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1.
Nature ; 624(7992): 593-601, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38093005

RESUMO

The Indigenous peoples of Australia have a rich linguistic and cultural history. How this relates to genetic diversity remains largely unknown because of their limited engagement with genomic studies. Here we analyse the genomes of 159 individuals from four remote Indigenous communities, including people who speak a language (Tiwi) not from the most widespread family (Pama-Nyungan). This large collection of Indigenous Australian genomes was made possible by careful community engagement and consultation. We observe exceptionally strong population structure across Australia, driven by divergence times between communities of 26,000-35,000 years ago and long-term low but stable effective population sizes. This demographic history, including early divergence from Papua New Guinean (47,000 years ago) and Eurasian groups1, has generated the highest proportion of previously undescribed genetic variation seen outside Africa and the most extended homozygosity compared with global samples. A substantial proportion of this variation is not observed in global reference panels or clinical datasets, and variation with predicted functional consequence is more likely to be homozygous than in other populations, with consequent implications for medical genomics2. Our results show that Indigenous Australians are not a single homogeneous genetic group and their genetic relationship with the peoples of New Guinea is not uniform. These patterns imply that the full breadth of Indigenous Australian genetic diversity remains uncharacterized, potentially limiting genomic medicine and equitable healthcare for Indigenous Australians.


Assuntos
Povos Aborígenes Australianos e Ilhéus do Estreito de Torres , Genoma Humano , Variação Estrutural do Genoma , Humanos , Austrália/etnologia , Povos Aborígenes Australianos e Ilhéus do Estreito de Torres/genética , Povos Aborígenes Australianos e Ilhéus do Estreito de Torres/história , Conjuntos de Dados como Assunto , Genética Médica , Genoma Humano/genética , Variação Estrutural do Genoma/genética , Genômica , História Antiga , Homozigoto , Idioma , Nova Guiné/etnologia , Densidade Demográfica , Dinâmica Populacional
2.
Nature ; 624(7992): 602-610, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38093003

RESUMO

Indigenous Australians harbour rich and unique genomic diversity. However, Aboriginal and Torres Strait Islander ancestries are historically under-represented in genomics research and almost completely missing from reference datasets1-3. Addressing this representation gap is critical, both to advance our understanding of global human genomic diversity and as a prerequisite for ensuring equitable outcomes in genomic medicine. Here we apply population-scale whole-genome long-read sequencing4 to profile genomic structural variation across four remote Indigenous communities. We uncover an abundance of large insertion-deletion variants (20-49 bp; n = 136,797), structural variants (50 b-50 kb; n = 159,912) and regions of variable copy number (>50 kb; n = 156). The majority of variants are composed of tandem repeat or interspersed mobile element sequences (up to 90%) and have not been previously annotated (up to 62%). A large fraction of structural variants appear to be exclusive to Indigenous Australians (12% lower-bound estimate) and most of these are found in only a single community, underscoring the need for broad and deep sampling to achieve a comprehensive catalogue of genomic structural variation across the Australian continent. Finally, we explore short tandem repeats throughout the genome to characterize allelic diversity at 50 known disease loci5, uncover hundreds of novel repeat expansion sites within protein-coding genes, and identify unique patterns of diversity and constraint among short tandem repeat sequences. Our study sheds new light on the dimensions and dynamics of genomic structural variation within and beyond Australia.


Assuntos
Povos Aborígenes Australianos e Ilhéus do Estreito de Torres , Genoma Humano , Variação Estrutural do Genoma , Humanos , Alelos , Austrália/etnologia , Povos Aborígenes Australianos e Ilhéus do Estreito de Torres/genética , Conjuntos de Dados como Assunto , Variações do Número de Cópias de DNA/genética , Loci Gênicos/genética , Genética Médica , Variação Estrutural do Genoma/genética , Genômica , Mutação INDEL/genética , Sequências Repetitivas Dispersas/genética , Repetições de Microssatélites/genética , Genoma Humano/genética
3.
Proc Natl Acad Sci U S A ; 119(4)2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35074916

