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1.
Mol Ecol ; 27(20): 4066-4077, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30137660

RESUMEN

Deep-sea coral communities are key components of the Gulf of Mexico ecosystem and were adversely affected by the Deepwater Horizon (DWH) oil spill. Coral colonies exposed to oil and dispersant exhibited mortality, damage and physiological signatures of stress. Understanding how corals respond to oil and dispersant exposure at the molecular level is important to elucidate the sublethal effects of the DWH disaster and reveal broader patterns of coral stress responses. Gene expression profiles from RNAseq data were compared between corals at an impacted site and from a reference site. A total of 1,439 differentially expressed genes (≥twofold) were shared among impacted Paramuricea biscaya colonies. Genes involved in oxidative stress, immunity, wound repair, tissue regeneration and metabolism of xenobiotics were significantly differentially expressed in impacted corals. Enrichment among the overexpressed genes indicates the corals were enduring high metabolic demands associated with cellular stress responses and repair mechanisms. Underexpression of genes vital to toxin processing also suggests a diminished capacity to cope with environmental stressors. Our results provide evidence that deep-sea corals exhibited genome-wide cellular stress responses to oil and dispersant exposure and demonstrate the utility of next-generation sequencing for monitoring anthropogenic impacts in deep waters. These analyses will facilitate the development of diagnostic markers for oil and dispersant exposure in deep-sea invertebrates and inform future oil spill response efforts.


Asunto(s)
Antozoos/efectos de los fármacos , Antozoos/fisiología , Perfilación de la Expresión Génica/métodos , Contaminantes Químicos del Agua/toxicidad , Animales , Ecosistema , Invertebrados/efectos de los fármacos , Invertebrados/fisiología , Contaminación por Petróleo/efectos adversos
2.
Cancer ; 123(5): 849-860, 2017 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-27906459

RESUMEN

BACKGROUND: African Americans with head and neck squamous cell carcinoma (HNSCC) have a lower survival rate than whites. This study investigated the functional importance of ancestry-informative single-nucleotide polymorphisms (SNPs) in HNSCC and also examined the effect of functionally important genetic elements on racial disparities in HNSCC survival. METHODS: Ancestry-informative SNPs, RNA sequencing, methylation, and copy number variation data for 316 oral cavity and laryngeal cancer patients were analyzed across 178 DNA repair genes. The results of expression quantitative trait locus (eQTL) analyses were also replicated with a Gene Expression Omnibus (GEO) data set. The effects of eQTLs on overall survival (OS) and disease-free survival (DFS) were evaluated. RESULTS: Five ancestry-related SNPs were identified as cis-eQTLs in the DNA polymerase ß (POLB) gene (false discovery rate [FDR] < 0.01). The homozygous/heterozygous genotypes containing the African allele showed higher POLB expression than the homozygous white allele genotype (P < .001). A replication study using a GEO data set validated all 5 eQTLs and also showed a statistically significant difference in POLB expression based on genetic ancestry (P = .002). An association was observed between these eQTLs and OS (P < .037; FDR < 0.0363) as well as DFS (P = .018 to .0629; FDR < 0.079) for oral cavity and laryngeal cancer patients treated with platinum-based chemotherapy and/or radiotherapy. Genotypes containing the African allele were associated with poor OS/DFS in comparison with homozygous genotypes harboring the white allele. CONCLUSIONS: Analyses show that ancestry-related alleles could act as eQTLs in HNSCC and support the association of ancestry-related genetic factors with survival disparities in patients diagnosed with oral cavity and laryngeal cancer. Cancer 2017;123:849-60. © 2016 American Cancer Society.


Asunto(s)
Carcinoma de Células Escamosas/genética , ADN Polimerasa beta/genética , Estudios de Asociación Genética , Neoplasias de Cabeza y Cuello/genética , Neoplasias Laríngeas/genética , Sitios de Carácter Cuantitativo/genética , Adulto , Negro o Afroamericano/genética , Anciano , Alelos , Carcinoma de Células Escamosas/epidemiología , Carcinoma de Células Escamosas/patología , Variaciones en el Número de Copia de ADN , Supervivencia sin Enfermedad , Femenino , Regulación Neoplásica de la Expresión Génica , Genotipo , Neoplasias de Cabeza y Cuello/epidemiología , Neoplasias de Cabeza y Cuello/patología , Humanos , Neoplasias Laríngeas/epidemiología , Neoplasias Laríngeas/patología , Masculino , Persona de Mediana Edad , Boca/patología , Polimorfismo de Nucleótido Simple/genética , Análisis de Secuencia de ARN , Carcinoma de Células Escamosas de Cabeza y Cuello , Población Blanca/genética
3.
Genomics ; 107(2-3): 76-82, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26721311

