Aggregation of Leopardus geoffroyi hybrid embryos with domestic cat tetraploid blastomeres.

Heterospecific embryo transfer of an endangered species has been carried out using recipients from related domestic females. Aggregation of an embryo from an endangered species with a tetraploid embryo from the species to be transferred could improve the development of pregnancy to term. The main objective of the present study was to analyze embryo aggregation in domestic cat model using hybrid embryos. For this purpose, we compared in vitro development of synchronic (Sync) or asynchronic (Async) and asynchronic with a tetraploid (Async4n) aggregation of domestic cat IVF embryos. Furthermore, aggregated blastocyst quality was analyzed by evaluation of the total cell number, cell allocation by mitotrackers staining of embryonic cells, expression of Oct4, Nanog, Sox2, Cdx2 genes, number of OCT4+ nuclei, and presence of DNA fragmentation. Additionally, the developmental rates of Async4n aggregation of domestic cat with Leopardus geoffroyi hybrid (hLg) embryos were evaluated. Async aggregation increased blastocyst cell number and the number of OCT4+ nuclei as compared to non-aggregated diploid (2n) and tetraploid (4n) embryos. Moreover, blastocysts produced by Async4n aggregation showed reduced rates of fragmented DNA. No differences were found in the expression of the pluripotent genes, with exception of the Cdx2 expression, which was higher in 4n and aggregated embryos as compared to the control group. Interestingly, hybrids embryos derived by Async4n aggregation with domestic cat embryos had similar rates of blastocysts development as the control. Altogether, the findings support the use of two-cell-fused embryos to generate tetraploid blastomeres and demonstrate that Async4n aggregation generates good quality embryos.

HIPSTR and thousands of lncRNAs are heterogeneously expressed in human embryos, primordial germ cells and stable cell lines.

Eukaryotic genomes are transcribed into numerous regulatory long non-coding RNAs (lncRNAs). Compared to mRNAs, lncRNAs display higher developmental stage-, tissue-, and cell-subtype-specificity of expression, and are generally less abundant in a population of cells. Despite the progress in single-cell-focused research, the origins of low population-level expression of lncRNAs in homogeneous populations of cells are poorly understood. Here, we identify HIPSTR (Heterogeneously expressed from the Intronic Plus Strand of the TFAP2A-locus RNA), a novel lncRNA gene in the developmentally regulated TFAP2A locus. HIPSTR has evolutionarily conserved expression patterns, its promoter is most active in undifferentiated cells, and depletion of HIPSTR in HEK293 and in pluripotent H1BP cells predominantly affects the genes involved in early organismal development and cell differentiation. Most importantly, we find that HIPSTR is specifically induced and heterogeneously expressed in the 8-cell-stage human embryos during the major wave of embryonic genome activation. We systematically explore the phenomenon of cell-to-cell variation of gene expression and link it to low population-level expression of lncRNAs, showing that, similar to HIPSTR, the expression of thousands of lncRNAs is more highly heterogeneous than the expression of mRNAs in the individual, otherwise indistinguishable cells of totipotent human embryos, primordial germ cells, and stable cell lines.

Studies on in vitro bovine embryos during their transport / Estudo sobre o cultivo in vitro de embriões bovinos durante o transporte

The Brazilian livestock is based on the use and in the improvement of reproductive biotechnologies. Researches that aims to solve problems such as the distance between laboratories and the large cattle producing farms are necessary. The objective of this study was to evaluate the effectiveness of a culture system during long periods of transportation on bovine embryos produced in vitro. The oocytes obtained from slaughterhouse cows ovaries, passed through in vitro production of embryos procedures such as: maturation, fertilization and embryo culture and subsequently were allocated into the transportation system to compose the treatments: Tcontrol - control embryos kept in the incubator; T48 - embryos removed from the culture medium on the 5th day and transportation simulated for 48 hours; T24 - embryos removed from the culture medium on the 6th day and transportation simulated for 24 hours. After the treatments, the embryos were evaluated for blastocyst on the 7th day and hatching rate on the 9th day. The experimental design was completely randomized. No differences were found (P> 0.05) for blastocyst rate (31, 33 and 35%) and hatching rate (74, 78 and 80%), respectively, for Tcontrol, T48 and T24 treatments. It was concluded that the culture system during transport, up to 48 hours, was efficient when considering the embryonic viability, inferring that the transportation environment simulated atmosphere and temperature conditions of the laboratory in a satisfactory manner(AU)