RESUMO

Pogona vitticeps has female heterogamety (ZZ/ZW), but the master sex-determining gene is unknown, as it is for all reptiles. We show that nr5a1 (Nuclear Receptor Subfamily 5 Group A Member 1), a gene that is essential in mammalian sex determination, has alleles on the Z and W chromosomes (Z-nr5a1 and W-nr5a1), which are both expressed and can recombine. Three transcript isoforms of Z-nr5a1 were detected in gonads of adult ZZ males, two of which encode a functional protein. However, ZW females produced 16 isoforms, most of which contained premature stop codons. The array of transcripts produced by the W-borne allele (W-nr5a1) is likely to produce truncated polypeptides that contain a structurally normal DNA-binding domain and could act as a competitive inhibitor to the full-length intact protein. We hypothesize that an altered configuration of the W chromosome affects the conformation of the primary transcript generating inhibitory W-borne isoforms that suppress testis determination. Under this hypothesis, the genetic sex determination (GSD) system of P. vitticeps is a W-borne dominant female-determining gene that may be controlled epigenetically.


Assuntos
Alelos , Cromossomos/genética , Splicing de RNA , Processos de Determinação Sexual , Fator Esteroidogênico 1/genética , Sequência de Aminoácidos , Animais , Cromossomos/química , Feminino , Dosagem de Genes , Lagartos , Masculino , Modelos Moleculares , Conformação Molecular , Conformação Proteica , Répteis , Cromossomos Sexuais , Fatores Sexuais , Fator Esteroidogênico 1/química , Relação Estrutura-Atividade
4.
Proc Natl Acad Sci U S A ; 119(4)2022 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-35042810

RESUMO

The field of genomics has benefited greatly from its "openness" approach to data sharing. However, with the increasing volume of sequence information being created and stored and the growing number of international genomics efforts, the equity of openness is under question. The United Nations Convention of Biodiversity aims to develop and adopt a standard policy on access and benefit-sharing for sequence information across signatory parties. This standardization will have profound implications on genomics research, requiring a new definition of open data sharing. The redefinition of openness is not unwarranted, as its limitations have unintentionally introduced barriers of engagement to some, including Indigenous Peoples. This commentary provides an insight into the key challenges of openness faced by the researchers who aspire to protect and conserve global biodiversity, including Indigenous flora and fauna, and presents immediate, practical solutions that, if implemented, will equip the genomics community with both the diversity and inclusivity required to respectfully protect global biodiversity.


Assuntos
Povos Indígenas/genética , Disseminação de Informação/ética , Biodiversidade , Genômica/métodos , Humanos , Povos Indígenas/psicologia , Povos Indígenas/estatística & dados numéricos , Disseminação de Informação/métodos , Grupos Populacionais/genética
5.
Proc Natl Acad Sci U S A ; 118(45)2021 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-34725164

RESUMO

Microchromosomes, once considered unimportant shreds of the chicken genome, are gene-rich elements with a high GC content and few transposable elements. Their origin has been debated for decades. We used cytological and whole-genome sequence comparisons, and chromosome conformation capture, to trace their origin and fate in genomes of reptiles, birds, and mammals. We find that microchromosomes as well as macrochromosomes are highly conserved across birds and share synteny with single small chromosomes of the chordate amphioxus, attesting to their origin as elements of an ancient animal genome. Turtles and squamates (snakes and lizards) share different subsets of ancestral microchromosomes, having independently lost microchromosomes by fusion with other microchromosomes or macrochromosomes. Patterns of fusions were quite different in different lineages. Cytological observations show that microchromosomes in all lineages are spatially separated into a central compartment at interphase and during mitosis and meiosis. This reflects higher interaction between microchromosomes than with macrochromosomes, as observed by chromosome conformation capture, and suggests some functional coherence. In highly rearranged genomes fused microchromosomes retain most ancestral characteristics, but these may erode over evolutionary time; surprisingly, de novo microchromosomes have rapidly adopted high interaction. Some chromosomes of early-branching monotreme mammals align to several bird microchromosomes, suggesting multiple microchromosome fusions in a mammalian ancestor. Subsequently, multiple rearrangements fueled the extraordinary karyotypic diversity of therian mammals. Thus, microchromosomes, far from being aberrant genetic elements, represent fundamental building blocks of amniote chromosomes, and it is mammals, rather than reptiles and birds, that are atypical.


