scholarly journals Sex Chromosome Dosage Effects On Gene Expression In Humans

2017 ◽  
Author(s):  
Armin Raznahan ◽  
Neelroop Parikshak ◽  
Vijayendran Chandran ◽  
Jonathan Blumenthal ◽  
Liv Clasen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sex Differences ◽  
X Chromosome ◽  
Gene Networks ◽  
Sex Chromosome ◽  
Autosomal Gene ◽  
Expression Data ◽  
Systematic Map ◽  
Genome Wide ◽  
Genome Wide Expression

ABSTRACTA fundamental question in the biology of sex-differences has eluded direct study in humans: how does sex chromosome dosage (SCD) shape genome function? To address this, we developed a systematic map of SCD effects on gene function by analyzing genome-wide expression data in humans with diverse sex chromosome aneuploidies (XO, XXX, XXY, XYY, XXYY). For sex chromosomes, we demonstrate a pattern of obligate dosage sensitivity amongst evolutionarily preserved X-Y homologs, and update prevailing theoretical models for SCD compensation by detecting X-linked genes whose expression increases with decreasing X- and/or Y-chromosome dosage. We further show that SCD-sensitive sex chromosome genes regulate specific co-expression networks of SCD-sensitive autosomal genes with critical cellular functions and a demonstrable potential to mediate previously documented SCD effects on disease. Our findings detail wide-ranging effects of SCD on genome function with implications for human phenotypic variation.SIGNIFICANCE STATEMENTSex chromosome dosage (SCD) effects on human gene expression are central to the biology of sex differences and sex chromosome aneuploidy syndromes, but challenging to study given the co-segregation of SCD and gonadal status. We address this obstacle by systematically modelling SCD effects on genome wide expression data from a large and rare cohort of individuals with diverse SCDs (XO, XX, XXX, XXXX, XY, XXY, XYY, XXYY, XXXXY). Our findings update current models of sex chromosome biology by (i) pinpointing a core set of X- and Y-linked genes with “obligate” SCD sensitivity, (ii) discovering several non-canonical modes of X-chromosome dosage compensation, and (iii) dissecting complex regulatory effects of X-chromosome dosage on large autosomal gene networks with key roles in cellular functioning.

scholarly journals Sex differences in gene expression and proliferation are dependent on the epigenetic modifier HP1γ

2019 ◽  
Author(s):  
Pui-Pik Law ◽  
Ping-Kei Chan ◽  
Kirsten McEwen ◽  
Huihan Zhi ◽  
Bing Liang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Sex Differences ◽  
Sex Chromosome ◽  
Chromosome Complement ◽  
Autosomal Gene ◽  
Sexually Dimorphic ◽  
Heterochromatin Protein 1 ◽  
Epigenetic Modifier ◽  
Early Embryos ◽  
Males And Females

SummarySex differences in growth rate in very early embryos have been recognized in a variety of mammals and attributed to sex-chromosome complement effects as they occur before overt sexual differentiation. We previously found that sex-chromosome complement, rather than sex hormones regulates heterochromatin-mediated silencing of a transgene and autosomal gene expression in mice. Here, sex dimorphism in proliferation was investigated. We confirm that male embryonic fibroblasts proliferate faster than female fibroblasts and show that this proliferation advantage is completely dependent upon heterochromatin protein 1 gamma (HP1γ). To determine whether this sex-regulatory effect of HP1γ was a more general phenomenon, we performed RNA sequencing on MEFs derived from males and females, with or without HP1γ. Strikingly, HP1γ was found to be crucial for regulating nearly all sexually dimorphic autosomal gene expression because deletion of the HP1γ gene in males abolished sex differences in autosomal gene expression. The identification of a key epigenetic modifier as central in defining gene expression differences between males and females has important implications for understanding physiological sex differences and sex bias in disease.

scholarly journals Differential regulation of mouse hippocampal gene expression sex differences by chromosomal content and gonadal sex

