Purine utilisation, de novo synthesis and degradation in mouse preimplantation embryos

Development ◽  
1992 ◽  
Vol 114 (1) ◽  
pp. 185-192 ◽  
Author(s):  
M. Alexiou ◽  
H.J. Leese
Keyword(s):  
Uric Acid ◽  
De Novo ◽  
Single Step ◽  
Preimplantation Embryos ◽  
Purine Synthesis ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Salvage Pathways ◽  
Synthesis And Degradation ◽  
Purine Degradation

The importance of de novo purine synthesis as opposed to the reutilisation of metabolites by salvage pathways, and the nature of the excretory product(s) of purine degradation, have been examined in cultured preimplantation mouse embryos. In the presence of azaserine and mycophenolic acid, which inhibit de novo purine synthesis, embryo cleavage was blocked prior to compaction, the precise stages at which this occurred depended on whether the cultures were established on day 1 or day 2 after fertilisation, and indicated that salvage pathways were insufficient to fulfil the demand for nucleotides during early preimplantation development. The end-product of purine degradation appeared to be xanthine, which was excreted in very small amounts on days 1, 2 and 3, with a pronounced rise from the early to late blastocyst. Uric acid formation or excretion could not be detected. Exogenous hypoxanthine and adenine, which partially inhibited development, were taken up by the embryos and converted to xanthine, most probably by salvage pathways, since the enzyme xanthine oxidase, which converts hypoxanthine directly to xanthine and then to uric acid, could not be detected. Exogenous guanine had little effect on development and was also converted to xanthine, but in this case, the conversion was probably in a single step, via the enzyme guanase.

scholarly journals Effects of embryo culture on global pattern of gene expression in preimplantation mouse embryos

Reproduction ◽  
2004 ◽  
Vol 128 (3) ◽  
pp. 301-311 ◽  
Author(s):  
Paolo Rinaudo ◽  
Richard M Schultz
Keyword(s):  
Gene Expression ◽  
Preimplantation Embryos ◽  
Expression Analysis Systematic Explorer ◽  
Cell Stage ◽  
Global Pattern ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Global Patterns ◽  
The One

Culture of preimplantation embryos affects gene expression. The magnitude of the effect on the global pattern of gene expression, however, is not known. We compared global patterns of gene expression in blastocysts cultured from the one-cell stage in either Whitten’s medium or KSOM + amino acids (KSOM/AA) with that of blastocysts that developed in vivo, using the Affymetrix MOE430A chip. The analysis revealed that expression of 114 genes was affected after culture in Whitten’s medium, whereas only 29 genes were mis-expressed after culture in KSOM/AA. Expression Analysis Systematic Explorer was used to identify biological and molecular processes that are perturbed after culture and indicated that genes involved in protein synthesis, cell proliferation and transporter function were down-regulated after culture in Whitten’s medium. A common set of genes involved in transporter function was also down-regulated after culture in KSOM/AA. These results provide insights as to why embryos develop better in KSOM/AA than in Whitten’s medium, and highlight the power of microarray analysis to assess global patterns of gene expression.

Quantification of basigin mRNA in mouse oocytes and preimplantation embryos by competitive RT-PCR

Zygote ◽  
2002 ◽  
Vol 10 (3) ◽  
pp. 239-243 ◽  
Author(s):  
Nai-Zheng Ding ◽  
Cheng-Qiang He ◽  
Zeng-Ming Yang
Keyword(s):  
Embryo Implantation ◽  
Preimplantation Embryos ◽  
Immunoglobulin Superfamily ◽  
Competitive Polymerase Chain Reaction ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Cell Embryo ◽  
Blastocyst Implantation ◽  
Polymerase Chain ◽  
High Level

Basigin is a member of the immunoglobulin superfamily and a key molecule related to mouse blastocyst implantation. Whether preimplantation mouse embryos express basigin mRNA is still unknown. The aim of this study was to use a quantitative competitive polymerase chain reaction to assess quantitatively the levels of basigin mRNA in mouse oocyte and preimplantation embryos. Basigin mRNA was detected in the oocyte and all the stages of preimplantation embryos. The levels of basigin mRNA were 0.0606 ± 0.0282 in the oocyte, 0.0102 ± 0.0036 in the zygote, 0.0007 ± 0.0003 in the 2-cell embryo, 0.0031 ± 0.0017 in the 4-cell embryo, 0.0084 ± 0.0024 in the 8-cell embryo, 0.0537 ± 0.0121 in the morula and 0.0392 ± 0.0161 attomoles in the blastocyst, respectively. The levels of basigin mRNA in the oocyte, morula and blastocyst were significantly higher than those in the zygote and embryos at the 2-cell, 4-cell and 8-cell stages. The high level of basigin expression in the blastocyst may play a role during embryo implantation.