Assuntos
Evolução Biológica , Cordados/genética , Cromossomos de Mamíferos , Genoma , Animais , Sequência de Bases , Sequência Conservada
6.
BMC Genomics ; 24(1): 243, 2023 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-37147622

RESUMO

BACKGROUND: Sex determination is the process whereby the bipotential embryonic gonads become committed to differentiate into testes or ovaries. In genetic sex determination (GSD), the sex determining trigger is encoded by a gene on the sex chromosomes, which activates a network of downstream genes; in mammals these include SOX9, AMH and DMRT1 in the male pathway, and FOXL2 in the female pathway. Although mammalian and avian GSD systems have been well studied, few data are available for reptilian GSD systems. RESULTS: We conducted an unbiased transcriptome-wide analysis of gonad development throughout differentiation in central bearded dragon (Pogona vitticeps) embryos with GSD. We found that sex differentiation of transcriptomic profiles occurs at a very early stage, before the gonad consolidates as a body distinct from the gonad-kidney complex. The male pathway genes dmrt1 and amh and the female pathway gene foxl2 play a key role in early sex differentiation in P. vitticeps, but the central player of the mammalian male trajectory, sox9, is not differentially expressed in P. vitticeps at the bipotential stage. The most striking difference from GSD systems of other amniotes is the high expression of the male pathway genes amh and sox9 in female gonads during development. We propose that a default male trajectory progresses if not repressed by a W-linked dominant gene that tips the balance of gene expression towards the female trajectory. Further, weighted gene expression correlation network analysis revealed novel candidates for male and female sex differentiation. CONCLUSION: Our data reveal that interpretation of putative mechanisms of GSD in reptiles cannot solely depend on lessons drawn from mammals.


Assuntos
Répteis , Processos de Determinação Sexual , Diferenciação Sexual , Animais , Feminino , Masculino , Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Gônadas/metabolismo , Répteis/genética , Processos de Determinação Sexual/genética , Diferenciação Sexual/genética , Fatores de Transcrição SOX9/genética
7.
Am J Hum Genet ; 107(2): 175-182, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32763188

RESUMO

Expanded carrier screening (ECS) for recessive monogenic diseases requires prior knowledge of genomic variation, including DNA variants that cause disease. The composition of pathogenic variants differs greatly among human populations, but historically, research about monogenic diseases has focused mainly on people with European ancestry. By comparison, less is known about pathogenic DNA variants in people from other parts of the world. Consequently, inclusion of currently underrepresented Indigenous and other minority population groups in genomic research is essential to enable equitable outcomes in ECS and other areas of genomic medicine. Here, we discuss this issue in relation to the implementation of ECS in Australia, which is currently being evaluated as part of the national Government's Genomics Health Futures Mission. We argue that significant effort is required to build an evidence base and genomic reference data so that ECS can bring significant clinical benefit for many Aboriginal and/or Torres Strait Islander Australians. These efforts are essential steps to achieving the Australian Government's objectives and its commitment "to leveraging the benefits of genomics in the health system for all Australians." They require culturally safe, community-led research and community involvement embedded within national health and medical genomics programs to ensure that new knowledge is integrated into medicine and health services in ways that address the specific and articulated cultural and health needs of Indigenous people. Until this occurs, people who do not have European ancestry are at risk of being, in relative terms, further disadvantaged.


