scholarly journals Characterization of the Exoglucanase-Encoding Gene PaEXG2 and Study of Its Role in the Biocontrol Activity of Pichia anomala Strain K

2003 ◽  
Vol 93 (9) ◽  
pp. 1145-1152 ◽  
Author(s):  
Cathy Grevesse ◽  
Philippe Lepoivre ◽  
Mohamed Haïssam Jijakli
Keyword(s):  
Marker Gene ◽  
Glycosylation Site ◽  
Pichia Anomala ◽  
Gene Encoding ◽  
Biocontrol Activity ◽  
Monophosphate Decarboxylase ◽  
Uracil Auxotroph

The PaEXG2 gene, encoding an exo-β-1,3-glucanase, was isolated from the biocontrol agent Pichia anomala strain K. PaEXG2 has the capacity for coding an acidic protein of 427 amino acids with a predicted molecular weight of 45.7 kDa, a calculated pI of 4.7, and one potential N-glycosylation site. PaEXG2 was disrupted by the insertion of the URA3 marker gene, encoding orotidine monophosphate decarboxylase in strain KU1, a uracil auxotroph derived from strain K. Strain KU1 showed inferior biocontrol activity and colonization of wounds on apples, compared to the prototrophic strain. Antagonism and colonization were recovered after the restoration of prototrophy by transformation with the URA3 gene. Integrative transformation was shown to be mostly ectopic in strain K descendants (only 4% of integration by homologous recombination). PaEXG2 disruption abolished all detectable extracellular exo-β-1,3-glucanase activity in vitro and in situ but did not affect biocontrol of Botrytis cinerea on wounded apples.

scholarly journals Enlisting the Ixodes scapularis Embryonic ISE6 Cell Line to Investigate the Neuronal Basis of Tick—Pathogen Interactions

Pathogens ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 70
Author(s):  
Lourdes Mateos-Hernández ◽  
Natália Pipová ◽  
Eléonore Allain ◽  
Céline Henry ◽  
Clotilde Rouxel ◽  
...  
Keyword(s):  
Cell Line ◽  
Peripheral Nerves ◽  
Ixodes Scapularis ◽  
Embryonic Cell ◽  
Cell Subpopulation ◽  
In Vivo Experiments

Neuropeptides are small signaling molecules expressed in the tick central nervous system, i.e., the synganglion. The neuronal-like Ixodes scapularis embryonic cell line, ISE6, is an effective tool frequently used for examining tick–pathogen interactions. We detected 37 neuropeptide transcripts in the I. scapularis ISE6 cell line using in silico methods, and six of these neuropeptide genes were used for experimental validation. Among these six neuropeptide genes, the tachykinin-related peptide (TRP) of ISE6 cells varied in transcript expression depending on the infection strain of the tick-borne pathogen, Anaplasma phagocytophilum. The immunocytochemistry of TRP revealed cytoplasmic expression in a prominent ISE6 cell subpopulation. The presence of TRP was also confirmed in A. phagocytophilum-infected ISE6 cells. The in situ hybridization and immunohistochemistry of TRP of I. scapularis synganglion revealed expression in distinct neuronal cells. In addition, TRP immunoreaction was detected in axons exiting the synganglion via peripheral nerves as well as in hemal nerve-associated lateral segmental organs. The characterization of a complete Ixodes neuropeptidome in ISE6 cells may serve as an effective in vitro tool to study how tick-borne pathogens interact with synganglion components that are vital to tick physiology. Therefore, our current study is a potential stepping stone for in vivo experiments to further examine the neuronal basis of tick–pathogen interactions.

scholarly journals Recovery of Fusarium oxysporum Fo47 Mutants Affected in Their Biocontrol Activity After Transposition of the Fot1 Element

2002 ◽  
Vol 92 (9) ◽  
pp. 936-945 ◽  
Author(s):  
Sophie Trouvelot ◽  
Chantal Olivain ◽  
Ghislaine Recorbet ◽  
Quirico Migheli ◽  
Claude Alabouvette
Keyword(s):  
Fusarium Oxysporum ◽  
Insertional Mutagenesis ◽  
Wild Type Strain ◽  
Growth Habit ◽  
Antagonistic Activity ◽  
Phenotypic Characterization ◽  
Wild Type ◽  
Biocontrol Activity

To investigate the biocontrol mechanisms by which the antagonistic Fusarium oxysporum strain Fo47 is active against Fusarium wilt, a Fot1 transposon-mediated insertional mutagenesis approach was adopted to generate mutants affected in their antagonistic activity. Ninety strains in which an active Fot1 copy had transposed were identified with a phenotypic assay for excision and tested for their biocontrol activity against F. oxysporum f. sp. lini on flax in greenhouse experiments. Sixteen strains were affected in their capacity to protect flax plants, either positively (more antagonistic than Fo47) or negatively (less antagonistic). The molecular characterization of these mutants confirms the excision of Fot1 and its reinsertion in most of the cases. Moreover, we demonstrate that other transposable elements such as Fot2, impala, and Hop have no transposition activity in the mutant genomes. The phenotypic characterization of these mutants shows that they are affected neither in their in vitro growth habit nor in their competitiveness in soil compared with wild-type strain Fo47. These results show that mutants are not impaired in their saprophytic phase and suggest that the altered biocontrol phenotype should likely be expressed during the interaction with the host plant.