RESUMEN

Laryngeal cancer disproportionately affects more African-Americans than European-Americans. Here, we analyze the genome-wide somatic point mutations from the tumors of 13 African-Americans and 57 European-Americans from TCGA to differentiate between environmental and ancestrally-inherited factors. The mean number of mutations was different between African-Americans (151.31) and European-Americans (277.63). Other differences in the overall mutational landscape between African-American and European-American were also found. The frequency of C>A, and C>G were significantly different between the two populations (p-value<0.05). Context nucleotide signatures for some mutation types significantly differ between these two populations. Thus, the context nucleotide signatures along with other factors could be related to the observed mutational landscape differences between two races. Finally, we show that mutated genes associated with these mutational differences differ between the two populations. Thus, at the molecular level, race appears to be a factor in the progression of laryngeal cancer with ancestral genomic signatures best explaining these differences.


Asunto(s)
Negro o Afroamericano/genética , Predisposición Genética a la Enfermedad/etnología , Neoplasias Laríngeas/genética , Mutación Puntual , Frecuencia de los Genes , Genética de Población , Humanos , Neoplasias Laríngeas/etnología , Estados Unidos/etnología , Población Blanca/genética
4.
Semin Cancer Biol ; 35 Suppl: S25-S54, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25892662

RESUMEN

Proliferation is an important part of cancer development and progression. This is manifest by altered expression and/or activity of cell cycle related proteins. Constitutive activation of many signal transduction pathways also stimulates cell growth. Early steps in tumor development are associated with a fibrogenic response and the development of a hypoxic environment which favors the survival and proliferation of cancer stem cells. Part of the survival strategy of cancer stem cells may manifested by alterations in cell metabolism. Once tumors appear, growth and metastasis may be supported by overproduction of appropriate hormones (in hormonally dependent cancers), by promoting angiogenesis, by undergoing epithelial to mesenchymal transition, by triggering autophagy, and by taking cues from surrounding stromal cells. A number of natural compounds (e.g., curcumin, resveratrol, indole-3-carbinol, brassinin, sulforaphane, epigallocatechin-3-gallate, genistein, ellagitannins, lycopene and quercetin) have been found to inhibit one or more pathways that contribute to proliferation (e.g., hypoxia inducible factor 1, nuclear factor kappa B, phosphoinositide 3 kinase/Akt, insulin-like growth factor receptor 1, Wnt, cell cycle associated proteins, as well as androgen and estrogen receptor signaling). These data, in combination with bioinformatics analyses, will be very important for identifying signaling pathways and molecular targets that may provide early diagnostic markers and/or critical targets for the development of new drugs or drug combinations that block tumor formation and progression.


Asunto(s)
Proteínas de Ciclo Celular/genética , Proliferación Celular/efectos de los fármacos , Neoplasias/patología , Neoplasias/terapia , Antineoplásicos/uso terapéutico , Proteínas de Ciclo Celular/biosíntesis , Transición Epitelial-Mesenquimal/efectos de los fármacos , Humanos , Terapia Molecular Dirigida , Neoplasias/genética , Células Madre Neoplásicas/efectos de los fármacos , Células Madre Neoplásicas/patología , Transducción de Señal/efectos de los fármacos
5.
BMC Evol Biol ; 16: 6, 2016 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-26728183

RESUMEN

BACKGROUND: Domesticated animals quickly evolve docile and submissive behaviors after isolation from their wild conspecifics. Model organisms reared for prolonged periods in the laboratory also exhibit similar shifts towards these domesticated behaviors. Yet whether this divergence is due to inadvertent selection in the lab or the fixation of deleterious mutations remains unknown. RESULTS: Here, we compare the genomes of lab-reared and wild-caught Drosophila melanogaster to understand the genetic basis of these recently endowed behaviors common to laboratory models. From reassembled genomes of common lab strains, we identify unique, derived variants not present in global populations (lab-specific SNPs). Decreased selective constraints across low frequency SNPs (unique to one or two lab strains) are different from patterns found in the wild and more similar to neutral expectations, suggesting an overall accumulation of deleterious mutations. However, high-frequency lab SNPs found in most or all lab strains reveal an enrichment of X-linked loci and neuro-sensory genes across large extended haplotypes. Among shared polymorphisms, we also find highly differentiated SNPs, in which the derived allele is higher in frequency in the wild (Fst*wild>lab), enriched for similar neurogenetic ontologies, indicative of relaxed selection on more active wild alleles in the lab. CONCLUSIONS: Among random mutations that continuously accumulate in the laboratory, we detect common adaptive signatures in domesticated lab strains of fruit flies. Our results demonstrate that lab animals can quickly evolve domesticated behaviors via unconscious selection by humans early on a broad pool of disproportionately large neurogenetic targets followed by the fixation of accumulated deleterious mutations on functionally similar targets.