Assuntos
Metagenômica/métodos , Grupos Populacionais/genética , Austrália , Variação Genética/genética , Humanos
8.
Int J Mol Sci ; 24(22)2023 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-38003344

RESUMO

Huntington's disease (HD) is a genetic disorder caused by a CAG trinucleotide expansion in the huntingtin (HTT) gene. Juan de Acosta, Atlántico, a city located on the Caribbean coast of Colombia, is home to the world's second-largest HD pedigree. Here, we include 291 descendants of this pedigree with at least one family member with HD. Blood samples were collected, and genomic DNA was extracted. We quantified the HTT CAG expansion using an amplicon sequencing protocol. The genetic heterogeneity was measured as the ratio of the mosaicism allele's read peak and the slippage ratio of the allele's read peak from our sequence data. The statistical and bioinformatic analyses were performed with a significance threshold of p < 0.05. We found that the average HTT CAG repeat length in all participants was 21.91 (SD = 8.92). Of the 291 participants, 33 (11.3%, 18 females) had a positive molecular diagnosis for HD. Most affected individuals were adults, and the most common primary and secondary alleles were 17/7 (CAG/CCG) and 17/10 (CAG/CCG), respectively. The mosaicism increased with age in the participants with HD, while the slippage analyses revealed differences by the HD allele type only for the secondary allele. The slippage tended to increase with the HTT CAG repeat length in the participants with HD, but the increase was not statistically significant. This study analyzed the genetic and molecular features of 291 participants, including 33 with HD. We found that the mosaicism increased with age in the participants with HD, particularly for the secondary allele. The most common haplotype was 17/7_17/10. The slippage for the secondary allele varied by the HD allele type, but there was no significant difference in the slippage by sex. Our findings offer valuable insights into HD and could have implications for future research and clinical management.


Assuntos
Doença de Huntington , Adulto , Feminino , Humanos , Doença de Huntington/genética , Doença de Huntington/diagnóstico , Colômbia , Alelos , DNA , Linhagem , Proteína Huntingtina/genética , Expansão das Repetições de Trinucleotídeos
9.
Pharmacogenomics J ; 22(2): 100-108, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34824386

RESUMO

Indigenous Australians face a disproportionately severe burden of chronic disease relative to other Australians, with elevated rates of morbidity and mortality. While genomics technologies are slowly gaining momentum in personalised treatments for many, a lack of pharmacogenomic research in Indigenous peoples could delay adoption. Appropriately implementing pharmacogenomics in clinical care necessitates an understanding of the frequencies of pharmacologically relevant genetic variants within Indigenous populations. We analysed whole-genome sequence data from 187 individuals from the Tiwi Islands and characterised the pharmacogenomic landscape of this population. Specifically, we compared variant profiles and allelic distributions of previously described pharmacologically significant genes and variants with other population groups. We identified 22 translationally relevant pharmacogenomic variants and 18 clinically actionable guidelines with implications for drug dosing and treatment of conditions including heart disease, diabetes and cancer. We specifically observed increased poor and intermediate metabolizer phenotypes in the CYP2C9 (PM:19%, IM:44%) and CYP2C19 (PM:18%, IM:44%) genes.


Assuntos
Povos Indígenas , Testes Farmacogenômicos , Austrália , Citocromo P-450 CYP2C9/genética , Humanos , Variantes Farmacogenômicos
10.
Transfusion ; 62(5): 1110-1120, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35403234

RESUMO

BACKGROUND: Red blood cell (RBC) membrane-associated blood group systems are clinically significant. Alloimmunisation is a persistent risk associated with blood transfusion owing to the antigen polymorphisms among these RBC-associated blood groups. Next-generation sequencing (NGS) offers an opportunity to characterize the blood group variant profile of a given individual. Australia comprises a large multiethnic population where most blood donors are Caucasian and blood group variants remain poorly studied among Indigenous Australians. In this study, we focused on the Tiwi Islanders, who have lived in relative isolation for thousands of years. METHODS AND MATERIALS: We predicted the blood group phenotype profiles in the Tiwi (457) and 1000 Genomes Phase 3 (1KGP3-2504) cohort individuals using RBCeq (https://www.rbceq.org/). The predicted phenotype prevalence was compared with the previous literature report. RESULTS: We report, for the first time, comprehensive blood group profiles corresponding to the 35 known blood group systems among the Indigenous Tiwi islander population and identify possible novel antigen variants therein. Our results demonstrate that the genetic makeup of the Tiwi participants is distinct from that of other populations, with a low prevalence of LU (Au[a-b+]) and ABO (A2) and D+C+c+E+e- phenotype, an absence of Diego blood group variants, and a unique RHD (DIII type4) variant. CONCLUSION: Our results may contribute to the development of a database of predicted phenotype donors among the Tiwi population and aid in improving transfusion safety for the ~2800 Tiwi people and the ~800,000 other Indigenous Australians throughout the nation.


