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PubMed1969

The chick embryo neutralization test in the assay of meningococcal antibody. 2. Response of the embryo to meningococcal endotoxin and to infection.

A previous report described the infection of the chick embryo with Neisseria meningitidis. Although death of embryos was preceded by multiplication of the organisms, the possibility exists that death is caused by the endotoxin contained in the inoculum or released by the bacteria lysing in vivo. A second important condition for the establishment of a satisfactory sero-protection test is that the embryo should act as a host and not merely as a growth medium for N. meningitidis.Results of tests with cortisone-treated embryos show that the pathogenic effect of live meningococcal challenge is mainly due to infection elicited by the meningococci and not to toxaemia. Also, the rate of clearance of meningococci from the blood of the embryo, increased by the addition of meningococcal immune serum, suggests that at this stage of embryonic development (12 days) the phagocytes are active in combating meningococcal infection.

Animals↗
PubMed1994

[Comparison of pregnancies issued from frozen embryo transfers and pregnancies issued from fresh embryo transfers in fertilization in vitro. FIVNAT].

The French in vitro fertilization registry FIVNAT allowed us to describe the most important cohort of pregnancies resulting from the replacement of frozen-thawed embryos, and to compare them with pregnancies issued from fresh embryos transfers. From 1987 to 1992, 465 and 8,757 clinical pregnancies were respectively collected, and resulted in the birth of 386 et 8729 babies. Whereas the miscarriage rate was higher, pregnancy evolution was more normal after transfer of frozen-thawed embryos. Multiple pregnancies were less frequent; preterm birth rates and low birth rate were also significantly lower. Nevertheless, after cryopreservation of embryos, more complications were noted. However, further analysis involving more pregnancies after transfer of frozen-thawed embryos is necessary before reaching conclusion. Finally, congenital malformation rate was not different between the two groups.

Abortion, Spontaneous↗
PubMed1997

N-cadherin protein distribution in normal embryos and in embryos carrying mutations in the homeobox gene Hoxa-4.

N-cadherin is a calcium-dependent adhesion molecule with a potential role in a variety of morphogenetic events. Although a dynamic pattern of expression in the mouse embryo has been suggested by in situ hybridization analysis, to date there has been no report of N-cadherin protein expression. In this immunohistochemical study we surveyed N-cadherin protein expression in the mid-late gestation mouse embryo utilizing a recently characterized monoclonal antibody. We found N-cadherin expression in a wide array of tissues, including the brain, the eye, various cranial ganglia, the spinal cord, spinal ganglia, somites, vertebral and limb cartilage and perichondria, the developing lung and kidney, the enteric nervous system, and germ cells. These results suggest that N-cadherin protein expression, as in the chick embryo, correlates with the segregation of cells and with organogenesis. As cadherins have been proposed as targets of vertebrate Hox genes, we also examined N-cadherin expression in two lines of Hoxa-4 mutant mice. We did not observe any alterations in N-cadherin expression in either Hoxa-4 null embryos or in transgenic embryos that overexpress Hoxa-4 in the mesenchyme of the gut. However, the partial overlap in expression between Hox genes and N-cadherin, and the likelihood of redundancy in the regulation of target genes, leaves open the possibility that cadherins are direct or indirect targets of Hox genes during mouse embryogenesis.

Animals↗
PubMed1991

Prediction of successful embryo implantation by measuring interleukin-1-alpha and immunosuppressive factor(s) in preimplantation embryo culture fluid.