Asunto(s)
Evolución Biológica , Drosophila melanogaster/genética , Alelos , Animales , Animales Domésticos/genética , Animales de Laboratorio/genética , Animales Salvajes/genética , Genoma , Haplotipos , Polimorfismo de Nucleótido Simple
6.
J Cell Physiol ; 230(10): 2304-10, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25740260

RESUMEN

Males and females differ across a broad spectrum of morphological, physiological, and behavioral characters. In fact, sexually dimorphic traits typically contribute the largest component of phenotypic variance in most taxa that use sex to reproduce. However, we know very little about the mechanisms that maintain these dimorphic states and how these sexually dimorphic traits evolve. Here, we review our current knowledge of the underlying genetic basis of sexual dimorphism in humans. First, we briefly review the etiology of sex differences starting from sex determination's initial switch early in embryogenesis. We then survey recent sex-biased transcriptomic expression literature in order to provide additional insight into the landscape of sex-biased gene expression in both gonadal and non-gonadal tissues: from overall prevalence to tissue specificity to conservation across species. Finally, we discuss implications of sex-biased genetic architecture to human health and disease in light of the National Institute of Health's recently proposed initiative to promote study samples from both sexes.


Asunto(s)
Expresión Génica/genética , Especificidad de Órganos/genética , Caracteres Sexuales , Procesos de Determinación del Sexo/genética , Animales , Evolución Biológica , Perfilación de la Expresión Génica , Humanos
7.
Biol Sex Differ ; 14(1): 30, 2023 05 19.
Artículo en Inglés | MEDLINE | ID: mdl-37208698

RESUMEN

BACKGROUND: Mammalian gonadal sex is determined by the presence or absence of a Y chromosome and the subsequent production of sex hormones contributes to secondary sexual differentiation. However, sex chromosome-linked genes encoding dosage-sensitive transcription and epigenetic factors are expressed well before gonad formation and have the potential to establish sex-biased expression that persists beyond the appearance of gonadal hormones. Here, we apply a comparative bioinformatics analysis on a pair of published single-cell datasets from mouse and human during very early embryogenesis-from two-cell to pre-implantation stages-to characterize sex-specific signals and to assess the degree of conservation among early acting sex-specific genes and pathways. RESULTS: Clustering and regression analyses of gene expression across samples reveal that sex initially plays a significant role in overall gene expression patterns at the earliest stages of embryogenesis which potentially may be the byproduct of signals from male and female gametes during fertilization. Although these transcriptional sex effects rapidly diminish, sex-biased genes appear to form sex-specific protein-protein interaction networks across pre-implantation stages in both mammals providing evidence that sex-biased expression of epigenetic enzymes may establish sex-specific patterns that persist beyond pre-implantation. Non-negative matrix factorization (NMF) on male and female transcriptomes generated clusters of genes with similar expression patterns across sex and developmental stages, including post-fertilization, epigenetic, and pre-implantation ontologies conserved between mouse and human. While the fraction of sex-differentially expressed genes (sexDEGs) in early embryonic stages is similar and functional ontologies are conserved, the genes involved are generally different in mouse and human. CONCLUSIONS: This comparative study uncovers much earlier than expected sex-specific signals in mouse and human embryos that pre-date hormonal signaling from the gonads. These early signals are diverged with respect to orthologs yet conserved in terms of function with important implications in the use of genetic models for sex-specific disease.


Sex differences are traditionally assumed to arise after the reproductive systems are set up in male and female embryos, and especially after these organs begin producing sex hormones. However, very early in embryo development, the sex chromosomes distinguish males (XY) and females (XX) and genes on these chromosomes are expressed differentially. In this study, we have analyzed gene expression data from mouse and human early embryos to determine whether there is sex-biased expression before implantation. Our results confirm that there is abundant sex-biased expression from the earliest stages of development, soon after fertilization. The comparison between human and mouse embryos shows comparable function of the sex-biased genes, although the specific genes involved differ between the two species.


