990 resultados para embryo sac
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The aim of the present study was to evaluate the effect of bovine somatotropin (bST; 500 mg) administration on lactating buffalo donors submitted to two different ovum pick-up (OPU) and in vitro embryo production schemes with a 7 or 14 d intersession OPU interval. A total of 16 lactating buffalo cows were randomly assigned into one of four experimental groups according to the bST treatment (bST or No-bST) and the OPU intersession interval (7 or 14 d) in a 2 x 2 factorial design (16 weeks of OPU sessions). The females submitted to OPU every 14d had a larger (P < 0.001) number of ovarian follicles suitable for puncture (15.6 +/- 0.7 vs. 12.8 +/- 0.4) and an increased (P = 0.004) number of cumulus-oocyte complexes (COCs) recovered (10.0 +/- 0.5 vs. 8.5 +/- 0.3) compared to the 7 d interval group. However, a 7 or 14 d interval between OPU sessions had no effect (P = 0.34) on the number of blastocysts produced per OPU (1.0 +/- 0.1 vs. 13 +/- 0.2, respectively). In addition, bST treatment increased (P < 0.001) the number of ovarian follicles suitable for puncture (15.3 +/- 0.5 vs. 12.1 +/- 0.4) but reduced the percentage (18.9% vs. 10.9%; P = 0.009) and the number (1.4 +/- 0.2 vs. 0.8 +/- 0.1; P = 0.003) of blastocysts produced per OPU session compared with the non-bST-treated buffaloes. In conclusion, the 14d interval between OPU sessions and bST treatment efficiently increased the number of ovarian follicles suitable for puncture. However, the OPU session interval had no effect on embryo production, and bST treatment reduced the in vitro blastocyst outcomes in lactating buffalo donors.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Different cell cycle synchronization methods were used to increase the mitotic index and accuracy of sex determination in murine and bovine embryos. For sexing purposes, colchicine treatment for 2, 4, 6 and 8 h and the FdU-thymidine-colchicine combination were tested in murine embryos. The best results were obtained with colchicine treatment for 8 h (96.88% accuracy) and with FdU-thymidine-colchicine (97.22% accuracy). Mitotic indexes differed significantly between the 2 treatments (21.71% for colchicine and 32.95% for FdU-thymidine-colchicine). For sex identification of murine and bovine demi-embryos, both treatments were demonstrated to be equally effective (nearly 90%). The mitotic index for the FdU-treated murine demi-embryos (19.04%) was higher than the one obtained for the 8-h colchicine treatment (15.62%).
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Pregnancy establishment, followed by birth of live offspring, is essential to all mammals. The biological processes leading up to pregnancy establishment, maintenance, and birth are complex and dependent on the coordinated timing of a series of events at the molecular, cellular, and physiological level. The ability to ovulate a competent oocyte, which is capable of undergoing fertilization, is only the initial step in achieving a successful pregnancy. Once fertilization has occurred and early embryonic development is initiated, early pregnancy detection is critical to provide proper prenatal care (humans) or appropriate management (domestic livestock). However, the simple presence of an embryo, early in gestation, does not guarantee the birth of a live offspring. Pregnancy loss (embryonic mortality, spontaneous abortions, etc.) has been well documented in all mammals, especially in humans and domestic livestock species, and is a major cause of reproductive loss. It has been estimated that only about 25-30 % of all fertilized oocytes in humans result in birth of a live offspring; however, identifying the embryos that will not survive to parturition has not been an easy task. Therefore, investigators have focused the identification of products in maternal circulation that permit the detection of an embryo and assessment of its well-being. This review will focus on the advances in predicting embryonic presence and viability, in vivo.
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In the early vertebrate embryo, cardiac progenitor/precursor cells (CPs) give rise to cardiac structures. Better understanding their biological character is critical to understand the heart development and to apply CPs for the clinical arena. However, our knowledge remains incomplete. With the use of single-cell expression profiling, we have now revealed rapid and dynamic changes in gene expression profiles of the embryonic CPs during the early phase after their segregation from the cardiac mesoderm. Progressively, the nascent mesodermal gene Mesp1 terminated, and Nkx2-5+/Tbx5+ population rapidly replaced the Tbx5low+ population as the expression of the cardiac genes Tbx5 and Nkx2-5 increased. At the Early Headfold stage, Tbx5-expressing CPs gradually showed a unique molecular signature with signs of cardiomyocyte differentiation. Lineage-tracing revealed a developmentally distinct characteristic of this population. They underwent progressive differentiation only towards the cardiomyocyte lineage corresponding to the first heart field rather than being maintained as a progenitor pool. More importantly, Tbx5 likely plays an important role in a transcriptional network to regulate the distinct character of the FHF via a positive feedback loop to activate the robust expression of Tbx5 in CPs. These data expands our knowledge on the behavior of CPs during the early phase of cardiac development, subsequently providing a platform for further study.