To find a better predictor of pregnancy after in vitro fertilization (IVF), supernatant fluids from embryo culture media were analyzed after 24 hours and 48 hours for the presence of interleukin-1-alpha (IL-1), interleukin-2, and the percent of immunosuppression. The measurements were performed on 108 consecutive IVF cycles between June 1989 and October 1989. The IL-1 level +/- SD in the 24-hour aliquots of the supernatant of embryo culture fluid was 66.2 +/- 10.2 pg/mL in all viable pregnancy cycles and 35.4 +/- 9.01 pg/mL in unsuccessful cycles. The percent of immunosuppression after 24 hours was 22.06% +/- 4.5% in viable pregnancy cycles and 7.3 +/- 5.5% in unsuccessful cycles. The percent of immunosuppression 48 hours after ovum pick-up was generally decreased in all embryo culture fluid, showing 17.5% +/- 4.4% in viable pregnancy cycles and 3.8% +/- 3.6% in unsuccessful cycles. Interleukin-1 levels in the 48-hour aliquots were moderately decreased, being 39.0 +/- 6.3 pg/mL in viable pregnancy cycles and 34.3 +/- 4.7 pg/mL in the unsuccessful cycles. In 24 hours, embryo culture aliquots IL-1 level greater than 60 pg/mL was seen in 17 of 21 (80.9%) pregnancy cycles, and the combined data of IL-1 level greater than 60 pg/mL and/or greater than 20 percent of immunosuppression predicted 21 of 21 (100%) pregnancy cycles.

Culture Techniques↗
PubMed1996

Morphological aspects of the vascularization in intraventricular neural transplants from embryo to embryo.

Intraventricular transplants of neural tissues were performed in ovo from embryo to embryo. Fragments of the nervous wall of the optic lobe (tectum) from 14-day chick or 12-day quail embryos (donor) were inserted into the ventricle of the right optic lobe of 6-day chick or 5-day quail embryos (host). Chick-to-chick, chick-to-quail and quail-to-chick grafts were carried out. The vascularization changes occurring in the host tectum and in the grafted neural tissues were analysed under light, transmission, and scanning electron microscopes and by morphometric methods. In the host embryo tectum, the neural graft stimulates a statistically significant increment in vessel density and a vessel sprouting into the ventricle of the optic lobe. The vascular sprouts reach the transplanted tissue and establish connections with its native microvasculature. The chick-to-quail and quail-to-chick grafts, submitted to immunoreaction with a quail-specific antibody which recognizes an antigen (MB1) present on endothelial cells, indicate that re-establishment of the circulation in the graft depends upon anastomoses between host and donor vasculatures and the rapid new growth of host-derived and donor-native vessels. The presence of macrophage-like cells escorting the new-growing vessels suggests that these cells are involved in the host and donor tissue angiogenesis.

Animals↗
PubMed2002

Gametic embryos of maize as a target for biolistic transformation: comparison to immature zygotic embryos.

The aim of the present study was to determine the suitability of maize gametic embryos of three ETH genotypes as a target for biolistic transformation. We studied parameters considered essential for a successful transformation, such as the frequency of secondary embryo formation, their regeneration ability and the transient transgene expression. Transformable zygotic embryos of one of the ETH genotypes were used as positive control. Our results indicate that gametic embryos can potentially be transformed by particle bombardment, since they responded positively to all the studied parameters, although with lower efficiencies than the zygotic embryos. In particular, differences were found in the rate of secondary embryogenesis and the density of transformed cells.

Biolistics↗
PubMed1986

Synchronization of estrus in embryo transfer recipients receiving demi-embryos with Syncro-Mate B or estrumate.

