scholarly journals Flight Performance and Teneral Energy Reserves of Two Genetically-Modified and One Wild-Type Strain of the Yellow Fever Mosquito Aedes aegypti

2012 ◽  
Vol 12 (12) ◽  
pp. 1053-1058 ◽  
Author(s):  
Irka Bargielowski ◽  
Christian Kaufmann ◽  
Luke Alphey ◽  
Paul Reiter ◽  
Jacob Koella
Keyword(s):  
Aedes Aegypti ◽  
Yellow Fever ◽  
Type Strain ◽  
Wild Type Strain ◽  
Genetically Modified ◽  
Flight Performance ◽  
Energy Reserves ◽  
Yellow Fever Mosquito ◽  
Wild Type

scholarly journals Spectral Sensitivity of Larval Mosquito Ocelli

1972 ◽  
Vol 59 (4) ◽  
pp. 415-420 ◽  
Author(s):  
Edward B. Seldin ◽  
Richard H. White ◽  
Paul K. Brown
Keyword(s):  
Absorption Spectrum ◽  
Aedes Aegypti ◽  
Spectral Sensitivity ◽  
Yellow Fever ◽  
Reasonable Agreement ◽  
Secondary Peak ◽  
Yellow Fever Mosquito ◽  
Wild Type ◽  
Eye Tissues

The spectral sensitivity of lateral ocelli in both wild-type and white-eyed larvae of the yellow fever mosquito Aedes aegypti L. (reared in darkness) was measured by means of the electroretinogram. The spectral sensitivity is maximal at about 520 nm, with a small secondary peak near 370 nm. When allowance is made for some screening and filtering by the eye tissues, the spectral sensitivity is in reasonable agreement with the absorption spectrum of ocellar rhodopsin (λmax = 515 nm).

scholarly journals Comparative study on growth and morphological characteristics of a wild type strain Rhizobium spp. (RCA-220) and a genetically engineered E. coli BL21

2014 ◽  
Vol 20 ◽  
pp. 75-82
Author(s):  
MM Rahman ◽  
M Salah Uddin ◽  
S Zaman ◽  
MA Saleh ◽  
AE Ekram ◽  
...  
Keyword(s):  
Growth Rate ◽  
Carbon Source ◽  
Salt Concentration ◽  
Type Strain ◽  
Wild Type Strain ◽  
Genetically Modified ◽  
Growth Characteristics ◽  
Wild Type ◽  
E Coli ◽  
Rhizobium Spp

Context: Comparison between a wild type strain Rhizobium spp. (RCA-220) and a genetically modified strain E. coli BL21 in context of growth features. Objective: To observe the comparative growth characteristics of a genetically modified E. coli BL21 and an isolated wild type strain Rhizobium spp. (RCA-220). Materials and Methods: Different kinds of investigations were accomplished in both Luria-Bertani (LB) liquid and semi-solid media to observe the growth and maintenance of these strains. For the isolation of Rhizobium spp. selective Yeast Extract Manitol Agar (YEMA) was used. Colony morphology, pH, temperature, carbon source, salt concentration and light were taken under consideration and optimized for growth characteristics. Results: For the strain E. coli BL21, the maximum growth rate was 1.9 at incubation time 72 h, pH 7.2, temperature 37°C (optimized) while for Rhizobium spp. the growth rate was significantly higher (OD 2) at pH 6.8, temperature 28°C (optimized). Among all used carbon sources, strains grown in the medium supplemented with peptone showed rapid and good performance. So, peptone was proved as the best carbon source for both strains. The maximum growths of these strains were observed at 0g/100ml NaCl salt concentration. RCA-220 strain was comparatively more tolerable to salt than E. coli BL21 strain. In this work, E. coli BL21 showed rapid and good performance in presence of light while Rhizobium spp. showed better performance in absence of light. Statistical analysis showed that the growth rate of Rhizobium spp. was significantly higher than E. coli BL21. Conclusion: From the experimental results, it can be concluded that naturally obtained microbial strains were stable and could tolerate any stress condition where the modified strains lose their growth capability and the overall growth performances were reduced or slowed down than the wild type strain. DOI: http://dx.doi.org/10.3329/jbs.v20i0.17718 J. bio-sci.  20:  75-82, 2012

