scholarly journals Transcriptional Analysis of Carotenoids Accumulation and Metabolism in a Pink-Fleshed Lemon Mutant

Genes ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1294
Author(s):  
Giuseppe Lana ◽  
Jaime Zacarias-Garcia ◽  
Gaetano Distefano ◽  
Alessandra Gentile ◽  
María J. Rodrigo ◽  
...  
Keyword(s):  
Transcriptional Analysis ◽  
Citrus Limon ◽  
Wild Type ◽  
Abscisic Acid Biosynthesis ◽  
Lycopene Cyclase ◽  
Associated Proteins ◽  
Fibrillin 1 ◽  
Transcriptomic Level ◽  
Carotenoid Profile ◽  
Storage Structures

Pink lemon is a spontaneous bud mutation of lemon (Citrus limon, L. Burm. f) characterized by the production of pink-fleshed fruits due to an unusual accumulation of lycopene. To elucidate the genetic determinism of the altered pigmentation, comparative carotenoid profiling and transcriptional analysis of both the genes involved in carotenoid precursors and metabolism, and the proteins related to carotenoid-sequestering structures were performed in pink-fleshed lemon and its wild-type. The carotenoid profile of pink lemon pulp is characterized by an increased accumulation of linear carotenoids, such as lycopene, phytoene and phytofluene, from the early stages of development, reaching their maximum in mature green fruits. The distinctive phenotype of pink lemon is associated with an up-regulation and down-regulation of the genes upstream and downstream the lycopene cyclase, respectively. In particular, 9-cis epoxycarotenoid dioxygenase genes were overexpressed in pink lemon compared with the wild-type, suggesting an altered regulation of abscisic acid biosynthesis. Similarly, during early development of the fruits, genes of the carotenoid-associated proteins heat shock protein 21, fibrillin 1 and 2 and orange gene were overexpressed in the pulp of the pink-fleshed lemon compared to the wild-type, indicating its increased capacity for sequestration, stabilization or accumulation of carotenes. Altogether, the results highlighted significant differences at the transcriptomic level between the pink-fleshed lemon and its wild-type, in terms of carotenoid metabolism and the capacity of stabilization in storage structures between the two accessions. Such changes may be either responsible for the altered carotenoid accumulation or in contrast, a metabolic consequence.

scholarly journals Abrogation of Neuraminidase Reduces Biofilm Formation, Capsule Biosynthesis, and Virulence of Porphyromonas gingivalis

2011 ◽  
Vol 80 (1) ◽  
pp. 3-13 ◽  
Author(s):  
Chen Li ◽  
Kurniyati ◽  
Bo Hu ◽  
Jiang Bian ◽  
Jianlan Sun ◽  
...  
Keyword(s):  
Porphyromonas Gingivalis ◽  
Biofilm Formation ◽  
Adult Population ◽  
Transcriptional Analysis ◽  
Wild Type ◽  
Content Type ◽  
Multiple Organs ◽  
Biochemical Analyses

ABSTRACTThe oral bacteriumPorphyromonas gingivalisis a key etiological agent of human periodontitis, a prevalent chronic disease that affects up to 80% of the adult population worldwide.P. gingivalisexhibits neuraminidase activity. However, the enzyme responsible for this activity, its biochemical features, and its role in the physiology and virulence ofP. gingivalisremain elusive. In this report, we found thatP. gingivalisencodes a neuraminidase, PG0352 (SiaPg). Transcriptional analysis showed thatPG0352is monocistronic and is regulated by a sigma70-like promoter. Biochemical analyses demonstrated that SiaPgis an exo-α-neuraminidase that cleaves glycosidic-linked sialic acids. Cryoelectron microscopy and tomography analyses revealed that thePG0352deletion mutant (ΔPG352) failed to produce an intact capsule layer. Compared to the wild type,in vitrostudies showed that ΔPG352 formed less biofilm and was less resistant to killing by the host complement.In vivostudies showed that while the wild type caused a spreading type of infection that affected multiple organs and all infected mice were killed, ΔPG352 only caused localized infection and all animals survived. Taken together, these results demonstrate that SiaPgis an important virulence factor that contributes to the biofilm formation, capsule biosynthesis, and pathogenicity ofP. gingivalis, and it can potentially serve as a new target for developing therapeutic agents againstP. gingivalisinfection.