Asunto(s)
Desarrollo Embrionario , Regulación del Desarrollo de la Expresión Génica , Masculino , Animales , Humanos , Femenino , Ratones , Desarrollo Embrionario/genética , Transcriptoma , Genómica , Mamíferos/genética
8.
Front Genet ; 14: 1061781, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36911410

RESUMEN

Introduction: Human populations are often highly structured due to differences in genetic ancestry among groups, posing difficulties in associating genes with diseases. Ancestry-informative markers (AIMs) aid in the detection of population stratification and provide an alternative approach to map population-specific alleles to disease. Here, we identify and characterize a novel set of African AIMs that separate populations of African ancestry from other global populations including those of European ancestry. Methods: Using data from the 1000 Genomes Project, highly informative SNP markers from five African subpopulations were selected based on estimates of informativeness (In) and compared against the European population to generate a final set of 46,737 African ancestry-informative markers (AIMs). The AIMs identified were validated using an independent set and functionally annotated using tools like SIFT, PolyPhen. They were also investigated for representation of commonly used SNP arrays. Results: This set of African AIMs effectively separates populations of African ancestry from other global populations and further identifies substructure between populations of African ancestry. When a subset of these AIMs was studied in an independent dataset, they differentiated people who self-identify as African American or Black from those who identify their ancestry as primarily European. Most of the AIMs were found to be in their intergenic and intronic regions with only 0.6% in the coding regions of the genome. Most of the commonly used SNP array investigated contained less than 10% of the AIMs. Discussion: While several functional annotations of both coding and non-coding African AIMs are supported by the literature and linked these high-frequency African alleles to diseases in African populations, more effort is needed to map genes to diseases in these genetically diverse subpopulations. The relative dearth of these African AIMs on current genotyping platforms (the array with the highest fraction, llumina's Omni 5, harbors less than a quarter of AIMs), further demonstrates a greater need to better represent historically understudied populations.

9.
PLoS Genet ; 5(7): e1000550, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19578407

RESUMEN

In nature, closely related species may hybridize while still retaining their distinctive identities. Chromosomal regions that experience reduced recombination in hybrids, such as within inversions, have been hypothesized to contribute to the maintenance of species integrity. Here, we examine genomic sequences from closely related fruit fly taxa of the Drosophila pseudoobscura subgroup to reconstruct their evolutionary histories and past patterns of genic exchange. Partial genomic assemblies were generated from two subspecies of Drosophila pseudoobscura (D. ps.) and an outgroup species, D. miranda. These new assemblies were compared to available assemblies of D. ps. pseudoobscura and D. persimilis, two species with overlapping ranges in western North America. Within inverted regions, nucleotide divergence among each pair of the three species is comparable, whereas divergence between D. ps. pseudoobscura and D. persimilis in non-inverted regions is much lower and closer to levels of intraspecific variation. Using molecular markers flanking each of the major chromosomal inversions, we identify strong crossover suppression in F(1) hybrids extending over 2 megabase pairs (Mbp) beyond the inversion breakpoints. These regions of crossover suppression also exhibit the high nucleotide divergence associated with inverted regions. Finally, by comparison to a geographically isolated subspecies, D. ps. bogotana, our results suggest that autosomal gene exchange between the North American species, D. ps. pseudoobscura and D. persimilis, occurred since the split of the subspecies, likely within the last 200,000 years. We conclude that chromosomal rearrangements have been vital to the ongoing persistence of these species despite recent hybridization. Our study serves as a proof-of-principle on how whole genome sequencing can be applied to formulate and test hypotheses about species formation in lesser-known non-model systems.


Asunto(s)
Drosophila/genética , Evolución Molecular , Especiación Genética , Variación Genética , Genoma de los Insectos , Genómica , Animales , Aberraciones Cromosómicas , Drosophila/química , Modelos Genéticos , Análisis de Secuencia de ADN
10.
BMC Genomics ; 12: 554, 2011 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-22077994

