Browsing by Subject "Oocyte"

Now showing 1 - 7 of 7
  • Thumbnail Image
    Publication
    Open Access
    Composition of marsupial zona pellucida: a molecular and phylogenetic approach
    (2017) Moros-Nicolás, C.; Chevret, P.; Izquierdo-Rico, M.J.; Holt, W.V.; Esteban-Dían, D.; López-Béjar, M.; Martínez-Nevado, E.; Nilsson, M.A.; Ballesta, J.; Avilés, M.; Biología Celular e Histología
    The zona pellucida (ZP) is an extracellular matrix that surrounds mammalian oocytes. In eutherians it is formed from three or four proteins (ZP1, ZP2, ZP3, ZP4). In the few marsupials that have been studied, however, only three of these have been characterised (ZP2, ZP3, ZP4). Nevertheless, the composition in marsupials may be more complex, since a duplication of the ZP3 gene was recently described in one species. The aim of this work was to elucidate the ZP composition in marsupials and relate it to the evolution of the ZP gene family. For that, an in silico and molecular analysis was undertaken, focusing on two South American species (gray short-tailed opossum and common opossum) and five Australian species (brushtail possum, koala, Bennett’s wallaby, Tammar wallaby and Tasmanian devil). This analysis identified the presence of ZP1 mRNA and mRNA from two or three paralogues of ZP3 in marsupials. Furthermore, evidence for ZP1 and ZP4 pseudogenes in the South American subfamily Didelphinae and for ZP3 pseudogenes in two marsupials is provided. In conclusion, two different composition models are proposed for marsupials: a model with four proteins (ZP1, ZP2 and ZP3 (two copies)) for the South American species and a model with six proteins (ZP1, ZP2, ZP3 (three copies) and ZP4) for the Australasian species
  • Thumbnail Image
    Publication
    Open Access
    Effect of cumulus cell removal and sperm pre‐incubation with progesterone on in vitro fertilization of equine gametes in the presence of oviductal fluid or cells
    (2019-05-30) Moros-Nicolás, C; Douet, C; Reigner, F; Goudet, G; Biología Celular e Histología
    In spite of many attempts to establish an in vitro fertilization (IVF) technique in the equine, no efficient conventional IVF technique is available. The presence of oviductal fluid or oviductal cells during IVF help to improve embryo production in vitro but is not sufficient to reach high fertilization rates. Thus, our aim was to perform equine IVF either after sperm preincubation with oviductal fluid or in the presence of oviductal cells, and to evaluate the effect of cumulus removal from the oocyte or sperm preincubation with progesterone. In experiment 1 and 2, IVF was performed in the presence of porcine oviduct epithelial cells. The removal of cumulus cells from equine oocytes after in vitro maturation tended to increase the percentage of fertilization when fresh sperm was used (1/33 vs 4/31, p > 0.05) but had no effect when frozen sperm was used (1/32 vs 1/32). Equine sperm preincubation with progesterone did not significantly influence the fertilization rate when fresh or frozen sperm was used (2/14 vs 2/18 for fresh, 1/29 vs 1/25 for frozen). In experiment 3 and 4, IVF was performed after preincubation of sperm with porcine oviductal fluid. The removal of cumulus cells tented to increase the percentage of fertilization when fresh sperm was used (1/24 vs 3/26, p>0.05). Sperm preincubation with progesterone did not significantly influence the fertilization rate when fresh or frozen sperm was used (2/39 vs 2/36 for fresh, 2/37 vs 1/46 for frozen), but two 3-4 cells stage zygotes were obtained with fresh sperm preincubated with progesterone. This is an encouraging result for the setting up of an efficient IVF procedure in equine.