A pecuária brasileira é, em parte, sustentada pela utilização e aperfeiçoamento de biotecnologias da reprodução. Pesquisas que buscam solucionar problemas como a distância existente entre os laboratórios e as grandes fazendas produtoras de gado são necessárias. O objetivo deste trabalho foi avaliar a eficácia de um sistema de cultivo durante períodos longos de transporte de embriões bovinos produzidos in vitro. Os oócitos, obtidos de ovários de vacas de abatedouro, passaram pelos procedimentos de produção de embriões in vitro, e no quinto dia do cultivo, foram alocados no sistema de transporte para compor os tratamentos: Tcontrole embriões controle mantidos na incubadora; T48 - embriões retirados do meio de cultivo no 5º dia e simulado o transporte por 48 horas; T24 - embriões retirados do meio de cultivo no 6º dia e simulado o transporte por 24 horas. Após os tratamentos, os embriões foram avaliados quanto à taxa de blastocistos no 7º dia e a taxa eclosão no 9º dia. O delineamento experimental foi inteiramente casualizado com três tratamentos e cinco repetições cada. Não foram observadas diferenças (P> 0,05) na taxa de blastocisto (31, 33 e 35%) e na taxa de eclosão (74, 78 e 80%), respectivamente para os tratamentos Tcontrole, T48 e T24. Concluiu-se que o sistema de cultivo durante o transporte, por até 48 horas, foi eficiente quanto à viabilidade embrionária inferindo que o ambiente de transporte simulou as condições de atmosfera e de temperatura do laboratório de forma satisfatória(AU)

Studies on in vitro bovine embryos during their transport / Estudo sobre o cultivo in vitro de embriões bovinos durante o transporte

The Brazilian livestock is based on the use and in the improvement of reproductive biotechnologies. Researches that aims to solve problems such as the distance between laboratories and the large cattle producing farms are necessary. The objective of this study was to evaluate the effectiveness of a culture system during long periods of transportation on bovine embryos produced in vitro. The oocytes obtained from slaughterhouse cows ovaries, passed through in vitro production of embryos procedures such as: maturation, fertilization and embryo culture and subsequently were allocated into the transportation system to compose the treatments: Tcontrol - control embryos kept in the incubator; T48 - embryos removed from the culture medium on the 5th day and transportation simulated for 48 hours; T24 - embryos removed from the culture medium on the 6th day and transportation simulated for 24 hours. After the treatments, the embryos were evaluated for blastocyst on the 7th day and hatching rate on the 9th day. The experimental design was completely randomized. No differences were found (P> 0.05) for blastocyst rate (31, 33 and 35%) and hatching rate (74, 78 and 80%), respectively, for Tcontrol, T48 and T24 treatments. It was concluded that the culture system during transport, up to 48 hours, was efficient when considering the embryonic viability, inferring that the transportation environment simulated atmosphere and temperature conditions of the laboratory in a satisfactory manner

A pecuária brasileira é, em parte, sustentada pela utilização e aperfeiçoamento de biotecnologias da reprodução. Pesquisas que buscam solucionar problemas como a distância existente entre os laboratórios e as grandes fazendas produtoras de gado são necessárias. O objetivo deste trabalho foi avaliar a eficácia de um sistema de cultivo durante períodos longos de transporte de embriões bovinos produzidos in vitro. Os oócitos, obtidos de ovários de vacas de abatedouro, passaram pelos procedimentos de produção de embriões in vitro, e no quinto dia do cultivo, foram alocados no sistema de transporte para compor os tratamentos: Tcontrole embriões controle mantidos na incubadora; T48 - embriões retirados do meio de cultivo no 5º dia e simulado o transporte por 48 horas; T24 - embriões retirados do meio de cultivo no 6º dia e simulado o transporte por 24 horas. Após os tratamentos, os embriões foram avaliados quanto à taxa de blastocistos no 7º dia e a taxa eclosão no 9º dia. O delineamento experimental foi inteiramente casualizado com três tratamentos e cinco repetições cada. Não foram observadas diferenças (P> 0,05) na taxa de blastocisto (31, 33 e 35%) e na taxa de eclosão (74, 78 e 80%), respectivamente para os tratamentos Tcontrole, T48 e T24. Concluiu-se que o sistema de cultivo durante o transporte, por até 48 horas, foi eficiente quanto à viabilidade embrionária inferindo que o ambiente de transporte simulou as condições de atmosfera e de temperatura do laboratório de forma satisfatória

Morphometric of blastomeres in Salmo salar.