RESUMEN

BACKGROUND: Comparative studies of amniotes have been hindered by a dearth of reptilian molecular sequences. With the genomic assembly of the green anole, Anolis carolinensis available, non-avian reptilian genes can now be compared to mammalian, avian, and amphibian homologs. Furthermore, with more than 350 extant species in the genus Anolis, anoles are an unparalleled example of tetrapod genetic diversity and divergence. As an important ecological, genetic and now genomic reference, it is imperative to develop a standardized Anolis gene nomenclature alongside associated vocabularies and other useful metrics. RESULTS: Here we report the formation of the Anolis Gene Nomenclature Committee (AGNC) and propose a standardized evolutionary characterization code that will help researchers to define gene orthology and paralogy with tetrapod homologs, provide a system for naming novel genes in Anolis and other reptiles, furnish abbreviations to facilitate comparative studies among the Anolis species and related iguanid squamates, and classify the geographical origins of Anolis subpopulations. CONCLUSIONS: This report has been generated in close consultation with members of the Anolis and genomic research communities, and using public database resources including NCBI and Ensembl. Updates will continue to be regularly posted to new research community websites such as lizardbase. We anticipate that this standardized gene nomenclature will facilitate the accessibility of reptilian sequences for comparative studies among tetrapods and will further serve as a template for other communities in their sequencing and annotation initiatives.


Asunto(s)
Genómica/normas , Lagartos/genética , Terminología como Asunto , Animales , Secuencia Conservada , Elementos Transponibles de ADN , Evolución Molecular , Marcadores Genéticos , Lagartos/clasificación , Repeticiones de Microsatélite , Secuencias Repetitivas de Ácidos Nucleicos
11.
Proc Natl Acad Sci U S A ; 105(29): 10051-6, 2008 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-18621713

RESUMEN

Regional rates of recombination often correlate with levels of nucleotide diversity, and either selective or neutral hypotheses can explain this relationship. Regional recombination rates also correlate with nucleotide differences between human and chimpanzee, consistent with models where recombination is mutagenic; however, a lack of correlation is observed in the Drosophila melanogaster group, consistent with models invoking natural selection. Here, we revisit the relationship among recombination, diversity, and interspecies difference by generating empirical estimates of these parameters in Drosophila pseudoobscura. To measure recombination rate, we genotyped 1,294 backcross hybrids at 50 markers across the largest assembled linkage group in this species. Genome-wide diversity was estimated by sequencing a second isolate of D. pseudoobscura at shallow coverage. Alignment to the sequenced genome of the closely related species, Drosophila persimilis, provided nucleotide site orthology. Our findings demonstrate that scale is critical in determining correlates to recombination rate: fine-scale cross-over rate estimates are far stronger predictors of both diversity and interspecies difference than broad-scale estimates. The correlation of fine-scale recombination rate to diversity and interspecies difference appears to be genome-wide, evidenced by examination of an X-linked region in greater detail. Because we observe a strong correlation of cross-over rate with interspecies difference, even after correcting for segregating ancestral variation, we suggest that both mutagenic and selective forces generate these correlations, the latter in regions of low crossing over. We propose that it is not cross-overs per se that are mutagenic, but rather repair of DNA double-strand break precursors via crossing over and gene conversion.


Asunto(s)
Drosophila/genética , Recombinación Genética , Animales , Secuencia de Bases , Mapeo Cromosómico , Cruzamientos Genéticos , Intercambio Genético , ADN/genética , Roturas del ADN , Reparación del ADN , Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Evolución Molecular , Conversión Génica , Variación Genética , Genoma de los Insectos , Modelos Genéticos , Mutación , Polimorfismo Genético , Especificidad de la Especie
12.
Genome Biol Evol ; 13(12)2021 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-34788814

RESUMEN

Molecular evolutionary studies usually focus on genes with clear roles in adult fitness or on developmental genes expressed at multiple time points during the life of the organism. Here, we examine the evolutionary dynamics of Drosophila glue genes, a set of eight genes tasked with a singular primary function during a specific developmental stage: the production of glue that allows animal pupa to attach to a substrate for several days during metamorphosis. Using phenotypic assays and available data from transcriptomics, PacBio genomes, and sequence variation from global populations, we explore the selective forces acting on glue genes within the cosmopolitan Drosophila melanogaster species and its five closely related species, D. simulans, D. sechellia, D. mauritiana, D. yakuba, and D. teissieri. We observe a three-fold difference in glue adhesion between the least and the most adhesive D. melanogaster strain, indicating a strong genetic component to phenotypic variation. These eight glue genes are among the most highly expressed genes in salivary glands yet they display no notable codon bias. New copies of Sgs3 and Sgs7 are found in D. yakuba and D. teissieri with the Sgs3 coding sequence evolving rapidly after duplication in the D. yakuba branch. Multiple sites along the various glue genes appear to be constrained. Our population genetics analysis in D. melanogaster suggests signals of local adaptive evolution for Sgs3, Sgs5, and Sgs5bis and traces of selective sweeps for Sgs1, Sgs3, Sgs7, and Sgs8. Our work shows that stage-specific genes can be subjected to various dynamic evolutionary forces.


