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At least 559 records · Page 31Linked to original sources
PubMed2003

Gene expression in mouse oocytes and preimplantation embryos: use of suppression subtractive hybridization to identify oocyte- and embryo-specific genes.

The paucity of biological material has inhibited identifying genes that are differentially expressed during mammalian oogenesis and preimplantation development. We report here the linear amplification of mRNA from small numbers of mouse oocytes and preimplantation embryos to generate amounts of sense RNA that are sufficient for suppression subtractive hybridization. The resulting oocyte-specific and 8-cell-specific cDNA libraries were partially characterized, and the known oocyte-specific ZP1, ZP2, GDF-9, BMP15, and H1(oo) genes were found in the oocyte-specific cDNA library but not in the 8-cell-specific library. Further characterization of the subtracted oocyte and 8-cell embryo cDNA libraries should furnish a trove of information regarding temporal changes in gene expression during oogenesis and preimplantation development in the mouse.

Animals↗
PubMed1999

Embryo-specific gene expression in microspore-derived embryos of brassica napus. An interaction between abscisic acid and jasmonic acid1,2

The induction of napin and oleosin gene expression in Brassica napus microspore-derived embryos (MDEs) was studied to assess the possible interaction between abscisic acid (ABA) and jasmonic acid (JA). Napin and oleosin transcripts were detected sooner following treatment with ABA than JA. Treatment of MDEs with ABA plus JA gave an additive accumulation of both napin and oleosin mRNA, the absolute amount being dependent on the concentration of each hormone. Endogenous ABA levels were reduced by 10-fold after treatment with JA, negating the possibility that the observed additive interaction was due to JA-induced ABA biosynthesis. Also, JA did not significantly increase the uptake of [3H-ABA] from the medium into MDEs. This suggests that the additive interaction was not due to an enhanced carrier-mediated ABA uptake by JA. Finally, when JA was added to MDEs that had been treated with the ABA biosynthesis inhibitor fluridone, napin mRNA did not increase. Based on these results with the MDE system, it is possible that embryos of B. napus use endogenous JA to modulate ABA effects on expression of both napin and oleosin. In addition, JA could play a causal role in the reduction of ABA that occurs during late stages of seed development.

Journal Article↗
PubMed1981

A comparison of the efficiency of human embryo intestine, Hep 2 cells, and human embryo kidney cells for the primary isolation of ophthalmic viruses.

A comparison has been made of the efficiency of 3 cell systems, human embryo kidney (HEK), Hep 2, and a continuous line of human embryo intestine (HEI), for the isolation of ophthalmic viruses. A total of 40 herpes simplex, 51 adenoviruses, and 2 vaccinia viruses were isolated from 323 specimens. HEK cells were found to be the optimal system, 85 out of 93 (91%) of the viruses being detected in these cells alone. However, HEK cells are difficult to obtain, and therefore the use of a combination of the continuous cell lines HEI and Hep 2 is recommended as an alternative. 89% of the viruses were detected by this combination. The use of either HEI or Hep 2 cells alone was unsatisfactory.

Adenoviruses, Human↗
PubMed1981

Comparative neoplastic transformation responses of Balb/3T3 cells, Syrian hamster embryo cells, and Rauscher murine leukemia virus-infected Fischer 344 rat embryo cells to chemical compounds.

This study provides a preliminary comparative evaluation of the responses to a series of 49 chemicals, in in vitro transformation assays, of Balb/3T3 cells, Syrian hamster embryo cells, and Fischer 344 rat embryo cells infected with Rauscher murine leukemia virus. The chemicals assayed included aromatic amines; polycyclic aromatic hydrocarbons; alkylating agents; nitrosamines, hydrazines, and related compounds; heterocyclic compounds; amides, ureas, and acylating agents; inorganic compounds; and hormones. In all three assays 37 of the chemicals were tested. The most uniform test responses were obtained with the polycyclic aromatic hydrocarbons and inorganic compounds With the other groups of chemicals, more variation in response was observed. This study expands the base of information on the potential of these in vitro transformation systems, and the lack of responses with some of the chemicals underscores the need for incorporation of exogenous metabolic activating systems into these assay systems.

