44 research outputs found
Evidence for positive selection in the gene fruitless in Anastrepha fruit flies
<p>Abstract</p> <p>Background</p> <p>Many genes involved in the sex determining cascade have indicated signals of positive selection and rapid evolution across different species. Even though <it>fruitless </it>is an important gene involved mostly in several aspects of male courtship behavior, the few studies so far have explained its high rates of evolution by relaxed selective constraints. This would indicate that a large portion of this gene has evolved neutrally, contrary to what has been observed for other genes in the sex cascade.</p> <p>Results</p> <p>Here we test whether the <it>fruitless </it>gene has evolved neutrally or under positive selection in species of <it>Anastrepha </it>(Tephritidae: Diptera) using two different approaches, a long-term evolutionary analysis and a populational genetic data analysis. The first analysis was performed by using sequences of three species of <it>Anastrepha </it>and sequences from several species of <it>Drosophila </it>using the ratio of nonsynonymous to synonymous rates of evolution in PAML, which revealed that the <it>fru </it>region here studied has evolved by positive selection. Using Bayes Empirical Bayes we estimated that 16 sites located in the connecting region of the <it>fruitless </it>gene were evolving under positive selection. We also investigated for signs of this positive selection using populational data from 50 specimens from three species of <it>Anastrepha </it>from different localities in Brazil. The use of standard tests of selection and a new test that compares patterns of differential survival between synonymous and nonsynonymous in evolutionary time also provide evidence of positive selection across species and of a selective sweep for one of the species investigated.</p> <p>Conclusions</p> <p>Our data indicate that the high diversification of <it>fru </it>connecting region in <it>Anastrepha </it>flies is due at least in part to positive selection, not merely as a consequence of relaxed selective constraint. These conclusions are based not only on the comparison of distantly related taxa that show long-term divergence time, but also on recently diverged lineages and suggest that episodes of adaptive evolution in <it>fru </it>may be related to sexual selection and/or conflict related to its involvement in male courtship behavior.</p
RNA-seq analyses of blood-induced changes in gene expression in the mosquito vector species, Aedes aegypti
<p>Abstract</p> <p>Background</p> <p>Hematophagy is a common trait of insect vectors of disease. Extensive genome-wide transcriptional changes occur in mosquitoes after blood meals, and these are related to digestive and reproductive processes, among others. Studies of these changes are expected to reveal molecular targets for novel vector control and pathogen transmission-blocking strategies. The mosquito <it>Aedes aegypti </it>(Diptera, Culicidae), a vector of Dengue viruses, Yellow Fever Virus (YFV) and Chikungunya virus (CV), is the subject of this study to look at genome-wide changes in gene expression following a blood meal.</p> <p>Results</p> <p>Transcriptional changes that follow a blood meal in <it>Ae. aegypti </it>females were explored using RNA-seq technology. Over 30% of more than 18,000 investigated transcripts accumulate differentially in mosquitoes at five hours after a blood meal when compared to those fed only on sugar. Forty transcripts accumulate only in blood-fed mosquitoes. The list of regulated transcripts correlates with an enhancement of digestive activity and a suppression of environmental stimuli perception and innate immunity. The alignment of more than 65 million high-quality short reads to the <it>Ae. aegypti </it>reference genome permitted the refinement of the current annotation of transcript boundaries, as well as the discovery of novel transcripts, exons and splicing variants. <it>Cis</it>-regulatory elements (CRE) and <it>cis</it>-regulatory modules (CRM) enriched significantly at the 5'end flanking sequences of blood meal-regulated genes were identified.</p> <p>Conclusions</p> <p>This study provides the first global view of the changes in transcript accumulation elicited by a blood meal in <it>Ae. aegypti </it>females. This information permitted the identification of classes of potentially co-regulated genes and a description of biochemical and physiological events that occur immediately after blood feeding. The data presented here serve as a basis for novel vector control and pathogen transmission-blocking strategies including those in which the vectors are modified genetically to express anti-pathogen effector molecules.</p
De Novo assembly and transcriptome analysis of the mediterranean fruit fly ceratitis capitata early embryos