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O objetivo deste trabalho foi relatar o potencial da técnica de MALDI-MS para caracterizar espécies de lipídios presentes em um único embrião equino e estudar algumas estruturas lipídicas detectadas por dissociação induzida por colisão (CID). No espectro de modo íon positivo, pudemos observar espécies, principalmente, protonadas e sodiadas de esfingomielinas (SM), fosfatidileolinas (PC) e triacilgliceróis (TAG). No modo negativo, observamos fosfatidiletanolaminas (PE) e fosfatidilinositos (PI). Espectros de íons de lípidos com maior intensidade foram utilizados para demonstrar o potencial da informação estrutural por MALDI-MS/MS. O espectro no modo positivo de m/z (massa sobre carga) 760,6 (atribuída como PC34:1) apresentou características de fragmentos PC de m/z 184,1 (denominada cabeça polar de colina), além de perda neutral (NL) de m/z 183 (fosforilcolina). Para o íon de m/z 766,6 (atribuída como PE38:5), observou-se a NL de 140, característica do PE. Para o íon de m/z 808,7 (38,5 atribuído como PC), além do fragmento m/z 184,1 na NL de 183, foi possível observar a perda de trimetilamina (íon de m/z 749,6) e o ciclofosfano (íon de m/z 147,0). Finalmente, para o modo de íon negativo, foram isolados e fragmentados o íon de m/z 863,6 que foi atribuído como PI36:1, devido à presença de m/z 153 (fosfato de glicerol – H2O-H ), 223 (inositol fosfo - 2H2O-H) , 241 (fosfoinositol – H2O-H), 281 (ácido oleico) e 581,3 (lisofosfoinositol – H2O+H). Concluímos que a MALDI - MS permite a detecção de uma ampla gama de espécies de PC, SM, PE, PI e TAG lipídicas, bem como a caracterização rápida e confiante de estruturas lipídicas a partir de um único embrião equino.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The evolutionary history of Hystricognathi is associated with major transformations in their placental system. Data so far indicate that key characters are independent from size dimensions in medium to very large species. To better understand the situation in smaller species, we analyzed placental development in a spiny rat, Thrichomys laurentinus. Fourteen individuals ranging from early implantation to near term were investigated by histology, immunohistochemistry, proliferation activity and electron microscopy. Placentation in Thrichomys revealed major parallels to the guinea pig and other hystricognath rodents with respect to the early and invasive implantation, the process of trophoblast invasion, the internal organization of the labyrinth and the trophospongium as well as the establishment of the complete inverted yolk sac placenta. In contrast to systematically related small-sized species, the placental regionalization in Thrichomys was characterized by a remarkable lobulated structure and associated growing processes. Reverse to former perspectives, these conditions represented ancient character states of hystricognaths. The subplacenta was temporarily supplied by both the maternal and fetal blood systems, a rare condition among hystricognaths. The extraplacental trophoblast originating from the subplacenta was partly proliferative in mid gestation. In conclusion, the presented results indicated that only minor variations occurred in small-sized hystricognath species, independent of their systematic interrelationships. Previous views were supported that placentation in hystricognaths followed an extraordinary stable pattern, although the group had distinct habitats in South America and Africa that were separated 30-40 million years ago. J. Exp. Zool. (Mol. Dev. Evol.) 318:13-25, 2012. (C) 2011 Wiley Periodicals, Inc.
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The effect of melatonin during in vitro maturation (IVM) on DNA damage of cumulus cells (CCs) from bovine cumulus-oocyte complexes (COCs) and embryo development was evaluated. COCs from abattoir ovaries were cultured in maturation medium (MM) with 0.5 mu g/ml FSH and 5.0 mu g/ml LH (FSH-LH); 10(-9) M melatonin (MEL) or FSH-LH + MEL (FSH-LH-MEL). After 24 h of in vitro maturation, the CCs surrounding the oocyte were subjected to DNA analysis by Comet assay. After in vitro fertilization and in vitro embryo culture, the embryo development rates were evaluated on day 2 post insemination (cleavage) and days 7-8 (blastocyst). The percentage of CCs with no DNA damage was significantly superior in MEL group (37.6 +/- 2.4) than in FSH-LH-MEL (28.0 +/- 2.4) and FSH-LH (17.8 +/- 2.41) groups. Cleavage and blastocysts rates were similar among groups. Melatonin during IVM protects the CCs from DNA damage but this effect did not influence embryo development in vitro. (C) 2010 Elsevier Ltd. All rights reserved.