Animals↗
PubMed1993

Gonadal sex differentiation in embryos and neonates of the marsupial, Monodelphis domestica: arrest of testis development in postterm embryos.

Growth and histological differentiation were studied in 8 litters of embryos and 4 litters of neonate grey short-tailed opossums, Monodelphis domestica. The embryonic litters included 2 that had passed their expected birth date, and whose weights exceeded the usual birthweights; we refer to these litters as 'postmature'. There was an abrupt increase in the growth rate of XY gonads after birth, but this was not seen in XX gonads. Although there was evidence of testicular differentiation in XY gonads on the day before the expected birth, testicular differentiation was found to be blocked in postmature litters. The growth of XX gonads in postmature embryos was not affected. In view of evidence that exogenous oestrogens feminise the gonads of genetic males in some species of marsupials including Monodelphis domestica, the question arises whether oestrogen is responsible for the failure of testes to continue their development in utero. We suggest that the ability of functional testes to develop in the presence of oestrogen may be a fundamental requirement distinguishing eutherian mammals from other vertebrates, including marsupials.

Animals↗
PubMed1996

Delayed embryo implantation following in vitro fertilization and embryo transfer (IVFET).

PURPOSE: Our goal was to compare serum human chorionic gonadotropin (hCG) levels in singleton pregnancies achieved following IVFET with those achieved following spontaneous conception. RESULTS: The mean serum hCG level of patients who became pregnant following IVFET lagged 1.5 days behind that of patients who became pregnant spontaneously. CONCLUSIONS: The use of gonadotropin releasing hormone analogue as part of the stimulation protocol leading to egg retrieval and IVFET results in a delay in embryo implantation.

Adult↗
PubMed1992

Prevalence of antibodies to selected viruses in bovine embryo donors and recipients from Brazil, and its implications in international embryo trade.

The prevalence of serum antibody to enzootic bovine leukosis (EBL), blue-tongue (BT), bovine herpesvirus 1 (BHV 1) and bovine virus diarrhoea (BVD) viruses in bovine embryo donors (D) and recipients (R) from Minas Gerais State, Brazil was investigated. Of 451 sera (130 D plus 321 R) tested for antibodies against EBL virus 104 (23.1%) were positive. Of 410 sera (130 D plus 280 R) tested for antibody to BT, BHV 1 and BVD viruses the respective number of positive sera were 313 (76.3%), 209 (51.0%) and 153 (37.3%). Donors had significantly (Chi-square test, p < 0.05) higher prevalence rates of antibody than recipients to EBL and BVD viruses. The donors were 60 Bos indicus and 70 Bos taurus purebred cows. Antibody to EBL virus was significantly less common among Bos indicus.

Animals↗
PubMed1980

Cell surfaces and embryos: expression of the F9 teratocarcinoma antigen in T-region lethal, other lethal, and normal pre-implantation mouse embryos.

F9 teratocarcinoma antigen is expressed normally on embryos which are homozygous recessive for each of 4 mutations lethal in early development, including t12. Homozygosity for two post-implantation T-region developmental lethal genes, tw5 and T0r1, may alter F9 antigen expression but the results were not definitive. In addition, the time of appearance of the antigen may be affected by some of the genotypes.

Animals↗
PubMed1996

Intravenous immunoglobulin preceding in vitro fertilization-embryo transfer for patients with repeated failure of embryo transfer.

OBJECTIVE: To determine the effectiveness of immunotherapy with high-dose IV immunoglobulin preceding IVF-ET for patients with repeated failure of ET. DESIGN: Prospective, observational. SETTING: Assisted Reproduction Unit of the Hospital Clínic i Provincial in Barcelona, a tertiary care setting. PATIENTS: Twelve consecutive tubal infertility patients experiencing repeated unexplained IVF-ET failure including at least three ETs replacing three to four fresh embryos each. Two women shared three or more human leukocyte antigens (HLA) with the husband. INTERVENTION: During the subsequent new IVF-ET cycle, each patient received 400 mg/kg IV immunoglobulin daily for 5 days during ovarian stimulation, that is, 5 to 7 days before ET. MAIN OUTCOME MEASURES: Clinical pregnancies. RESULTS: No implantation occurred. There were no side effects. CONCLUSIONS: High-dose IV immunoglobulin is not a useful tool for IVF-ET failure.