Asunto(s)
Drosophila melanogaster , Drosophila , Animales , Drosophila/genética , Drosophila melanogaster/genética , Drosophila simulans , Evolución Molecular , Genética de Población
13.
BMC Genomics ; 11: 271, 2010 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-20429934

RESUMEN

BACKGROUND: Genome-wide analysis of sequence divergence among species offers profound insights into the evolutionary processes that shape lineages. When full-genome sequencing is not feasible for a broad comparative study, we propose the use of array-based comparative genomic hybridization (aCGH) in order to identify orthologous genes with high sequence divergence. Here we discuss experimental design, statistical power, success rate, sources of variation and potential confounding factors. We used a spotted PCR product microarray platform from Drosophila melanogaster to assess sequence divergence on a gene-by-gene basis in three fully sequenced heterologous species (D. sechellia, D. simulans, and D. yakuba). Because complete genome assemblies are available for these species this study presents a powerful test for the use of aCGH as a tool to measure sequence divergence. RESULTS: We found a consistent and linear relationship between hybridization ratio and sequence divergence of the sample to the platform species. At higher levels of sequence divergence (< 92% sequence identity to D. melanogaster) approximately 84% of features had significantly less hybridization to the array in the heterologous species than the platform species, and thus could be identified as "diverged". At lower levels of divergence (>or= 97% identity), only 13% of genes were identified as diverged. While approximately 40% of the variation in hybridization ratio can be accounted for by variation in sequence identity of the heterologous sample relative to D. melanogaster, other individual characteristics of the DNA sequences, such as GC content, also contribute to variation in hybridization ratio, as does technical variation. CONCLUSIONS: Here we demonstrate that aCGH can accurately be used as a proxy to estimate genome-wide divergence, thus providing an efficient way to evaluate how evolutionary processes and genomic architecture can shape species diversity in non-model systems. Given the increased number of species for which microarray platforms are available, comparative studies can be conducted for many interesting lineages in order to identify highly diverged genes that may be the target of natural selection.


Asunto(s)
Hibridación Genómica Comparativa , Drosophila melanogaster/genética , Drosophila/genética , Animales , Secuencia de Bases , Genoma , Análisis por Micromatrices
14.
Biol Sex Differ ; 10(1): 46, 2019 09 05.
Artículo en Inglés | MEDLINE | ID: mdl-31488212

RESUMEN

BACKGROUND: Expression patterns between males and females vary in every adult tissue, even in organs with no conspicuous dimorphisms such as the heart. While studies of male and female differences have traditionally focused on the influence of sex hormones, these do not account for all the differences at the molecular and epigenetic levels. We previously reported that a substantial number of genes were differentially expressed in male and female mouse embryonic stem (ES) cells and revealed dose-dependent enhancer activity in response to Prdm14, a key pluripotency factor expressed more highly in female ES cells. In this work, we investigated the role of Prdm14 in establishing sex-specific gene expression networks. We surveyed the sex-specific landscape in early embryogenesis with special reference to cardiac development. We generated sex-specific co-expression networks from mouse ES cells, examined the presence of sex-specific chromatin domains, and analyzed previously published datasets from different developmental time points to characterize how sex-biased gene expression waxes and wanes to evaluate whether sex-biased networks are detectable throughout heart development. RESULTS: We performed ChIP-seq on male and female mouse ES cells to determine differences in chromatin status. Our study reveals sex-biased histone modifications, underscoring the potential for the sex chromosome complement to prime the genome differently in early development with consequences for later expression biases. Upon differentiation of ES cells to cardiac precursors, we found sex-biased expression of key transcription and epigenetic factors, some of which persisted from the undifferentiated state. Using network analyses, we also found that Prdm14 plays a prominent role in regulating a subset of dimorphic expression patterns. To determine whether sex-biased expression is present throughout cardiogenesis, we re-analyzed data from two published studies that sampled the transcriptomes of mouse hearts from 8.5 days post-coitum embryos to neonates and adults. We found sex-biased expression at every stage in heart development, and interestingly, identified a subset of genes that exhibit the same bias across multiple cardiogenic stages. CONCLUSIONS: Overall, our results support the existence of sexually dimorphic gene expression profiles and regulatory networks at every stage of cardiac development, some of which may be established in early embryogenesis and epigenetically perpetuated.


