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1.
Poult Sci ; 102(6): 102675, 2023 Jun.
Article En | MEDLINE | ID: mdl-37088046

The effects of concurrent reduction of dietary metabolizable energy (ME) and crude protein (CP) levels combined or not with the dietary inclusion of a phytogenic feed additive (PFA) were studied using a nutrigenomics approach. In particular, the expression of 26 critical genes relevant for inflammation control (TLR pathway), cellular apoptosis (MAPK pathway) cell growth and nutrient metabolism (PI3K-Akt-mTOR pathway) was profiled along the broiler intestine. Two dietary types (L and H) differing in metabolizable energy and crude protein levels (L: 95% and H: 100% of optimal Cobb 500 recommendations for ME and CP requirements) supplemented or not with PFA (- or +) and their interactions (L-, L+, H-, H+) were evaluated. There were only 3 total interactions (mTOR, IL8, and HRAS P < 0.05) between diet type and PFA inclusion indicating limited concurrent effects. Diet type, L upregulated genes related with inflammation mainly in the jejunum, ileum, and cecum (P < 0.05) and MAPK pathway in the ileum and cecum (P < 0.05). Moreover, diet type L negatively affected the expression of genes related to PI3K-Akt-mTOR pathway mainly in duodenum and cecum (P < 0.05). On the other hand, PFA inclusion downregulated (P < 0.05) genes related with TLR signaling pathway (TLR2B, MyD88, TLR3, IL8, LITAF) along the intestine and MAPK pathway genes (APO1, FOS) in jejunum (P < 0.05). Finally, PFA supplementation regulated nutrient sensing and metabolism in the cecum in a manner perceived as beneficial for growth. In conclusion, the study results highlight that the reduced ME and CP specifications, especially in the absence of PFA, regulate inflammation, apoptosis and nutrient metabolism processes at homeostatic control levels that hinder maximizing the availability of dietary energy and nutrients for growth purposes. Inclusion of PFA helped to adjust the respective homeostatic responses and control to levels supporting broiler performance, especially at reduced specification diets.


Phosphatidylinositol 3-Kinases , Proto-Oncogene Proteins c-akt , Animals , Phosphatidylinositol 3-Kinases/genetics , Phosphatidylinositol 3-Kinases/pharmacology , Proto-Oncogene Proteins c-akt/genetics , Mitogen-Activated Protein Kinases , Interleukin-8 , Nutrigenomics , Digestion , Chickens/physiology , Diet/veterinary , Dietary Supplements , Toll-Like Receptors/genetics , Signal Transduction , TOR Serine-Threonine Kinases/genetics , Gene Components , Apoptosis , Animal Feed/analysis , Animal Nutritional Physiological Phenomena
2.
Reumatol. clín. (Barc.) ; 18(10): 614-620, dic. 2022. tab
Article Es | IBECS | ID: ibc-211898

El propósito de esta revisión es presentar los principales aspectos del componente genético de las enfermedades reumatológicas autoinmunes, incluyendo las características del modelo de herencia multifactorial o poligénico y sus formas monogénicas, así como los principales genes asociados en ambos casos. De igual manera, los cambios epigenéticos implicados, además de la influencia del ambiente y el sexo para conferir mayor riesgo a las mujeres de padecer alguna de estas enfermedades. Finalmente, se comenta acerca de los avances logrados por el estudio de las ciencias ómicas, abriendo camino a una nueva clasificación molecular de estas enfermedades, y así dirigirlo a una medicina personalizada. Se revisó la literatura de los últimos 5 años de publicaciones en lengua inglesa mediante la base de datos PubMed, se incluyeron 28 artículos de revisión y 19 artículos originales. Se discutió el papel de los factores genéticos que participan en la etiología de las enfermedades reumatológicas autoinmunes, gracias a la disponibilidad de estudios moleculares, lo que permite mayor comprensión de la fisiopatología y la posibilidad de realizar en un futuro cercano un diagnóstico y tratamiento basado en marcadores moleculares.(AU)


The purpose of this review is to present the main aspects of the genetic component of autoimmune rheumatic diseases, including the characteristics of the multifactorial or polygenic inheritance model, and its monogenic forms, as well as the main associated genes in both cases. The epigenetic changes involved, and the influence of the environment and sex that confer greater risk to women suffering from any of these diseases. Finally, to make known the advances that the study of omic sciences has allowed, opening the way to a new molecular classification of these diseases, aimed at personalized medicine. A review of the literature of the last 5 years, of English-language publications, in the PubMed database was performed and 28 review articles, and 19 original articles were included. Knowledge of the genetic factors involved in the aetiology of autoimmune rheumatic diseases, thanks to the availability of molecular studies, allows a better understanding of their pathophysiology and the possibility of diagnosis and treatment based on molecular markers in the future.(AU)