Adult↗
PubMed2006

Bovine blastocyst diameter as a morphological tool to predict embryo cell counts, embryo sex, hatching ability and developmental characteristics after transfer to recipients.

The aim of the present study was to explore whether the blastocyst diameter and the zona thickness at 168 h after fertilisation are useful parameters to predict quality and viability of bovine in-vitro-produced (IVP)-embryos. Although significant (P <l 0.05), the blastocyst diameter at 168 h correlated only poorly with the total number of cells (R(2) = 0.13) and with the number of trophectoderm (TE) cells (R(2) = 0.17). Hatched blastocysts (n = 66) at 216 h had a significantly greater mean diameter at 168 h (194.8 +/- 16.8 microm) compared with either blastocysts that had started but not finished hatching at 216 h (n = 26, 178.4 +/- 16.7 microm) or failed to commence hatching (n = 136, 162.7 +/- 12.9 microm). Transfer of 101 IVP blastocysts to synchronised recipients resulted in the birth of 38 calves (38%). There were significantly more bull calves born than cow calves (P < 0.05), but this was not correlated with blastocyst diameter or zona thickness at 168 h. There was also no correlation between the diameter of blastocysts or the zona thickness at 168 h and parameters of subsequent developmental characteristics, including rates of pregnancy, resorptions and abortions, pregnancy duration, delivery to term and birthweight. Overall, the present results indicate that the blastocyst diameter and the zona thickness at 168 h are good predictors for subsequent hatching ability in vitro, but not for the number of TE cells, inner cell mass cells or total cells and neither for subsequent developmental characteristics after transfer to recipients.

Animals↗
PubMed1992

Influence of number of pre-embryos transferred, progesterone level and oestradiol/progesterone ratio at thaw on pregnancy results during replacement of cryopreserved pre-embryos in natural cycles.

When frozen-thawed pre-embryos were transferred in a natural menstrual cycle, a clinical pregnancy rate of 22% per transfer cycle was obtained. The pregnancy rates were higher when serum progesterone levels at thaw were less than or equal to 3.4 ng/ml than when they were greater than or equal to 3.5 ng/ml. This was reflected in a significantly higher oestradiol/progesterone ratio at thaw in the conception cycles than in the non-conception cycles.

Adult↗
PubMed1985

Effects of anticonvulsant drugs on brain cultures from chick embryos: a comparison with cultures from embryos treated in ovo.

The effects of anticonvulsant drugs phenytoin, phenobarbitone, and sodium valproate on neurons and glia from embryonic chicken brain have been tested. These effects have been compared with those produced in neuronal and glial cultures established from embryos that were injected with the drugs in ovo. Choline acetyl transferase activity and accumulation of gamma-aminobutyric acid were measured in neuronal cultures, and carbonic anhydrase and 2,'3'-cyclic nucleotide 3' phosphohydrolase activities were measured in glial cultures. Similarities have been observed in the morphological and biochemical changes brought about by the in vitro and in vivo treatment with the drugs. The use of in vitro cell culture systems for screening drugs for potential behavioural teratogenic effects is discussed.

2',3'-Cyclic-Nucleotide Phosphodiesterases↗
PubMed1984

Cell death of motoneurons in the chick embryo spinal cord. VIII. Motoneurons prevented from dying in the embryo persist after hatching.

A chronic neuromuscular blockade during those embryonic stages when naturally occurring spinal motoneuron death occurs, results in the prevention of this cell loss. The excess motoneurons are maintained as long as the neuromuscular blockade is continued; once embryonic neuromuscular activity resumes, however, the excess motoneurons undergo a delayed period of cell death. By contrast, the resumption of neuromuscular activity in these same preparations after hatching did not result in a delayed cell death. The excess motoneurons, prevented from dying in the embryo, persisted for as long as 4 days postnatally despite the presence of considerable limb motility. The maintenance of motoneurons may be regulated differently before and after hatching.

