11 research outputs found
Meiotic abnormalities in in vitro-matured marmoset monkey (Callithrix jacchus) oocytes: development of a non-human primate model to investigate causal factors
No full textVariations of chromatin, tubulin and actin structures in primate oocytes arrested during in vitro maturation and fertilization—what is this telling us about the relationships between cytoskeletal and chromatin meiotic defects?
No full textCritical estradiol dose optimization for oocyte in vitro maturation in the common marmoset
No full texthttps://doi.org/10.13039/501100001655 DAADhttps://doi.org/10.13039/501100004938 German Primate CenterBulgarian Ministry in Education and Scienc
Numerical chromosome disorders in the common marmoset ( Callithrix jacchus ) - comparison between two captive colonies
No full textA retrospective analysis of adverse effects of an in vivo fluoroquinolone antibiotic enrofloxacin treatment on oocyte quality in the common marmoset
No full textEpidermal growth factor effects on marmoset monkey (Callithrix jacchus) oocyte in vitro maturation, IVF and embryo development are altered by gonadotrophin concentration during oocyte maturation
No full textThis is the first study of the effect of epidermal growth factor (EGF) on marmoset monkey oocytes matured in vitro. We have evaluated the effects of 10 ng/ml EGF in combination with 1 or 10 IU/ml of gonadotrophins (FSH/hCG 1:1 ratio) during in vitro maturation (IVM) of marmoset oocytes. Immature cumulus-oocyte complexes (COCs) were retrieved from ovarian antral follicles of unprimed monkeys. COCs from six animals (n= 268) used in this study were randomly distributed among four experimental groups: (A) 1 FSH +1 hCG; (B) 10 FSH +10 hCG; (C) 1 FSH +1 hCG + EGF; and (D) 10 FSH +10 hCG + EGF (where 1 and 10 are concentrations, IU/ml). After IVM, oocytes were fertilized in vitro and embryos were allowed to progress up to 87-88 h. the highest rate of total and radial cumulus expansion was observed in Group A, with the lowest in Group B (P < 0.05). Neither maturation nor fertilization rate were affected by gonadotrophin concentration or presence of EGF. Addition of EGF increased degeneration and decreased first cleavage rate, which was significantly lower in Group C than Group A (P < 0.005). Interestingly, in the EGF groups some embryos cleaved faster than without EGF. The effects of EGF are highly dependent on concentration of gonadotrophins present in IVM medium. EGF has a negative effect on oocytes in the presence of low gonadotrophins, but contrastingly partially protects oocytes from the negative effects of high gonadotrophins. We propose that these observed negative effects of EGF may suggest use of an inappropriate dose of growth factor
Chromatin Quality as a Crucial Factor for the Success of Fluorescent in Situ Hybridization Analyses of Unfertilized Oocytes, Polar Bodies and Arrested Zygotes
No full textChromatin Quality as a Crucial Factor for the Success of Fluorescent in Situ Hybridization Analyses of Unfertilized Oocytes, Polar Bodies and Arrested Zygotes
No full textChromatin Quality as a Crucial Factor for the Success of Fluorescent in Situ Hybridization Analyses of Unfertilized Oocytes, Polar Bodies and Arrested ZygotesMaterial that is supernumerary or unsuitable for in vitro fertilization (IVF) procedures is used for basic and for IVF-related research. Despite the disadvantages of such cells, they have contributed much to our understanding of the mechanisms and prevalence of different abnormalities.Fifty-four human unfertilized oocytes, 34 arrested bipronuclear zygotes and 15 polar bodies were fixed for analysis on the third day after in vitro insemination and were subjected to fluorescent in situ hybridization (FISH) with probes for chromosomes 18, 21, X and Y (centromere for 18, X, Y and locus-specific for 21). The aim of the study was the comparison of FISH efficiency in differently condensed chromatin.The success of FISH analysis was over 60% of analyzed cells and it was dependent on the chromatin changes (condensation and/or fragmentation) during the culture period before cell fixation. Chromatin ageing was the crucial factor for the reduced success of FISH in both oocyte chromosomes (60.0%) and pronuclei (61.76%). The chromatin of second polar bodies (PBII), and premature chromosome condensation (PCC) of the sperm chromatin in oocytes was more suitable for FISH analysis (FISH success 75.0% in PBII and 64.29% in PCC) with both centromere and locus-specific probes.These results revealed the significance of early signs of in vitro cell ageing for the success of FISH analysis and for the interpretation of results in case of analysis of unfertilized human ova, polar bodies and arrested zygotes.</jats:p
Telomere lengths in human oocytes, cleavage stage embryos and blastocysts
No full textTelomeres are repeated sequences that protect the ends of chromosomes and harbour DNA-repair proteins. Telomeres shorten during each cell division in the absence of telomerase. When telomere length becomes critically short, cell senescence occurs. Telomere length therefore reflects both cellular ageing and capacity for division. We have measured telomere length in human germinal vesicle (GV) oocytes and pre-implantation embryos, by quantitative fluorescence in-situ hybridisation (Q-FISH), providing baseline data towards our hypothesis that telomere length is a marker of embryo quality. The numbers of fluorescent foci suggest that extensive clustering of telomeres occurs in mature GV stage oocytes, and in pre-implantation embryos. When calculating average telomere length by assuming that each signal presents one telomere, the calculated telomere length decreased from the oocyte to the cleavage stages, and increased between the cleavage stages and the blastocyst (11.12 vs 8.43 vs 12.22kb respectively, p<0.001). Other methods of calculation, based upon expected maximum and minimum numbers of telomeres, confirm that telomere length in blastocysts is significantly longer than cleavage stages. Individual blastomeres within an embryo showed substantial variation in calculated average telomere length. This study implies that telomere length changes according to the stage of pre-implantation embryo development
CHROMATIN QUALITY AS A CRUCIAL FACTOR FOR THE SUCCESS OF FLUORESCENT IN SITU HYBRIDIZATION ANALYSES OF UNFERTILIZED OOCYTES, POLAR BODIES AND ARRESTED ZYGOTES
No full textABSTRACT Material that is supernumerary or unsuitable for in vitro fertilization (IVF) procedures is used for basic and for IVF-related research. Despite the disadvantages of such cells, they have contributed much to our understanding of the mechanisms and prevalence of different abnormalities. Fifty-four human unfertilized oocytes, 34 arrested bipronuclear zygotes and 15 polar bodies were fixed for analysis on the third day after in vitro insemination and were subjected to fluorescent in situ hybridization (FISH) with probes for chromosomes 18, 21, X and Y (centromere for 18, X, Y and locus-specific for 21). The aim of the study was the comparison of FISH efficiency in differently condensed chromatin. The success of FISH analysis was over 60% of analyzed cells and it was dependent on the chromatin changes (condensation and/or fragmentation) during the culture period before cell fixation. Chromatin ageing was the crucial factor for the reduced success of FISH in both oocyte chromosomes (60.0%) and pronuclei (61.76%). The chromatin of second polar bodies (PBII), and premature chromosome condensation (PCC) of the sperm chromatin in oocytes was more suitable for FISH analysis (FISH success 75.0% in PBII and 64.29% in PCC) with both centromere and locus-specific probes. These results revealed the significance of early signs of in vitro cell ageing for the success of FISH analysis and for the interpretation of results in case of analysis of unfertilized human ova, polar bodies and arrested zygotes