One hundred thirty-five crossbred heifers were used to compare the effectiveness of Estrumate and Syncro-Mate B in synchronizing estrus in recipient heifers for transfer of demi-embryos. A higher percentage (P<0.01) of Syncro-Mate B heifers showed estrus within 5 d following treatment than did Estrumate heifers (100.0 vs 85.1%). Demi-embryos were transferred to 41 and 26 heifers treated with Syncro-Mate B and Estrumate, respectively. The pregnancy rate of heifers synchronized with Estrumate was higher (P<0.01) than that of heifers synchronized with Syncro-Mate B (64.3 vs 27.8%). A single blood sample was collected on the day of embryo transfer from all heifers receiving demi-embryos, and progesterone concentration was determined. There were no significant differences in mean serum progesterone concentrations either between heifers synchronized with Syncro-Mate B and Estrumate or between pregnant and open heifers within synchronization treatment. There was no relationship between serum progesterone concentration and pregnancy rate in the Estrumate recipients (P>0.10). However, 25.0% of the Syncro-Mate B recipients had serum progesterone levels <1.00 ng/ml, and these heifers had a lower pregnancy rate (P<0.05) than Syncro-Mate B heifers with serum progesterone levels between 1.00 to 3.00 ng/ml. It appears that the Syncro-Mate B heifers with <1.00 ng/ml progesterone had either a delay in corpora lutea function or a continuously reduced concentration of serum progesterone which altered the uterine environment of these heifers and caused the lower pregnancy rate in the Syncro-Mate B group. Based on the large difference in pregnancy rates, Estrumate appears to be a more effective method to synchronize estrus in recipient heifers receiving demi-embryos.

Journal Article↗
PubMed1991

Laparoscopy for intrauterine insemination and embryo recovery in superovulated ewes at a commercial embryo transfer unit.

Of 111 variable age, pedigree ewes subjected to a range of superovulatory regimens and then submitted to embryo recovery by laparoscopy, nine had adhesions corresponding to a mid-line laparotomy (presumably from a previous attempt to recover embryos) and could not have their embryos recovered by the laparoscopic technique. Of the remainder, 27 ewes (26.5%) had less than three ovulations or had prematurely regressing corpora lutea at the selected time for embryo recovery (Days 5 to 6 following insemination), and no attempt was made to recover embryos from them. For the 75 ewes subjected to laparoscopic ovum recovery following laparoscopic intrauterine insemination, the average number of ovulations (+/- SEM) was 7.9 +/- 0.6; the average ovum recovery (mean of values for each ewe) was 51.7% +/- 3.5; and the percentage of recovered ova that were fertilized was 87.3%. For a further nine 3-yr-old crossbred ewes the mean values for ovulation and ovum recovery were 7.6 +/- 1.2 and 70.1 +/- 7.7, and were not significantly different for the two insemination methods used (laparoscopic intrauterine vs cervical). In general, ovulation rates for ewes given pregnant mare serum gonadotrophin (PMSG) tended to be lower (5.2 +/- 0.7) than for those given porcine follicle stimulating hormone (pFSH, 7.7 +/- 0.8) or human menopausal gonadotrophin (hMG, 7.7 +/- 2.3). Ova recovery rates were similar on Days 5 and 6 (Day 0 = insemination), and were not affected by method of insemination (laparoscopic intrauterine vs cervical).

Journal Article↗
PubMed1993

Effects of media NaCl concentration and osmolarity on the culture of early-stage porcine embryos and the viability of embryos cultured in a selected superior medium.

One- and 2-cell porcine embryos were obtained from oviductal flushes and cultured for 96 hours in media with varied osmolarity that resulted from alterations in NaCl and sorbitol content. The viability of experimental embryos cultured to advanced stages was determined by comparison with that of the controls, noncultured embryos transferred to recipient gilts. The data suggest that variation in embryonic development in the experimental media is related to the NaCl concentration rather than to osmolarity. Increased NaCl concentration impairs development of the embryos to the advanced morula/blastocyst stages (P<0.001). There was no difference in the pregnancy rate between the recipients of cultured (45%) and noncultured (57%) embryos on Day 25. There was, however, a higher embryonic survival rate (P<0.05) within the control gilts.

Journal Article↗
PubMed1981

Non-surgical embryo transfer in cattle embryo-recipient interactions.