2021 ◽  
Author(s):  
Sarah R Ocanas ◽  
Victor A Ansere ◽  
Kyla B Tooley ◽  
Niran Hadad ◽  
Ana J Chucair-Elliott ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Sex Differences ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Chromosome Complement ◽  
Experimental Models ◽  
Ctcf Binding ◽  
Autosomal Gene ◽  
Sex Effects

Sex differences in the brain as they relate to health and disease are often overlooked in experimental models. Many neurological disorders, like Alzheimer's disease (AD), multiple sclerosis (MS), and autism, differ in prevalence between males and females. Sex differences originate either from differential gene expression on sex chromosomes or from hormonal differences, either directly or indirectly. To disentangle the relative contributions of genetic sex (XX v. XY) and gonadal sex (ovaries v. testes) to the regulation of hippocampal sex effects, we use the "sex-reversal" Four Core Genotype (FCG) mouse model which uncouples sex chromosome complement from gonadal sex. Transcriptomic and epigenomic analyses of hippocampal RNA and DNA from ~12 month old FCG mice, reveals differential regulatory effects of sex chromosome content and gonadal sex on X- versus autosome-encoded gene expression and DNA modification patterns. Gene expression and DNA methylation patterns on the X chromosome were driven primarily by sex chromosome content, not gonadal sex. The majority of DNA methylation changes involved hypermethylation in the XX genotypes (as compared to XY) in the CpG context, with the largest differences in CpG islands, promoters, and CTCF binding sites. Autosomal gene expression and DNA modifications demonstrated regulation by sex chromosome complement and gonadal sex. These data demonstrate the importance of sex chromosomes themselves, independent of hormonal status, in regulating hippocampal sex effects. Future studies will need to further interrogate specific CNS cell types, identify the mechanisms by which sex chromosome regulate autosomes, and differentiate organizational from activational hormonal effects.

scholarly journals Sex-chromosome dosage effects on gene expression in humans

2018 ◽  
Vol 115 (28) ◽  
pp. 7398-7403 ◽  
Author(s):  
Armin Raznahan ◽  
Neelroop N. Parikshak ◽  
Vijay Chandran ◽  
Jonathan D. Blumenthal ◽  
Liv S. Clasen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Sex Chromosome ◽  
Theoretical Models ◽  
Cellular Functions ◽  
Systematic Map ◽  
Genome Expression ◽  
Dosage Effects ◽  
Genome Wide ◽  
Coexpression Networks

A fundamental question in the biology of sex differences has eluded direct study in humans: How does sex-chromosome dosage (SCD) shape genome function? To address this, we developed a systematic map of SCD effects on gene function by analyzing genome-wide expression data in humans with diverse sex-chromosome aneuploidies (XO, XXX, XXY, XYY, and XXYY). For sex chromosomes, we demonstrate a pattern of obligate dosage sensitivity among evolutionarily preserved X-Y homologs and update prevailing theoretical models for SCD compensation by detecting X-linked genes that increase expression with decreasing X- and/or Y-chromosome dosage. We further show that SCD-sensitive sex-chromosome genes regulate specific coexpression networks of SCD-sensitive autosomal genes with critical cellular functions and a demonstrable potential to mediate previously documented SCD effects on disease. These gene coexpression results converge with analysis of transcription factor binding site enrichment and measures of gene expression in murine knockout models to spotlight the dosage-sensitive X-linked transcription factor ZFX as a key mediator of SCD effects on wider genome expression. Our findings characterize the effects of SCD broadly across the genome, with potential implications for human phenotypic variation.

scholarly journals Cloudy with a Chance of Insights: Context Dependent Gene Regulation and Implications for the Evolution of Gene Expression

2019 ◽  
Author(s):  
Elisa Buchberger ◽  
Micael Reis ◽  
Ting-Hsuan Lu ◽  
Nico Posnien
Keyword(s):  
Gene Expression ◽  
Gene Regulation ◽  
Evolutionary Biology ◽  
Expression Data ◽  
Regulatory Evolution ◽  
Specific Expression ◽  
Genome Wide ◽  
Key Driver ◽  
Context Dependent ◽  
Genome Wide Expression

