Rapid Identification and Molecular Characterization of Phytoene Desaturase Mutations in Fluridone-Resistant Hydrilla (Hydrilla verticillata)

Florida hydrilla populations have shown an alarming increase in resistance to fluridone, an herbicide used extensively for controlling invasive US hydrilla populations. A rapid PCR and sequencing method was developed to identify and screen hydrilla genomic DNA for three previously identified phytoene desaturase (pds) gene mutations that confer resistance to fluridone. Ninety hydrilla accessions were screened for fluridone resistant genotypes including 46 accessions from the US and 44 accessions from 15 other countries. In Florida, hydrilla from five of nine sites tested was heterozygous for wild-type and herbicide-resistant alleles. Additionally, a new resistant population was identified from Lake Seminole in Georgia, the first genetically confirmed strain of resistant hydrilla outside of Florida. All resistance-conferring mutations were located on the same homologous haplotype of US dioecious hydrilla. All other hydrilla samples tested possessed only wild type alleles, including monoecious strains that had been exposed to fluridone. Management implications are discussed.

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EDL933 Strains of Escherichia coli O157 can Demonstrate Genetic Diversity and Differential Adherence to Bovine Recto-Anal Junction Squamous Epithelial Cells

The Open Microbiology Journal ◽

10.2174/1874285802115010129 ◽

2021 ◽

Vol 15 (1) ◽

pp. 129-138

Author(s):

Raegan S. Hoefler ◽

Indira T. Kudva

Keyword(s):

Escherichia Coli ◽

Wild Type ◽

Cell Adherence ◽

O157 Strain ◽

Shiga Toxins ◽

The Us ◽

Strain Type ◽

Enterocyte Effacement ◽

Different Sources

Background: Differences between Escherichia coli O157 (O157) strains are well-established with some of these strains being associated with major outbreaks in the US. EDL933 is one such O157 strain that caused a multistate outbreak in 1982 and has since been used as a prototype in various O157-related experiments. Objective: As O157 can readily acquire genetic mutations, we sought to determine if the genetic and phenotypic profiles of EDL933 strains from different sources would be consistent. Methods: We evaluated wild-type O157 strains stocked as EDL933 from three different laboratories, in the strain typing Polymorphic Amplified Typing Sequence (PATS) and the bovine rectal-anal junction squamous epithelial (RSE) cell- and HEp-2 cell- adherence assays. In addition, we also verified if Shiga toxins (Stx), the Locus of Enterocyte Effacement (LEE) or curli fimbriae contributed to the adherence phenotypes observed using mutant and wild-type EDL933 isolates. Results: Our results showed differences in PATS profiles and RSE cell-adherence phenotype, with no influence from the Stx or LEE genes, between EDL933 from different sources. Interestingly, the EDL933 strain that demonstrated the most contrasting diffuse adherence phenotype on RSE cells, EDL933-T, had decreased curli production that may have contributed to this phenotype. Conclusion: Our observations suggest that a comprehensive characterization of bacterial isolates, even if assigned to the same strain type prior to use in experiments, is warranted to ensure consistency and reproducibility of results.

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Inheritance and Molecular Characterization of a Novel Mutated AHAS Gene Responsible for the Resistance of AHAS-Inhibiting Herbicides in Rapeseed (Brassica napus L.)

International Journal of Molecular Sciences ◽

10.3390/ijms21041345 ◽

2020 ◽

Vol 21 (4) ◽

pp. 1345

Author(s):

Qianxin Huang ◽

Jinyang Lv ◽

Yanyan Sun ◽

Hongmei Wang ◽

Yuan Guo ◽

...

Keyword(s):

Brassica Napus ◽

Molecular Characterization ◽

Herbicide Resistance ◽

Acetohydroxyacid Synthase ◽

Cross Resistance ◽

Single Point Mutation ◽

Wild Type ◽

Brassica Napus L ◽

Herbicide Resistant

The use of herbicides is an effective and economic way to control weeds, but their availability for rapeseed is limited due to the shortage of herbicide-resistant cultivars in China. The single-point mutation in the acetohydroxyacid synthase (AHAS) gene can lead to AHAS-inhibiting herbicide resistance. In this study, the inheritance and molecular characterization of the tribenuron-methyl (TBM)-resistant rapeseed (Brassica napus L.) mutant, K5, are performed. Results indicated that TBM-resistance of K5 was controlled by one dominant allele at a single nuclear gene locus. The novel substitution of cytosine with thymine at position 544 in BnAHAS1 was identified in K5, leading to the alteration of proline with serine at position 182 in BnAHAS1. The TBM-resistance of K5 was approximately 100 times that of its wild-type ZS9, and K5 also showed cross-resistance to bensufuron-methyl and monosulfuron-ester sodium. The BnAHAS1544T transgenic Arabidopsis exhibited higher TBM-resistance than that of its wild-type, which confirmed that BnAHAS1544T was responsible for the herbicide resistance of K5. Simultaneously, an allele-specific marker was developed to quickly distinguish the heterozygous and homozygous mutated alleles BnAHAS1544T. In addition, a method for the fast screening of TBM-resistant plants at the cotyledon stage was developed. Our research identified and molecularly characterized one novel mutative AHAS allele in B. napus and laid a foundation for developing herbicide-resistant rapeseed cultivars.

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Characterization of plasminogen variants in healthy subjects and plasminogen mutants in patients with inherited plasminogen deficiency by isoelectric focusing gel electrophoresis

Thrombosis and Haemostasis ◽

10.1160/th04-01-0041 ◽

2004 ◽

Vol 92 (08) ◽

pp. 352-357 ◽

Cited By ~ 6

Author(s):

Katrin Tefs ◽

Maria Georgieva ◽

Stefan Seregard ◽

Campbell Tait ◽

Lori Luchtman-Jones ◽

...

Keyword(s):

Isoelectric Focusing ◽

Gel Electrophoresis ◽

Healthy Subjects ◽

Molecular Genetic ◽

Gene Mutations ◽

Molecular Genetic Analysis ◽

Compound Heterozygous ◽

Wild Type ◽

Ligneous Conjunctivitis

SummaryPlasmin(ogen) plays an important role in fibrinolysis and wound healing. Severe hypoplasminogenemia has recently been linked to ligneous conjunctivitis. Plasminogen (plg) is known as a polymorphic protein and most of these variants have been identified using isoelectric focusing (IEF) gel electrophoresis. Here, we studied common plg variants from healthy subjects and plg mutants from three patients with hypoplasminogenemia and three subjects with dysplasminogenemia by molecular genetic analysis and IEF. Analysis of 24 healthy subjects showed that subjects with the most common IEF plg phenotype A (n = 12) were homozygous for aspartate at position 453 (453D), while both subjects with IEF plg phenotype B were homozygous for asparagine at this position (453N). Subjects with IEF plg phenotype AB (n = 10) were compound-heterozygous for 453D/453N. Three patients with severe hypoplasminogenemia and different plg gene mutations exhibited characteristic “abnormal” IEF band patterns when compared with IEF plg phenotypes A and B. In all heterozygous family members the observed IEF plg phenotype was derived from the wild type plg molecule only, probably due to low concentration of the mutant plg molecule in plasma. In contrast, in three unrelated subjects with heterozygous dysplasminogenemia an equal “mixture” of wild type and mutant plg was found by IEF analysis. In conclusion, plg phenotyping by IEF in combination with molecular analysis of the plg gene seems to be a useful method for characterization of plg variants and mutants.

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Characterization of a norflurazon-resistant mutant of Chlamydomonas reinhardtii

Weed Science ◽

10.1017/s0043174500093000 ◽

1997 ◽

Vol 45 (3) ◽

pp. 374-377 ◽

Cited By ~ 4

Author(s):

Varsha Vartak ◽

Sujata Bhargava

Keyword(s):

Chlamydomonas Reinhardtii ◽

Mode Of Action ◽

Resistant Mutant ◽

Phytoene Desaturase ◽

Wild Type ◽

Cross Tolerance ◽

In The Wild ◽

Similar Mode ◽

Target Enzyme

A norflurazon-resistant mutant has been isolated from Chlamydomonas reinhardtii that showed a three-fold factor of resistance over wild type cultures. In comparison to wild type cultures, the mutant showed better retention of chlorophylls and carotenoids when grown in light in the presence of norflurazon. When grown in the dark, chlorophyll losses were similar, while carotenoid losses were lower than in the wild type cultures. Higher levels of phytoene accumulated in the wild type cultures in the presence of norflurazon than in the resistant cultures. The resistant cultures also showed cross tolerance to EMD-IT 5914, a herbicide with a similar mode of action. Norflurazon resistance in this alga appears to arise from alterations in the target enzyme phytoene desaturase.

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A PCR-oligonucleotide ligation assay to determine the prevalence of 23S rRNA gene mutations in clarithromycin-resistant Helicobacter pylori.

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.41.3.712 ◽

1997 ◽

Vol 41 (3) ◽

pp. 712-714 ◽

Cited By ~ 89

Author(s):

G G Stone ◽

D Shortridge ◽

J Versalovic ◽

J Beyer ◽

R K Flamm ◽

...

Keyword(s):

Helicobacter Pylori ◽

Gene Mutations ◽

23S Rrna ◽

Rrna Gene ◽

Wild Type ◽

Single Base ◽

Rapid Pcr ◽

Clarithromycin Resistance ◽

23S Rrna Gene ◽

Oligonucleotide Ligation Assay

We have developed a rapid PCR-oligonucleotide ligation assay that can discriminate single base substitutions that are associated with clarithromycin resistance in Helicobacter pylori. Susceptible isolates were wild type at positions 2143 and 2144 (cognate to 2058 and 2059 in Escherichia coli), while 93% of the resistant isolates contained A-to-G mutations at either position and 7% of the isolates contained A-to-C mutations at position 2143. In addition, the MIC for 86% of the resistant isolates with an A2143 mutation was > or = 64 micrograms per ml, and that for 89% of the resistant isolates with an A2144 mutation was < or = 32 micrograms per ml.

