Genetics and Genetic Manipulation in Francisella Tularensis

2007 ◽  
Vol 1105 (1) ◽  
pp. 67-97 ◽  
Author(s):  
D. W. FRANK ◽  
T. C. ZAHRT
Keyword(s):  
Francisella Tularensis ◽  
Genetic Manipulation

scholarly journals Single-copy chromosomal integration systems for Francisella tularensis

Microbiology ◽  
2009 ◽  
Vol 155 (4) ◽  
pp. 1152-1163 ◽  
Author(s):  
Eric D. LoVullo ◽  
Claudia R. Molins-Schneekloth ◽  
Herbert P. Schweizer ◽  
Martin S. Pavelka
Keyword(s):  
Francisella Tularensis ◽  
High Frequency ◽  
Genetic Manipulation ◽  
Single Copy ◽  
Gene Encoding ◽  
Highly Pathogenic ◽  
Pathogenic Organism ◽  
Allelic Exchange ◽  
Specific Manner ◽  
A Site

Francisella tularensis is a fastidious Gram-negative bacterium responsible for the zoonotic disease tularemia. Investigation of the biology and molecular pathogenesis of F. tularensis has been limited by the difficulties in manipulating such a highly pathogenic organism and by a lack of genetic tools. However, recent advances have substantially improved the ability of researchers to genetically manipulate this organism. To expand the molecular toolbox we have developed two systems to stably integrate genetic elements in single-copy into the F. tularensis genome. The first system is based upon the ability of transposon Tn7 to insert in both a site- and orientation-specific manner at high frequency into the attTn7 site located downstream of the highly conserved glmS gene. The second system consists of a sacB-based suicide plasmid used for allelic exchange of unmarked elements with the blaB gene, encoding a β-lactamase, resulting in the replacement of blaB with the element and the loss of ampicillin resistance. To test these new tools we used them to complement a novel d-glutamate auxotroph of F. tularensis LVS, created using an improved sacB-based allelic exchange plasmid. These new systems will be helpful for the genetic manipulation of F. tularensis in studies of tularemia biology, especially where the use of multi-copy plasmids or antibiotic markers may not be suitable.

scholarly journals Genetic Manipulation of Francisella Tularensis

2011 ◽  
Vol 1 ◽  
Author(s):  
Xhavit Zogaj ◽  
Karl E. Klose
Keyword(s):  
Francisella Tularensis ◽  
Genetic Manipulation

scholarly journals Application of Cas12j for Streptomyces editing and cluster activation

2021 ◽  
Author(s):  
Lee Ling Tan ◽  
Elena Heng ◽  
Nadiah Zulkarnain ◽  
Chuang Yan Leong ◽  
Veronica Ng ◽  
...  
Keyword(s):  
Natural Product ◽  
Francisella Tularensis ◽  
Genetic Manipulation ◽  
Tularensis Subsp ◽  
Streptomyces Sp ◽  
Natural Product Discovery ◽  
Type V ◽  
Strain Dependent ◽  
Cas Proteins

In recent years, CRISPR-Cas toolboxes for Streptomyces editing have rapidly accelerated natural product discovery and engineering. However, Cas efficiencies are also oftentimes strain dependent, subsequently a variety of Cas proteins would allow for flexibility and enable genetic manipulation within a wider range of Streptomyces strains. In this work, we have further expanded the Cas toolbox by presenting the first example of Cas12j mediated editing in Streptomyces sp. A34053. In our study, we have also observed significantly improved editing efficiencies with Acidaminococcus sp. Cas12j compared to Cas12a, Francisella tularensis subsp. novicida U112's type V-A Cas (FnCpf1).

Metabolic engineering of CHO cells to prepare glycoproteins

2018 ◽  
Vol 2 (3) ◽  
pp. 433-442 ◽  
Author(s):  
Qiong Wang ◽  
Michael J. Betenbaugh
Keyword(s):  
Metabolic Engineering ◽  
Cho Cells ◽  
Genetic Manipulation ◽  
Chinese Hamster ◽  
Post Translational Modification ◽  
Effector Functions ◽  
Recombinant Glycoproteins ◽  
Production Platform ◽  
Chemical Inhibitors ◽  
Amino Acid Mutations

