scholarly journals RetroScan: An Easy-to-Use Pipeline for Retrocopy Annotation and Visualization

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhaoyuan Wei ◽  
Jiahe Sun ◽  
Qinhui Li ◽  
Ting Yao ◽  
Haiyue Zeng ◽  
...  
Keyword(s):  
Gene Duplication ◽  
False Positive ◽  
Annotation Tool ◽  
Biological Functions ◽  
Analysis Pipeline ◽  
Shiny App ◽  
Bioinformatics Software ◽  
New Gene ◽  
Visual Interface ◽  
Positive Results

Retrocopies, which are considered “junk genes,” are occasionally formed via the insertion of reverse-transcribed mRNAs at new positions in the genome. However, an increasing number of recent studies have shown that some retrocopies exhibit new biological functions and may contribute to genome evolution. Hence, the identification of retrocopies has become very meaningful for studying gene duplication and new gene generation. Current pipelines identify retrocopies through complex operations using alignment programs and filter scripts in a step-by-step manner. Therefore, there is an urgent need for a simple and convenient retrocopy annotation tool. Here, we report the development of RetroScan, a publicly available and easy-to-use tool for scanning, annotating and displaying retrocopies, consisting of two components: an analysis pipeline and a visual interface. The pipeline integrates a series of bioinformatics software programs and scripts for identifying retrocopies in just one line of command. Compared with previous methods, RetroScan increases accuracy and reduces false-positive results. We also provide a Shiny app for visualization. It displays information on retrocopies and their parental genes that can be used for the study of retrocopy structure and evolution. RetroScan is available at https://github.com/Vicky123wzy/RetroScan.

Critical Evaluation of Impedance Phlebography for the Diagnosis of Deep Vein Thrombosis

1974 ◽  
Vol 31 (02) ◽  
pp. 273-278
Author(s):  
Kenneth K Wu ◽  
John C Hoak ◽  
Robert W Barnes ◽  
Stuart L Frankel
Keyword(s):  
Deep Vein Thrombosis ◽  
False Positive ◽  
False Negative ◽  
Critical Evaluation ◽  
Original Method ◽  
Vein Thrombosis ◽  
Negative Results ◽  
False Negative Results ◽  
Deep Vein ◽  
Positive Results

SummaryIn order to evaluate its daily variability and reliability, impedance phlebography was performed daily or on alternate days on 61 patients with deep vein thrombosis, of whom 47 also had 125I-fibrinogen uptake tests and 22 had radiographic venography. The results showed that impedance phlebography was highly variable and poorly reliable. False positive results were noted in 8 limbs (18%) and false negative results in 3 limbs (7%). Despite its being simple, rapid and noninvasive, its clinical usefulness is doubtful when performed according to the original method.

Comparison of two rapid tests for the detection of legionellaceae in water: a microbiological-immunological method and a commercial gene-probe testkit

1995 ◽  
Vol 31 (5-6) ◽  
pp. 403-406 ◽  
Author(s):  
E. Frahm ◽  
U. Obst
Keyword(s):  
Monoclonal Antibodies ◽  
Conventional Method ◽  
Standard Method ◽  
False Positive ◽  
Gene Probe ◽  
Immunological Method ◽  
Probe Test ◽  
Rapid Tests ◽  
Positive Results

Two recently developed Legionella detection tests, a microbiological-immunological method based on monoclonal antibodies (carried out as a colony-blot assay) and a commercial gene-probe testkit (the EnvironAmp Legionella Kit), are compared with the standard method. The colony-blot assay is faster than the conventional method; the gene-probe test is much faster still and is the most sensitive, but in consequence is at greater risk of false-positive results.

scholarly journals Biochemical characterization of specific Alanine Decarboxylase (AlaDC) and its ancestral enzyme Serine Decarboxylase (SDC) in tea plants (Camellia sinensis)

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Peixian Bai ◽  
Liyuan Wang ◽  
Kang Wei ◽  
Li Ruan ◽  
Liyun Wu ◽  
...  
Keyword(s):  
Gene Duplication ◽  
Camellia Sinensis ◽  
Biochemical Characterization ◽  
Specific Activity ◽  
Protein Sequences ◽  
Biochemical Properties ◽  
High Similarity ◽  
New Gene ◽  
Tea Plants