For Salmo salar, there is a lack of information on the morphology of the first blastomeres formed during embryonic development and which could be used as a diagnostic tool for the first stages of development. The purpose of this investigation, therefore, was to characterize morphometrically the first blastomeres of S. salar. From a pool of eggs incubated at 7.5°C, 100 microphotographs of blastodiscs were extracted and analyzed at different incubation periods: 12, 14, 16, 20 or 24 h. Blastodiscs were characterized morphologically after 16, 20 or 24 h incubation, and classified into symmetric or asymmetric groups according to their morphology. The ratio of length (L) versus width (W) of each blastomere was determined, to establish its symmetry. In addition, 20 microphotographs of blastodiscs of normal appearance were analysed morphologically (control blastodisc: CB) for comparison (20 or 24 h). Results show that the first cleavage ends after 16 h of development. Seven categories were established during blastomere characterization: 47% normal (G1); 27% with dispersed margins (G2); 10% unequal (G3); 9% 'pie-shaped' (G4); 3% amorphous (G5); 2% three equal blastomeres and one different one (G6); and 2% with eccentric cleavage (G7). Although the incidence of abnormal cleavage in S. salar is uncertain, there is a potential for some asymmetries to be corrected during embryogenesis to generate viable individuals. More studies are necessary to correlate these abnormal cleavage patterns with indicators of quality in the later stages of embryogenesis in this species, to establish a quality assessment tool for gametes and/or embryos in salmonid species.

Oocyte genome cloning used in biparental bovine embryo reconstruction.

Oocyte genome cloning is a method by which haploid maternal embryos are obtained in such a way that parthenogenetic haploid blastomeres from these embryos can be considered as a clone of the original gamete. Our objective was to generate oocyte genome replicates and use them to reconstruct biparental embryos by fusion with haploid male hemizygotes. Furthermore, we generated biparental homogeneous transgene-expressing embryos using parthenogenetic haploid blastomeres that expressed a transgene (EGFP). In the first experiment, parthenogenetic haploid embryos were generated by incubation of oocytes in ionomycin and 6-dimethylaminopurine (DMAP) with a 3 h interval to permit their second polar body extrusion. The cleavage rate was 87.3%. To generate transgene-expressing blastomeres, activated oocytes were injected with pCX-EGFP-liposome complexes 3 h post ionomycin exposure, resulting in a cleavage rate of 84.4%. In the second experiment, haploid parthenogenetic blastomeres that were positive or negative for EGFP expression were used to reconstruct biparental embryos. Cleavage and blastocyst rates for the reconstructed embryos were 78.4% and 61.1% and 10.8% and 8.4%, using EGFP-positive or -negative blastomeres, respectively (P < 0.05). All of the reconstructed embryos showed EGFP expression, with 96.6% of them showing homogenic expression. Oct-4 expression in the reconstructed blastocysts displayed a similar pattern as IVF-blastocyst controls. In conclusion, our results proved that it is possible to use oocyte genome replicates to reconstruct biparental bovine embryos and that this technique is efficient to generate homogeneous transgene-expressing embryos.

Post-biopsy bovine embryo viability and whole genome amplification in preimplantation genetic diagnosis.

OBJECTIVE: To evaluate the effect of the biopsy of 8-cell to 16-cell bovine embryos on their subsequent development and the effect of whole genome amplification (WGA) on removed blastomeres. DESIGN: Randomized study. SETTING: Molecular genetics and animal reproduction laboratories. PATIENT(S): Cow ovaries obtained from slaughterhouses. INTERVENTION(S): The ovaries were punctured, and the oocytes were matured and fertilized in vitro. On the fourth day after fertilization, 8-cell to 16-cell bovine embryos were biopsied, one quarter of each embryo being removed. The blastomeres were submitted to WGA followed by polymerase chain reaction (PCR). The embryos were returned to culture for evaluation of their development. MAIN OUTCOME MEASURE(S): Subsequent rate of blastocyst development, embryo cell number, WGA efficiency, and sex determination. RESULT(S): A total of 92 embryos were submitted to biopsy. The blastocyst production was 53.3%, with 44.9% of hatching rate. These results were similar to those of the control group (66.0% and 42.6%) of 103 embryos. Overall, no impact was detected on embryo quality in blastocyst cell number between the two groups. Removed blastomeres were submitted to WGA, resulting in 98.2% of efficiency. However, only 59% of the samples were sexed by PCR. CONCLUSION(S): Biopsy of 8-cell to 16-cell bovine embryos did not affect their subsequent development. WGA was successful in removed blastomeres.

Interaction of the IP3-Ca2+ and MAPK signaling systems in the Xenopus blastomere: a possible frequency encoding mechanism for the control of the Xbra gene expression.