Angiopoietin-1 and -2 mRNA and protein expression in mouse preimplantation embryos and uteri suggests a role in angiogenesis during implantation

2006 ◽  
Vol 18 (5) ◽  
pp. 509 ◽  
Author(s):  
A. P. Hess ◽  
J. Hirchenhain ◽  
A. Schanz ◽  
S. Talbi ◽  
A. E. Hamilton ◽  
...  
Keyword(s):  
Protein Expression ◽  
Embryo Implantation ◽  
Mouse Embryos ◽  
Preimplantation Embryos ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Mrna And Protein Expression ◽  
Implantation Process ◽  
Endometrial Epithelium ◽  
Angiopoietin 1

After attachment and migration through the endometrial epithelium, the embryo must induce angiogenesis within the endometrial stroma to successfully complete the implantation process. Growth factors have been shown to play an important role in embryo implantation and placentation. The aim of the study was to investigate the expression of angiopoietin-1 and -2 (Ang-1 and -2) mRNA and protein expression during the development of single preimplantation mouse embryos and of possible complementary expression in mouse uteri. Angiopoietin-1 mRNA was expressed throughout development in 78% of zygotes, 66% of 2-cell-embryos, 71% of 4-cell-embryos, 70% of 8-cell-embryos, 60% of morula stages, 48% of early blastocysts and 78% of late blastocysts. The number of Ang-1-expressing embryos in the early-blastocyst group was significantly different in comparison with zygotes, 4-cell-embryos, 8-cell-embryos and late blastocysts. Angiopoietin-2 mRNA and protein expression could not be detected in preimplantation embryos. Examination of the uteri revealed Ang-2 mRNA and protein expression in the oestrogen-dominated cycling phase and the progesterone-dominated mated phase, whereas Ang-1 expression was restricted to the mated phase. Herein, Ang-1 expression in preimplantation mouse embryos as well as Ang-1 and -2 expression in mouse uteri is demonstrated, suggesting a possible role for angiopoietins in the embryo–maternal dialogue of the implantation process via an enhancement of the vascular remodelling in favour of an implanting conceptus.

Maternal versus paternal expression of a LacZ transgene in preimplantation mouse embryos: effects of genetic background and 2-cell block

Zygote ◽  
2001 ◽  
Vol 9 (3) ◽  
pp. 219-228
Author(s):  
Irina Neganova ◽  
Martin Augustin ◽  
Ursula Eichenlaub-Ritter ◽  
Harald Jockusch
Keyword(s):  
Genetic Background ◽  
Transgene Expression ◽  
In Utero ◽  
Mouse Embryos ◽  
Preimplantation Embryos ◽  
Parental Origin ◽  
Cell Block ◽  
Maternal Origin ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse

The expression of a transgene NI-ROSA LacZ (LacZtg) trapped into the genes for two presumably untranslated, ubiquitously expressed RNAs, was studied in preimplantation mouse embryos with respect to penetrance (fraction of expressing embryos) and to localisation of β-galactosidase activity. With maternal origin in NMRI mice β-galactosidase was first detected within one dot in the cytoplasm of zygotes at 30 h post-hCG. The staining pattern progressed to small clusters and to dense, homogeneous staining of the entire cytoplasm during further development. Within the NMRI background, penetrance in utero was delayed by at least 6 h when the transgene was of paternal as compared with maternal origin. Paternal transgene expression increased marginally during culture to 50 h after explantation of embryos at 30-48 h post-hCG and remained low or decreased in the ‘2-cell block’. Expression of a paternal transgene in preimplantation embryos developing in utero was further delayed in the maternal MF1 as compared with the NMRI background. In contrast to NMRI × NMRI embryos with paternally derived transgene, expression increased with time during the 2-cell block in MF1 × NMRI embryos. Thus, in the earliest phase of mammalian development expression of this LacZtg is influenced by parental origin, maternal genetic background and environment. The spatial distribution of the gene product is developmentally controlled.