Humans , Male , Female , Autoimmune Diseases , Gene Components , Multifactorial Inheritance , Epigenomics , Sex , Genetics , Rheumatology , Rheumatic Diseases
4.
Mol Biol Evol ; 38(2): 486-501, 2021 01 23.
Article En | MEDLINE | ID: mdl-32946576

Bumblebees are a diverse group of globally important pollinators in natural ecosystems and for agricultural food production. With both eusocial and solitary life-cycle phases, and some social parasite species, they are especially interesting models to understand social evolution, behavior, and ecology. Reports of many species in decline point to pathogen transmission, habitat loss, pesticide usage, and global climate change, as interconnected causes. These threats to bumblebee diversity make our reliance on a handful of well-studied species for agricultural pollination particularly precarious. To broadly sample bumblebee genomic and phenotypic diversity, we de novo sequenced and assembled the genomes of 17 species, representing all 15 subgenera, producing the first genus-wide quantification of genetic and genomic variation potentially underlying key ecological and behavioral traits. The species phylogeny resolves subgenera relationships, whereas incomplete lineage sorting likely drives high levels of gene tree discordance. Five chromosome-level assemblies show a stable 18-chromosome karyotype, with major rearrangements creating 25 chromosomes in social parasites. Differential transposable element activity drives changes in genome sizes, with putative domestications of repetitive sequences influencing gene coding and regulatory potential. Dynamically evolving gene families and signatures of positive selection point to genus-wide variation in processes linked to foraging, diet and metabolism, immunity and detoxification, as well as adaptations for life at high altitudes. Our study reveals how bumblebee genes and genomes have evolved across the Bombus phylogeny and identifies variations potentially linked to key ecological and behavioral traits of these important pollinators.


Adaptation, Biological/genetics , Bees/genetics , Biological Evolution , Genome, Insect , Animals , Codon Usage , DNA Transposable Elements , Diet , Feeding Behavior , Gene Components , Genome Size , Selection, Genetic
5.
IEEE/ACM Trans Comput Biol Bioinform ; 18(6): 2471-2482, 2021.
Article En | MEDLINE | ID: mdl-32078558

Recognition of the functional sites of genes, such as translation initiation sites, donor and acceptor splice sites and stop codons, is a relevant part of many current problems in bioinformatics. The best approaches use sophisticated classifiers, such as support vector machines. However, with the rapid accumulation of sequence data, methods for combining many sources of evidence are necessary as it is unlikely that a single classifier can solve this problem with the best possible performance. A major issue is that the number of possible models to combine is large and the use of all of these models is impractical. In this paper we present a methodology for combining many sources of information to recognize any functional site using "floating search", a powerful heuristics applicable when the cost of evaluating each solution is high. We present experiments on four functional sites in the human genome, which is used as the target genome, and use another 20 species as sources of evidence. The proposed methodology shows significant improvement over state-of-the-art methods. The results show an advantage of the proposed method and also challenge the standard assumption of using only genomes not very close and not very far from the human to improve the recognition of functional sites.


Computational Biology/methods , Gene Components/genetics , Genome, Human/genetics , Sequence Analysis, DNA/methods , Algorithms , Base Sequence/genetics , Humans , Models, Genetic
6.
Oncología (Guayaquil) ; 29(3): 220-228, 31 de diciembre del 2019.
Article Es | LILACS | ID: biblio-1140799

Introducción: Existen factores de riesgo que se asocian a desarrollo cáncer de tiroides diferenciado; la Tiroglobulina es una proteína ligada al tamaño tumoral, su rol dentro de las patologías oncológicas es controversial. El objetivo del estudio fue determinarsi las variaciones del gen de Tiroglobulina se asocian a la presencia de cáncer tiroideo. Métodos:Este estudio observacional de casos y controles se realizó con muestra no probabilística con muestras de patología de casos de cáncertiroideo diagnosticados en elHospital Oncológico Solón Espinosa Ayala de Quito. Se estableció un grupocontrol con voluntarios sanos. Se mide las variaciones SER734Ala y ARG1980 trp del gen de la Tiroglobulina. Se comparan las frecuencias con Chi cuadrado. Resultados:Un total de 51casos de cáncertiroideo y 50 controles. Variaciones en SER734Ala en el grupo de casos fueron homocigotos 24/51casos (53.3% (IC95% 38.8 -67.9%)en el grupo controlfueron24/50(53.3% (IC95% 38.8-67.9%)P=0.83. La variaciónheterocigotaARG1980 trp fueron en el grupo de casos 47/51(92.2%IC95% 84.3 -100%), en los controles 35/50(70% IC95% 56.6-83.4%)P=0.004. Conclusión:Se demostró que lasvariaciones del gen de laTiroglobulina pueden presentarse en pacientes con Cáncer Tiroideo en igual frecuencia que en voluntarios sanos