Research in various fields of evolutionary biology has shown that divergence in gene expression is a key driver for phenotypic variation. An exceptional contribution of cis-regulatory evolution has for instance been found to contribute to morphological diversification. In the light of these findings, the analysis of genome-wide expression data has become one of the central tools to link genotype and phenotype information on a more mechanistic level. However, in many studies, especially if general conclusions are drawn from such data, a key feature of gene regulation is often neglected. With our article, we want to raise awareness that gene regulation and thus gene expression is highly context dependent. Genes show tissue- and developmental stage-specific expression. We argue that the regulatory context must be considered when studying evolution of gene expression.

scholarly journals Slide-seq: A scalable technology for measuring genome-wide expression at high spatial resolution

Science ◽  
2019 ◽  
Vol 363 (6434) ◽  
pp. 1463-1467 ◽  
Author(s):  
Samuel G. Rodriques ◽  
Robert R. Stickels ◽  
Aleksandrina Goeva ◽  
Carly A. Martin ◽  
Evan Murray ◽  
...  
Keyword(s):  
Gene Expression ◽  
High Spatial Resolution ◽  
Expression Patterns ◽  
Cell Types ◽  
Expression Data ◽  
Tissue Sections ◽  
Spatially Resolved ◽  
Genome Wide ◽  
Cell Type Specific ◽  
Genome Wide Expression

Spatial positions of cells in tissues strongly influence function, yet a high-throughput, genome-wide readout of gene expression with cellular resolution is lacking. We developed Slide-seq, a method for transferring RNA from tissue sections onto a surface covered in DNA-barcoded beads with known positions, allowing the locations of the RNA to be inferred by sequencing. Using Slide-seq, we localized cell types identified by single-cell RNA sequencing datasets within the cerebellum and hippocampus, characterized spatial gene expression patterns in the Purkinje layer of mouse cerebellum, and defined the temporal evolution of cell type–specific responses in a mouse model of traumatic brain injury. These studies highlight how Slide-seq provides a scalable method for obtaining spatially resolved gene expression data at resolutions comparable to the sizes of individual cells.

scholarly journals A measure of agreement across numerous conditions: Reproducibility of co-expression networks across tissues

2017 ◽  
Author(s):  
Alejandro Cáceres ◽  
Juan R. González
Keyword(s):  
Gene Expression ◽  
Gene Networks ◽  
Expression Data ◽  
Full Agreement ◽  
Statistical Measures ◽  
Expression Studies ◽  
Genome Wide ◽  
Gene Expression Studies ◽  
Microarray Studies ◽  
Level Of Agreement

AbstractThere is great interest to study how co-expression gene networks change across tissues. However, the reproducibility assessment of these studies is challenged by a lack of fully confirmatory experiments from independent researchers. While an increment in the number of studies with expression data for several tissues is expected, statistical measures are still needed to assess the reproducibility between studies. We identified a gap in the statistical literature concerning the assessment of agreement between studies across numerous conditions. The gap precluded us to test, using standard statistics, the level of agreement between the GTEX (RNAseq) and BRAINEAC (microarray) studies to distinguish the structure of co-expression networks across four brain tissues. We propose a generalization of a classical measure of agreement, Cohen’s κ, derive its distributional characteristics and determine its reliability properties. In the gene expression studies, our generalization of κ showed full agreement for genome-wide networks in BRAINEAC benchmarked against GTEX, and highest agreement for brain specific pathways. Our highly interpretable measure can contribute to anticipated efforts on reproducibility research.

scholarly journals Stage-specific disruption of X chromosome expression during spermatogenesis in sterile house mouse hybrids

2021 ◽  
Author(s):  
Erica Larson ◽  
Emily Emiko Konishi Kopania ◽  
Kelsie E Hunnicutt ◽  
Dan Vanderpool ◽  
Sara Keeble ◽  
...  
Keyword(s):  
Gene Expression ◽  
X Chromosome ◽  
Gene Networks ◽  
Sex Chromosome ◽  
Hybrid Sterility ◽  
Critical Role ◽  
F1 Hybrids ◽  
House Mice ◽  
Mus Musculus Domesticus ◽  
Hybrid Male