In vitro characterization of an injectable in situ forming composite system for bone reconstruction

2015 ◽  
Vol 119 ◽  
pp. 151-158 ◽  
Author(s):  
R. Dorati ◽  
C. Colonna ◽  
I. Genta ◽  
A. De Trizio ◽  
T. Modena ◽  
...  
Keyword(s):  
Composite System ◽  
Bone Reconstruction ◽  
In Situ Forming ◽  
In Vitro Characterization

scholarly journals Characterization of the tyramine-producing pathway in Sporolactobacillus sp. P3J

Microbiology ◽  
2011 ◽  
Vol 157 (6) ◽  
pp. 1841-1849 ◽  
Author(s):  
Monika Coton ◽  
María Fernández ◽  
Hein Trip ◽  
Victor Ladero ◽  
Niels L. Mulder ◽  
...  
Keyword(s):  
Trna Synthetase ◽  
Cloning And Expression ◽  
Clear Correlation ◽  
Tyrosine Decarboxylase ◽  
Gene Encoding ◽  
Polycistronic Mrna ◽  
Tyrosine Concentration ◽  
Putative Phage

A sporulated lactic acid bacterium (LAB) isolated from cider must was shown to harbour the tdc gene encoding tyrosine decarboxylase. The isolate belonged to the Sporolactobacillus genus and may correspond to a novel species. The ability of the tdc-positive strain, Sporolactobacillus sp. strain P3J, to produce tyramine in vitro was demonstrated by using HPLC. A 7535 bp nucleotide sequence harbouring the putative tdc gene was determined. Analysis of the obtained sequence showed that four tyramine production-associated genes [tyrosyl-tRNA synthetase (tyrS), tyrosine decarboxylase (tdc), tyrosine permease (tyrP) and Na+/H+ antiporter (nhaC)] were present and were organized as already described in other tyramine-producing LAB. This operon was surrounded by genes showing the highest identities with mobile elements: a putative phage terminase and a putative transposase (downstream and upstream, respectively), suggesting that the tyramine-forming trait was acquired through horizontal gene transfer. Transcription analyses of the tdc gene cluster suggested that tyrS and nhaC are expressed as monocistronic genes while tdc would be part of a polycistronic mRNA together with tyrP. The presence of tyrosine in the culture medium induced the expression of all genes except for tyrS. A clear correlation was observed between initial tyrosine concentration and tyramine production combined with an increase in the final pH reached by the culture. Finally, cloning and expression of the tyrP gene in Lactococcus lactis demonstrated that its product catalyses the exchange of tyrosine and tyramine.

Characterization of distinct mesenchymal-like cell populations from human skeletal muscle in situ and in vitro

2010 ◽  
Vol 316 (15) ◽  
pp. 2513-2526 ◽  
Author(s):  
Séverine Lecourt ◽  
Jean-Pierre Marolleau ◽  
Olivia Fromigué ◽  
Karine Vauchez ◽  
Rina Andriamanalijaona ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Human Skeletal Muscle ◽  
Cell Populations

Characterization of the tomato (Lycopersicon esculentum) genome using in vitro and in situ DNA reassociation

Genome ◽  
1998 ◽  
Vol 41 (3) ◽  
pp. 346-356 ◽  
Author(s):  
Daniel G. Peterson ◽  
William R. Pearson ◽  
Stephen M. Stack
Keyword(s):  
Lycopersicon Esculentum ◽  
Dna Reassociation

A Uracil Auxotroph Toxoplasma gondii Exerting Immunomodulation to Inhibit Breast Cancer Growth and Metastasis

2021 ◽  
Author(s):  
Li-Qing Xu ◽  
Li-Jie Yao ◽  
Dan Jiang ◽  
Min Chen ◽  
Wen-Zhong Liao ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Toxoplasma Gondii ◽  
Tumor Growth ◽  
Lung Metastasis ◽  
Tumor Bearing ◽  
Uracil Auxotroph ◽  
Ifn Γ

Abstract Background: Breast cancer is the most common cause of cancer-related death among women, and patients with triple-negative breast cancer (TNBC) have poor prognosis, so it is necessary to develop new effective therapies urgently. Recent studies have demonstrated that uracil auxotroph Toxoplasma gondii vaccine displays antitumor effects. Here, we examined the immunotherapy effects of an attenuated uracil auxotroph strain of T. gondii against 4T1 murine breast cancer.Methods: We constructed a uracil auxotroph strain, the orotidine 5′-monophosphate decarboxylase gene deleted strain of T. gondii (RH-Δompdc) with the CRISPR/Cas9 technology. Its virulence in vitro and in vivo was determined by parasite replication assay, plaque assay, the parasite burden detection in mice peritoneal fluids and the survival analysis of T. gondii infection mice. Its immune modulation ability was evaluated by cytokines detection. Its antitumor effect was evaluated after its in situ inoculation to 4T1 tumors in mouse model, the tumor volume was measured, the 4T1 lung metastasis was detected by H&E and Ki67 antibody staining, and the cytokines levels were measured by ELISA.Results: RH-Δompdc strain could proliferate normally with uracil supplement, however, it was unable to propagate without uracil and in vivo, which implicated that it is avirulent to the hosts. This mutant showed vaccine characteristics that it could induce intense immune responses both in vitro and in vivo by boosting the expression of inflammatory cytokines significantly. RH-Δompdc in situ inoculation to the 4T1 tumors in mice could inhibit the tumor growth, reduce the lung metastasis, promote the survival of the tumor-bearing mice, and also increase the secretion of Th1 cytokines IL-12 and IFN-γ both in serum and in the tumor microenvironment (TME). Conclusion: The uracil auxotroph RH-Δompdc inoculation to the 4T1 tumors stimulated the anti-infection and antitumor immunity in mice, resulted in the inhibition of tumor growth and metastasis, the promotion in survival of the tumor-bearing mice, and the increasing secretion of IL-12 and IFN-γ both in serum and in the TME. Our findings implied that the immunomodulation resulted by RH-Δompdc could be a potential antitumor strategy.

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