Human cleavage stage embryos are chromosomally unstable
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE11663 | GEO | 2009/04/26
SECONDARY ACCESSION(S): PRJNA106175
REPOSITORIES: GEO
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Project description:Methylation profiles of chr12-16 were generated by meDIP and array hybridisation in 3 cases with maternal uniparental disomy of chromosome 15, and three cases of paternal uniparental disomy of chromosome 15. Comparison of these profiles reveals differentially methylated (imprinted) regions on chromosome 15.
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Project description:Ten volunteers underwent 13 research IVM cycles. Immature oocytes were retrieved after mild ovarian stimulation with gonadotropins but no hCG ovulation trigger, in vitro matured and fertilized using ICSI. Oocyte maturation rate in vitro was 47% (94/199), the mean fertilization rate was 71% (67/94) and 37% (25/67) of mature oocytes developed into a morphologically good quality embryo on day 3 after ICSI, after which the blastomeres were analysed by single-cell aCGH. Sixty-seven of the 111 blastomeres analysed showed at least one chromosomal abnormality. Two out of seventeen embryos had only normal cells while one embryo carried a meiotic abnormality, 11 were mosaic and three were chaotic. Although the number of embryos tested as well as the data available in the literature are too small to allow any statistical analysis, these data are comparable to the few data available on the total chromosome complement of day 3 ICSI embryos. This would indicate that other mechanisms than chromosomal abnormalities explain the low efficiency and high miscarriage rate in IVM cycles.
2014-11-12 | GSE56799 | GEO
Project description:The establishment of body axes and specification of early embryonic cells depend on maternally supplied transcripts and/or proteins, several of which are localized at specific regions of fertilized eggs and early embryos. The ascidian is known to exhibit a mosaic mode of development, and this mode is largely dependent on localized maternal factors. Using blastomere isolation, microarray and whole-mount in situ hybridization, the present study of Ciona intestinalis demonstrates that maternal transcripts of a total of 17 genes are localized at the posterior-most region of fertilized eggs and early embryos. Ten of them are newly identified in the present study, while the remaining seven genes have already been characterized in the previous studies. In addition, maternal transcripts of two genes, in addition to 14 genes encoded by the mitochondrial genome, showed a mitochondria-like distribution. Despite the present comprehensive approach, we could not identify maternal transcripts that are clearly localized to the animal-pole side, the vegetal-pole side, the anterior-side or other specific regions of the early embryo. Therefore, we concluded that the posterior-most localization and mitochondria-like distribution appear to be major specialized patterns of maternal transcripts in the early Ciona embryos. Four kinds of sample. Two series comparison (A4.1+a4.2+b4.2 blastomeres vs B4.1 blastomeres and Animal blastomeres vs Vegetal blastomeres) were examined including dye swap analyses.
2010-06-19 | E-GEOD-15637 | biostudies-arrayexpress
Project description:In multicellular organisms, heterogametes of oocytes and sperms are fertilized and resulting zygotes give rise to new individuals. The ability of zygotes that produce a fully formed individual from single cell when placed in a supportive environment is defined as totipotency. Given that totipotent cells are the source of all multicellular organisms, better understanding of totipotency has a profound effect on not only biology but also our society. However, the exact distribution of totipotent cells in mammals remains elusive, although zygotes and single blastomeres at 2-cell stage embryos has been thought to be only mouse cells to be totipotent. We now show that a single blastomere isolated from 2- and 4-cell stage embryos gives rise to a fertile adult individual when it placed in a uterus, although isolation of blastomeres at these stage results in the disturbance of transcriptome in single blastomere derived embryos. Single blastomeres from 8-cell and morula stage embryos that were separately cultured in vitro exhibited severe defects in the formation of epiblast and primitive endoderm in the inner cell mass and the development to blastocysts, respectively. Our results thus indicate that totipotency of mouse zygotes extends to single blastomeres of 4-cell stage embryos.
2021-05-27 | GSE163427 | GEO
Project description:Methylation profiles of chr12-16 were generated by meDIP and array hybridisation in 3 cases with maternal uniparental disomy of chromosome 15, and three cases of paternal uniparental disomy of chromosome 15. Comparison of these profiles reveals differentially methylated (imprinted) regions on chromosome 15. Methylated DNA was enriched by immunoprecipitation using antibodies against 5-methylcytosine. meDIP and input DNA was labeled with cy5 and cy3 respectively and hybridized to Nimblegen arrays comprising 2.1 million 50-85mers covering human chromosomes 12-16 at a mean density of ~1 probe per 100bp. Resulting log2 fluorescence ratios correspond to methylation levels. Six samples were analyzed, with technical replicates for each DNA.