Results from 2286 non-surgical embryo transfers were analyzed to find relationships between embryo factors and recipient factors that affect pregnancy. Pregnancy rates from morulae (44%) and advanced morulae (53%) were reduced (P < .05) when compared to early blastocysts (65%), blastocysts (65%), blastocysts (66%) and advanced blastocysts (64%). Pregnancy rates from good quality Grade 1 embryos (64%) were higher (P < .05) than from Grade 2 (45%) or Grade 3 (33%) embryos. Pregnancy rates related to synchronization of estrus between donor and recipients are: -36 hrs. (before donor) (59%), -24 hrs. (61%), -12 hrs. (68%), 0 hr. (59%), +12 hrs. (61%), +24 hrs. (58%) and +36 hrs. (41%). Differences in pregnancy rate were significant for -12 hrs. (P < .01) and +36 hrs. (P < .01) recipients. Overall pregnancy rates in recipients on day 5 (48%), 5 1/2 (50%) and 6 (53%) were reduced (P < .02) when compared to day 6 1/2 (62%), 7 (63%), and 7 1/2 (66%) and 8 (62%). Pregnancy rates within each embryo stage of development were not related to synchronization with the donor cow (-36 hrs. to +36 hrs.) or the day of the recipient cycle (day 5 to 8).

Journal Article↗
PubMed1997

Effect of glucose on embryo quality and post-thaw viability of in-vitro-produced bovine embryos.

The present study was carried out to evaluate the effect of glucose absence during the first 24 h of culture on blastocyst quality and survival after freezing and thawing. In Experiment 1, IVM/TVF bovine zygotes from a slaughterhouse were cultured for 24 h in SOFm, either in the absence or in the presence of 1.5 mM glucose and then further cultured for 7 d in SOFm with 1.5 mM glucose. Absence of glucose during the first 24 h of culture increased (P < 0.001) the percentage of embryos that developed to the morula and blastocyst stages. In Experiment 2, presumptive zygotes were incubated for 24 h in the absence of glucose and were then cultured for 7 d in the presence of 1.5, 3 or 5 mM glucose. There were no differences in the percentages of embryos developing to morula or blastocyst stages at 1.5 or 3 mM glucose, whereas the 5 mM concentration appeared to be detrimental (P < 0.001). Blastocysts from Experiments 1 and 2 were assessed for freezing resistance by means of the ability of frozen-thawed embryos to re-expand their blastocoelic cavity and hatch after culture for 72 h in vitro. For Grade 1 and 2 blastocysts, the post-freezing survival rate was unaffected when glucose was omitted during the first 24 h of culture, provided that the glucose was subsequently maintained between 1.5 and 3 mM. At 5 mM glucose, blastocoelic re-expansion was inhibited (P < 0.03). Addition of 1.5 or 3 mM glucose to the culture medium following 24 h of culture without glucose did not affect embryo cell number, whereas 5 mM significantly decreased it (P < 0.01). These results indicate that the first 24 h of culture without glucose do not affect embryo quality or post-thaw viability, but an increase in blastocyst yield was observed. After 24 h of culture addition of glucose in the range 1.5 to 3 mM was beneficial, while as higher concentrations decreased the efficacy of this in vitro production technique.

Journal Article↗
PubMed2004

The combination of polar body and embryo biopsy does not affect embryo viability.

BACKGROUND: The biopsy of both polar bodies and a blastomere from the same embryo was investigated as an approach aimed at increasing the quantity of DNA available for genetic analysis in preimplantation embryos. METHODS: In 113 cycles, preimplantation genetic diagnosis (PGD) was performed for aneuploidy: 19 cycles underwent polar body biopsy, 32 cycles had both polar body and blastomere biopsy done, and the remaining 62 cycles underwent blastomere biopsy. The chromosomal analysis was performed in a two-round fluorescence in situ hybridization (FISH) protocol with probes specific for the chromosomes X, Y, 13, 15, 16, 18, 21 and 22. RESULTS: The morphological evaluation of the analysed embryos demonstrated similar rates of development irrespective of the biopsy procedure. Accordingly, the implantation rate did not differ significantly in the three biopsy groups and was 15% after polar body biopsy, 26% after the combined biopsy procedures of polar bodies and blastomeres, and 25% after blastomere biopsy. CONCLUSIONS: The removal of a blastomere subsequent to polar body biopsy does not seem to have negative effects on embryo viability. This approach could be especially valuable for a combined diagnosis of aneuploidy and single-gene disorders in preimplantation embryos generated by couples at high reproductive risk.

