Exploring the diversity of marine-derived fungal polyketide synthases

2007 ◽  
Vol 53 (2) ◽  
pp. 291-302 ◽  
Author(s):  
Kimberly M. Mayer ◽  
Jermaine Ford ◽  
Gordon R. Macpherson ◽  
David Padgett ◽  
Brigitte Volkmann-Kohlmeyer ◽  
...  
Keyword(s):  
Polyketide Synthase ◽  
Sequence Similarity ◽  
Three Dimensional ◽  
Bioinformatic Analysis ◽  
Sequence Information ◽  
Fungal Isolates ◽  
Specificity Determining Positions ◽  
Pcr Products ◽  
Polymerase Chain ◽  
Similarity Searches

Using an approach based on polymerase chain reaction (PCR), we examined the diversity of polyketide synthase (PKS) genes present in 160 marine fungal isolates, representing 142 species. We obtained ketosynthase (KS) domain PCR products from 99 fungal isolates, representing Dothideomycetes, Sordariomycetes, Eurotiomycetes, and incertae sedis. Sequence similarity searches and phylogenetic analysis of 29 marine partial-KS-encoding sequences revealed domains predicted to encode reducing, nonreducing, and 6-methylsalicylic acid PKSs. Bioinformatic analysis of an alignment of the KS sequences from marine-derived fungi revealed no unique motifs in this region. However, several specificity-determining positions were apparent between fungal 6-methylsalicylic acid PKSs as compared with either reducing or nonreducing PKSs. Evaluation of these positions in the context of a modelled three-dimensional protein structure highlighted their potential use as PKS classification markers. Evaluating primer-binding sites was necessary to obtain KS domain fragments from putative PKSs while maintaining a level of sequence information adequate to properly classify and characterize them.

Molecular Characterization of Aflatoxin Biosynthesis Genes of Aspergillus flavus from Peanuts Production Area

2019 ◽  
Author(s):  
I. Lavkor
Keyword(s):  
Fragment Length Polymorphism ◽  
Intergenic Spacer ◽  
Aflatoxin Contamination ◽  
Aflatoxin Biosynthesis ◽  
Fungal Isolates ◽  
Pcr Rflp ◽  
Pcr Products ◽  
Production Area ◽  
Polymerase Chain

In this study, molecular analysis of (100%) all fungal isolates, which were sampled from soil and air besides from infected peanut plants in the peanut planting area, were identified in â-tubulin gene by Polymerase Chain Reaction (PCR). PCR products of fungal isolates were restricted by BglII enzyme within Restriction Fragment Length Polymorphism (RFLP). The intergenic spacer (IGS) region for aflatoxin biosynthesis genes (aflJ-aflR) were determined in 254 (78.2%) A. flavus isolates using PCR-RFLP. Selected 100 isolates were detected as A. flavus by â-tubulin sequence gene fragments and comparisons of sequence showed 96–100% similarity. 254 out of 325 isolates contained aflatoxin biosynthesis genes (aflJ-aflR), whereas 213 out of 254 isolates produced aflatoxin. The results acquired in study remarked that A. flavus was the species responsible for aflatoxin contamination. Aflatoxin gene cluster in populations can be advantage for comprehension of the toxicological risk as well as the election of biocontrol isolates.

scholarly journals GRAde: a long-read sequencing approach to efficiently identifying the CYP11B1/CYP11B2 chimeric form in patients with glucocorticoid-remediable aldosteronism

2021 ◽  
Vol 22 (S10) ◽  
Author(s):  
Yu-Ching Wu ◽  
Chia-I Chen ◽  
Peng-Ying Chen ◽  
Chun-Hung Kuo ◽  
Yi-Hsuan Hung ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Chimeric Gene ◽  
Sequencing Analysis ◽  
High Sequence Similarity ◽  
Clinical Presentations ◽  
Long Read ◽  
Pcr Products ◽  
Polymerase Chain ◽  
Hybrid Genes ◽  
Genomic Regions

Abstract Background Glucocorticoid-remediable aldosteronism (GRA) is a form of heritable hypertension caused by a chimeric fusion resulting from unequal crossing over between 11β‐hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2), which are two genes with similar sequences. Different crossover patterns of the CYP11B1 and CYP11B2 chimeric genes may be associated with a variety of clinical presentations. It is therefore necessary to develop an efficient approach for identifying the differences between the hybrid genes of a patient with GRA. Results We developed a long-read analysis pipeline named GRAde (GRA deciphering), which utilizes the nonidentical bases in the CYP11B1 and CYP11B2 genomic sequences to identify and visualize the chimeric form. We sequenced the polymerase chain reaction (PCR) products of the CYP11B1/CYP11B2 chimeric gene from 36 patients with GRA using the Nanopore MinION device and analyzed the sequences using GRAde. Crossover events were identified for 30 out of the 36 samples. The crossover sites appeared in the region exhibiting high sequence similarity between CYP11B1 and CYP11B2, and 53.3% of the cases were identified as having a gene conversion in intron 2. More importantly, there were six cases for whom the PCR products indicated a chimeric gene, but the GRAde results revealed no crossover pattern. The crossover regions were further verified by Sanger sequencing analysis. Conclusions PCR-based target enrichment followed by long-read sequencing is an efficient and precise approach to dissecting complex genomic regions, such as those involved in GRA mutations, which could be directly applied to clinical diagnosis. The scripts of GRAde are available at https://github.com/hsu-binfo/GRAde.