The intense periodic calcium activity experimentally observed in the Xenopus embryo at the Mid Blastula Transition stage is closely related to the competence of the embryonic cells of the marginal zone to respond to the posterior-mesodermal inducting signals from the Fibroblast Growth Factor (FGF). In this work we do a stability analysis and study numerically an extension of a mathematical model previously introduced by us [Diaz, J., Baier, G., Martinez-Mekler, G., Pastor, N., 2002. Interaction of the IP(3)-Ca(2+) and the FGF-MAPK signaling pathways in the Xenopus laevis embryo: a qualitative approach to the mesodermal induction problem. Biophys. Chem. 97, 55-72] for the interaction of the Inositol 1,4,5-triphosphate-Calcium (IP(3)-Ca(2+)) and the Mitogen-Activated Protein Kinase (MAPK) signaling pathways at the Mid Blastula Transition stage or stage 8 of development. This allows us to consider the effect of the oscillatory calcium dynamics on the FGF input signal carried by the MAP kinase (ERK) into the nucleus. We find that this interaction of the pathways induces a limit cycle behavior for ERK with frequency-encoding characteristics. We believe that this periodic increase of the ERK levels in the nucleus is related to the ability of the cell to express posteriorizing mesodermal features induced by the FGF signal at stage 8.

Fisiologia da Implantação do Blastocito / Physiology of Blastocyst Implantation

Apresenta-se uma revisão não exaustiva, abrangendo a morfologia e a fisiologia da implantação do blastocisto.

Blastomere development after embryo biopsy: a new model to predict embryo development and to select for transfer.

One of the most important and unsolved problems in in-vitro fertilization is to decide which embryos are more suitable to implant and therefore should be transferred. We analysed the in-vitro development of isolated biopsied blastomeres and compared it to the development of the original embryo, in order to find a relationship that could show the embryo's potential future development and so increase implantation rates. A total of 66 normally fertilized human embryos were biopsied at the 6- to 10-cell stages. At day 6, blastomeres were counted by nuclear labelling. A total of 33 embryos (50%) reached the blastocyst stage. Of the isolated blastomeres, 63% divided and 53% cavitated over 3 days in culture. Of the blastomeres taken from embryos that developed to the blastocyst stage, 88% divided, 79% cavitated, 76% divided and cavitated and 9% neither divided nor cavitated. In those from arrested embryos, 39% divided (P < 0.001), 21% cavitated (P < 0.001), 15% divided and cavitated (P < 0.001) and 55% neither divided nor cavitated (P < 0.001). Blastomeres biopsied from embryos that reached the blastocyst stage showed a significantly higher proportion of division and cavitation than those originated from arrested embryos. Culture of the isolated blastomeres can demonstrate those embryos more likely to develop to the blastocyst stage and that are probably more suitable to implant. Cryopreserving biopsed embryos and culturing blastomeres would increase implantation rates. Embryos can then be selected according to the blastomere development and thawed for transfer in a future cycle.

Influence of combined activation treatments on the success of bovine nuclear transfer using young or aged oocytes.

This study was determined if the combined activation of young or aged oocytes influence their development. The 16-cell stage in vitro maturation/fertilization embryos were exposed to 10 microL nocodazole for 18-20 h, blastomeres that divided within 3 h after the release from nocodazole were used as synchronized donor blastomeres. Metaphase II oocytes were enucleated at 20-22 h post onset of maturation. Enucleated oocytes were divided into 2 groups: oocytes activated at 24 h (young) and oocytes activated at 38 h (aged). In both groups (young and aged), one group of oocytes was activated in 7% ethanol alone for 5 min (alone) and the other group (combination) was activated in ethanol and subsequently incubated in 5 micrograms/ml cycloheximide in TCM199 for 6 h (combination). Electrofusion was carried out at 30 h (young) and 44 h (aged). The nuclear morphology of the blastomere-oocyte complexes at 1 h post-fusion and their development to the blastocyst stage after 6 days of culture in modified synthetic oviduct fluid were examined. Interphase and swollen nuclei were observed at 1 h post-fusion following nuclear transfer to the cytoplasm from young oocytes of combined activation and aged oocytes of combined and ethanol alone activation. When young oocytes were treated with the combined activation method, the reconstituted embryos had a significantly higher developmental rate to the blastocyst stage than the aged oocyte groups (P < 0.05). We conclude that the combined activation of young oocytes leads to a more efficient development of bovine nuclear transfer embryos.

Mola hidatiforme / Hydatiforme mole

Se estudian 39 casos de embarazo molar atendidos en el Servicio de Ginecologia del Hospital de Clìnicas Universitario de La Paz entre los años 1986-90. La frecuencia de la mola es alta en este hospital y existe un aumento progresivo. Se observò en cualquier edad comprendida entre los 15 a 44 años. En el 11,9 porciento ocurre en adolescentes. La quinta parte de los pacientes son nuligestas y casi la cuarta parte son nuliparas. Las pacientes acuden a la consulta por la hemorragia que en muchos casos es profusa, pudiendo constituirse en causa de muerte. No en todo los casos existe la desproporciòn uterina-retraso mestrual. El tratamiento de rutina es la evaluaciòn por raspado uterino precidido o no de inducciòn. El seguimiento y control de las pacientes es deficiente