Assuntos
Antígenos de Grupos Sanguíneos , Alelos , Austrália , Doadores de Sangue , Antígenos de Grupos Sanguíneos/genética , Genômica , Humanos
11.
BMC Bioinformatics ; 22(1): 417, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34470617

RESUMO

BACKGROUND: Variation in mitochondrial DNA (mtDNA) identified by genotyping microarrays or by sequencing only the hypervariable regions of the genome may be insufficient to reliably assign mitochondrial genomes to phylogenetic lineages or haplogroups. This lack of resolution can limit functional and clinical interpretation of a substantial body of existing mtDNA data. To address this limitation, we developed and evaluated a large, curated reference alignment of complete mtDNA sequences as part of a pipeline for imputing missing mtDNA single nucleotide variants (mtSNVs). We call our reference alignment and pipeline MitoImpute. RESULTS: We aligned the sequences of 36,960 complete human mitochondrial genomes downloaded from GenBank, filtered and controlled for quality. These sequences were reformatted for use in imputation software, IMPUTE2. We assessed the imputation accuracy of MitoImpute by measuring haplogroup and genotype concordance in data from the 1000 Genomes Project and the Alzheimer's Disease Neuroimaging Initiative (ADNI). The mean improvement of haplogroup assignment in the 1000 Genomes samples was 42.7% (Matthew's correlation coefficient = 0.64). In the ADNI cohort, we imputed missing single nucleotide variants. CONCLUSION: These results show that our reference alignment and panel can be used to impute missing mtSNVs in existing data obtained from using microarrays, thereby broadening the scope of functional and clinical investigation of mtDNA. This improvement may be particularly useful in studies where participants have been recruited over time and mtDNA data obtained using different methods, enabling better integration of early data collected using less accurate methods with more recent sequence data.


Assuntos
DNA Mitocondrial , Polimorfismo de Nucleotídeo Único , DNA Mitocondrial/genética , Frequência do Gene , Genoma Humano , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Filogenia
12.
Mol Biol Evol ; 37(3): 811-827, 2020 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-31770430

RESUMO

The diversity of color vision systems found in extant vertebrates suggests that different evolutionary selection pressures have driven specializations in photoreceptor complement and visual pigment spectral tuning appropriate for an animal's behavior, habitat, and life history. Aquatic vertebrates in particular show high variability in chromatic vision and have become important models for understanding the role of color vision in prey detection, predator avoidance, and social interactions. In this study, we examined the capacity for chromatic vision in elasmobranch fishes, a group that have received relatively little attention to date. We used microspectrophotometry to measure the spectral absorbance of the visual pigments in the outer segments of individual photoreceptors from several ray and shark species, and we sequenced the opsin mRNAs obtained from the retinas of the same species, as well as from additional elasmobranch species. We reveal the phylogenetically widespread occurrence of dichromatic color vision in rays based on two cone opsins, RH2 and LWS. We also confirm that all shark species studied to date appear to be cone monochromats but report that in different species the single cone opsin may be of either the LWS or the RH2 class. From this, we infer that cone monochromacy in sharks has evolved independently on multiple occasions. Together with earlier discoveries in secondarily aquatic marine mammals, this suggests that cone-based color vision may be of little use for large marine predators, such as sharks, pinnipeds, and cetaceans.