Abstract Background Alanine decarboxylase (AlaDC), specifically present in tea plants, is crucial for theanine biosynthesis. Serine decarboxylase (SDC), found in many plants, is a protein most closely related to AlaDC. To investigate whether the new gene AlaDC originate from gene SDC and to determine the biochemical properties of the two proteins from Camellia sinensis, the sequences of CsAlaDC and CsSDC were analyzed and the two proteins were over-expressed, purified, and characterized. Results The results showed that exon-intron structures of AlaDC and SDC were quite similar and the protein sequences, encoded by the two genes, shared a high similarity of 85.1%, revealing that new gene AlaDC originated from SDC by gene duplication. CsAlaDC and CsSDC catalyzed the decarboxylation of alanine and serine, respectively. CsAlaDC and CsSDC exhibited the optimal activities at 45 °C (pH 8.0) and 40 °C (pH 7.0), respectively. CsAlaDC was stable under 30 °C (pH 7.0) and CsSDC was stable under 40 °C (pH 6.0–8.0). The activities of the two enzymes were greatly enhanced by the presence of pyridoxal-5′-phosphate. The specific activity of CsSDC (30,488 IU/mg) was 8.8-fold higher than that of CsAlaDC (3467 IU/mg). Conclusions Comparing to CsAlaDC, its ancestral enzyme CsSDC exhibited a higher specific activity and a better thermal and pH stability, indicating that CsSDC acquired the optimized function after a longer evolutionary period. The biochemical properties of CsAlaDC might offer reference for theanine industrial production.

scholarly journals The Effect of Genomic DNA Contamination on the Detection of Circulating Long Non-Coding RNAs: The Paradigm of MALAT1

Diagnostics ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1160
Author(s):  
Athina N. Markou ◽  
Stavroula Smilkou ◽  
Emilia Tsaroucha ◽  
Evi Lianidou
Keyword(s):  
False Positive ◽  
Tissue Samples ◽  
Dna Contamination ◽  
Dnase Treatment ◽  
Circular Dnas ◽  
Non Coding Rnas ◽  
Nsclc Patients ◽  
Treatment Step ◽  
Primary Tissue ◽  
Positive Results

The presence of contaminating gDNA in RNA preparations is a frequent cause of false positives in RT-PCR-based analysis. However, in some cases, this cannot be avoided, especially when there are no exons–intron junctions in the lncRNA sequences. Due to the lack of exons in few of long noncoding RNAs (lncRNAs) and the lack of DNAse treatment step in most studies reported so far, serious questions are raised about the specificity of lncRNA detection and the potential of reporting false-positive results. We hypothesized that minute amounts of gDNA usually co-extracted with RNA could give false-positive signals since primers would specifically bind to gDNA due to the lack of junction. In the current study, we evaluated the effect of gDNA and other forms of DNA like extrachromosomal circular DNAs (eccDNAs) contamination and the importance of including a DNAse treatment step on lncRNAsexpression.As a model, we have chosen as one of the most widely studied lncRNAs in cancer namely MALAT1, which lacks exons. When we tested this hypothesis in plasma and primary tissue samples from NSCLC patients, our findings clearly indicated that results on MALAT1 expression are highly affected by the presence of DNA contamination and that the DNAse treatment step is absolutely necessary to avoid false positive results.

Clinical features and cause analysis of false positive results of Aspergillus galactomannan assay in pulmonary cryptococcosis patients

2019 ◽  
Vol 38 (4) ◽  
pp. 735-741 ◽  
Author(s):  
Takahiro Takazono ◽  
Tomomi Saijo ◽  
Nobuyuki Ashizawa ◽  
Kazuhiro Oshima ◽  
Keitaro Nishimura ◽  
...  
Keyword(s):  
Clinical Features ◽  
False Positive ◽  
Pulmonary Cryptococcosis ◽  
Cause Analysis ◽  
Positive Results
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