2010-06-12 | E-GEOD-22188 | biostudies-arrayexpress
Project description:In this study, we extend array CGH technology by making the accurate detection of chromosomal imbalances possible from a single fibroblast and blastomere following Phi29 DNA polymerase amplification. Firstly, array CGH experiments were performed on four different fibroblast cell lines, derived from patients affected by, respectively, trisomy 13, 18, 21, and monosomy X. For each cell line, three single cells were amplified. Following DNA amplification, all cells showed the expected DNA yields (n=12; 1.87 µg plus:minus 0.39). Sex-mismatch array CGH experiments were conducted on amplified DNA samples obtained from each cell. Sex chromosome ploidy levels, as well as all expected autosomal abnormalities were clearly identified. Secondly, we applied single-cell aneuploidy screening for the detection of chromosomal imbalances in preimplantation embryos. DNA from blastomeres from three 7-8 cell-stage embryos was amplified by ï¦29 DNA polymerase. Following DNA amplification, all cells yielded the expected amount of DNA (n=16; 2.45 µg plus:minus 0.41). Chromosomal aneuploidies were accurately detected using a simple and rapid array CGH protocol.
2010-07-01 | E-GEOD-3642 | biostudies-arrayexpress
Project description:Aneuploidy has been well documented in blastocyst embryos, but prior studies have been limited in scale and/or lack mechanistic data. We previously reported preclinical validation of microarray 24-chromosome preimplantation genetic screening (PGS) in a 24-hour protocol. The method diagnoses chromosome copy number, structural chromosome aberrations, parental source of aneuploidy, and distinguishes certain meiotic from mitotic errors. In this study our objective was to examine aneuploidy in human blastocysts and determine correspondence of karyotypes between trophectoderm (TE) and inner cell mass (ICM). We disaggregated 51 blastocysts from seventeen couples into ICM and one or two TE fractions. The average maternal age was 31. Next, we ran 24-chromosome microarray molecular karyotyping on all of the samples, and then performed a retrospective analysis of the data. The average per-chromosome confidence was 99.95%. Approximately 80% of blastocysts were euploid. The majority of aneuploid embryos were simple aneuploid, i.e., one or two whole-chromosome imbalances. Structural chromosome aberrations, which are common in cleavage stage embryos, occurred in only three blastocysts (5.8%). All TE biopsies derived from the same embryos were concordant. Forty-nine of fifty-one (96.1%) inner cell mass (ICM) samples were concordant with TE biopsies derived from the same embryos. Discordance between TE and ICM occurred only in the two embryos with structural chromosome aberration. We conclude that trophectoderm karyotype is an excellent predictor of inner cell mass karyotype. Discordance between TE and ICM occurred only in embryos with structural chromosome aberrations. We thawed all fractions at 22°C, and then added Arcturus PicoPure Lysis Buffer (Molecular Devices, Sunnyvale, CA) to each of the biopsies. The tubes were incubated at 56°C for one hour, and then heat inactivated at 95°C for 10 minutes. DNA from the lysed biospsies was amplified using a commercial kit (GE Healthcare, Waukesha, WI) for multiple displacement amplification (MDA). MDA reactions were incubated at 30°C for 2.5 hours and then heat-inactivated at 65°C for five minutes. The amplified samples were genotyped using Illumina (San Diego, CA, USA) Infinium II genotyping microarrays (CytoSNP-12 chips) using a modified 24-hour protocol, as described previously*. Previously, we developed a genotyping microarray molecular karyotyping technology that uses parental genetic data to increase accuracy and determine mechanism and source of aneuploidy*. The algorithm uses parental genotypes and the observed distribution of unprocessed single cell microarray channel intensities to diagnose whole-chromosome imbalances and structural chromosome aberrations*. Because parental genotypes are available, the algorithm readily identifies parental source of whole-chromosome imbalances and structural chromosome aberrations. Additionally, the algorithm uses parental information, high confidence disomic single cell measurements on children, and recombination probabilities (genome.ucsc.edu) to determine the phase of the parental chromosomes. The phased data is then used to determine whether certain trisomies and uniparental disomies were mitotic or meiotic in origin*. *Johnson DS, Gemelos G, Baner J, Ryan A, Cinnioglu C, Banjevic M, Ross R, Alper M, Barrett B, Frederick J, Potter D, Behr B, Rabinowitz M. (2010). Preclinical validation of a microarray method for full molecular karyotyping of blastomeres in a 24-hour protocol. Human Reproduction January 24 [Epub ahead of print].
