scholarly journals Array-based sequencing of filaggrin gene for comprehensive detection of disease-associated variants

2017 ◽  

ABSTRACTThe filaggrin gene (FLG) is essential for skin differentiation and epidermal barrier formation with links to skin diseases, however it has a highly repetitive nucleotide sequence containing very limited stretches of unique nucleotides for precise mapping to reference genomes. Sequencing strategies using polymerase chain reaction (PCR) and conventional Sanger sequencing have been successful for complete FLG coding DNA sequence amplification to identify pathogenic mutations but this time-consuming, labour intensive method has restricted utility. Next-generation sequencing (NGS) offers obvious benefits to accelerate FLG analysis but standard re-sequencing techniques such as oligoprobe-based exome or customized targeted-capture can be expensive, especially for a single target gene of interest. We therefore designed a protocol to improve FLG sequencing throughput using a set of FLG-specific PCR primer assays compatible with microfluidic amplification, multiplexing and current NGS protocols. Using DNA reference samples with known FLG genotypes for benchmarking, this protocol is shown to be concordant for variant detection across different sequencing methodologies. We applied this methodology to analyze cohorts from ethnicities previously not studied for FLG variants and demonstrate usefulness for discovery projects. This comprehensive coverage sequencing protocol is labour-efficient and offers an affordable solution to scale up FLG sequencing for larger cohorts. Robust and rapid FLG sequencing can improve patient stratification for research projects and provide a framework for gene specific diagnosis in the future.

Plant Disease ◽  
2009 ◽  
Vol 93 (3) ◽  
pp. 208-214 ◽  
Author(s):  
Lia W. Liefting ◽  
Paul W. Sutherland ◽  
Lisa I. Ward ◽  
Kerry L. Paice ◽  
Bevan S. Weir ◽  
...  

A new disease of glasshouse-grown tomato and pepper in New Zealand has resulted in plant decline and yield loss. Affected plants are characterized by spiky, chlorotic apical growth, curling or cupping of the leaves, and overall stunting. Transmission electron microscopy revealed the presence of phloem-limited bacterium-like organisms in symptomatic plants. The strategy used to identify the bacterium involved using specific prokaryote polymerase chain reaction (PCR) primers in combination with universal 16S rRNA primers. Sequence analysis of the 16S rRNA gene, the 16S/23S rRNA spacer region, and the rplKAJL-rpoBC operon revealed that the bacterium shared high identity with ‘Candidatus Liberibacter’ species. Phylogenetic analysis showed that the bacterium is distinct from the three citrus liberibacter species previously described and has been named ‘Candidatus Liberibacter solanacearum’. This is the first report of a liberibacter naturally infecting a host outside the Rutaceae family. A specific PCR primer pair was developed for its detection.


2018 ◽  
Vol 50 (1) ◽  
pp. 123-138 ◽  
Author(s):  
Arántzazu MOLINS ◽  
Patricia MOYA ◽  
Francisco J. GARCÍA-BREIJO ◽  
José REIG-ARMIÑANA ◽  
Eva BARRENO

AbstractLichen thalli represent the most conspicuous examples of fungal-algal interactions. Studies that describe phycobiont diversity within entire thalli are based mainly on Sanger sequencing. In some lichen species, this technique could underestimate the intrathalline coexistence of multiple microalgae. In this study different multi-tool approaches were applied to two lichen taxa, Circinaria hispida and Flavoparmelia soredians, to detect algal coexistence. Here, we combined Sanger sequencing, a specific polymerase chain reaction (PCR) primer, 454-pyrosequencing, phycobiont isolation and ultrastructural characterization. Furthermore, we compared pyrenoid ultrastructural features of lichenized phycobionts with microalgae isolated in culture. An improved methodology was used to isolate and propagate phycobionts which, in combination with fast genetic identification, resulted in a considerable reduction in time and cost to complete the process. This isolation method, coupled with a specific PCR primer, allowed for the detection of coexisting algae in C. hispida (four Trebouxia lineages). 454-pyrosequencing detected only a fraction of such diversity, while Sanger sequencing identified only the primary phycobiont. Ultrastructural features of the isolated algae were observed by transmission electron microscopy; the maintenance of the pyrenoid characteristics suggested the existence of different Trebouxia lineages. In F. soredians a single Trebouxia lineage was identified using all these approaches.In cases of lichens with algal coexistence, a combination of different molecular and ultrastructural approaches may be required to reveal the underlying algal diversity within a single thallus. The approach proposed in this study provides information about the relationship between molecular and ultrastructural data, and represents an improvement in the delimitation of taxonomic features which is needed to recognize intrathalline Trebouxia diversity.