Histone macroH2A1 is concentrated in the inactive X chromosome of female preimplantation mouse embryos

Development ◽  
2000 ◽  
Vol 127 (11) ◽  
pp. 2283-2289 ◽  
Author(s):  
C. Costanzi ◽  
P. Stein ◽  
D.M. Worrad ◽  
R.M. Schultz ◽  
J.R. Pehrson
Keyword(s):  
X Chromosome ◽  
Hybrid Structure ◽  
X Inactivation ◽  
Preimplantation Embryos ◽  
Histone H2a ◽  
Mouse Development ◽  
X Chromosomes ◽  
Inactive X Chromosome ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse

MacroH2As are core histone proteins with a hybrid structure consisting of a domain that closely resembles a full-length histone H2A followed by a large nonhistone domain. We recently showed that one of the macroH2A subtypes, macroH2A1.2, is concentrated in the inactive X chromosome in adult female mammals. Here we examine the timing of the association of macroH2A1.2 with the inactive X chromosome during preimplantation mouse development in order to assess the possibility that macroH2A1 participates in the initiation of X inactivation. The association of macroH2A1.2 with one of the X chromosomes was observed in 50% of blastocysts, occurring mostly, if not exclusively, in extraembryonic cells as was expected from previous studies, which indicated that X inactivation in embryonic lineages happens after implantation. Examination of earlier embryonic stages indicates that the association of macroH2A1 with the inactive X chromosome begins between the 8- and 16-cell stages. Of the changes that are known to happen during X inactivation in preimplantation embryos, the accumulation of macroH2A1 appears to be the earliest marker of the inactive X chromosome and is the only change that has been shown to occur during the period when transcriptional silencing is initiated.

Intracellular ion concentrations and their maintennance by Na+/K+ -ATPase in preimplantation mouse embroys

Zygote ◽  
1997 ◽  
Vol 5 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Jay M. Baltz ◽  
Stephen S. Smith ◽  
John D. Biggers ◽  
Claude Lechene
Keyword(s):  
Atpase Activity ◽  
Mammalian Cells ◽  
Mouse Embryos ◽  
Preimplantation Embryos ◽  
X Ray ◽  
Ion Concentrations ◽  
Preimplantation Mouse Embryos ◽  
High K ◽  
Intracellular Ion Concentrations ◽  
Preimplantation Mouse

SummaryWe have measured the amounts of Na+, K+ and C− in preimplantation mouse embryos (1-cell, 2-cell and morula) using electron probe X-ray microanalysis. The levels of these ions do not vary much over this period, and are approximately the same as those found in other mammalian cells, contrary to previous reports. We have confirmed that preimplantation embryos exhibit Na+/K+-ATPase activity at all stages examined, and have shown that the ATPase maintains high K+/Na+ ratios (12–16) in all these embryonic stages, comparable to those seen in other healthy cells; this is in contrast to the low ratios reported in earlier work. Inhibition of the Na+/K+-ATPase results in the slow exchange of intracellular K+ for extracellular Na+ (half-time approximately 5 h), indicating that Na+/K+-ATPase activity maintains steep Na+ and K+ gradients in preimplantation mouse embryos as it does in most other cells.

Enzymes of the de novo and Salvage Pathways of Purine Synthesis in Renal Hypertrophy

Enzyme ◽  
1988 ◽  
Vol 40 (4) ◽  
pp. 231-237 ◽  
Author(s):  
Steven Beardsley ◽  
Sirilaksana Kunjara ◽  
Milena Sochor ◽  
Leslie Greenbaum
Keyword(s):  
De Novo ◽  
Renal Hypertrophy ◽  
Purine Synthesis ◽  
Salvage Pathways

scholarly journals The serine 106 residue within the N-terminal transactivation domain is crucial for Oct4 function in mice