  • Thumbnail Image
    Publication
    Open Access
    Effect of Superovulation Treatment on Oocyte's DNA Methylation
    (MDPI, 2022-12-18) S. Lopes, Jordana; Ivanova, Elena; Ruiz, Salvador; Andrews, Simon; Kelsey, Gavin; Coy, Pilar; Didáctica y Organización Escolar
    Controlled ovarian stimulation is a necessary step in some assisted reproductive procedures allowing a higher collection of female gametes. However, consequences of this stimulation for the gamete or the offspring have been shown in several mammals. Most studies used comparisons between oocytes from different donors, which may contribute to different responses. In this work, we use the bovine model in which each animal serves as its own control. DNA methylation profiles were obtained by single-cell whole-genome bisulfite sequencing of oocytes from pre-ovulatory unstimulated follicles compared to oocytes from stimulated follicles. Results show that the global percentage of methylation was similar between groups, but the percentage of methylation was lower for non-stimulated oocytes in the imprinted genes APEG3, MEG3, and MEG9 and higher in TSSC4 when compared to stimulated oocytes. Differences were also found in CGI of imprinted genes: higher methylation was found among non-stimulated oocytes in MEST (PEG1), IGF2R, GNAS (SCG6), KvDMR1 ICR UMD, and IGF2. In another region around IGF2, the methylation percentage was lower for non-stimulated oocytes when compared to stimulated oocytes. Data drawn from this study might help to understand the molecular reasons for the appearance of certain syndromes in assisted reproductive technologies-derived offspring.
  • Thumbnail Image
    Publication
    Open Access
    Effect of superovulation treatment on oocyte´s DNA methylation.
    (MDPI, 2022-12-18) Lopes, J.S.; Ivanova, E.; Ruiz, S.; Andrews, S.; Kelsey, G.; Coy, P.; Fisiología; Epigenetics Programme. Babraham Institute. Cambridge, U.K.; Bioinformatics Group. Babraham Institute. Cambridge, U.K.; Centre for Trophoblast Research. Cambridge University. U.K.
    Controlled ovarian stimulation is a necessary step in some assisted reproductive procedures allowing a higher collection of female gametes. However, consequences of this stimulation for the gamete or the offspring have been shown in several mammals. Most studies used comparisons between oocytes from different donors, which may contribute to different responses. In this work, we use the bovine model in which each animal serves as its own control. DNA methylation profiles were obtained by single-cell whole-genome bisulfite sequencing of oocytes from pre-ovulatory unstimulated follicles compared to oocytes from stimulated follicles. Results show that the global percentage of methylation was similar between groups, but the percentage of methylation was lower for non-stimulated oocytes in the imprinted genes APEG3, MEG3, and MEG9 and higher in TSSC4 when compared to stimulated oocytes. Differences were also found in CGI of imprinted genes: higher methylation was found among non-stimulated oocytes in MEST (PEG1), IGF2R, GNAS (SCG6), KvDMR1 ICR UMD, and IGF2. In another region around IGF2, the methylation percentage was lower for non-stimulated oocytes when compared to stimulated oocytes. Data drawn from this study might help to understand the molecular reasons for the appearance of certain syndromes in assisted reproductive technologies-derived offspring.
  • Thumbnail Image
    Publication
    Open Access
    Rabbit zona pellucida composition: A molecular, proteomic and phylogenetic approach
    (2012) Stetson, I.; Izquierdo-Rico, M.J.; Moros, C.; Chevret, P.; Lorenzo, P.L.; Ballesta, J.; Rebollar, P.G.; Gutiérrez-Gallego, R.; Avilés, M.; Biología Celular e Histología
    The zona pellucida (ZP) participates in sperm–egg interactions during the first steps of 22 fertilization. Recent studies have shown that the ZP matrix of oocytes in several species is 23 composed of four glycoproteins, designated as ZP1, ZP2, ZP3 and ZP4, rather than the three 24 described in mouse, pig and cow. In this study, investigations were carried out to unveil a Q425 fourth glycoprotein in the rabbit (Oryctolagus cuniculus) ZP. Using total RNA isolated from 26 rabbit ovaries, the complementary deoxyribonucleic acid (cDNA) encoding rabbit ZP1 was 27 amplified by reverse transcribed polymerase chain reaction (RT-PCR). The ZP1 cDNA 28 contains an open reading frame of 1825 nucleotides encoding a polypeptide of 608 amino 29 acid residues. The deduced amino acid sequence of rabbit ZP1 showed high identity with 30 other species: 70% identity with human and horse ZP1, and 67% identity with mouse and rat 31 ZP1. At the proteomic level, peptides corresponding to the four proteins were detected by 32 mass spectrometry. In addition, a molecular phylogenetic analysis of ZP1 showed that 33 pseudogenization of this gene has occurred at least four times during the evolution of 34 mammals. The data presented in this manuscript provide evidence, for the first time, that 35 the rabbit ZP is composed of four glycoproteins.