The agricultural pest Ceratitis capitata, also known as the Mediterranean fruit fly or Medfly, belongs to the Tephritidae family, which includes a large number of other damaging pest species. The Medfly has been the first non-drosophilid fly species which has been genetically transformed paving the way for designing geneticbased pest control strategies. Furthermore, it is an experimentally tractable model, in which transient and transgene-mediated RNAi have been successfully used. We applied Illumina sequencing to total RNA preparations of 8-10 hours old embryos of C. capitata, This developmental window corresponds to the blastoderm cellularization stage. In summary, we assembled 42,614 transcripts which cluster in 26,319 unique transcripts of which 11,045 correspond to protein coding genes; we identified several hundreds of long ncRNAs; we found an enrichment of transcripts encoding RNA binding proteins among the highly expressed transcripts, such as CcTRA-2, known to be necessary to establish and, most likely, to maintain female sex of C. capitata. Our study is the first de novo assembly performed for Ceratitis capitata based on Illumina NGS technology during embryogenesis and it adds novel data to the previously published C. capitata EST databases. We expect that it will be useful for a variety of applications such as gene cloning and phylogenetic analyses, as well as to advance genetic research and biotechnological applications in the Medfly and other related Tephritidae
Pemetaan Profil Mahasiswa Untuk Memprediksi Peminatan Mahasiswa
Program sarjana terapan merupakan pendidikan akademik yang ditempuh melalui perguruan tinggi atau sederajat yang memiliki tujuan untuk memperoleh gelar sarjana terapan. Mahasiswa yang akan memperoleh gelar sarjana perlu dibimbing oleh dosen agar dapat mempersiapkan penelitian akhir sejak menjadi mahasiswa baru. Dalam rangka membuat profil mahasiswa untuk mempersiapkan tugas akhir, dibuatlah sistem prediksi minat mahasiswa dan rekomendasi dosen (siprenatredo) supaya mahasiswa bisa mengetahui minatnya dan mendapatkan dosen pembimbing yang mempunyai sesuai dengan minat mahasiswa. Siprenatredo dibangun dengan memanfaatkan sistem prediksi dan rekomendasi yang diproses dengan teknik data mining. Metode rekomendasi yang digunakan adalah metode content-based filtering algoritma yang digunakan adalah naïve bayes classifier dan term frequency invers document frequency (tfidf). Penulis penyimpulkan dengan mengimplementasikan metode content based filtering menggunakan algoritma naïve bayes classifier dan algoritma tfidf dapat memberikan hasil yang sesuai dengan kriteria mahasiswa sehingga mahasiswa bisa mendapatkan rekomendasi yang sesuai minat
Identification of e19a2 BCR–ABL fusions (μ-BCR breakpoints) at the DNA level by ligation-mediated PCR
Detection of biomarkers using recombinant antibodies coupled to nanostructured platforms
The utility of biomarker detection in tomorrow's personalized health care field will mean early and accurate diagnosis of many types of human physiological conditions and diseases. In the search for biomarkers, recombinant affinity reagents can be generated to candidate proteins or post-translational modifications that differ qualitatively or quantitatively between normal and diseased tissues. The use of display technologies, such as phage-display, allows for manageable selection and optimization of affinity reagents for use in biomarker detection. Here we review the use of recombinant antibody fragments, such as scFvs and Fabs, which can be affinity-selected from phage-display libraries, to bind with both high specificity and affinity to biomarkers of cancer, such as Human Epidermal growth factor Receptor 2 (HER2) and Carcinoembryonic antigen (CEA). We discuss how these recombinant antibodies can be fabricated into nanostructures, such as carbon nanotubes, nanowires, and quantum dots, for the purpose of enhancing detection of biomarkers at low concentrations (pg/mL) within complex mixtures such as serum or tissue extracts. Other sensing technologies, which take advantage of ‘Surface Enhanced Raman Scattering’ (gold nanoshells), frequency changes in piezoelectric crystals (quartz crystal microbalance), or electrical current generation and sensing during electrochemical reactions (electrochemical detection), can effectively provide multiplexed platforms for detection of cancer and injury biomarkers. Such devices may soon replace the traditional time consuming ELISAs and Western blots, and deliver rapid, point-of-care diagnostics to market
Respiratory and cardiac function in congenital muscular dystrophies with alpha dystroglycan deficiency.
The aim of this retrospective study was to assess respiratory and cardiac function in a large cohort of patients with congenital muscular dystrophies (CMD) with reduced glycosylation of alphadystroglycan (\u3b1-DG). Thirteen of the 115 patients included in the study died between the age of 1 month and 20 years. The age at last follow up of the surviving 102 ranged between 1 year and 68 years (median: 9.3 years). Cardiac involvement was found in 7 of the 115 (6%), 5 with dilated cardiomyopathy, 1 cardiac conductions defects and 1 mitral regurgitation. Respiratory function was impaired in 14 (12%). Ten of the 14 required non invasive nocturnal respiratory support, while the other four required invasive ventilation. Cardiac or respiratory involvement was found in patients with mutations in FKRP, POMT1, POMT2. All of the patients in whom mutation in POMGnT1 were identified had normal cardiac and respiratory function
BCR-ABL Mutations in Chronic Myeloid Leukemia (CML) Patients (pts) with Failure and Warning to First-and Second-Line Tyrosine Kinase Inhibitor (TKI) Therapy: What Is the Advantage of Next-Generation Sequencing (NGS) over Conventional Sequencing?
