unknown mutations of the GPI gene associated with, severe neurologic abnormalities and hemolytic anemia. Case 1 He was born at 38 weeks gestation; marked pallor and hepatosplenomegaly were noted at birth. The bilirubin was elevated at birth (indirect 7.5 mg/dl and direct 2.2mg/dl) requiring phototherapy. He has transfusion dependent anemia since birth. Enzymes studied were performed which showed GPI levels of 2.02 EU/gm hb ( normal range 16.3-24.7 ) and elevated glucose 6 phosphate dehydrogenase , pyruvate kinase and hexokinase. The pyrimidine 5'-nucleotidase screen was normal. In his subsequent course, he started to have seizures at 6 months of age, refractory to anticonvulsant therapy. He has severe hypotonia and global developmental delay. Magnetic resonance imaging of the brain showed generalized cerebral atrophy with no evidence of kernicterus. Case 2 He was noted to have anemia and marked hepatosplenomegaly at birth. He required exchange transfusions and phototherapy in the neonatal period. He has subsequently suffered from lifelong transfusion-dependent hemolytic anemia. He also suffers from developmental delay, ataxia, spasticity, and seizures. Of note, MRI did not exhibit evidence of kernicterus. The mutations were predicted to be pathogenic (probably damaging) by PolyPhen. Both these mutations were in a highly conserved residue. Genetic probe for preimplantation diagnosis is being used for selection of an embryo which is does not have GPI deficiency and is also a potential HLA match with the hope of undergoing hematopoietic stem cell transplantation to avoid the complications of chronic transfusions and iron overload. Discussion GPI has many functions. In dimeric form, it exhibits its catalytic function. In monomeric form, it acts as a neurotrophic growth factor, neuroleukin, which in vitro promotes survival of neurons. Abnormalities in neuroleukin have been found in motor neuron disease and in patients with central nervous system abnormalities in patients with acquired immunodeficiency disease. These effects of GPI/neuroleukin and relative deficiency in brain and neurons of this protein may explain the neurologic presentation. Decreased phosphatide phosphatase 1 activity, a lipogeneic enzyme due to mTOR activation by accumulated glucose-6-phosphate has been suggested to contribute to the neurologic symptoms. Why some of these mutation are associated with neurologic deficits while most others are not is not known. It has been speculated that the mutations which affect the folding may cause altered structure and function causing neurologic symptoms as well as hemolytic anemia while mutations affecting the catalytic site presents only as hemolytic anemia without neurologic symptoms. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Methotrexate impaired in-vivo matured mouse oocyte quality and the possible mechanisms

2020 ◽  
Author(s):  
Ning Tian ◽  
Dan-yu Lv ◽  
Ji Yu ◽  
Wan-yun Ma
Keyword(s):  
Oocyte Quality ◽  
Mouse Oocyte ◽  
Control Group ◽  
Single Treatment ◽  
Embryo Formation ◽  
Blastocyst Quality ◽  
Chromosome Alignment ◽  
Chromosome Separation

Abstract Background：Methotrexate (MTX) is an antifolate agent which is widely used in clinic for treating malignancies, rheumatoid arthritis and ectopic pregnancy. As reported, MTX has side effects on gastrointestinal system, nervous system and reproductive system, while its potential damages on oocyte quality are still unclear. It is known that oocyte quality is essential for healthy conception and the forthcoming embryo development. Thus, this work studied the effects of MTX on the oocyte quality. Results: We established MTX model mice by single treatment with 5 mg/Kg MTX. Both morphological and molecular biology studies were performed to assess the in-vivo matured oocytes quality and to analyze the related mechanisms. The in-vivo matured oocytes from MTX-treated mice had poor in-vitro fertilization ability, and the resulting embryo formation rates and blastocyst quality were lower than the control group. We found that the in-vivo matured MTX-treated mouse oocytes displayed abnormal transcript expressions for genes of key enzymes in the folate cycles. MTX increased the rate of abnormal chromosome alignment and affected the regulation of chromosome separation via disrupting the spindle morphology and reducing the mRNA expressions of MAD2 and Sgo1. MTX reduced the DNA methylation levels in the in-vivo matured oocytes, and further studies showed that MTX altered the expressions of DNMT1 and DNMT 3b, and may also affect the levels of the methyl donor and its metabolite. Conclusions: MTX impaired the in-vivo matured mouse oocyte quality by disturbing folate metabolism and affecting chromosome stability and methylation modification.

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