Introduction: There are risk factors associated with the development of differentiated thyroid cancer; Thyroglobulin is a protein linked to tumor size, its role in oncological pathologies is controversial. The objective of the study was to determine whether variations in the thyroglobulin gene are associated with the presence of thyroid cancer. Methods: This observational case-control study was conducted with a non-probabilistic sample with pathology samples from thyroid cancer cases diagnosed at the Solón Espinosa Ayala Oncological Hospital in Quito. A control group with healthy volunteers was established. The SER734Ala and ARG1980 trp variations of the Thyroglobulin gene are measured. The frequencies werecompared with Chi square. Results:A total of 51 thyroid cancer cases and 50 controls. Variations in SER734Ala in the group of cases were homozygous 24/51 cases (53.3% (CI95% 38.8 -67.9%) in the control group were 24/50 (53.3% (CI95% 38.8-67.9%) P = 0.83. Heterozygous ARG1980 trp were in the case group 47/51 (92.2% 95% CI 84.3 -100%), in the controls 35/50 (70% 95% CI 56.6-83.4%) P = 0.004. Conclusion:It was shown that variations of the Thyroglobulin gene couldoccur in patients with Thyroid Cancer in the same frequency as in healthy volunteers


Humans , Thyroglobulin , Thyroid Neoplasms , Gene Components , Volunteers
7.
Am J Hum Genet ; 104(2): 299-309, 2019 02 07.
Article En | MEDLINE | ID: mdl-30686509

Different parts of a gene can be of differential importance to development and health. This regional heterogeneity is also apparent in the distribution of disease-associated mutations, which often cluster in particular regions of disease-associated genes. The ability to precisely estimate functionally important sub-regions of genes will be key in correctly deciphering relationships between genetic variation and disease. Previous methods have had some success using standing human variation to characterize this variability in importance by measuring sub-regional intolerance, i.e., the depletion in functional variation from expectation within a given region of a gene. However, the ability to precisely estimate local intolerance was restricted by the fact that only information within a given sub-region is used, leading to instability in local estimates, especially for small regions. We show that borrowing information across regions using a Bayesian hierarchical model stabilizes estimates, leading to lower variability and improved predictive utility. Specifically, our approach more effectively identifies regions enriched for ClinVar pathogenic variants. We also identify significant correlations between sub-region intolerance and the distribution of pathogenic variation in disease-associated genes, with AUCs for classifying de novo missense variants in Online Mendelian Inheritance in Man (OMIM) genes of up to 0.86 using exonic sub-regions and 0.91 using sub-regions defined by protein domains. This result immediately suggests that considering the intolerance of regions in which variants are found may improve diagnostic interpretation. We also illustrate the utility of integrating regional intolerance into gene-level disease association tests with a study of known disease-associated genes for epileptic encephalopathy.


Gene Components/genetics , Models, Genetic , Mutation/genetics , Spasms, Infantile/genetics , Spasms, Infantile/pathology , Bayes Theorem , Exons/genetics , Humans
8.
J Glob Antimicrob Resist ; 17: 309-311, 2019 06.
Article En | MEDLINE | ID: mdl-30684654

OBJECTIVES: Alteration of the porin-encoding gene oprD by insertion sequences (ISs) is one mechanism conferring carbapenem resistance in Pseudomonas aeruginosa. Here we describe a carbapenem-resistant clinical P. aeruginosa isolate 36-989 harbouring a novel IS (ISPa195) in oprD. METHODS: Minimum inhibitory concentrations (MICs) of antimicrobial agents were determined by the broth microdilution method. Carbapenemase activity was assessed using a MALDI-TOF/MS-based assay of meropenem hydrolysis. Efflux-dependent carbapenem resistance was evaluated using an assay with carbonyl cyanide 3-chlorophenylhydrazone (CCCP). The oprD gene and IS sequence were analysed by the Sanger method. Whole-genome sequencing was performed on an Illumina HiSeq 2500 platform. RESULTS: Antimicrobial susceptibility testing demonstrated that P. aeruginosa 36-989 was resistant to imipenem (MIC=32mg/L) and meropenem (MIC=16mg/L). No carbapenemase activity was detected, however an efflux-mediated component of carbapenem resistance was revealed. A new IS element (ISPa195) was found in the oprD gene of P. aeruginosa 36-989. ISPa195 was 1190bp in length, belonging to the IS3 family, and contained two open reading frames that overlapped through a ribosomal slippage to translate the full-size transposase enzyme. There was an IS-associated 284-bp deletion in the oprD gene; no direct repeats at flanking regions of the IS were detected. CONCLUSION: The absence of direct repeats at flanking regions in combination with the IS-associated deletion distinguished ISPa195 from other ISs previously detected in oprD. Carbapenem resistance in P. aeruginosa 36-989 was conferred by a combination of oprD alteration and carbapenem efflux.