Zygote ◽  
2017 ◽  
Vol 25 (2) ◽  
pp. 197-204
Author(s):  
Atsushi Mitani ◽  
Atsushi Fukuda ◽  
Toshiyuki Miyashita ◽  
Akihiro Umezawa ◽  
Hidenori Akutsu
Keyword(s):  
Protein Conformation ◽  
Mouse Embryos ◽  
Preimplantation Embryos ◽  
Transactivation Domain ◽  
Wild Type ◽  
Specific Antibodies ◽  
Developmental Arrest ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
Oct4 Protein

SummaryPou5f1/Oct4 is a key transcription factor for the induction of pluripotency and totipotency in preimplantation mouse embryos. In mice, loss or gain of function experiments have demonstrated an important role for Oct4 in preimplantation and developmental ability. In this study, using mouse preimplantation embryos as a model for the evaluation of Oct4 function, we constructed Oct4 overexpression embryos with various mutations at the N-terminal transactivation domain. Developmental competency and molecular biological phenotypes depended on the type of mutation. The replacement of serine 106 with alanine resulted in more severe phenotypes similar to that of wild type Oct4, indicating that this alteration using alanine is negligible for Oct4 function. In contrast, we found that Oct4-specific antibodies could not recognize Oct4 protein when this residue was replaced by aspartic acid (Oct4-S106D). Oct4-S106D overexpressing embryos did not show developmental arrest and aberrant chromatin structure. Thus, these results demonstrated that the Ser-106 residue within the N-terminal transactivation domain is crucial for Oct4 function and suggested that this mutation might affect Oct4 protein conformation.

Maternal hyperglycemia alters glucose transport and utilization in mouse preimplantation embryos

1998 ◽  
Vol 275 (1) ◽  
pp. E38-E47 ◽  
Author(s):  
Kelle H. Moley ◽  
Maggie M.-Y. Chi ◽  
Mike M. Mueckler
Keyword(s):  
Glucose Transport ◽  
Glucose Utilization ◽  
Preimplantation Embryos ◽  
Enzyme Assays ◽  
Glut 1 ◽  
Protein Levels ◽  
Preimplantation Mouse Embryos ◽  
Quantitative Immunofluorescence ◽  
Preimplantation Mouse ◽  
Free Glucose

Glucose utilization was studied in preimplantation embryos from normal and diabetic mice. With use of ultramicrofluorometric enzyme assays, intraembryonic free glucose in single embryos recovered from control and streptozotocin-induced hyperglycemic mice was measured at 24, 48, 72, and 96 h after mating. Free glucose concentrations dropped significantly in diabetics at 48 and 96 h, corresponding to the two-cell and blastocyst stages (48 h: diabetic 0.23 ± 0.09 vs. control 2.30 ± 0.43 mmol/kg wet wt; P < 0.001; 96 h: diabetic 0.31 ± 0.29 vs. control 5.12 ± 0.17 mmol/kg wet wt; P < 0.001). Hexokinase activity was not significantly different in the same groups. Transport was then compared using nonradioactive 2-deoxyglucose uptake and microfluorometric enzyme assays. The 2-deoxyglucose uptake was significantly lower at both 48 and 96 h in embryos from diabetic vs. control mice (48 h diabetic, 0.037 ± 0.003; control, 0.091 ± 0.021 mmol ⋅ kg wet wt−1 ⋅ 10 min−1, P < 0.05; 96 h diabetic, 0.249 ± 0.008; control, 0.389 ± 0.007 mmol ⋅ kg wet wt−1 ⋅ 10 min−1, P < 0.02). When competitive quantitative reverse transcription-polymerase chain reaction was used, there was 44 and 68% reduction in the GLUT-1 mRNA at 48 h ( P < 0.001) and 96 h ( P < 0.05), respectively, in diabetic vs. control mice. GLUT-2 and GLUT-3 mRNA values were decreased 63 and 77%, respectively ( P < 0.01, P < 0.01) at 96 h. Quantitative immunofluorescence microscopy demonstrated 49 ± 6 and 66 ± 4% less GLUT-1 protein at 48 and 96 h and 90 ± 5 and 84 ± 6% less GLUT-2 and -3 protein, respectively, at 96 h in diabetic embryos. These findings suggest that, in response to a maternal diabetic state, preimplantation mouse embryos experience a decrease in glucose utilization directly related to a decrease in glucose transport at both the mRNA and protein levels.

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