2010-09-28 | E-GEOD-22864 | biostudies-arrayexpress
Project description:Chromosomal instability (CIN) is a hallmark of tumor cells caused by changes in the dynamics and control of microtubules that compromise the mitotic spindle. Thus, CIN cells may respond differently than diploid cells to treatments that target mitotic spindle regulation. Here, we test this idea by inhibiting a subset of kinesin motor proteins involved in mitotic spindle control. KIF18A is required for proliferation of CIN cells derived from triple negative breast cancer or colorectal cancer tumors but is not required in near-diploid cells. Following KIF18A inhibition, CIN tumor cells exhibit mitotic delays, multipolar spindles, and increased cell death. Sensitivity to KIF18A knockdown is strongly correlated with centrosome fragmentation, which requires dynamic microtubules but does not depend on bipolar spindle formation or mitotic arrest. Our results indicate the altered spindle microtubule dynamics characteristic of CIN tumor cells can be exploited to reduce the proliferative capacity of CIN cells.
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Project description:Preimplantation genetic diagnosis (PGD) of aneuploidy by fluorescence in situ hybridisation (FISH) has not delivered the expected clinical benefit. Many previous re-analysis studies of embryos deemed aneuploid by FISH on day 3 have found a high degree of chromosomal normalcy at the blastocyst stage. While most have interpreted this as “self correction,” there remains a lack of evidence for such a phenomenon. A more comprehensive technique for 24 chromosome aneuploidy screening was utilised here to re-evaluate blastocysts previously diagnosed as abnormal by FISH and investigate possible self correction mechanisms, including extrusion or duplication of aneuploid chromosomes resulting in uniparental isodisomy (UPID), and preferential segregation of aneuploidy to the trophectoderm (TE). Embryos that developed to a morphologically normal blastocyst after an aneuploidy diagnosis by cleavage stage FISH were biopsed into 4 sections, 3 TE and 1 inner cell mass (ICM), and randomised for evaluation by single nucleotide polymorphism (SNP) microarray based 24 chromosome aneuploidy screening (MA-PGD). Fifty-eight percent of blastocysts were euploid for all 24 chromosomes despite an aneuploid FISH result on day 3. Only 18% were consistent with the original FISH diagnosis, while the remaining 24% identified abnormalities that were different from the original FISH diagnosis. Abnormalities did not preferentially segregate to the TE and aneuploid chromosome extrusion or duplication resulting in UPID did not occur. Cleavage stage FISH is poorly predictive of aneuploidy in an embryo that develops into a morphologically normal blastocyst. Clinicians should consider re-evaluating embryos diagnosed as aneuploid by FISH that form morphologically normal blastocysts using a validated comprehensive 24 chromosome aneuploidy screening method.
2010-05-19 | GSE18932 | GEO
Project description:The study of genomic imprinting in mammals started with analysis of parthenogenetic embryos. At the phenotypic level, embryos with two maternal genomes and no paternal genome proceed through early development unimpaired, and only begin to fail after implantation. The most recognizable early defect is reduced or non-existent trophoblast, the tissue that gives rise to the placenta. We applied the procedure for establishing Trophoblast Stem cells (TS cells) developed in the Rossant lab to parthenogenetic embryos, and were successful in making four different TS cell lines, three from MI oocyte derived blastocysts and one from MII derived blastocysts. Initial molecular characterization, including microarray analysis, indicates that these cells are indistinguishable from fertilized TS cells, with the single exception of null expression of the paternally expressed gene Snrpn. The only significant difference between parthenogenetic and fertilized TS cells was the frequency with which they could be derived. In our hands, fertilized blastocyst outgrowths produced TS cells at robust rates (10-12 colonies per blastocyst), while parthenogenetic blastocyst outgrowths produced only 4 colonies in 50 outgrowths, 100 times less frequently than fertilized embryos. This led us to hypothesize that those few TS cells that arose in parthenogenetic outgrowths were probably a result of very low frequency stochastic variation in the imprint status of a gene or genes required for either establishment or maintenance of stem cells, or both. The corollary to this hypothesis posits that the early failure of parthenogenetic embryos, and in particular parthenogenetic trophoblast, is a function of impaired stem cell function. This raises the intriguing possibility that microarray comparisons of parthenogenetic, fertilized and androgenetic blastocysts may reveal the identities of genes important for stem cell biology. To this end, my colleague Keith Latham, at the Fels Institute, Temple University, Philadelphia, made amplified cDNAs from pools of ten each of androgenetic, gynogenetic, or fertilized blastocysts. Three separate pools for each type of embryo were prepared for microarray analysis. The embryos were all produced by nuclear transfers between zygotes, a difficult technique that is Keith's special expertise. He used the Brady/Iscove protocol to generate quantitative 3' end biased cDNAs. We would like to compare the transcriptomes of these embryos using the MOE430 2.0 arrays. We expect that important insights into the biology of uniparental embryos in general, and stem cells in particular may be revealed. Keywords: other
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