Age Factors↗
PubMed2001

Expression patterns of histone deacetylases in bovine oocytes and early embryos, and the effect of their inhibition on embryo development.

Gene expression at the onset of bovine embryogenesis is developmentally regulated and histone deacetylases (HDACs) have been shown to play a key role in the control of gene expression during this period of development in other species. We determined expression pattern(s) of powerful repressors, namely histone deacetylase-1, -2 and -3, that may in part regulate gene expression during bovine oogenesis and early embryogenesis at the mRNA and protein levels. Detected fragments of the hdac genes were sequenced and comparison of the sequences showed very high homologies between DNA and amino acid sequences of bovine HDACs and those of human and mouse. RPD3, a yeast global regulator of transcription, was also detected in bovine oocytes and embryos. Results suggest that HDACs may be operative in regulation of zygotic/embryonic gene expression in cattle.

Amino Acid Sequence↗
PubMed2005

Generation of embryos directly from embryonic stem cells by tetraploid embryo complementation reveals a role for GATA factors in organogenesis.

Gene targeting in ES (embryonic stem) cells has been used extensively to study the role of proteins during embryonic development. In the traditional procedure, this requires the generation of chimaeric mice by introducing ES cells into blastocysts and allowing them to develop to term. Once chimaeric mice are produced, they are bred into a recipient mouse strain to establish germline transmission of the allele of interest. Although this approach has been used very successfully, the breeding cycles involved are time consuming. In addition, genes that are essential for organogenesis often have roles in the formation of extra-embryonic tissues that are essential for early stages of post-implantation development. For example, mice lacking the GATA transcription factors, GATA4 or GATA6, arrest during gastrulation due to an essential role for these factors in differentiation of extra-embryonic endoderm. This lethality has frustrated the study of these factors during the development of organs such as the liver and heart. Extraembryonic defects can, however, be circumvented by generating clonal mouse embryos directly from ES cells by tetraploid complementation. Here, we describe the usefulness and efficacy of this approach using GATA factors as an example.

Animals↗
PubMed1989

[Differential indications for surgical technics in reproductive medicine--microsurgery, in vitro fertilization and embryo transfer, gamete intrafallopian transfer and tubal embryo transfer].

The birth of the first baby following in-vitro fertilisation and embryo transfer (IVF/ET) in 1978 and the introduction of gamete intrafallopian transfer (GIFT) in 1984 have increased the treatment modalities in operative reproductive medicine. In tubal pathology, there are besides micro-surgery now so-called additive methods available for treating infertility. With regard to the indications, there has been severe confusion, and it is therefore imperative to define special indications for IVF/ET, microsurgery and GIFT. We do not consider these treatment modalities as alternative methods. Reproductive centres should offer all these treatments to guarantee an appropriate individual programme for each couple. Therefore, knowledge of pregnancy rates is a prerequisite for the doctor. The aim of this paper is, to define the optimal therapy while taking into account the individual problems of each couple.

Embryo Transfer↗
PubMed1993

Differentiation and characterization of B-cell precursors detected in the yolk sac and embryo body of embryos beginning at the 10- to 12-somite stage.

The embryonic sites in which progenitors of the hematopoietic lineages first emerge are ideal regions to characterize both the cells and environment needed to initiate blood cell development. For a number of years both the murine yolk sac and embryo have been recognized to contain progenitors of B lymphocytes. However, clonal, quantitative in vitro assays, which allow precise observation of precursors and their progeny, have been lacking. Moreover, the site of origin of the initial events remains controversial. In this report we document the presence of B-cell progenitors in yolk sac and embryonic tissue obtained from mouse fetuses beginning at the 10-somite stage, day 8.5. We determine the frequency, cell-surface phenotype, and growth properties of these progenitors. We show that these cells can differentiate into immunoglobulin-secreting cells and that the progeny derived from single progenitors are diverse with respect to immunoglobulin heavy-chain allotype expression, diversity-joining region use, and heavy-chain variable-region utilization.

Animals↗