Search results for "chromosomes"
showing 10 items of 509 documents
Type of chromosome abnormality affects embryo morphology dynamics.
2016
Objective To study the differences in the cleavage time between types of embryo chromosomal abnormalities and elaborate algorithm to exclude aneuploid embryos according to the likelihood to be euploid. Design Retrospective cohort study. Setting University affiliated private center. Patient(s) Preimplantational genetic screening patients (n = 112) including cases of advanced maternal age, repeated implantation failure, and recurrent miscarriage. A total of 485 embryos were analyzed. Intervention(s) None. Main Outcome Measure(s) All biopsied embryos were cultured in an incubator with time-lapse technology, cleavage timing from insemination to day 3 and all kinetic parameters that have been de…
Transcriptomic behavior of genes associated with chromosome 21 aneuploidies in early embryo development.
2019
To analyze how chromosome 21 (HSA21) ploidy affects global gene expression of early human blastocysts.Prospective study.University-affiliated in vitro fertilization clinic.A total of 26 high-quality donated embryos from in vitro fertilization (IVF) patients: trisomy 21 (n = 8), monosomy 21 (n = 10), and euploid (n = 8) blastocysts.None.Blastocyst transcriptome changes and its associated functions.Trisomy 21, monosomy 21, and euploid blastocysts were classified by comparative genomic hybridization. The global transcriptome of whole blastocysts was analyzed with small cell number RNA sequencing, and they were compared to understand the gene expression behavior at early development and its imp…
What the human sperm methylome tells us.
2017
Aim: To characterize the sperm methylome in semen samples from 19 donors with proven fertility. Materials & methods: Bisulfite-converted sperm DNA was hybridized on the HumanMethylation450 Infinium BeadChip platform. CpG fluorescence intensities were extracted and converted to β-values. Results: The sperm methylome is highly homogeneous and hypomethylated. Genes with hypomethylated promoters are ontologically associated to biological functions related to spermatogenesis and embryogenesis. Sex chromosomes are the most hypomethylated chromosomes, supporting data that indicated their essential role in spermatogenesis. A total of 94 genes are resistant to demethylation, being strong candid…
Impact of somatic mutations in myelodysplastic patients with isolated partial or total loss of chromosome 7
2020
Monosomy 7 [-7] and/or partial loss of chromosome 7 [del(7q)] are associated with poor and intermediate prognosis, respectively, in myelodysplastic syndromes (MDS), but somatic mutations may also play a key complementary role. We analyzed the impact on the outcomes of deep targeted mutational screening in 280 MDS patients with -7/del(7q) as isolated cytogenetic abnormality (86 with del(7q) and 194 with -7). Patients with del(7q) or -7 had similar demographic and disease-related characteristics. Somatic mutations were detected in 79% (93/117) of patients (82% in -7 and 73% in del(7q) group). Median number of mutations per patient was 2 (range 0-8). There was no difference in mutation frequen…
Preimplantation genetic testing for aneuploidy in patients with partial X monosomy using their own oocytes: is this a suitable indication?
2019
Objective To describe the outcome of preimplantation genetic testing (PGT-A) using their own oocytes in patients with mosaic Turner Syndrome (MTS). The impact of the assisted reproduction technique (ART) performed (PGT-A or oocyte donation) and the type of absence of the X chromosome (total or partial) were considered. Design Retrospective observational multicenter study. Setting University-affiliated private in vitro fertilization center. Patient(s) Fifty-six patients with MTS with whom 65 ovarian stimulation cycles for PGT-A (fluorescence in situ hybridization/arrays-next generation sequencing) were performed. The study included 90 women with MTS and 20 women with pure Turner Syndrome (PT…
Genome-wide scan for runs of homozygosity identifies potential candidate genes associated with local adaptation in Valle del Belice sheep
2017
Background Because very large numbers of single nucleotide polymorphisms (SNPs) are now available throughout the genome, they are particularly suitable for the detection of genomic regions where a reduction in heterozygosity has occurred and they offer new opportunities to improve the accuracy of inbreeding (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$F$$\end{document}F) estimates. Runs of homozygosity (ROH) are contiguous lengths of homozygous segments of the genome where the two haplotypes inherited from t…
Genome-wide association mapping for milk fat composition and fine mapping of a QTL for de novo synthesis of milk fatty acids on bovine chromosome 13
2017
Background Bovine milk is widely regarded as a nutritious food source for humans, although the effects of individual fatty acids on human health is a subject of debate. Based on the assumption that genomic selection offers potential to improve milk fat composition, there is strong interest to understand more about the genetic factors that influence the biosynthesis of bovine milk and the molecular mechanisms that regulate milk fat synthesis and secretion. For this reason, the work reported here aimed at identifying genetic variants that affect milk fatty acid composition in Norwegian Red cattle. Milk fatty acid composition was predicted from the nation-wide recording scheme using Fourier tr…
Computational Prediction of Position Effects of Apparently Balanced Human Chromosomal Rearrangements.
2017
Interpretation of variants of uncertain significance, especially chromosomal rearrangements in non-coding regions of the human genome, remains one of the biggest challenges in modern molecular diagnosis. To improve our understanding and interpretation of such variants, we used high-resolution three-dimensional chromosomal structural data and transcriptional regulatory information to predict position effects and their association with pathogenic phenotypes in 17 subjects with apparently balanced chromosomal abnormalities. We found that the rearrangements predict disruption of long-range chromatin interactions between several enhancers and genes whose annotated clinical features are strongly …
Establishing gene models from the Pinus pinaster genome using gene capture and BAC sequencing
2016
Background In the era of DNA throughput sequencing, assembling and understanding gymnosperm mega-genomes remains a challenge. Although drafts of three conifer genomes have recently been published, this number is too low to understand the full complexity of conifer genomes. Using techniques focused on specific genes, gene models can be established that can aid in the assembly of gene-rich regions, and this information can be used to compare genomes and understand functional evolution. Results In this study, gene capture technology combined with BAC isolation and sequencing was used as an experimental approach to establish de novo gene structures without a reference genome. Probes were design…
Rescuing monopronucleated-derived human blastocysts: a model to study chromosomal topography and fingerprinting.
2021
Objective To quantify the percentage of monopronuclear-derived blastocysts (MNBs) that are potentially useful for reproductive purposes using classic and state-of-the-art chromosome analysis approaches, and to study chromosomal distribution in the inner cell mass (ICM) and trophectoderm (TE) for intertissue/intratissue concordance comparison. Design Prospective experimental study. Setting Single-center in vitro fertilization clinic and reproductive genetics laboratory. Patient(s) A total of 1,128 monopronuclear zygotes were obtained between June 2016 and December 2018. Intervention(s) MNBs were whole-fixed or biopsied to obtain a portion of ICM and 2 TE portions (TE1 and TE2) and were subse…