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Cytochemical localization of hydrogen peroxide-generating sites suggests NADPH (nicotinamide adenine dinucleotide 3-phosphate [ reduced form]) oxidase expression at the maternal-fetal interface. To explore this possibility, we have characterized the expression and activity of the NADPH oxidase complex in trophoblast cells during the postimplantation period. Implantation sites and ectoplacental cones (EPCs) from 7.5-gestational day embryos from CD1 mice were used as a source for expression analyses of NADPH oxidase catalytic and regulatory subunits. EPCs grown in primary culture were used to investigate the production of superoxide anion through dihydroxyethidium oxidation in confocal microscopy and immunohistochemical assays. NADPH subunits Cybb (gp91phox), Cyba (p22phox), Ncf4 (p40phox), Ncf1 (p47phox), Ncf2 (p67phox), and Rac1 were expressed by trophoblast cells. The fundamental subunits of membrane CYBB and cytosolic NCF2 were markedly upregulated after phorbol-12-myristate-13-acetate (PMA) treatment, as detected by quantitative real-time PCR, Western blotting, and immunohistochemistry. Fluorescence microscopy imaging showed colocalization of cytosolic and plasma membrane NADPH oxidase subunits mainly after PMA treatment, suggesting assembly of the complex after enzyme activation. Cultured EPCs produced superoxide in a NADPH-dependent manner, associating the NADPH oxidase-mediated superoxide production with postimplantation trophoblast physiology. NADPH-oxidase cDNA subunit sequencing showed a high degree of homology between the trophoblast and neutrophil isoforms of the oxidase, emphasizing a putative role for reactive oxygen species production in phagocytic activity and innate immune responses.
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Steindachneridion parahybae is a freshwater catfish endemic to the Paraiba do Sul River and is classified as an endangered Neotropical species. An increasing number of conservation biologists are incorporating morphological and physiological research data to help conservation managers in rescue these endangered species. This study investigated the embryonic and larval development of S. parahybae in captivity, with emphasis in major events during the ontogeny of S. parahybae. Broodstocks were artificially induced to reproduce, and the extrusion occurred 200-255 degree-hours after hormonal induction at 24 degrees C. Larval ontogeny was evaluated every 10 minutes under microscopic/stereomicroscopic using fresh eggs samples. The main embryogenic development stages were identified: zygote, cleavage, including the morula, blastula, gastrula phase, organogenesis, and hatching. The extruded oocytes showed an average diameter of 1.10 +/- 0.10 mm, and after fertilization and hydration of eggs, the average diameter of eggs increased to about 1.90 +/- 0.60 mm, characterized by a large perivitelline space that persisted up to embryo development, the double chorion, and the poles (animal and vegetative). Cell division started about 2 minutes after fertilization (AF), resulting in 2, 4, 8 (4 x 2 arrangement of cells), 16 (4 x 4), 32 (4 x 8) and 64 (2 x 4 x 8) cells. Furthermore, the blastula and gastrula stages followed after these cells divisions. The closed blastopore occurred at 11 h 20 min AF; following the development, the organogenetic stages were identified and subdivided respectively in: early segmentation phase and late segmentation phase. In the early segmentation phase, there was the establishment of the embryonic axis, and it was possible to distinguish between the cephalic and caudal regions; somites, and the optic vesicles developed about 20 h AF. Total hatching occurred at 54 h AF, and the larvae average length was 4.30 +/- 0.70 mm. Gradual yolk sac reduction was observed during the first two days of larval development. The first feeding occurred at the end of the second day. During the larval phase, cannibalism, heterogeneous larval growth and photophobia were also observed. This information will be important in improving the artificial reproduction protocols of S. parahybae in controlled breeding programs.
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Caviomorph development includes an inverted yolk sac. Since principle processes are not understood, we investigated its differentiation in Galen and re-examined material from the guinea pig. Galea showed the typical caviomorph conditions in blastocyst development and the nature of the definitive yolk sac, formed of the visceral layer that became villous, proliferative, vascularized and attached to the uterus and placenta. In contrast to what was known before, in both species parts of the parietal yolk sac and a yolk sac cavity were temporarily present. Data suggest that early yolk sac development in caviomorphs is more complex than thought before. (C) 2012 Elsevier Ltd. All rights reserved.
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We studied the development of the inverted yolk sac in a New World rodent, Necromys lasiurus during early placentation. Ten implantation sites were investigated by means of histology, immunohistochemistry and electron microscopy. The yolk sac was villous near its attachment to the placenta. Elsewhere it was non-villous and closely attached to the uterus. The uterine glands were shallow and wide mouthed. They were associated with vessels and filled with secretion, suggesting the release of histotroph. This feature was absent at later stages. The intimate association of the yolk sac with specialized glandular regions of the uterus may represent a derived character condition of Necromys and/or sigmodont rodents. (C) 2012 Elsevier Ltd. All rights reserved.