scholarly journals Discovery of Viruses and Virus-Like Pathogens in Pistachio using High-Throughput Sequencing

Plant Disease ◽  
2018 ◽  
Vol 102 (7) ◽  
pp. 1419-1425 ◽  
Author(s):  
Maher Al Rwahnih ◽  
Adib Rowhani ◽  
Nathaniel Westrick ◽  
Kristian Stevens ◽  
Alfredo Diaz-Lara ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Sequencing ◽  
Amino Acid Sequence Identity ◽  
Sequence Similarity ◽  
Sequence Information ◽  
Virus Species ◽  
Significant Sequence Similarity ◽  
Novel Virus ◽  
Polymerase Chain ◽  
Multiple Samples

Pistachio (Pistacia vera L.) trees from the National Clonal Germplasm Repository (NCGR) and orchards in California were surveyed for viruses and virus-like agents by high-throughput sequencing (HTS). Analyses of sequence information from 60 trees identified a novel virus, provisionally named “Pistachio ampelovirus A” (PAVA), in the NCGR that showed low amino acid sequence identity (approximately 42%) compared with members of the genus Ampelovirus (family Closteroviridae). A putative viroid, provisionally named “Citrus bark cracking viroid-pistachio” (CBCVd-pis), was also found in the NCGR and showed approximately 87% similarity to Citrus bark cracking viroid (CBCVd, genus Cocadviroid, family Pospiviroidae). Both PAVA and CBCVd-pis were graft transmissible to healthy UCB-1 hybrid rootstock seedlings (P. atlantica × P. integerrima). A field survey of 123 trees from commercial orchards found no incidence of PAVA but five (4%) samples were infected with CBCVd-pis. Of 675 NCGR trees, 16 (2.3%) were positive for PAVA and 172 (25.4%) were positive for CBCVd-pis by reverse-transcription polymerase chain reaction. Additionally, several contigs across multiple samples exhibited significant sequence similarity to a number of other plant virus species in different families. These findings require further study and confirmation. This study establishes the occurrence of viral and viroid populations infecting pistachio trees.

Sequence variability in the FUM1 gene of Fusarium verticillioides strains

2007 ◽  
Vol 53 (3) ◽  
pp. 446-449 ◽  
Author(s):  
Valéria Nascimento da Silva ◽  
Jansen de Araujo ◽  
Edison Luiz Durigon ◽  
Benedito Corrêa
Keyword(s):  
Polymerase Chain Reaction ◽  
Polyketide Synthase ◽  
Sequence Similarity ◽  
Fusarium Verticillioides ◽  
Sequence Variability ◽  
Chain Reaction ◽  
Polymerase Chain

Fumonisins are mycotoxins, produced mainly by Fusarium verticillioides , that are potentially carcinogenic to humans and toxic to animals. Synthesis of these toxins is directed by a cluster of 15 genes, among which FUM1 is the largest; it encodes a polyketide synthase. This enzyme probably catalyzes the synthesis of a polyketide that forms a large portion of the fumonisin structure. In this study, 27 strains possessing the FUM1 gene, as determined by polymerase chain reaction, were analyzed. A portion of the FUM1 gene was amplified and sequenced from 6 of 27 Brazilian strains isolated from corn and sorghum. The sequence similarity for the six F. verticillioides strains was almost 100%.

GB Virus C/Hepatitis G Virus Isolates in Japanese Haemophiliacs and their Origins

1998 ◽  
Vol 80 (08) ◽  
pp. 242-245 ◽  
Author(s):  
Yoshihide Fukuda ◽  
Tetsuo Hayakawa ◽  
Junki Takamatsu ◽  
Hidehiko Saito ◽  
Hiroaki Okamoto ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
West African ◽  
Blood Products ◽  
Hepatitis G Virus ◽  
Gb Virus C ◽  
Route Of Transmission ◽  
Polymerase Chain ◽  
Hepatitis G ◽  
Virus C ◽  
Virus Isolates