Assuntos
Opsinas/genética , Opsinas/metabolismo , Retina/metabolismo , Tubarões/metabolismo , Rajidae/metabolismo , Animais , Visão de Cores , Proteínas de Peixes/genética , Proteínas de Peixes/metabolismo , Perfilação da Expressão Gênica , Microespectrofotometria , Filogenia , Células Fotorreceptoras Retinianas Cones/metabolismo , Análise de Sequência de RNA , Tubarões/genética , Rajidae/genética
13.
Nature ; 516(7530): 198-206, 2014 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-25503233

RESUMO

Somatic cell reprogramming to a pluripotent state continues to challenge many of our assumptions about cellular specification, and despite major efforts, we lack a complete molecular characterization of the reprograming process. To address this gap in knowledge, we generated extensive transcriptomic, epigenomic and proteomic data sets describing the reprogramming routes leading from mouse embryonic fibroblasts to induced pluripotency. Through integrative analysis, we reveal that cells transition through distinct gene expression and epigenetic signatures and bifurcate towards reprogramming transgene-dependent and -independent stable pluripotent states. Early transcriptional events, driven by high levels of reprogramming transcription factor expression, are associated with widespread loss of histone H3 lysine 27 (H3K27me3) trimethylation, representing a general opening of the chromatin state. Maintenance of high transgene levels leads to re-acquisition of H3K27me3 and a stable pluripotent state that is alternative to the embryonic stem cell (ESC)-like fate. Lowering transgene levels at an intermediate phase, however, guides the process to the acquisition of ESC-like chromatin and DNA methylation signature. Our data provide a comprehensive molecular description of the reprogramming routes and is accessible through the Project Grandiose portal at http://www.stemformatics.org.


Assuntos
Reprogramação Celular/genética , Genoma/genética , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Animais , Cromatina/química , Cromatina/genética , Cromatina/metabolismo , Montagem e Desmontagem da Cromatina , Metilação de DNA , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Epistasia Genética/genética , Fibroblastos/citologia , Fibroblastos/metabolismo , Histonas/química , Histonas/metabolismo , Internet , Camundongos , Proteoma/genética , Proteômica , RNA Longo não Codificante/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcrição Gênica/genética , Transcriptoma/genética , Transgenes/genética
14.
BMC Genomics ; 20(1): 460, 2019 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-31170930

RESUMO

BACKGROUND: Hibernation is a physiological state exploited by many animals exposed to prolonged adverse environmental conditions associated with winter. Large changes in metabolism and cellular function occur, with many stress response pathways modulated to tolerate physiological challenges that might otherwise be lethal. Many studies have sought to elucidate the molecular mechanisms of mammalian hibernation, but detailed analyses are lacking in reptiles. Here we examine gene expression in the Australian central bearded dragon (Pogona vitticeps) using mRNA-seq and label-free quantitative mass spectrometry in matched brain, heart and skeletal muscle samples from animals at late hibernation, 2 days post-arousal and 2 months post-arousal. RESULTS: We identified differentially expressed genes in all tissues between hibernation and post-arousal time points; with 4264 differentially expressed genes in brain, 5340 differentially expressed genes in heart, and 5587 differentially expressed genes in skeletal muscle. Furthermore, we identified 2482 differentially expressed genes across all tissues. Proteomic analysis identified 743 proteins (58 differentially expressed) in brain, 535 (57 differentially expressed) in heart, and 337 (36 differentially expressed) in skeletal muscle. Tissue-specific analyses revealed enrichment of protective mechanisms in all tissues, including neuroprotective pathways in brain, cardiac hypertrophic processes in heart, and atrophy protective pathways in skeletal muscle. In all tissues stress response pathways were induced during hibernation, as well as evidence for gene expression regulation at transcription, translation and post-translation. CONCLUSIONS: These results reveal critical stress response pathways and protective mechanisms that allow for maintenance of both tissue-specific function, and survival during hibernation in the central bearded dragon. Furthermore, we provide evidence for multiple levels of gene expression regulation during hibernation, particularly enrichment of miRNA-mediated translational repression machinery; a process that would allow for rapid and energy efficient reactivation of translation from mature mRNA molecules at arousal. This study is the first molecular investigation of its kind in a hibernating reptile, and identifies strategies not yet observed in other hibernators to cope stress associated with this remarkable state of metabolic depression.


Assuntos
Hibernação/genética , Répteis/genética , Adaptação Fisiológica , Animais , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Especificidade de Órgãos , Estresse Oxidativo/genética , Répteis/metabolismo , Répteis/fisiologia , Proteínas de Répteis/genética , Proteínas de Répteis/metabolismo
15.
Phytopathology ; 108(4): 495-509, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29135360

RESUMO

Plants have developed complex defense mechanisms to protect themselves against pathogens. A wide-host-range fungus, Austropuccinia psidii, which has caused severe damage to ecosystems and plantations worldwide, is a major threat to Australian ecosystems dominated by members of the family Myrtaceae. In particular, the east coast wetland foundation tree species Melaleuca quinquenervia, appears to be variably susceptible to this pathogen. Understanding the molecular basis of host resistance would enable better management of this rust disease. We identified resistant and susceptible individuals of M. quinquenervia and explored their differential gene expression in order to discover the molecular basis of resistance against A. psidii. Rust screening of germplasm showed a varying degree of response, with fully resistant to highly susceptible individuals. We used transcriptome profiling in samples collected before and at 5 days postinoculation (dpi). Differential gene expression analysis showed that numerous defense-related genes were induced in susceptible plants at 5 dpi. Mapping reads against the A. psidii genome showed that only susceptible plants contained fungal-derived transcripts. Resistant plants exhibited an overexpression of candidate A. psidii resistance-related genes such as receptor-like kinases, nucleotide-binding site leucine-rich repeat proteins, glutathione S-transferases, WRKY transcriptional regulators, and pathogenesis-related proteins. We identified large differences in the expression of defense-related genes among resistant individuals.


Assuntos
Basidiomycota/fisiologia , Resistência à Doença/genética , Melaleuca/genética , Doenças das Plantas/imunologia , Transcriptoma , Austrália , Ecossistema , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Melaleuca/imunologia , Melaleuca/microbiologia , Modelos Biológicos , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Folhas de Planta/imunologia , Folhas de Planta/microbiologia , Análise de Sequência de RNA , Árvores
16.
J Am Soc Nephrol ; 27(11): 3331-3344, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26961349

RESUMO

Cisplatin is an effective anticancer drug; however, cisplatin use often leads to nephrotoxicity, which limits its clinical effectiveness. In this study, we determined the effect of dichloroacetate, a novel anticancer agent, in a mouse model of cisplatin-induced AKI. Pretreatment with dichloroacetate significantly attenuated the cisplatin-induced increase in BUN and serum creatinine levels, renal tubular apoptosis, and oxidative stress. Additionally, pretreatment with dichloroacetate accelerated tubular regeneration after cisplatin-induced renal damage. Whole transcriptome sequencing revealed that dichloroacetate prevented mitochondrial dysfunction and preserved the energy-generating capacity of the kidneys by preventing the cisplatin-induced downregulation of fatty acid and glucose oxidation, and of genes involved in the Krebs cycle and oxidative phosphorylation. Notably, dichloroacetate did not interfere with the anticancer activity of cisplatin in vivo. These data provide strong evidence that dichloroacetate preserves renal function when used in conjunction with cisplatin.


Assuntos
Antineoplásicos/efeitos adversos , Cisplatino/efeitos adversos , Ácido Dicloroacético/uso terapêutico , Nefropatias/induzido quimicamente , Nefropatias/prevenção & controle , Animais , Antineoplásicos/uso terapêutico , Cisplatino/uso terapêutico , Feminino , Masculino , Camundongos , Camundongos Endogâmicos BALB C
17.
J Autoimmun ; 72: 65-72, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27209085

RESUMO

OBJECTIVES: Familial autoimmunity and polyautoimmunity represent extreme phenotypes ideal for identifying major genomic variants contributing to autoimmunity. Whole exome sequencing (WES) and linkage analysis are well suited for this purpose due to its strong resolution upon familial segregation patterns of functional protein coding and splice variants. The primary objective of this study was to identify potentially autoimmune causative variants using WES data from extreme pedigrees segregating polyautoimmunity phenotypes. METHODS: DNA of 47 individuals across 10 extreme pedigrees, ascertained from probands affected with polyautoimmunity and familial autoimmunity, were selected for WES. Variant calls were obtained through Genome Analysis Toolkit. Filtration and prioritization framework to identify mutation(s) were applied, and later implemented for genetic linkage analysis. Sanger sequencing corroborated variants with significant linkage. RESULTS: Novel and mostly rare variants harbored in SRA1, MLL4, ABCB8, DHX34 and PLAUR showed significant linkage (LOD scores are >3.0). The strongest signal was in SRA1, with a LOD score of 5.48. Network analyses indicated that SRA1, PLAUR and ABCB8 contribute to regulation of apoptotic processes. CONCLUSIONS: Novel and rare variants in genetic linkage with polyautoimmunity were identified throughout WES. Genes harboring these variants might be major players of autoimmunity.


