Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
1.
Nature ; 583(7815): 259-264, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32494014

RESUMO

Meiosis, although essential for reproduction, is also variable and error-prone: rates of chromosome crossover vary among gametes, between the sexes, and among humans of the same sex, and chromosome missegregation leads to abnormal chromosome numbers (aneuploidy)1-8. To study diverse meiotic outcomes and how they covary across chromosomes, gametes and humans, we developed Sperm-seq, a way of simultaneously analysing the genomes of thousands of individual sperm. Here we analyse the genomes of 31,228 human gametes from 20 sperm donors, identifying 813,122 crossovers and 787 aneuploid chromosomes. Sperm donors had aneuploidy rates ranging from 0.01 to 0.05 aneuploidies per gamete; crossovers partially protected chromosomes from nondisjunction at the meiosis I cell division. Some chromosomes and donors underwent more-frequent nondisjunction during meiosis I, and others showed more meiosis II segregation failures. Sperm genomes also manifested many genomic anomalies that could not be explained by simple nondisjunction. Diverse recombination phenotypes-from crossover rates to crossover location and separation, a measure of crossover interference-covaried strongly across individuals and cells. Our results can be incorporated with earlier observations into a unified model in which a core mechanism, the variable physical compaction of meiotic chromosomes, generates interindividual and cell-to-cell variation in diverse meiotic phenotypes.


Assuntos
Genoma Humano/genética , Meiose/genética , Espermatozoides/citologia , Espermatozoides/metabolismo , Adolescente , Adulto , Alelos , Aneuploidia , Troca Genética/genética , Haplótipos/genética , Humanos , Masculino , Não Disjunção Genética , Análise de Célula Única , Doadores de Tecidos , Adulto Jovem
2.
J Assist Reprod Genet ; 38(11): 2975-2983, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34417660

RESUMO

PURPOSE: This pilot study sought to (1) validate the use of a novel technology for single-sperm-cell genome sequencing (Sperm-seq) in infertile men who may not have optimal quantity or quality of sperm for genomic analysis and (2) compare these results to fertile donors. METHODS: Infertile men undergoing IVF with female partners with a previous history of failed fertilization with ICSI (FF) or poor blastulation of embryos (PB) were recruited from a large IVF center. Sperm-seq was used to analyze thousands of individual sperm and was carried out at an affiliated university research institute. Global aneuploidy rate, crossover locations, and crossover frequencies were assessed in the infertile population, and compared with a control group of 20 fertile donors, which were analyzed previously at the same laboratory. RESULTS: Eight patients were initially included, but 3 samples did not yield high-quality genomic data for analysis. A total of 10,042 sperm were analyzed from 5 patients, 2 in the FF group, and 3 in the PB group. The global aneuploidy rate among the samples was 2-4%, similar to the control group. Likewise, crossover locations and frequencies were similar. CONCLUSION: Sperm-seq provides a robust analysis but may not be applicable to all male infertility cases due to technical limitations. This group of male infertility patients did not have higher rates of aneuploidy or abnormal crossover patterns compared to a fertile donor population. Our data may suggest that FF and PB phenotypes may not be related to sperm aneuploidy or meiotic errors but rather to other intrinsic nuclear anomalies.


Assuntos
Aneuploidia , Perfilação da Expressão Gênica/métodos , Marcadores Genéticos , Infertilidade Masculina/epidemiologia , Infertilidade Masculina/genética , Análise de Célula Única/métodos , Espermatozoides/metabolismo , Adulto , Feminino , Fertilização in vitro , Predisposição Genética para Doença , Humanos , Masculino , Projetos Piloto , Gravidez , Taxa de Gravidez , Estudos Retrospectivos , Injeções de Esperma Intracitoplásmicas/métodos , Espermatozoides/patologia , Estados Unidos/epidemiologia
3.
Cell Rep ; 42(1): 111896, 2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36596304