  • Thumbnail Image
    Publication
    Open Access
    Respuesta a la estimulación ovárica mediante FSH (folltropin®) y rendimiento de opu en vacas adultas obtenidas por diferentes técnicas de reproducción asistida
    (Universidad de Murcia. Servicio de publicaciones, 2022-11-15) Morera Jiménez, Alba; Velasco García, Elena; Romero Aguirregomezcorta, Jon; Ruiz López, Salvador; Anatomía y Anatomía Patológica Comparadas
    Los objetivos de este trabajo han sido realizar un seguimiento ecográfico de los ovarios bovinos para comprobar la respuesta folicular de vacas adultas nacidas por diferentes técnicas de reproducción asistida (TRA), tras aplicar un protocolo de estimulación ovárica con FSH (Folltropin®); y determinar la eficacia reproductiva de los animales estudiados, analizando la cantidad y calidad de los ovocitos obtenidos por aspiración folicular (Ovum Pick-Up, OPU) antes y después del protocolo de estimulación empleado. La experiencia se ha llevado a cabo en las instalaciones del santuario bovino de la Granja Docente Veterinaria de la Universidad de Murcia. Se han utilizado 4 hembras bovinas obtenidas por distintas TRA: inseminación artificial (IA), transferencia de embriones (TE) producidos por TRA con ovocitos cultivados in vitro en medios convencionales y por TE obtenidos por TRA con ovocitos cultivados con fluidos naturales (folicular y oviductal).Los animales fueron estimulados durante 5 semanas mediante un protocolo que consistía en la aplicación de GnRH y posteriormente, FSH (Folltropin®, 350 UI/animal) durante 3 días en dosis decrecientes. Una vez a la semana, al finalizar el protocolo de estimulación ovárica, se realizaba una ecografía de los ovarios y una aspiración folicular ecoguiada (OPU) para comprobar la respuesta al protocolo de estimulación y determinar el número de folículos y de ovocitos obtenidos tras la OPU y su calidad ovocitaria. Previamente al periodo de estimulación con FSH, las vacas fueron ecografiadas y sometidas a OPU 3 semanas sin estimulación ovárica como grupo control.A lo largo del trabajo realizado, se ha comprobado la respuesta al protocolo de estimulación ovárica ensa-yado, y se ha determinado la eficacia reproductiva de los animales, según el número de folículos aspirados y la cantidad y calidad de los ovocitos obtenidos por OPU en cada una de ellas.
  • Thumbnail Image
    Publication
    Open Access
    Transferencia nuclear de células somáticas interespecie en félidos salvajes: Una revisión sistemática y metaanálisis
    (Facultad de Veterinaria y el Servicio de Publicaciones de la Universidad de Murcia, 2023) Hernández Navas, Alicia; González Plaza, Alejandro; Cuello Medina, Cristina
    El objetivo de este trabajo fue realizar una revisión sistemática sobre la transferencia nuclear de células so-máticas de félidos salvajes utilizando ovocitos maduros de gato doméstico (Felis catus). Además, se realizaron dos metaanálisis con el programa Comprehensive Meta-Analysis V4 para evaluar el efecto de la transferencia nuclear de células somáticas interespecie (TNCSi) en la división embrionaria y formación de blastocisto en comparación con la técnica intraespecie con células somáticas y ovocitos de gato (TNCSg-g). El metaanálisis se realizó con un modelo aleatorio y el tamaño del efecto se determinó mediante el riesgo relativo (RR). En la revisión sistemática se seleccionaron 16 artículos científicos de un total de 248 y 3230 referencias inicia-les en PubMed y ScienceDirect, respectivamente. Los artículos publicaban tasas de división embrionaria del 27.5% al 96.7% y una tasa máxima de formación de blastocisto del 41.5%. Solo 2 de los 8 artículos obtuvieron descendencia viva, con una eficiencia del 1% aproximadamente sobre el total de embriones transferidos. El riesgo de sesgo de los 10 artículos seleccionados para el metaanálisis fue bajo. No se encontraron diferencias significativas (p>0.05) en la división embrionaria entre la TNCSi y la TNCSg-g. Sin embargo, se observó una menor (p=0.016; RR=0.4) probabilidad de formación de blastocistos en el grupo experimental de TNCSi en comparación con la TNCSg-g. En conclusión, la bibliografía sobre TNCSi en félidos salvajes es escasa y es-tudia especies muy distintas, lo que dificulta los metaanálisis. Aunque la división embrionaria hasta el estadio de 2-4 células es similar en la TNCSi y la TNCSg-g, la formación de blastocisto es menor cuando la célula somática es de una especie de félido distinta al gato