Comparative Neuropathology of Ovine Enterotoxemia Produced byClostridium perfringensType D Wild-Type Strain CN1020 and Its Genetically Modified Derivatives

2014 ◽  
Vol 52 (3) ◽  
pp. 465-475 ◽  
Author(s):  
J. P. Garcia ◽  
F. Giannitti ◽  
J. W. Finnie ◽  
J. Manavis ◽  
J. Beingesser ◽  
...  
Keyword(s):  
Type Strain ◽  
Wild Type Strain ◽  
Genetically Modified ◽  
Wild Type ◽  
Comparative Neuropathology

scholarly journals Effects of Mutations of RAD50, RAD51, RAD52, and Related Genes on Illegitimate Recombination in Saccharomyces cerevisiae

Genetics ◽  
1996 ◽  
Vol 142 (2) ◽  
pp. 383-391 ◽  
Author(s):  
Yasumasa Tsukamoto ◽  
Jun-ichi Kato ◽  
Hideo Ikeda
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Quantitative Analysis ◽  
Structural Analysis ◽  
Recombination Rate ◽  
Type Strain ◽  
Negative Selection ◽  
Wild Type Strain ◽  
Illegitimate Recombination ◽  
Wild Type ◽  
In The Wild

Abstract To examine the mechanism of illegitimate recombination in Saccharomyces cerevisiae, we have developed a plasmid system for quantitative analysis of deletion formation. A can1 cyh2 cell carrying two negative selection markers, the CAN1 and CYH2 genes, on a YCp plasmid is sensitive to canavanine and cycloheximide, but the cell becomes resistant to both drugs when the plasmid has a deletion over the CAN1 and CYH2 genes. Structural analysis of the recombinant plasmids obtained from the resistant cells showed that the plasmids had deletions at various sites of the CAN1-CYH2 region and there were only short regions of homology (1-5 bp) at the recombination junctions. The results indicated that the deletion detected in this system were formed by illegitimate recombination. Study on the effect of several rad mutations showed that the recombination rate was reduced by 30-, 10-, 10-, and 10-fold in the rad52, rad50, mre11, and xrs2 mutants, respectively, while in the rud51, 54, 55, and 57 mutants, the rate was comparable to that in the wild-type strain. The rad52 mutation did not affect length of homology at junction sites of illegitimate recombination.

scholarly journals The role of Zur-regulated lipoprotein A in bacterial morphology, antimicrobial susceptibility, and production of outer membrane vesicles in Acinetobacter baumannii

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Nayeong Kim ◽  
Hyo Jeong Kim ◽  
Man Hwan Oh ◽  
Se Yeon Kim ◽  
Mi Hyun Kim ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Outer Membrane ◽  
Mutant Strain ◽  
Antimicrobial Susceptibility ◽  
Type Strain ◽  
Wild Type Strain ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Wild Type ◽  
Bacterial Morphology

Abstract Background Zinc uptake-regulator (Zur)-regulated lipoprotein A (ZrlA) plays a role in bacterial fitness and overcoming antimicrobial exposure in Acinetobacter baumannii. This study further characterized the zrlA gene and its encoded protein and investigated the roles of the zrlA gene in bacterial morphology, antimicrobial susceptibility, and production of outer membrane vesicles (OMVs) in A. baumannii ATCC 17978. Results In silico and polymerase chain reaction analyses showed that the zrlA gene was conserved among A. baumannii strains with 97–100% sequence homology. Recombinant ZrlA protein exhibited a specific enzymatic activity of D-alanine-D-alanine carboxypeptidase. Wild-type A. baumannii exhibited more morphological heterogeneity than a ΔzrlA mutant strain during stationary phase. The ΔzrlA mutant strain was more susceptible to gentamicin than the wild-type strain. Sizes and protein profiles of OMVs were similar between the wild-type and ΔzrlA mutant strains, but the ΔzrlA mutant strain produced 9.7 times more OMV particles than the wild-type strain. OMVs from the ΔzrlA mutant were more cytotoxic in cultured epithelial cells than OMVs from the wild-type strain. Conclusions The present study demonstrated that A. baumannii ZrlA contributes to bacterial morphogenesis and antimicrobial resistance, but its deletion increases OMV production and OMV-mediated host cell cytotoxicity.