DNA Transposable Elements/genetics , Drug Resistance, Multiple, Bacterial/genetics , Porins/genetics , Pseudomonas aeruginosa/genetics , Sequence Deletion , Anti-Bacterial Agents/pharmacology , Bacterial Proteins , Carbapenems/pharmacology , Gene Components , Humans , Imipenem/pharmacology , Meropenem/metabolism , Microbial Sensitivity Tests , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/drug effects , beta-Lactamases
9.
Nucleic Acids Res ; 46(D1): D794-D801, 2018 01 04.
Article En | MEDLINE | ID: mdl-29126249

The Encyclopedia of DNA Elements (ENCODE) Data Coordinating Center has developed the ENCODE Portal database and website as the source for the data and metadata generated by the ENCODE Consortium. Two principles have motivated the design. First, experimental protocols, analytical procedures and the data themselves should be made publicly accessible through a coherent, web-based search and download interface. Second, the same interface should serve carefully curated metadata that record the provenance of the data and justify its interpretation in biological terms. Since its initial release in 2013 and in response to recommendations from consortium members and the wider community of scientists who use the Portal to access ENCODE data, the Portal has been regularly updated to better reflect these design principles. Here we report on these updates, including results from new experiments, uniformly-processed data from other projects, new visualization tools and more comprehensive metadata to describe experiments and analyses. Additionally, the Portal is now home to meta(data) from related projects including Genomics of Gene Regulation, Roadmap Epigenome Project, Model organism ENCODE (modENCODE) and modERN. The Portal now makes available over 13000 datasets and their accompanying metadata and can be accessed at: https://www.encodeproject.org/.


DNA/genetics , Databases, Genetic , Gene Components , Genomics , High-Throughput Nucleotide Sequencing , Metadata , Animals , Caenorhabditis elegans/genetics , Data Display , Datasets as Topic , Drosophila melanogaster/genetics , Forecasting , Genome, Human , Humans , Mice/genetics , User-Computer Interface
10.
Insect Mol Biol ; 26(5): 616-632, 2017 10.
Article En | MEDLINE | ID: mdl-28636075

Pheromone biosynthesis activating neuropeptide (PBAN) is a member of the pyrokinin (FXPRLamide) insect neuropeptides. Here, we report the cloning of the gene Ostnu-PBAN from the E and Z pheromone strains of the European corn borer (ECB), Ostrinia nubilalis (Lepidoptera: Crambidae), a major pest of maize. The Ostnu-PBAN genomic sequence is > 5 kb in length and consists of six exons. The deduced amino acid sequence revealed a 200-residue precursor protein including a signal peptide, a 24-amino acid (aa) diapause hormone, a 37-aa PBAN and three other FXPRLamide neuropeptides. Our in vivo assays suggest that the 37-aa synthetic Ostnu-PBAN is hormonally active in the pheromone gland. It restores sex pheromone production to normal levels in mated females and decapitated virgins of both E and Z cultures. The results of a real-time PCR analysis indicated that Ostnu-PBAN mRNA levels reached a plateau in the brain-suboesophageal ganglion complexes 1 day after eclosion, and mating did not affect the mRNA expression. Three size classes of Ostnu-PBAN mRNA (1.9, 2.0 and 2.1 kb) were obtained, differing only in the length of the 3' untranslated region. However, there was no correlation between sequence divergence and the pheromone composition, voltinism or geographical origin (Hungary, Slovenia, Sweden, Turkey) of ECB moths.


Moths/genetics , Neuropeptides/genetics , Amino Acid Sequence , Animals , Base Sequence , Female , Gene Components , Male , Molecular Sequence Data , Moths/chemistry , Moths/growth & development , Moths/metabolism , Neuropeptides/chemistry , Neuropeptides/metabolism
11.
Insect Mol Biol ; 26(3): 317-331, 2017 06.
Article En | MEDLINE | ID: mdl-28234413

We expanded the view of Clock (Clk) and cycle (cyc) gene evolution in Diptera by studying the fruit fly Anastrepha fraterculus (Afra), a Brachycera. Despite the high conservation of clock genes amongst insect groups, striking structural and functional differences of some clocks have appeared throughout evolution. Clk and cyc nucleotide sequences and corresponding proteins were characterized, along with their mRNA expression data, to provide an evolutionary overview in the two major groups of Diptera: Lower Diptera and Higher Brachycera. We found that AfraCYC lacks the BMAL (Brain and muscle ARNT-like) C-terminus region (BCTR) domain and is constitutively expressed, suggesting that AfraCLK has the main transactivation function, which is corroborated by the presence of poly-Q repeats and an oscillatory pattern. Our analysis suggests that the loss of BCTR in CYC is not exclusive of drosophilids, as it also occurs in other Acalyptratae flies such as tephritids and drosophilids, however, but it is also present in some Calyptratae, such as Muscidae, Calliphoridae and Sarcophagidae. This indicates that BCTR is missing from CYC of all higher-level Brachycera and that it was lost during the evolution of Lower Brachycera. Thus, we can infer that CLK protein may play the main role in the CLK\CYC transcription complex in these flies, like in its Drosophila orthologues.


ARNTL Transcription Factors/genetics , CLOCK Proteins/genetics , Drosophila Proteins/genetics , Drosophila/genetics , Evolution, Molecular , Tephritidae/genetics , Amino Acid Sequence , Animals , Female , Gene Components , Male , Molecular Sequence Data , Tephritidae/metabolism
12.
Acta Biochim Pol ; 63(4): 623-630, 2016.
Article En | MEDLINE | ID: mdl-27830839

Enteroviruses are small RNA(+) viruses that encode one open reading frame flanked by two extensive noncoding regions carrying structural RNA regulatory elements that control replication and translation processes. For a long time the central, coding region was thought to remain single-stranded and its only function was supposed to be as the template for polyprotein synthesis. It turned out, however, that the protein coding region also encodes important RNA structures crucial for the viral life cycle and virus persistence in the host cells. This review considers the RNA structures in enteroviral genomes identified and characterized to date.


Enterovirus/genetics , RNA, Viral/genetics , 3' Untranslated Regions , Base Sequence , Gene Components , Genome, Viral , Humans , Inverted Repeat Sequences , Protein Biosynthesis , Viral Proteins/genetics , Virus Replication
13.
Br J Haematol ; 174(5): 806-14, 2016 09.
Article En | MEDLINE | ID: mdl-27292444

Hereditary haemolytic anaemias are genetically and phenotypically heterogeneous disorders characterized by increased red cell destruction, with consequences ranging from innocuous to severe life-threatening anaemia. Diagnostic laboratories endeavour to assist clinicians reach the exact patient diagnosis by using tests principally based on morphological and biochemical techniques. However, these routine studies may be inconclusive, particularly in newborn infants and when transfusions have recently been administered. Large numbers and size of the potentially involved genes also impose a practical challenge for molecular diagnosis using routine sequencing approaches. To overcome these diagnostic shortcomings, we have utilized next-generation sequencing to provide a high-throughput, highly sensitive assay. We developed a panel interrogating 28 genes encoding cytoskeletal proteins and enzymes with sequencing coverage of the coding regions, splice site junctions, deep intronic and regulatory regions. We then evaluated 19 samples, including infants with unexplained extreme hyperbilirubinaemia and patients with transfusion-dependent haemolytic anaemia. Where possible, inheritance patterns of pathogenic mutations were determined by sequencing of immediate relatives. We conclude that this next-generation sequencing panel could be a cost-effective approach to molecular diagnosis of hereditary haemolytic anaemia, especially when the family history is uninformative or when routine laboratory testing fails to identify the causative haemolytic process.


Anemia, Hemolytic, Congenital/diagnosis , High-Throughput Nucleotide Sequencing/methods , Adolescent , Adult , Anemia, Hemolytic, Congenital/genetics , Child , Child, Preschool , Cytoskeletal Proteins/genetics , Enzymes/genetics , Gene Components/genetics , High-Throughput Nucleotide Sequencing/economics , Humans , Hyperbilirubinemia, Hereditary/diagnosis , Infant , Infant, Newborn , Molecular Diagnostic Techniques/economics , Molecular Diagnostic Techniques/methods , Mutation , Young Adult
14.
Proc Natl Acad Sci U S A ; 113(11): 2922-7, 2016 Mar 15.
Article En | MEDLINE | ID: mdl-26936952

Sesquiterpenes play important roles in insect communication, for example as pheromones. However, no sesquiterpene synthases, the enzymes involved in construction of the basic carbon skeleton, have been identified in insects to date. We investigated the biosynthesis of the sesquiterpene (6R,7S)-himachala-9,11-diene in the crucifer flea beetle Phyllotreta striolata, a compound previously identified as a male-produced aggregation pheromone in several Phyllotreta species. A (6R,7S)-himachala-9,11-diene-producing sesquiterpene synthase activity was detected in crude beetle protein extracts, but only when (Z,E)-farnesyl diphosphate [(Z,E)-FPP] was offered as a substrate. No sequences resembling sesquiterpene synthases from plants, fungi, or bacteria were found in the P. striolata transcriptome, but we identified nine divergent putative trans-isoprenyl diphosphate synthase (trans-IDS) transcripts. Four of these putative trans-IDSs exhibited terpene synthase (TPS) activity when heterologously expressed. Recombinant PsTPS1 converted (Z,E)-FPP to (6R,7S)-himachala-9,11-diene and other sesquiterpenes observed in beetle extracts. RNAi-mediated knockdown of PsTPS1 mRNA in P. striolata males led to reduced emission of aggregation pheromone, confirming a significant role of PsTPS1 in pheromone biosynthesis. Two expressed enzymes showed genuine IDS activity, with PsIDS1 synthesizing (E,E)-FPP, whereas PsIDS3 produced neryl diphosphate, (Z,Z)-FPP, and (Z,E)-FPP. In a phylogenetic analysis, the PsTPS enzymes and PsIDS3 were clearly separated from a clade of known coleopteran trans-IDS enzymes including PsIDS1 and PsIDS2. However, the exon-intron structures of IDS and TPS genes in P. striolata are conserved, suggesting that this TPS gene family evolved from trans-IDS ancestors.


Alkyl and Aryl Transferases/classification , Coleoptera/enzymology , Genes, Insect , Insect Proteins/classification , Multigene Family , Pheromones/biosynthesis , Sesquiterpenes/metabolism , Alkyl and Aryl Transferases/genetics , Alkyl and Aryl Transferases/isolation & purification , Amino Acid Sequence , Animals , Cloning, Molecular , Coleoptera/classification , Coleoptera/genetics , Evolution, Molecular , Female , Gene Components , Genetic Speciation , Insect Proteins/genetics , Insect Proteins/isolation & purification , Male , Molecular Sequence Data , Open Reading Frames/genetics , Phylogeny , Recombinant Fusion Proteins/metabolism , Sequence Homology, Amino Acid , Transcriptome
15.
Mol Biochem Parasitol ; 203(1-2): 25-33, 2015.
Article En | MEDLINE | ID: mdl-26523948

Trypanosoma cruzi is a protozoan parasite that causes Chagas disease, an illness that affects 6-7 million people and for which there is no effective drug therapy or vaccine. The publication of its complete genome sequence allowed a rapid advance in molecular studies including in silico screening of genes involved with pathogenicity as well as molecular targets for the development of new diagnostic methods, drug therapies and prophylactic vaccines. Alongside with in silico genomic analyses, methods to study gene function in this parasite such as gene deletion, overexpression, mutant complementation and reporter gene expression have been largely explored. More recently, the use of genome-wide strategies is producing a shift towards a global perspective on gene function studies, with the examination of the expression and biological roles of gene networks in different stages of the parasite life cycle and under different contexts of host parasite interactions. Here we describe the molecular tools and protocols currently available to perform genetic manipulation of the T. cruzi genome, with emphasis on recently described strategies of gene editing that will facilitate large-scale functional genomic analyses. These new methodologies are long overdue, since more efficient protocols for genetic manipulation in T. cruzi are urgently needed for a better understanding of the biology of this parasite and molecular processes involved with the complex and often harmful, interaction with its human host.