RESUMO

Human pluripotent stem cells (hPSCs) are a powerful tool for disease modeling of hard-to-access tissues (such as the brain). Current protocols either direct neuronal differentiation with small molecules or use transcription-factor-mediated programming. In this study, we couple overexpression of transcription factor Neurogenin2 (Ngn2) with small molecule patterning to differentiate hPSCs into lower induced motor neurons (liMoNes/liMNs). This approach induces canonical MN markers including MN-specific Hb9/MNX1 in more than 95% of cells. liMNs resemble bona fide hPSC-derived MN, exhibit spontaneous electrical activity, express synaptic markers, and can contact muscle cells in vitro. Pooled, multiplexed single-cell RNA sequencing on 50 hPSC lines reveals reproducible populations of distinct subtypes of cervical and brachial MNs that resemble their in vivo, embryonic counterparts. Combining small molecule patterning with Ngn2 overexpression facilitates high-yield, reproducible production of disease-relevant MN subtypes, which is fundamental in propelling our knowledge of MN biology and its disruption in disease.


Assuntos
Sinais (Psicologia) , Células-Tronco Pluripotentes Induzidas , Humanos , Diferenciação Celular , Neurônios Motores/metabolismo , Fatores de Transcrição/metabolismo , Regulação da Expressão Gênica , Células-Tronco Pluripotentes Induzidas/metabolismo , Proteínas de Homeodomínio/metabolismo
4.
Cell Stem Cell ; 30(3): 312-332.e13, 2023 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-36796362

RESUMO

Human genome variation contributes to diversity in neurodevelopmental outcomes and vulnerabilities; recognizing the underlying molecular and cellular mechanisms will require scalable approaches. Here, we describe a "cell village" experimental platform we used to analyze genetic, molecular, and phenotypic heterogeneity across neural progenitor cells from 44 human donors cultured in a shared in vitro environment using algorithms (Dropulation and Census-seq) to assign cells and phenotypes to individual donors. Through rapid induction of human stem cell-derived neural progenitor cells, measurements of natural genetic variation, and CRISPR-Cas9 genetic perturbations, we identified a common variant that regulates antiviral IFITM3 expression and explains most inter-individual variation in susceptibility to the Zika virus. We also detected expression QTLs corresponding to GWAS loci for brain traits and discovered novel disease-relevant regulators of progenitor proliferation and differentiation such as CACHD1. This approach provides scalable ways to elucidate the effects of genes and genetic variation on cellular phenotypes.


Assuntos
Células-Tronco Neurais , Infecção por Zika virus , Zika virus , Humanos , Células-Tronco Neurais/metabolismo , Diferenciação Celular/genética , Encéfalo/metabolismo , Zika virus/metabolismo , Expressão Gênica , Proteínas de Membrana/metabolismo , Proteínas de Ligação a RNA/metabolismo
5.
Sci Rep ; 12(1): 12025, 2022 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-35835769

RESUMO

Non-invasive prenatal testing (NIPT) to detect fetal aneuploidy by sequencing the cell-free DNA (cfDNA) in maternal plasma is being broadly adopted. To detect fetal aneuploidies from maternal plasma, where fetal DNA is mixed with far-larger amounts of maternal DNA, NIPT requires a minimum fraction of the circulating cfDNA to be of placental origin, a level which is usually attained beginning at 10 weeks gestational age. We present an approach that leverages the arrangement of alleles along homologous chromosomes-also known as chromosomal phase-to make NIPT analyses more conclusive. We validate our approach with in silico simulations, then re-analyze data from a pregnant mother who, due to a fetal DNA fraction of 3.4%, received an inconclusive aneuploidy determination through NIPT. We find that the presence of a trisomy 18 fetus can be conclusively inferred from the patient's same molecular data when chromosomal phase is incorporated into the analysis. Key to the effectiveness of our approach is the ability of homologous chromosomes to act as natural controls for each other and the ability of chromosomal phase to integrate subtle quantitative signals across very many sequence variants. These results show that chromosomal phase increases the sensitivity of a common laboratory test, an idea that could also advance cfDNA analyses for cancer detection.


Assuntos
Ácidos Nucleicos Livres , Diagnóstico Pré-Natal , Aneuploidia , Ácidos Nucleicos Livres/genética , Cromossomos , DNA/genética , Feminino , Feto , Humanos , Placenta , Gravidez , Diagnóstico Pré-Natal/métodos , Trissomia/diagnóstico , Trissomia/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA