Development of Sensitive Crop-Specific Polymerase Chain Reaction Assays Using 5S DNA:  Applications in Food Traceability

2007 ◽  
Vol 55 (12) ◽  
pp. 4640-4644 ◽  
Author(s):  
Silvia Doveri ◽  
David Lee
2020 ◽  
Vol 48 (1) ◽  
pp. 62-72
Author(s):  
E. A. Ershova

Сalanoid copepods of the genus Pseudocalanus play an important role in the plankton communities of the Arctic and boreal seas, often dominating in numbers and constituting a significant proportion of the biomass of zooplankton. Despite their high presence and significance in the shelf plankton communities, species-specific studies of the biology of these are significantly hampered by extremely small morphological differences between them, especially at the juvenile stages, at which they are virtually indistinguishable. In this paper, we describe a new, routine and low-cost molecular method for identifying all Pseudocalanus species found in the Atlantic sector of the Arctic: the Arctic P. acuspes, P. minutus and the boreal P. moultoni and P. elongatus, and apply it to describe the relative distribution of these species in four locations of the Arctic and sub-Arctic. With this method, species-specific polymerase chain reaction (ssPCR), mass identification of individuals of any developmental stage, including nauplii, is possible. This method can serve as an excellent tool for studying the species-specific biology of this group, describing their life cycles, as well as monitoring changes in Arctic marine ecosystems under the influence of changing climate.


Plant Disease ◽  
2002 ◽  
Vol 86 (11) ◽  
pp. 1237-1239 ◽  
Author(s):  
R. H. Brlansky ◽  
V. D. Damsteegt ◽  
J. S. Hartung

Citrus variegated chlorosis (CVC) is an economically important, destructive disease in Brazil and is caused by the bacterium Xylella fastidiosa Wells. The bacterium has been found to be transmitted in Brazil by sharpshooter leafhoppers (Cicadellidae). Sharpshooters are present in most citrus growing areas of the United States. The sharpshooter leafhopper, Oncometopia nigricans Walker, frequently is found feeding on citrus in Florida. This sharpshooter transmits the X. fastidiosa strains that cause Pierce's disease of grape and ragweed stunt. Research was initiated to determine if O. nigricans was capable of vectoring the X. fastidiosa that causes CVC. In 59 different transmission tests, using 1 to 57 insects per test, transmission of the bacterium was observed 12 times (20.3%). Symptom development in the greenhouse was not a reliable indicator of transmission. Transmission was verified by specific polymerase chain reaction-based assays. Individual insects were able to transmit the bacterium. This information on sharpshooter transmission of CVC is needed to assess the threat posed by the CVC disease to the citrus industries in the United States.


2008 ◽  
Vol 57 (4) ◽  
pp. 754-763 ◽  
Author(s):  
O. Bahar ◽  
M. Efrat ◽  
E. Hadar ◽  
B. Dutta ◽  
R. R. Walcott ◽  
...  

2007 ◽  
Vol 131 (6) ◽  
pp. 936-941
Author(s):  
A. Mazin Safar ◽  
Horace Spencer ◽  
Xiaobo Su ◽  
Craig A. Cooney ◽  
Ali Shwaiki ◽  
...  

Abstract Context.— Even among cases of non–small cell lung cancer (NSCLC) in the most favorable stage (IA), the disease-specific mortality is 25% or greater. One plausible explanation implicates the simplistic standard pathologic procedures used to designate lymph node involvement. A more sensitive assessment of the nodal status may improve staging. Objective.—To determine the prognostic impact of detecting an abnormal molecular event (promoter hypermethylation in a set of relevant genes) in histologically uninvolved lymph nodes in resected NSCLC. Design.—In this retrospective analysis of archived material, we examined DNA extracted from lymph nodes of stage I NSCLC (n = 180). Patients underwent surgery between 1991 and 1995 in a single institution. Methylation-specific polymerase chain reaction was used to detect promoter hypermethylation in a panel of 8 genes. Survival data were extracted from the computerized database at the Tumor Registry. Results.—Evidence of promoter hypermethylation in at least 1 gene was detected in 67% of these N0 nodes. The most commonly hypermethylated gene was E-cadherin (53%). The hypermethylation frequency for the remaining genes were as follows: APC, 5%; p16, 9%; MGMT, 11%; hMLH1, 15%; RASSF1A, 4%; DAP kinase, 9%; and ATM, 19%. The presence of promoter hypermethylation in 2 or more genes did not influence the overall, median, or 5-year survival rates. Conclusions.—Identifying promoter hypermethylation (in our panel) in N0 lymph nodes in stage I NSCLC cannot be recommended for clinical decision making. Molecular abnormalities, including those found in cancer by qualitative methylation-specific polymerase chain reaction, are not synonymous with established, histologically detectable metastasis.


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