Chagas Disease/parasitology , Gene Expression Regulation , Gene Knockdown Techniques/methods , Gene Targeting/methods , Genome, Protozoan/genetics , Trypanosoma cruzi/genetics , Gene Components , Gene Regulatory Networks , Genes, Reporter , Host-Parasite Interactions/genetics , Host-Parasite Interactions/physiology , Humans , Life Cycle Stages , RNA, Spliced Leader/genetics , Trypanosoma cruzi/growth & development
16.
Proc Natl Acad Sci U S A ; 112(45): 14036-41, 2015 Nov 10.
Article En | MEDLINE | ID: mdl-26504242

RNAIII, the effector of the agr quorum-sensing system, plays a key role in virulence gene regulation in Staphylococcus aureus, but how RNAIII transcriptionally regulates its downstream genes is not completely understood. Here, we show that RNAIII stabilizes mgrA mRNA, thereby increasing the production of MgrA, a global transcriptional regulator that affects the expression of many genes. The mgrA gene is transcribed from two promoters, P1 and P2, to produce two mRNA transcripts with long 5' UTR. Two adjacent regions of the mgrA mRNA UTR transcribed from the upstream P2 promoter, but not the P1 promoter, form a stable complex with two regions of RNAIII near the 5' and 3' ends. We further demonstrate that the interaction has several biological effects. We propose that MgrA can serve as an intermediary regulator through which agr exerts its regulatory function.


Gene Expression Regulation, Bacterial/genetics , Quorum Sensing/genetics , RNA, Bacterial/metabolism , Regulatory Elements, Transcriptional/genetics , Staphylococcus aureus/enzymology , Base Pairing , Base Sequence , Blotting, Western , Electrophoretic Mobility Shift Assay , Gene Components , Molecular Sequence Data , Promoter Regions, Genetic/genetics , Real-Time Polymerase Chain Reaction
17.
Med Sci (Paris) ; 31(6-7): 680-6, 2015.
Article Fr | MEDLINE | ID: mdl-26152174

In September 2012, a batch of more than 30 articles presenting the results of the ENCODE (Encyclopaedia of DNA Elements) project was released. Many of these articles appeared in Nature and Science, the two most prestigious interdisciplinary scientific journals. Since that time, hundreds of other articles dedicated to the further analyses of the Encode data have been published. The time of hundreds of scientists and hundreds of millions of dollars were not invested in vain since this project had led to an apparent paradigm shift: contrary to the classical view, 80% of the human genome is not junk DNA, but is functional. This hypothesis has been criticized by evolutionary biologists, sometimes eagerly, and detailed refutations have been published in specialized journals with impact factors far below those that published the main contribution of the Encode project to our understanding of genome architecture. In 2014, the Encode consortium released a new batch of articles that neither suggested that 80% of the genome is functional nor commented on the disappearance of their 2012 scientific breakthrough. Unfortunately, by that time many biologists had accepted the idea that 80% of the genome is functional, or at least, that this idea is a valid alternative to the long held evolutionary genetic view that it is not. In order to understand the dynamics of the genome, it is necessary to re-examine the basics of evolutionary genetics because, not only are they well established, they also will allow us to avoid the pitfall of a panglossian interpretation of Encode. Actually, the architecture of the genome and its dynamics are the product of trade-offs between various evolutionary forces, and many structural features are not related to functional properties. In other words, evolution does not produce the best of all worlds, not even the best of all possible worlds, but only one possible world.


DNA/genetics , Encyclopedias as Topic , Gene Components , Genome, Human , Publishing , Animals , Humans , Phylogeny , Publishing/ethics , Publishing/standards , Scientific Misconduct
18.
Am J Hum Genet ; 96(6): 992-1000, 2015 Jun 04.
Article En | MEDLINE | ID: mdl-26046367

Autosomal-dominant lateral temporal epilepsy (ADLTE) is a genetic epilepsy syndrome clinically characterized by focal seizures with prominent auditory symptoms. ADLTE is genetically heterogeneous, and mutations in LGI1 account for fewer than 50% of affected families. Here, we report the identification of causal mutations in reelin (RELN) in seven ADLTE-affected families without LGI1 mutations. We initially investigated 13 ADLTE-affected families by performing SNP-array linkage analysis and whole-exome sequencing and identified three heterozygous missense mutations co-segregating with the syndrome. Subsequent analysis of 15 small ADLTE-affected families revealed four additional missense mutations. 3D modeling predicted that all mutations have structural effects on protein-domain folding. Overall, RELN mutations occurred in 7/40 (17.5%) ADLTE-affected families. RELN encodes a secreted protein, Reelin, which has important functions in both the developing and adult brain and is also found in the blood serum. We show that ADLTE-related mutations significantly decrease serum levels of Reelin, suggesting an inhibitory effect of mutations on protein secretion. We also show that Reelin and LGI1 co-localize in a subset of rat brain neurons, supporting an involvement of both proteins in a common molecular pathway underlying ADLTE. Homozygous RELN mutations are known to cause lissencephaly with cerebellar hypoplasia. Our findings extend the spectrum of neurological disorders associated with RELN mutations and establish a link between RELN and LGI1, which play key regulatory roles in both the developing and adult brain.