As a complex and common post-translational modification, N-linked glycosylation affects a recombinant glycoprotein's biological activity and efficacy. For example, the α1,6-fucosylation significantly affects antibody-dependent cellular cytotoxicity and α2,6-sialylation is critical for antibody anti-inflammatory activity. Terminal sialylation is important for a glycoprotein's circulatory half-life. Chinese hamster ovary (CHO) cells are currently the predominant recombinant protein production platform, and, in this review, the characteristics of CHO glycosylation are summarized. Moreover, recent and current metabolic engineering strategies for tailoring glycoprotein fucosylation and sialylation in CHO cells, intensely investigated in the past decades, are described. One approach for reducing α1,6-fucosylation is through inhibiting fucosyltransferase (FUT8) expression by knockdown and knockout methods. Another approach to modulate fucosylation is through inhibition of multiple genes in the fucosylation biosynthesis pathway or through chemical inhibitors. To modulate antibody sialylation of the fragment crystallizable region, expressions of sialyltransferase and galactotransferase individually or together with amino acid mutations can affect antibody glycoforms and further influence antibody effector functions. The inhibition of sialidase expression and chemical supplementations are also effective and complementary approaches to improve the sialylation levels on recombinant glycoproteins. The engineering of CHO cells or protein sequence to control glycoforms to produce more homogenous glycans is an emerging topic. For modulating the glycosylation metabolic pathways, the interplay of multiple glyco-gene knockouts and knockins and the combination of multiple approaches, including genetic manipulation, protein engineering and chemical supplementation, are detailed in order to achieve specific glycan profiles on recombinant glycoproteins for superior biological function and effectiveness.

Drug-Induced Agranulocytosis: A Mini Review

2016 ◽  
Vol 2 (1) ◽  
pp. 57-59
Author(s):  
Pavithra D ◽  
Praveen D ◽  
Vijey Aanandhi M
Keyword(s):  
Bone Marrow ◽  
Complete Blood Count ◽  
Genetic Manipulation ◽  
White Blood Cells ◽  
Deep Infection ◽  
Morbidity Rate ◽  
Drug Induced ◽  
Serious Adverse Event ◽  
Mortality And Morbidity ◽  
The Individual

Agranulocytosis is also known to be granulopenia, causing neutropenia in circulating blood streams .The destruction of white blood cells takes place which leads to increase in the infection rate in an individual where immune system of the individual is suppressed. The symptoms includes fever, sore throat, mouth ulcers. These are commonly seen as adverse effects of a particular drug and are prescribed for the common diagnostic test for regular monitoring of complete blood count in an admitted patient. Drug-induced agranulocytosis remains a serious adverse event due to occurrence of severe sepsis with deep infection leading to pneumonia, septicaemia, and septic shock in two/third of the patient. Antibiotics seem to be the major causative weapon for this disorder. Certain drugs mainly anti-thyroid drugs, ticlopidine hydrochloride, spironolactone, clozapine, antileptic drugs (clozapine), non-steroidal anti-inflammatory agents, dipyrone are the potential causes. Bone marrow insufficiency followed by destruction or limited proliferative bone marrow destruction takes place. Chemotherapy is rarely seen as a causative agent for this disorder. Genetic manipulation may also include as one of the reason. Agranulocytosis can be recovered within two weeks but the mortality and morbidity rate during the acute phase seems to be high, appropriate adjuvant treatment with broad-spectrum antibiotics are prerequisites for the management of complicated neutropenia. Drugs that are treated for this are expected to change as a resistant drug to the patient. The pathogenesis of agranulocytosis is not yet known. A comprehensive literature search has been carried out in PubMed, Google Scholar and articles pertaining to drug-induced agranulocytosis were selected for review.

Improvement of effectiveness in maize breeding

2006 ◽  
Vol 54 (3) ◽  
pp. 351-358 ◽  
Author(s):  
P. Pepó
Keyword(s):  
Recurrent Selection ◽  
Genetic Manipulation ◽  
Field Testing ◽  
Tissue Cultures ◽  
Maize Breeding ◽  
Breeding Programmes ◽  
Speed Up ◽  
Selection For

Plant regeneration via tissue culture is becoming increasingly more common in monocots such as maize (Zea mays L.). Pollen (gametophytic) selection for resistance to aflatoxin in maize can greatly facilitate recurrent selection and the screening of germplasm for resistance at much less cost and in a shorter time than field testing. In vivo and in vitro techniques have been integrated in maize breeding programmes to obtain desirable agronomic attributes, enhance the genes responsible for them and speed up the breeding process. The efficiency of anther and tissue cultures in maize and wheat has reached the stage where they can be used in breeding programmes to some extent and many new cultivars produced by genetic manipulation have now reached the market.

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