SummaryJapanese haemophiliacs have been at high risk for infection with parenterally-transmissible viruses through the use of blood products, especially imported ones. Recently, novel transfusion-transmissible virus, GB virus C (GBV-C)/hepatitis G virus (HGV) were isolated. We investigated the origin and route of transmission of GBV-C/HGV isolates in haemophiliacs in Japan. GBV-C/HGV RNA was measured by nested reverse transcription polymerase chain reaction in 91 Japanese haemophiliacs. Phylogenetic analysis and genotypic grouping of GBV-C/HGV isolates in Japanese haemophiliacs were performed based on sequences in the 5’ untranslated region, and the characteristics were compared with those of reported isolates. GBV-C/HGV infection was present in 19 of 91 haemophiliacs (20.9%). Sequence analysis showed that 15 of the 19 isolates (78.9%) showed sequence similarity to a group in which mainly West African isolates have been reported. The other 4 isolates (21.1%) showed sequence similarity to Asian isolates. None of the GBV-C/HGV isolates showed sequences similar to those generally found in isolates from USA and Europe. The majority of GBV-C/HGV isolates found in Japanese haemophiliacs who are considered to have been infected by imported blood products were similar to those detected in West Africa.

IsoDetect: Detection of splice isoforms from third generation long reads based on short feature sequences

2020 ◽  
Vol 15 ◽  
Author(s):  
Hongdong Li ◽  
Wenjing Zhang ◽  
Yuwen Luo ◽  
Jianxin Wang
Keyword(s):  
Sequence Similarity ◽  
Detection Methods ◽  
Sequence Information ◽  
Third Generation ◽  
Sequencing Data ◽  
Splice Isoforms ◽  
Third Generation Sequencing ◽  
Long Reads ◽  
Feature Sequence ◽  
Generation Sequencing

Aims: Accurately detect isoforms from third generation sequencing data. Background: Transcriptome annotation is the basis for the analysis of gene expression and regulation. The transcriptome annotation of many organisms such as humans is far from incomplete, due partly to the challenge in the identification of isoforms that are produced from the same gene through alternative splicing. Third generation sequencing (TGS) reads provide unprecedented opportunity for detecting isoforms due to their long length that exceeds the length of most isoforms. One limitation of current TGS reads-based isoform detection methods is that they are exclusively based on sequence reads, without incorporating the sequence information of known isoforms. Objective: Develop an efficient method for isoform detection. Method: Based on annotated isoforms, we propose a splice isoform detection method called IsoDetect. First, the sequence at exon-exon junction is extracted from annotated isoforms as the “short feature sequence”, which is used to distinguish different splice isoforms. Second, we aligned these feature sequences to long reads and divided long reads into groups that contain the same set of feature sequences, thereby avoiding the pair-wise comparison among the large number of long reads. Third, clustering and consensus generation are carried out based on sequence similarity. For the long reads that do not contain any short feature sequence, clustering analysis based on sequence similarity is performed to identify isoforms. Result: Tested on two datasets from Calypte Anna and Zebra Finch, IsoDetect showed higher speed and compelling accuracy compared with four existing methods. Conclusion: IsoDetect is a promising method for isoform detection. Other: This paper was accepted by the CBC2019 conference.

scholarly journals PyMod: sequence similarity searches, multiple sequence-structure alignments, and homology modeling within PyMOL

2012 ◽  
Vol 13 (Suppl 4) ◽  
pp. S2 ◽  
Author(s):  
Emanuele Bramucci ◽  
Alessandro Paiardini ◽  
Francesco Bossa ◽  
Stefano Pascarella
Keyword(s):  
Homology Modeling ◽  
Sequence Similarity ◽  
Sequence Structure ◽  
Multiple Sequence ◽  
Similarity Searches

scholarly journals Streptomonospora litoralis sp. nov., a halophilic thiopeptides producer isolated from sand collected at Cuxhaven beach

2021 ◽  
Author(s):  
Shadi Khodamoradi ◽  
Richard L. Hahnke ◽  
Yvonne Mast ◽  
Peter Schumann ◽  
Peter Kämpfer ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Gene Sequence ◽  
Sequence Similarity ◽  
Bioinformatic Analysis ◽  
Biosynthetic Gene Cluster ◽  
16S Rrna Gene Sequence ◽  
Rrna Gene ◽  
Rrna Gene Sequence ◽  
Polar Lipid Profile