Adult↗
PubMed1992

Distribution of Cytosolic mRNAs Between Polysomal and Ribonucleoprotein Complex Fractions in Alfalfa Embryos : Stage-Specific Translational Repression of Storage Protein Synthesis during Early Somatic Embryo Development.

Cell-free translational and northern blot analyses were used to examine the distribution of storage protein messages in the cytoplasmic polysomal and mRNA-protein complex (mRNP) fractions during development of somatic and zygotic embryos of alfalfa (Medicago sativa cv Rangelander RL-34). No special array of messages was identified in the mRNP fraction; however, some messages were selectively enriched in either the polysome or mRNP fractions, and their distribution pattern varied quantitatively during development of the embryos. During the earliest stages of somatic embryo development, storage protein messages already were present, but there was no detectable accumulation of the proteins. Selective enrichment of messages for the 11S, 7S, and 2S storage proteins occurred in the mRNP fraction during the globular, heart, and torpedo stages of somatic embryogenesis, but the distribution pattern was shifted toward the polysomal fraction at the beginning of cotyledon development. Thus, there was translational repression of storage protein synthesis at the early stage of somatic embryo development that was relieved later. During the cotyledonary development stages in the somatic and zygotic embryos, storage protein synthesis and distribution of the messages were similar in that these specific messages were predominantly in the polysomal fraction.

Journal Article↗
PubMed1978

Wheat embryo ribonucleates XI. Conserved mRNA in dry wheat embryos and its relation to protein synthesis during early inhibition.

It has been found that bulk poly(A)-rich RNA from dry wheat embryos is broadly heterodisperse when examined by polyacrylamide gel electrophoresis. The poly(A)-rich RNA from dry wheat embryos has been translated in a cell-free protein-synthesizing system from the same commerically supplied, roller-milled wheat embryos. Compatiable with the electrophoretic heterodispersity observed for poly(A)-rich RNA, the radioactive products of its cell-free translation, when examined by sodium dodecyl sulphate polyacrylamide gel electrophoresis, have mobilities that are broadly coincident with the many dye-stained (nonradioactive) proteins present in wheat extracts. With due allowance for the limitations of the cell-free system, which is known to translate, selectively, lower molecular-weight species of mRNA, it has been concluded that the conserved poly(A)-rich mRNA in dry wheat embryos probably has the translational capacity required to account for the highly eclectic protein synthesis that we have observed during early (40-min) inhibition of viable wheat embryos.

Cell-Free System↗
PubMed1992

Ultrastructural localization of laminin on in vivo embryonic, neonatal, and adult rat cardiac myocytes and in early rat embryos raised in whole-embryo culture.

The temporal and spatial distribution of the basement membrane component laminin was examined in vivo in developing rat hearts at 11.5 and 15 days of embryonic development (ED), and in neonates and adults, by pre-embedding ultrastructural immunocytochemistry. In addition, the patterns observed at 11.5 days ED were compared to the distribution of laminin in embryos maintained in whole-embryo culture. At 11.5 days ED laminin was localized in punctate patches on the surface of the plasma membrane, with large gaps between areas of staining. The development of myocytes and localization of laminin in the whole embryo-cultured embryos was similar to that found in the in vivo embryos. At 15 days ED, laminin localization was limited to distinct patches of developing extracellular matrix material associated with the sarcolemma. Gaps between areas of localization were shorter than in the 11.5-day hearts. In neonates, distribution of laminin localization was more extensive with fewer gaps and was associated with the developing basement membrane. In adult hearts, laminin was localized along the entire length of the basement membrane and was heaviest in areas of morphological specialization, such as Z-bands, where collagen bundles contacted the sarcolemma.