Hybrid sterility is a complex phenotype that can result from the breakdown of spermatogenesis at multiple developmental stages. Here, we disentangle two proposed hybrid male sterility mechanisms in the house mice, Mus musculus domesticus and M. m. musculus, by comparing patterns of gene expression in sterile F1 hybrids from a reciprocal cross. We found that hybrid males from both cross directions showed disrupted X chromosome expression during prophase of meiosis I consistent with a loss of Meiotic Sex Chromosome Inactivation (MSCI) and Prdm9-associated sterility, but that the degree of disruption was greater in mice with an M. m. musculus X chromosome consistent with previous studies. During postmeiotic development, gene expression on the X chromosome was only disrupted in one cross direction, suggesting that misexpression at this later stage was genotype-specific and not a simple downstream consequence of MSCI disruption which was observed in both reciprocal crosses. Instead, disrupted postmeiotic expression may depend on the magnitude of earlier disrupted MSCI, or the disruption of particular X-linked genes or gene networks. Alternatively, only hybrids with a potential deficit of Sly copies, a Y-linked ampliconic gene family, showed overexpression in postmeiotic cells, consistent with a previously proposed model of antagonistic coevolution between the X and Y-linked ampliconic genes contributing to disrupted expression late in spermatogenesis. The relative contributions of these two regulatory mechanisms and their impact on sterility phenotypes awaits further study. Our results further support the hypothesis that X-linked hybrid sterility in house mice has a variable genetic basis, and that genotype-specific disruption of gene regulation contributes to overexpression of the X chromosome at different stages of development. Overall, these findings underscore the critical role of epigenetic regulation of the X chromosome during spermatogenesis and suggest that these processes are prone to disruption in hybrids.

scholarly journals Stage-specific disruption of X chromosome expression during spermatogenesis in sterile house mouse hybrids

2021 ◽  
Author(s):  
Erica L Larson ◽  
Emily E K Kopania ◽  
Kelsie E Hunnicutt ◽  
Dan Vanderpool ◽  
Sara Keeble ◽  
...  
Keyword(s):  
Gene Expression ◽  
X Chromosome ◽  
Gene Networks ◽  
Sex Chromosome ◽  
Hybrid Sterility ◽  
Critical Role ◽  
F1 Hybrids ◽  
House Mice ◽  
Mus Musculus Domesticus ◽  
Hybrid Male

Abstract Hybrid sterility is a complex phenotype that can result from the breakdown of spermatogenesis at multiple developmental stages. Here, we disentangle two proposed hybrid male sterility mechanisms in the house mice, Mus musculus domesticus and M. m. musculus, by comparing patterns of gene expression in sterile F1 hybrids from a reciprocal cross. We found that hybrid males from both cross directions showed disrupted X chromosome expression during prophase of meiosis I consistent with a loss of Meiotic Sex Chromosome Inactivation (MSCI) and Prdm9-associated sterility, but that the degree of disruption was greater in mice with an M. m. musculus X chromosome consistent with previous studies. During postmeiotic development, gene expression on the X chromosome was only disrupted in one cross direction, suggesting that misexpression at this later stage was genotype-specific and not a simple downstream consequence of MSCI disruption which was observed in both reciprocal crosses. Instead, disrupted postmeiotic expression may depend on the magnitude of earlier disrupted MSCI, or the disruption of particular X-linked genes or gene networks. Alternatively, only hybrids with a potential deficit of Sly copies, a Y-linked ampliconic gene family, showed overexpression in postmeiotic cells, consistent with a previously proposed model of antagonistic coevolution between the X and Y-linked ampliconic genes contributing to disrupted expression late in spermatogenesis. The relative contributions of these two regulatory mechanisms and their impact on sterility phenotypes awaits further study. Our results further support the hypothesis that X-linked hybrid sterility in house mice has a variable genetic basis, and that genotype-specific disruption of gene regulation contributes to overexpression of the X chromosome at different stages of development. Overall, these findings underscore the critical role of epigenetic regulation of the X chromosome during spermatogenesis and suggest that these processes are prone to disruption in hybrids.

Sign in / Sign up

Export Citation Format

Share Document