Cell Adhesion Molecules, Neuronal/genetics , Epilepsy, Frontal Lobe/genetics , Epilepsy, Frontal Lobe/pathology , Extracellular Matrix Proteins/genetics , Models, Molecular , Mutation, Missense/genetics , Nerve Tissue Proteins/genetics , Serine Endopeptidases/genetics , Sleep Wake Disorders/genetics , Sleep Wake Disorders/pathology , Animals , Base Sequence , Cell Adhesion Molecules, Neuronal/blood , Cell Adhesion Molecules, Neuronal/chemistry , Cell Adhesion Molecules, Neuronal/metabolism , Chromosome Mapping , Exome , Extracellular Matrix Proteins/blood , Extracellular Matrix Proteins/chemistry , Extracellular Matrix Proteins/metabolism , Fluorescent Antibody Technique , Gene Components , Humans , Immunoblotting , Intercellular Signaling Peptides and Proteins , Molecular Sequence Data , Nerve Tissue Proteins/blood , Nerve Tissue Proteins/chemistry , Nerve Tissue Proteins/metabolism , Pedigree , Polymorphism, Single Nucleotide/genetics , Protein Conformation , Protein Folding , Proteins/metabolism , Rats , Reelin Protein , Sequence Analysis, DNA , Serine Endopeptidases/blood , Serine Endopeptidases/chemistry , Serine Endopeptidases/metabolism
19.
Am J Hum Genet ; 96(6): 1001-7, 2015 Jun 04.
Article En | MEDLINE | ID: mdl-26046368

Fanconi anemia (FA) is a rare genetic disorder characterized by genome instability, increased cancer susceptibility, progressive bone marrow failure (BMF), and various developmental abnormalities resulting from the defective FA pathway. FA is caused by mutations in genes that mediate repair processes of interstrand crosslinks and/or DNA adducts generated by endogenous aldehydes. The UBE2T E2 ubiquitin conjugating enzyme acts in FANCD2/FANCI monoubiquitination, a critical event in the pathway. Here we identified two unrelated FA-affected individuals, each harboring biallelic mutations in UBE2T. They both produced a defective UBE2T protein with the same missense alteration (p.Gln2Glu) that abolished FANCD2 monoubiquitination and interaction with FANCL. We suggest this FA complementation group be named FA-T.


Fanconi Anemia/genetics , Fanconi Anemia/pathology , Models, Molecular , Mutation, Missense/genetics , Ubiquitin-Conjugating Enzymes/genetics , Amino Acid Sequence , Base Sequence , Child , Child, Preschool , Fanconi Anemia Complementation Group L Protein/metabolism , Female , Gene Components , Genotype , Humans , Japan , Male , Molecular Sequence Data , Pedigree , Protein Conformation , Sequence Alignment , Sequence Analysis, DNA , Ubiquitin-Conjugating Enzymes/chemistry , Ubiquitin-Conjugating Enzymes/metabolism , Ubiquitination/genetics
20.
Structure ; 23(6): 1028-38, 2015 Jun 02.
Article En | MEDLINE | ID: mdl-26004442

Replication Protein A (RPA) is an essential scaffold for many DNA processing machines; its function relies on its modular architecture. Here, we report (15)N-nuclear magnetic resonance heteronuclear relaxation analysis to characterize the movements of single-stranded (ss) DNA binding and protein interaction modules in the RPA70 subunit. Our results provide direct evidence for coordination of the motion of the tandem RPA70AB ssDNA binding domains. Moreover, binding of ssDNA substrate is found to cause dramatic reorientation and full coupling of inter-domain motion. In contrast, the RPA70N protein interaction domain remains structurally and dynamically independent of RPA70AB regardless of binding of ssDNA. This autonomy of motion between the 70N and 70AB modules supports a model in which the two binding functions of RPA are mediated fully independently, but remain differentially coordinated depending on the length of their flexible tethers. A critical role for linkers between the globular domains in determining the functional dynamics of RPA is proposed.


DNA/metabolism , Models, Molecular , Replication Protein A/chemistry , Replication Protein A/metabolism , Diffusion Tensor Imaging , Gene Components , Molecular Dynamics Simulation , Nuclear Magnetic Resonance, Biomolecular , Protein Binding , Protein Conformation , Protein Structure, Tertiary , Replication Protein A/genetics
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