2020 ◽  
Vol 48 (12) ◽  
pp. 030006052096777
Author(s):  
Peisong Chen ◽  
Xuegao Yu ◽  
Hao Huang ◽  
Wentao Zeng ◽  
Xiaohong He ◽  
...  

Introduction To evaluate a next-generation sequencing (NGS) workflow in the screening and diagnosis of thalassemia. Methods In this prospective study, blood samples were obtained from people undergoing genetic screening for thalassemia at our centre in Guangzhou, China. Genomic DNA was polymerase chain reaction (PCR)-amplified and sequenced using the Ion Torrent system and results compared with traditional genetic analyses. Results Of the 359 subjects, 148 (41%) were confirmed to have thalassemia. Variant detection identified 35 different types including the most common. Identification of the mutational sites by NGS were consistent with those identified by Sanger sequencing and Gap-PCR. The sensitivity and specificities of the Ion Torrent NGS were 100%. In a separate test of 16 samples, results were consistent when repeated ten times. Conclusion Our NGS workflow based on the Ion Torrent sequencer was successful in the detection of large deletions and non-deletional defects in thalassemia with high accuracy and repeatability.


2012 ◽  
Vol 32 (1) ◽  
pp. 201-208 ◽  
Author(s):  
Carla Bertechini Faria ◽  
Giovana Caputo Almeida-Ferreira ◽  
Karina Bertechine Gagliardi ◽  
Tatiane Cristina Albuquerque Alves ◽  
Dauri José Tessmann ◽  
...  

The detection of mycotoxigenic fungi in foodstuff is important because their presence may indicate the possible associated mycotoxin contamination. Fusarium graminearum is a wheat pathogen and a producer of micotoxins. The polymerase chain reaction (PCR) has been employed for the specific identification of F. graminearum. However, this methodology has not been commonly used for detection of F. graminearum in food. Thus, the objective of the present study was to develop a molecular methodology to detect F. graminearum in commercial samples of bulgur wheat. Two methods were tested. In the first method, a sample of this cereal was contaminated with F. graminearum mycelia. The genomic DNA was extracted from this mixture and used in a F. graminearum specific PCR reaction. The F. graminearum species was detected only in samples that were heavily contaminated. In the second method, samples of bulgur wheat were inoculated on a solid medium, and isolates having F. graminearum culture characteristics were obtained. The DNA extracted from these isolates was tested in F. graminearum specific PCR reactions. An isolate obtained had its trichothecene genotype identified by PCR. The established methodology could be used in surveys of food contamination with F. graminearum.


2006 ◽  
Vol 36 (2) ◽  
pp. 126-132 ◽  
Author(s):  
Anna Gillio-Tos ◽  
Laura De Marco ◽  
Valeria Ghisetti ◽  
Peter J.F. Snijders ◽  
Nereo Segnan ◽  
...  

2001 ◽  
Vol 67 (11) ◽  
pp. 5343-5348 ◽  
Author(s):  
Andrew E. Allen ◽  
Melissa G. Booth ◽  
Marc E. Frischer ◽  
Peter G. Verity ◽  
Jonathan P. Zehr ◽  
...  

ABSTRACT A PCR approach was used to construct a database of nasAgenes (called narB genes in cyanobacteria) and to detect the genetic potential for heterotrophic bacterial nitrate utilization in marine environments. A nasA-specific PCR primer set that could be used to selectively amplify the nasA gene from heterotrophic bacteria was designed. Using seawater DNA extracts obtained from microbial communities in the South Atlantic Bight, the Barents Sea, and the North Pacific Gyre, we PCR amplified and sequencednasA genes. Our results indicate that several groups of heterotrophic bacterial nasA genes are common and widely distributed in oceanic environments.


2017 ◽  
Vol 94 (2) ◽  
pp. 100-104 ◽  
Author(s):  
Jenny Dahlberg ◽  
Ronza Hadad ◽  
Karin Elfving ◽  
Inger Larsson ◽  
Jenny Isaksson ◽  
...  