AbstractStrain M2T was isolated from the beach of Cuxhaven, Wadden Sea, Germany, in course of a program to attain new producers of bioactive natural products. Strain M2T produces litoralimycin and sulfomycin-type thiopeptides. Bioinformatic analysis revealed a potential biosynthetic gene cluster encoding for the M2T thiopeptides. The strain is Gram-stain-positive, rod shaped, non-motile, spore forming, showing a yellow colony color and forms extensively branched substrate mycelium and aerial hyphae. Inferred from the 16S rRNA gene phylogeny strain M2T affiliates with the genus Streptomonospora. It shows 96.6% 16S rRNA gene sequence similarity to the type species Streptomonospora salina DSM 44593 T and forms a distinct branch with Streptomonospora sediminis DSM 45723 T with 97.0% 16S rRNA gene sequence similarity. Genome-based phylogenetic analysis revealed that M2T is closely related to Streptomonospora alba YIM 90003 T with a digital DNA-DNA hybridisation (dDDH) value of 26.6%. The predominant menaquinones of M2T are MK-10(H6), MK-10(H8), and MK-11(H6) (> 10%). Major cellular fatty acids are iso-C16:0, anteiso C17:0 and C18:0 10-methyl. The polar lipid profile consisted of diphosphatidylglycerol phosphatidyl glycerol, phosphatidylinositol, phosphatidylcholine, phosphatidylethanolamine, three glycolipids, two unknown phospholipids, and two unknown lipids. The genome size of type strain M2T is 5,878,427 bp with 72.1 mol % G + C content. Based on the results obtained from phylogenetic and chemotaxonomic studies, strain M2T (= DSM 106425 T = NCCB 100650 T) is considered to represent a novel species within the genus Streptomonospora for which the name Streptomonospora litoralis sp. nov. is proposed.

scholarly journals A Comparative Study of 5S rDNA Non-Transcribed Spacers in Elaeagnaceae Species

Plants ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 4
Author(s):  
Oleg S. Alexandrov ◽  
Olga V. Razumova ◽  
Gennady I. Karlov
Keyword(s):  
Polymerase Chain Reaction ◽  
Molecular Markers ◽  
Dna Markers ◽  
5S Rdna ◽  
Chain Reaction ◽  
Closely Related Species ◽  
Pcr Products ◽  
Polymerase Chain ◽  
Species Specific ◽  
Shepherdia Canadensis

5S rDNA is organized as a cluster of tandemly repeated monomers that consist of the conservative 120 bp coding part and non-transcribed spacers (NTSs) with different lengths and sequences among different species. The polymorphism in the 5S rDNA NTSs of closely related species is interesting for phylogenetic and evolutional investigations, as well as for the development of molecular markers. In this study, the 5S rDNA NTSs were amplified with universal 5S1/5S2 primers in some species of the Elaeagnaceae Adans. family. The polymerase chain reaction (PCR) products of five Elaeagnus species had similar lengths near 310 bp and were different from Shepherdia canadensis (L.) Nutt. and Sh. argentea (Pusch.) Nutt. samples (260 bp and 215 bp, respectively). The PCR products were cloned and sequenced. An analysis of the sequences revealed that intraspecific levels of NTS identity are high (approximately 95–96%) and similar in the Elaeagnus L. species. In Sh. argentea, this level was slightly lower due to the differences in the poly-T region. Moreover, the intergeneric and intervarietal NTS identity levels were studied and compared. Significant differences between species (except E. multiflora Thunb. and E. umbellata Thunb.) and genera were found. Herein, a range of the NTS features is discussed. This study is another step in the investigation of the molecular evolution of Elaeagnaceae and may be useful for the development of species-specific DNA markers in this family.

Diagnosis and Causative Species of Visceral Leishmaniasis in Southwest Saudi Arabia

2021 ◽  
Author(s):  
Aymen Abdelhaleem ◽  
Nabil Dhayhi ◽  
Mohamed Salih Mahfouz ◽  
Ommer Daffalla ◽  
Mansour Mubarki ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Visceral Leishmaniasis ◽  
Real Time ◽  
Real Time Pcr ◽  
Leishmania Donovani ◽  
Target Genes ◽  
Sample Volume ◽  
Pcr Products ◽  
Polymerase Chain ◽  
Robust Evidence

Visceral leishmaniasis (VL) is the most severe clinical form of the disease and has been reported in the Jazan region of southwest Saudi Arabia. This study aimed to diagnose VL by real-time polymerase chain reaction (PCR) and the direct agglutination test (DAT) and to identify the causative Leishmania species. A total of 80 participants, including 30 suspected VL patients, 30 healthy endemic control individuals, and 20 malaria disease controls, were enrolled in this study. Blood samples were collected and tested for Leishmania DNA by real-time PCR and for antibody by the DAT. Sequencing of some amplified PCR products was used to identify the causative Leishmania species. The diagnosis of VL was successfully achieved by both real-time PCR and by DAT with 100% sensitivity. Leishmania donovani and Leishmania infantum species were detected by sequencing both by the kDNA and ITS1 target genes, followed a BLASTn search. The detection of VL antibody by the DAT followed by the confirmatory detection of Leishmania DNA in patient blood by PCR could promote the adoption of the much less invasive and more sensitive methods for the routine diagnosis of VL. Further study with high sample volume to evaluate the PCR and the DAT are needed, to generate more robust evidence. Based on the sequencing results, emerging studies on VL should focus on the causative Leishmania species, reservoirs, and vectors that are important in the study area.

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