Animals↗
PubMed1986

[In vitro culture of mouse embryos for toxicological evaluation. (3): Effect of carcinogens on development of the embryos].

Mouse embryos were collected at the 2 cell or 8 cell stage. The embryos of each stage were exposed to 1 pM-10 nM 4-nitroquinoline-1-oxide (4-NQO) or 1 nM-10 microM N-methyl-nitro-nitrosoguanidine (MNNG) for 24 hr, and cultured to develop to blastocysts within clean medium. Since after exposure to 4-NQO, the appearance of early blastocysts and blastocysts were increased in exposure groups compared with controls, the growth to the 8 cell stage embryo (8-E) appeared to be late in development. Frequency of sister chromatid exchange (SCE) and mitotic index were increased with doses in the blastocysts (2-B) which derived from 2-E. There was little change in the SCE and mitotic index for blastocysts (8-B) which derived from the 8 cell stage embryo (8-E). Cessation of development in the 2 cell stage embryo (2-E) appeared in the 10 microM group during the period of exposure to MNNG. Development to the 8-E stage appeared to be slightly late in the other exposed groups. Thereafter at 48 hr after the initiation of culture, the exposed groups appeared to be more advanced in development than the controls. After this period, developmental rates to blastocysts were increased in the 10-100 nM groups. It appeared that the development of these groups was more advanced. In 2-B after exposure to MNNG, cell counts were dose-responsively increased in the 1 and 10 nM groups. The mitotic index in the 1 to 100 nM groups was higher than the controls.(ABSTRACT TRUNCATED AT 250 WORDS)

4-Nitroquinoline-1-oxide↗
PubMed2002

Developmental abnormalities in mouse embryos tetrasomic for chromosome 11: apparent similarity to embryos functionally disomic for the x chromosome.

Adopting a mating system involving two different Robertsonian translocations with monobrachial homology, we studied the early development of mouse embryos trisomic or tetrasomic for chromosome 11. A developmental delay of 12-24 hours was evident in trisomic embryos at embryonic day (E)7.5, whereas tetrasomic embryos apparently had stopped growth by E6.5 without formation of extraembryonic structures. This extremely severe developmental abnormality found in tetrasomic embryos is similar to that reported in embryos having two active X chromosomes in extraembryonic cell lineages. Autosomal tetrasomy, but not autosomal trisomy, can lead to such early developmental errors. Thus, a reasonable inference would be that the X chromosome is twice as active as the autosome. Probably, the X chromosome became upregulated in response to the evolutionary necessity of minimizing haplo-insufficiency brought about by miniaturization of the Y chromosome.

Aneuploidy↗
PubMed1988

[Immunohistochemical study of developing rat embryo--localization of vimentin, GFAP, neurofilament protein within rat embryo central nervous system].

The identification of intermediate filaments within immature cells is valuable as a means to investigate neuronal and glial differentiation. The purpose of this study is to investigate the time of appearance of neuron and glia within rat embryo by identifying cell-specific intermediate filaments. Pregnant rat were daily sacrificed from day 9-20 of pregnancy. Rat embryos were fixed with 100% ethanol and then we have made the paraffin section. We have stained the specimens for vimentin in accordance with ABC method and for GFAP in accordance with PAP method. We have performed Bodian stain. The neural plate of day 9 rat embryo is composed with vimentin positive immature cells which are disposed with pseudostratified arrangement. In midbrain of day 13 rat embryo, immature cells and their fibers are vimentin positive which are spanning from ventricular surface to marginal layer. NFP is detectable in immature cells and fibers of marginal layer. But GFAP positive cells and fibers are not identified in the same region. In anterior column of day 18 rat embryo, GFAP positive fibers are detectable. Summarizing of these results, we can display first: immature cells composing of neural plate are vimentin positive at day 9, second: NFP positive fibers and cells appear at day 13, third: NFP positive cells are vimentin positive, too, forth: GFAP positive fibers appear at day 18 and they are vimentin positive, too.

Animals↗