Asunto(s)
Células Madre Embrionarias/metabolismo , Regulación del Desarrollo de la Expresión Génica/fisiología , Corazón/crecimiento & desarrollo , Animales , Línea Celular , Cromatina , Femenino , Redes Reguladoras de Genes , Humanos , Masculino , Ratones , Miocitos Cardíacos/fisiología , Caracteres Sexuales
15.
Genetics ; 177(3): 1321-35, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-18039869

RESUMEN

A large portion of the annotated genes in Drosophila melanogaster show sex-biased expression, indicating that sex and reproduction-related genes (SRR genes) represent an appreciable component of the genome. Previous studies, in which subsets of genes were compared among few Drosophila species, have found that SRR genes exhibit unusual evolutionary patterns. Here, we have used the newly released genome sequences from 12 Drosophila species, coupled to a larger set of SRR genes, to comprehensively test the generality of these patterns. Among 2505 SRR genes examined, including ESTs with biased expression in reproductive tissues and genes characterized as involved in gametogenesis, we find that a relatively high proportion of SRR genes have experienced accelerated divergence throughout the genus Drosophila. Several testis-specific genes, male seminal fluid proteins (SFPs), and spermatogenesis genes show lineage-specific bursts of accelerated evolution and positive selection. SFP genes also show evidence of lineage-specific gene loss and/or gain. These results bring us closer to understanding the details of the evolutionary dynamics of SRR genes with respect to species divergence.


Asunto(s)
Evolución Biológica , Drosophila/genética , Genes de Insecto , Caracteres Sexuales , Animales , Drosophila/clasificación , Drosophila/crecimiento & desarrollo , Drosophila/fisiología , Proteínas de Drosophila/genética , Femenino , Masculino , Modelos Genéticos , Oogénesis/genética , Ovario/metabolismo , Filogenia , Reproducción/genética , Selección Genética , Procesos de Determinación del Sexo , Espermatogénesis/genética , Testículo/metabolismo
16.
J Genet ; 87(4): 327-38, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19147922

RESUMEN

The empirical study of speciation has brought us closer to unlocking the origins of life's vast diversity. By examining recently formed species, a number of general patterns, or rules, become apparent. Among fixed differences between species, sexual genes and traits are one of the most rapidly evolving and novel functional classes, and premating isolation often develops earlier than postmating isolation. Among interspecific hybrids, sterility evolves faster than inviability, the X-chromosome has a greater effect on incompatibilities than autosomes, and hybrid dysfunction affects the heterogametic sex more frequently than the homogametic sex (Haldane's rule). Haldane's rule, in particular, has played a major role in reviving interest in the genetics of speciation. However, the large genetic and reproductive differences between taxa and the multi-factorial nature of each rule have made it difficult to ascribe general mechanisms. Here, we review the extensive progress made since Darwin on understanding the origin of species. We revisit the rules of speciation, regarding them as landmarks as species evolve through time. We contrast these 'rules' of speciation to 'mechanisms' of speciation representing primary causal factors ranging across various levels of organization-from genic to chromosomal to organismal. To explain the rules, we propose a new 'hierarchical faster-sex' theory: the rapid evolution of sex and reproduction-related (SRR) genes (faster-SRR evolution), in combination with the preferential involvement of the X-chromosome (hemizygous X-effects) and sexually selected male traits (faster-male evolution). This unified theory explains a comprehensive set of speciation rules at both the prezyotic and postzygotic levels and also serves as a cohesive alternative to dominance, composite, and recent genomic conflict interpretations of Haldane's rule.


Asunto(s)
Especiación Genética , Modelos Biológicos , Animales , Femenino , Masculino , Reproducción , Selección Genética
17.
Soc Sci Med ; 198: 46-52, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-29275275

RESUMEN

Public and scientific conceptions of identity are changing alongside advances in biotechnology, with important relevance to health and medicine. In particular, biological identity, once predominantly conceived as static (e.g., related to DNA, dental records, fingerprints) is now being recognized as dynamic or fluid, mirroring contemporary understandings of psychological and social identity. The dynamism of biological identity comes from the individual body's unique relationship with the world surrounding it, and therefore may best be described as biosocial. This paper reviews advances in scientific understandings of identity and presents a model that contrasts prior static approaches to biological identity from more recent dynamically-relational ones. This emerging viewpoint is of broad significance to health and medicine, particularly as medicine recognizes the significance of biography - i.e. the multiple, dense interactions imparted on a body across spatio-temporal dimensions - to phenotypic prediction, especially disease risk.