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Resistance to Tomato Yellow Leaf Curl Virus by Combining Expression of a Natural Tolerance Gene and a Dysfunctional Movement Protein in a Single Cultivar

10.32747/2000.7573079.bard ◽

2000 ◽

Author(s):

Henryk Hanokh Czosnek ◽

Dani Zamir ◽

Robert L. Gilbertson ◽

Lucas J. William

Keyword(s):

Transgenic Plants ◽

Resistance Gene ◽

Movement Protein ◽

Tomato Yellow Leaf ◽

Yellow Leaf ◽

Wild Type ◽

Tomato Production ◽

Wild Tomato ◽

The Us

Background The tomato yellow leaf curl disease (TYLCV) has been a major deterrent to tomato production in Israel for the last 20 years. This whitefly-transmitted viral disease has been found in the Caribbean Island in the early 1990s, probably as an import from the Middle East. In the late 1990s, the virus has spread to the US and is now conspicuous in Florida and Georgia. Objectives Because of the urgency facing the TYLCV epidemics, there was a compelling need to mobilize scientists to develop tomato variety resistant to TYLCV. The major goal was to identify the virus movement protein (MP) and to express a defective from of MP in a cultivar that contained the natural Ty-1 resistance gene. The research included 1. cloning of the TYLCV isolate from the Dominican Republic (DR) which is (or a close variant) also present in the continental USA; 2. ddefining the role of the MP; 3. mutating the putative MP gene; 4. introducing the modified gene into an advance Ty-1 line; 5. testing the transgenic plants in the field. The pressing threat to tomato production in the US resulted in an extension of the objectives: more emphasis was placed on characterization of TYLCV i the DR, on determination of the epidemiology of the virus in the DR, and on using new TYLCV resistance sources for tomato breeding. Achievements and signification 1. The characterization of TYLCV-DR allowed for more effective TYLCV management strategies that are now implemented in the DR. 2. The identification of the TYLCV MPs and, more importantly, insight into their function has provided a model for how these proteins function in TYLCV movement and support the targeting of one or more of these proteins in a dominant lethal strategy to engineer plants for TYLCV resistance. 3. The transgenic plants that are being generated with wild-type and mutated TYLCV MPs will serve to test the hypothesis that interference with one or more of the TYLCV movement proteins will be a strategy for generating TYLCV-resistant plants. 4. The fine mapping of the resistance Ty-1 gene allowed eliminating deleterious chromosome segments from the wild tomato genitor L. chilense. It may in a near future allow the cloning of the first geminivirus resistance gene. 5. Another resistance source from the wild tomato species L. hirsitum was introgressed into the domesticated tomato, resulting in the production of resistant breeding lines. Implications 1. The monitoring of TYLCV in whiteflies has been applied in the DR. These tools are presently being used to assist in the evaluation of the host-free period and to help select the appropriate locations for growing tomatoes in the DR. 2. An overall strategy to obtain resistance against TYLCV has been used. The expression of wild-type or mutated TYLCV MPs in transgenic tomato is another addition to the arsenal used to fight TYLCV, together with marker assisted breeding and mobilization of additional resistant genes from the wild.

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Identification and Characterization of BTD Gene Mutations in Jordanian Children with Biotinidase Deficiency

Journal of Personalized Medicine ◽

10.3390/jpm10010004 ◽

2020 ◽

Vol 10 (1) ◽

pp. 4

Author(s):

Laith N. AL-Eitan ◽

Kifah Alqa’qa’ ◽

Wajdi Amayreh ◽

Rame Khasawneh ◽

Hanan Aljamal ◽

...

Keyword(s):

Enzymatic Activity ◽

Clinical Symptoms ◽

Family Members ◽

Gene Mutations ◽

Biotinidase Deficiency ◽

Genetic Sequencing ◽

Mutational Status ◽

Sequencing Method ◽

Healthy Family

Biotinidase deficiency is an autosomal recessive metabolic disorder whose diagnosis currently depends on clinical symptoms and a biotinidase enzyme assay. This study aimed to investigate the mutational status and enzymatic activity of biotinidase deficiency in seven unrelated Jordanian families including 10 patients and 17 healthy family members. Amplified DNA was analyzed by the automated Sanger sequencing method, and the enzymatic assay was performed using a colorimetric assessment. Biotinidase level was significantly lower (p < 0.001) in BTD children compare to their non-affected family members. Genetic sequencing revealed six different mutations in Jordanian patients. One mutation was novel and located in exon 4, which could be a prevalent mutation for biotinidase deficiency in the Jordanian population. Identification of these common mutations and combing the enzymatic activity with genotypic data will help clinicians with regard to better genetic counseling and management through implementing prevention programs in the future.

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