Assuntos
Autoimunidade/genética , Predisposição Genética para Doença/genética , Genômica/métodos , Mutação , Transportadores de Cassetes de Ligação de ATP/genética , Sequência de Bases , Proteínas de Transporte/genética , Proteínas de Ligação a DNA/genética , Exoma/genética , Saúde da Família , Feminino , Redes Reguladoras de Genes , Histona-Lisina N-Metiltransferase , Humanos , Escore Lod , Masculino , Linhagem , Fenótipo , RNA Helicases/genética , Receptores de Ativador de Plasminogênio Tipo Uroquinase/genética , Análise de Sequência de DNA
19.
Neural Plast ; 2016: 9760314, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26949549

RESUMO

We previously reported age of onset (AOO) modifier genes in the world's largest pedigree segregating early-onset Alzheimer's disease (AD), caused by the p.Glu280Ala (E280A) mutation in the PSEN1 gene. Here we report the results of a targeted analysis of functional exonic variants in those AOO modifier genes in sixty individuals with PSEN1 E280A AD who were whole-exome genotyped for ~250,000 variants. Standard quality control, filtering, and annotation for functional variants were applied, and common functional variants located in those previously reported as AOO modifier loci were selected. Multiloci linear mixed-effects models were used to test the association between these variants and AOO. An exonic missense mutation in the G72 (DAOA) gene (rs2391191, P = 1.94 × 10(-4), P FDR = 9.34 × 10(-3)) was found to modify AOO in PSEN1 E280A AD. Nominal associations of missense mutations in the CLUAP1 (rs9790, P = 7.63 × 10(-3), P FDR = 0.1832) and EXOC2 (rs17136239, P = 0.0325, P FDR = 0.391) genes were also found. Previous studies have linked polymorphisms in the DAOA gene with the occurrence of neuropsychiatric symptoms such as depression, apathy, aggression, delusions, hallucinations, and psychosis in AD. Our findings strongly suggest that this new conspicuous functional AOO modifier within the G72 (DAOA) gene could be pivotal for understanding the genetic basis of AD.


Assuntos
Doença de Alzheimer/genética , Proteínas de Transporte/genética , Mutação de Sentido Incorreto , Presenilina-1/genética , Idade de Início , Éxons , Feminino , Predisposição Genética para Doença , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Masculino
20.
Am J Med Genet B Neuropsychiatr Genet ; 171(8): 1116-1130, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27573710

RESUMO

The identification of mutations modifying the age of onset (AOO) in Alzheimer's disease (AD) is crucial for understanding the natural history of AD and, therefore, for early interventions. Patients with sporadic AD (sAD) from a genetic isolate in the extremes of the AOO distribution were whole-exome genotyped. Single- and multi-locus linear mixed-effects models were used to identify functional variants modifying AOO. A posteriori enrichment and bioinformatic analyses were applied to evaluate the non-random clustering of the associate variants to physiopathological pathways involved in AD. We identified more than 20 pathogenic, genome-wide statistically significant mutations of major modifier effect on the AOO. These variants are harbored in genes implicated in neuron apoptosis, neurogenesis, inflammatory processes linked to AD, oligodendrocyte differentiation, and memory processes. This set of new genes harboring these mutations could be of importance for prediction, follow-up and eventually as therapeutical targets of AD. © 2016 Wiley Periodicals, Inc.


Assuntos
Idade de Início , Doença de Alzheimer/genética , Idoso , Exoma , Feminino , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla/métodos , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Mutação
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