Asunto(s)
Modelos Teóricos , Identificación Social , Geografía , Humanos , Análisis Espacial , Tiempo
18.
Health Place ; 51: 182-188, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29655130

RESUMEN

Systemic lupus erythematosus (SLE), commonly known simply as lupus, is an autoimmune disease in which the body's immune system attacks healthy tissue and organs. Characteristic of the disease is a disproportionate effect on women and communities of color, both in terms of prevalence and severity of symptoms. Lupus is also both genetically driven and subject to external environmental conditions, many with place based corollaries. Thus, lupus presents a series of complex and intersecting biosocial questions regarding its origin and treatment, questions which transdisciplinary approaches are uniquely suited to address. In this paper, we propose a framework, incorporating critical approaches to the production of embodied formations of race and gender as well as new understandings of the impact of environmental conditions and lived experience at the genetic level, that can direct future research into lupus that is both more inclusive of a range of influences and more precise in its ability to treat and diagnose the disease.


Asunto(s)
Lupus Eritematoso Sistémico/epidemiología , Modelos Teóricos , Grupos Raciales , Adulto , Femenino , Humanos , Lupus Eritematoso Sistémico/etnología , Lupus Eritematoso Sistémico/genética , Masculino , Prevalencia , Factores Sexuales
19.
Genome Biol Evol ; 10(2): 489-506, 2018 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-29360978

RESUMEN

Squamates include all lizards and snakes, and display some of the most diverse and extreme morphological adaptations among vertebrates. However, compared with birds and mammals, relatively few resources exist for comparative genomic analyses of squamates, hampering efforts to understand the molecular bases of phenotypic diversification in such a speciose clade. In particular, the ∼400 species of anole lizard represent an extensive squamate radiation. Here, we sequence and assemble the draft genomes of three anole species-Anolis frenatus, Anolis auratus, and Anolis apletophallus-for comparison with the available reference genome of Anolis carolinensis. Comparative analyses reveal a rapid background rate of molecular evolution consistent with a model of punctuated equilibrium, and strong purifying selection on functional genomic elements in anoles. We find evidence for accelerated evolution in genes involved in behavior, sensory perception, and reproduction, as well as in genes regulating limb bud development and hindlimb specification. Morphometric analyses of anole fore and hindlimbs corroborated these findings. We detect signatures of positive selection across several genes related to the development and regulation of the forebrain, hormones, and the iguanian lizard dewlap, suggesting molecular changes underlying behavioral adaptations known to reinforce species boundaries were a key component in the diversification of anole lizards.


Asunto(s)
Evolución Molecular , Lagartos/genética , Animales , Evolución Biológica , ADN/genética , Variación Genética , Genómica , Lagartos/anatomía & histología , Lagartos/fisiología , Anotación de Secuencia Molecular , Filogenia , Selección Genética
20.
G3 (Bethesda) ; 7(8): 2791-2797, 2017 08 07.
Artículo en Inglés | MEDLINE | ID: mdl-28667017

RESUMEN

Gene expression patterns assayed across development can offer key clues about a gene's function and regulatory role. Drosophila melanogaster is ideal for such investigations as multiple individual and high-throughput efforts have captured the spatiotemporal patterns of thousands of embryonic expressed genes in the form of in situ images. FlyExpress (www.flyexpress.net), a knowledgebase based on a massive and unique digital library of standardized images and a simple search engine to find coexpressed genes, was created to facilitate the analytical and visual mining of these patterns. Here, we introduce the next generation of FlyExpress resources to facilitate the integrative analysis of sequence data and spatiotemporal patterns of expression from images. FlyExpress 7 now includes over 100,000 standardized in situ images and implements a more efficient, user-defined search algorithm to identify coexpressed genes via Genomewide Expression Maps (GEMs). Shared motifs found in the upstream 5' regions of any pair of coexpressed genes can be visualized in an interactive dotplot. Additional webtools and link-outs to assist in the downstream validation of candidate motifs are also provided. Together, FlyExpress 7 represents our largest effort yet to accelerate discovery via the development and dispersal of new webtools that allow researchers to perform data-driven analyses of coexpression (image) and genomic (sequence) data.


Asunto(s)
Drosophila melanogaster/genética , Regulación de la Expresión Génica , Imagenología Tridimensional , Hibridación in Situ , Programas Informáticos , Animales , Sitios de Unión/genética , Secuencia Conservada/genética , Genoma de los Insectos , Factores de Transcripción/metabolismo
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