NGS in detecting ABL mutation
BCR-ABL mutations in chronic myeloid leukemia (CML) patients (pts) with failure and warning to first- and second-lline tyrosine kinase inhibitor (TKI) therapy: what is the advantage of Next-Generation Sequencing (NGS) over conventional sequencing?
Background \u2013 Point mutations in the BCR-ABL kinase domain are associated with resistance to TKI therapy. The most recent (2013) European LeukemiaNet (ELN) recommendations have re(de)fined the criteria for failure in pts receiving 1st-line and 2nd-line TKI therapy and introduced the concept of warning. Assessing in how many CML patients with failure and warning mutations can be identified, especially now that more sensitive NGS-based mutation screening methods are available, would advance our knowledge of the biology of TKI resistance as well as contribute useful data to revise the ELN recommendations as to when and how BCR-ABL mutation analysis should be performed.
Aims \u2013 We aimed to determine the frequency of BCR-ABL mutations as assessed by NGS vs conventional Sanger sequencing (SS) in CML pts with failure and warning to 1st- or 2nd-line TKI therapy as per the latest, 2013 ELN definitions.
Methods \u2013 Between May 2013 and June 2015, 298 consecutive CML pts on TKI therapy were referred to our laboratory for BCR-ABL mutation screening by SS. One hundred and fifty-eight cases had no clinical data available, or were not in CP, or were receiving 653rd-line TKI therapy, or had confirmed/ suspected nonadherence, or had experienced dose reductions for toxicity \u2013 leaving 140 pts who could be included in this study. Pts who were negative for mutations as determined by SS (n=105/140) were retrospectively reanalyzed by NGS on a Roche GS Junior, using a protocol already set up and optimized in the framework of the IRON II (Interlaboratory RObustness of NGS) international consortium. Sequencing depth allowed to achieve a lower mutation detection limit of 1% in all samples.
Results \u2013 Failures and warnings to 1st-line therapy (imatinib, n=57; nilotinib, n=22; dasatinib, n=13) were 63 and 29, respectively. BCR-ABL mutations were found in 15/63 (24%) failures and 3/29 (10%) warnings by SS (Table 1).
NGS reanalysis of the 74 pts with no evidence of mutations by SS revealed low burden (median, 6.6%; range, 1.5-11.7%) mutations in 6 failures and 1 warning, so that, overall, 21/63 (33%) failures and 4/29 (14%) warnings turned out to have mutations (Table 1). Mutations were E462K, E279K, K262R, F359I, E255K, F317L, K378R, A399T, L364I, V280A. No compound mutation was detected.
Failures and warnings to 2nd-line therapy (nilotinib, n=27; dasatinib, n=21) were 35 and 13, respectively. SS identified mutations in 13/35 (37%) failures and 2/13 (15%) warnings (Table 1).
NGS reanalysis of the 33 pts with no evidence of mutations by SS revealed low burden (median, 5.4%; range, 1.9-10.0%) mutations in 5 failures and 2 warnings, so that, overall, 18/35 (51%) failures and 4/13 (31%) warnings turned out to have mutations (Table 1). Mutations were T315I, E255V, F317I, E258D, P480L, Y393C, W261L, L370P, V371A, L324Q, again with no compound mutations.Conclusions
1) NGS allowed to identify BCR-ABL mutations in a greater proportion of cases as compared to SS. Low burden mutations included a T315I mutation in 2 pts on 2nd-line therapy classified as warnings: this would have turned them into failures.
2) Still, a substantial proportion of cases was found to not harbor any mutation, even when using a more sensitive NGS-based method. In particular, non-optimal achievement of the key molecular response milestones (10%, 1%, 0.1%) on 1st-line therapy was mostly not associated with BCR-ABL mutations, indicating that other mechanisms of molecular disease persistence have to be investigated in an attempt to optimize therapeutic outcomes.
A national, multicenter study ('NEXT-IN-CML') aimed at the prospective assessment of NGS for routine BCR-ABL mutation screening of CML patients has just started