scholarly journals FixJ family regulator AcfR of Azorhizobium caulinodans is involved in symbiosis with the host plant

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wei Liu ◽  
Xue Bai ◽  
Yan Li ◽  
Haikun Zhang ◽  
Xiaoke Hu
Keyword(s):  
Signal Transduction ◽  
Host Plant ◽  
Type Strain ◽  
Wild Type Strain ◽  
Response Regulator ◽  
Azorhizobium Caulinodans ◽  
Wild Type ◽  
Response Regulators ◽  
Free Living ◽  
Two Component

Abstract Background A wide variety of bacterial adaptative responses to environmental conditions are mediated by signal transduction pathways. Two-component signal transduction systems are one of the predominant means used by bacteria to sense the signals of the host plant and adjust their interaction behaviour. A total of seven open reading frames have been identified as putative two-component response regulators in the gram-negative nitrogen-fixing bacteria Azorhizobium caulinodans ORS571. However, the biological functions of these response regulators in the symbiotic interactions between A. caulinodans ORS571 and the host plant Sesbania rostrata have not been elucidated to date. Results In this study, we identified and investigated a two-component response regulator, AcfR, with a phosphorylatable N-terminal REC (receiver) domain and a C-terminal HTH (helix-turn-helix) LuxR DNA-binding domain in A. caulinodans ORS571. Phylogenetic analysis showed that AcfR possessed close evolutionary relationships with NarL/FixJ family regulators. In addition, six histidine kinases containing HATPase_c and HisKA domains were predicted to interact with AcfR. Furthermore, the biological function of AcfR in free-living and symbiotic conditions was elucidated by comparing the wild-type strain and the ΔacfR mutant strain. In the free-living state, the cell motility behaviour and exopolysaccharide production of the ΔacfR mutant were significantly reduced compared to those of the wild-type strain. In the symbiotic state, the ΔacfR mutant showed a competitive nodule defect on the stems and roots of the host plant, suggesting that AcfR can provide A. caulinodans with an effective competitive ability for symbiotic nodulation. Conclusions Our results showed that AcfR, as a response regulator, regulates numerous phenotypes of A. caulinodans under the free-living conditions and in symbiosis with the host plant. The results of this study help to elucidate the involvement of a REC + HTH_LuxR two-component response regulator in the Rhizobium-host plant interaction.

scholarly journals Mab_3083c Is a Homologue of RNase J and Plays a Role in Colony Morphotype, Aggregation, and Sliding Motility of Mycobacterium abscessus

2021 ◽  
Vol 9 (4) ◽  
pp. 676
Author(s):  
Ting-Yu Liu ◽  
Sheng-Hui Tsai ◽  
Jenn-Wei Chen ◽  
Yu-Ching Wang ◽  
Shiau-Ting Hu ◽  
...  
Keyword(s):  
Type Strain ◽  
Wild Type Strain ◽  
Opportunistic Pathogen ◽  
Mycobacterium Abscessus ◽  
Colony Morphology ◽  
Clinical Strain ◽  
Immunocompromised Patients ◽  
Clinical Infection ◽  
Wild Type ◽  
Sliding Motility

Mycobacterium abscessus is an opportunistic pathogen causing human diseases, especially in immunocompromised patients. M. abscessus strains with a rough morphotype are more virulent than those with a smooth morphotype. Morphotype switch may occur during a clinical infection. To investigate the genes involved in colony morphotype switching, we performed transposon mutagenesis in a rough clinical strain of M. abscessus. A morphotype switching mutant (smooth) named mab_3083c::Tn was obtained. This mutant was found to have a lower aggregative ability and a higher sliding motility than the wild type strain. However, its glycopeptidolipid (GPL) content remained the same as those of the wild type. Complementation of the mutant with a functional mab_3083c gene reverted its morphotype back to rough, indicating that mab_3083c is associated with colony morphology of M. abscessus. Bioinformatic analyses showed that mab_3083c has a 75.4% identity in amino acid sequence with the well-characterized ribonuclease J (RNase J) of M. smegmatis (RNase JMsmeg). Complementation of the mutant with the RNase J gene of M. smegmatis also switched its colony morphology from smooth back to rough. These results suggest that Mab_3083c is a homologue of RNase J and involved in regulating M. abscessus colony morphotype switching.

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