ObjectivesIn 2006, a new variant of Chlamydia trachomatis (nvCT) was discovered in Sweden. It has a deletion in the plasmid resulting in failed detection by the single target systems from Abbott and Roche used at that time, whereas the third system used, from Becton Dickinson (BD), detects nvCT. The proportion of nvCT was initially up to 65% in counties using Abbott/Roche systems. This study analysed the proportion of nvCT from 2007 to 2015 in four selected counties and its impact on chlamydia-associated complications.MethodsC. trachomatis-positive specimens collected from 2007 to 2015 were analysed by a specific PCR to identify nvCT cases. Genotyping was performed by multilocus sequence typing (MLST) and ompA sequencing. Ectopic pregnancy and pelvic inflammatory disease records were extracted from the national registers.ResultsIn total, 5101 C. trachomatis-positive samples were analysed. The nvCT proportion significantly decreased in the two counties using Roche systems, from 56% in 2007 to 6.5% in 2015 (p<0.001). In the two counties using BD systems, a decrease was also seen, from 19% in 2007 to 5.2% in 2015 (p<0.001). Fifteen nvCT cases from 2015 and 102 cases from 2006 to 2009 had identical MLST profiles. Counties using Roche/Abbott systems showed higher mean rates of ectopic pregnancy and pelvic inflammatory disease compared with counties using BD systems.ConclusionsThe nvCT proportion has decreased in all counties and converged to a low prevalence irrespective of previous rates. Genotyping showed that nvCT is clonal and genetically stable. Failing detection only marginally affected complication rates.


Blood ◽  
1997 ◽  
Vol 89 (3) ◽  
pp. 1027-1034 ◽  
Author(s):  
Juergen Bux ◽  
Ernst-Ludwig Stein ◽  
Philippe Bierling ◽  
Patricia Fromont ◽  
Mary Clay ◽  
...  

Abstract Polymorphic structures of the neutrophil Fcγreceptor IIIb (FcγRIIIb) result in alloantibody formation that causes alloimmune neonatal neutropenia and transfusion reactions. Alloantigens located on FcγRIIIb include the antigens NA1 and NA2. In four cases of alloimmune neonatal neutropenia, granulocyte-specific alloantibodies directed against a thus far unknown antigen were detected by granulocyte agglutination and immunofluorescence tests in the maternal sera. By the use of the monoclonal antibody–specific immobilization of granulocyte antigens (MAIGA) assay, the new antigen, termed SH, was located on the FcγRIIIb. Nucleotide sequence analysis of the FcγRIIIb coding region from a SH(+) individual showed a single-base C→A mutation at position 266, which results in an Ala78Asp amino acid substitution. A family study confirmed that this nucleotide difference is inherited, and corresponds to the SH phenotype. Serologic typing of 309 randomly selected individuals showed an antigen frequency of 5% in the white population. The same frequency was found by genotyping, for which a technique based on polymerase chain reaction (PCR) using sequence-specific primers (PCR-SSP) was developed. Typing of all SH(+) individuals for NA1 and NA2, and PCR-restriction fragment length polymorphism analysis of the NA-specific PCR products from five SH(+) individuals using the SH-specific endonuclease SfaN I showed that SH antigen is very probably the result of an additional mutational event in the NA2 form of the FcγRIIIB gene. Immunochemical studies also demonstrated that the SH determinants reside on the 65- to 80-kD NA2 isoform of the FcγRIIIb. Our findings show the existence of an additional polymorphism of the FcγRIIIb, which can result in alloantibody formation causing alloimmune neonatal neutropenia.


2011 ◽  
Vol 140 (10) ◽  
pp. 1773-1779 ◽  
Author(s):  
J. YAKOOB ◽  
Z. ABBAS ◽  
M. ASIM BEG ◽  
W. JAFRI ◽  
S. NAZ ◽  
...  

SUMMARYWe determined the prevalence of microsporidiaEnterocytozoon(Ent.)bieneusiandEncephalitozoon(E.)intestinalisinfection in patients with chronic diarrhoea and hepatocellular carcinoma (HCC). A total of 330 stool samples were examined from 171 (52%) patients with chronic diarrhoea, 18 (5%) with HCC while 141 (43%) were controls. Stool microscopy, polymerase chain reaction (PCR) with species-specific primers forEnt. bieneusiandE. intestinalisand sequencing were carried out. Microsporidia were found by trichrome staining in 11/330 (3%) andE. intestinalisby PCR in 13/330 (4%) whileEnt. bieneusiwas not detected. PCR forE. intestinaliswas positive in 8/171 (5%) stool samples from patients with chronic diarrhoea, 2/141 (1·4%) samples from healthy controls and in 3/18 (17%) samples from patients with HCC. In the chronic diarrhoea group,E. intestinaliswas positive in 4/171 (2·3%) (P=0·69) stool samples compared to 2/18 (11%) (P=0·06) in the HCC group and 2/141 (1·4%) from healthy controls.E. intestinalisinfection was significantly associated with chronic diarrhoea and HCC in these patients who were negative for HIV. Stool examination with trichrome or species-specific PCR for microsporidia may help establish the cause of chronic diarrhoea.


Sign in / Sign up

Export Citation Format

Share Document