scholarly journals Identification of different putative outer membrane electron conduits necessary for Fe(III) citrate, Fe(III) oxide, Mn(IV) oxide, or electrode reduction by Geobacter sulfurreducens

2017 ◽  
Author(s):  
Fernanda Jiménez Otero ◽  
Chi Ho Chan ◽  
Daniel R. Bond
Keyword(s):  
Electron Transfer ◽  
Outer Membrane ◽  
Electron Acceptor ◽  
Single Gene ◽  
Gene Clusters ◽  
Geobacter Sulfurreducens ◽  
Transcriptional Analysis ◽  
Growth Defect ◽  
Redox Potentials ◽  
Wild Type

AbstractAt least five gene clusters in the Geobacter sulfurreducens genome encode putative ‘electron conduits’ implicated in electron transfer across the outer membrane, each containing a periplasmic multiheme c-type cytochrome, integral outer membrane anchor, and outer membrane redox lipoprotein(s). Markerless single gene cluster deletions and all possible multiple deletion combinations were constructed and grown with soluble Fe(III) citrate, Fe(III)- and Mn(IV)-oxides, and graphite electrodes poised at +0.24 V and −0.1 V vs. SHE. Different gene clusters were necessary for reduction of each electron acceptor. During metal oxide reduction, deletion of the previously described omcBC cluster caused defects, but deletion of additional components in an ΔomcBC background, such as extEFG, were needed to produce defects greater than 50% compared to wild type. Deletion of all five gene clusters abolished all metal reduction. During electrode reduction, only the ΔextABCD mutant had a severe growth defect at both redox potentials, while this mutation did not affect Fe(III)-oxide, Mn(IV)-oxide, or Fe(III) citrate reduction. Some mutants containing only one cluster were able to reduce particular terminal electron acceptors better than wild type, suggesting routes for improvement by targeting specific electron transfer pathways. Transcriptomic comparisons between fumarate and electrode-based growth showed all of these ext clusters to be constitutive, and transcriptional analysis of the triple-deletion strain containing only extABCD detected no significant changes in expression of known redox proteins or pili components. These genetic experiments reveal new outer membrane conduit complexes necessary for growth of G. sulfurreducens, depending on the available extracellular electron acceptor.

scholarly journals KIF18A's neck linker permits navigation of microtubule-bound obstacles within the mitotic spindle

2019 ◽  
Vol 2 (1) ◽  
pp. e201800169 ◽  
Author(s):  
Heidi LH Malaby ◽  
Dominique V Lessard ◽  
Christopher L Berger ◽  
Jason Stumpff
Keyword(s):  
Single Molecule ◽  
Mitotic Spindle ◽  
Binding Proteins ◽  
Mitotic Chromosome ◽  
Chromosome Movement ◽  
Wild Type ◽  
Microtubule Associated Proteins ◽  
Chromosome Alignment ◽  
Associated Proteins ◽  
Fiber Dynamics

KIF18A (kinesin-8) is required for mammalian mitotic chromosome alignment. KIF18A confines chromosome movement to the mitotic spindle equator by accumulating at the plus-ends of kinetochore microtubule bundles (K-fibers), where it functions to suppress K-fiber dynamics. It is not understood how the motor accumulates at K-fiber plus-ends, a difficult feat requiring the motor to navigate protein dense microtubule tracks. Our data indicate that KIF18A's relatively long neck linker is required for the motor's accumulation at K-fiber plus-ends. Shorter neck linker (sNL) variants of KIF18A display a deficiency in accumulation at the ends of K-fibers at the center of the spindle. Depletion of K-fiber–binding proteins reduces the KIF18A sNL localization defect, whereas their overexpression reduces wild-type KIF18A's ability to accumulate on this same K-fiber subset. Furthermore, single-molecule assays indicate that KIF18A sNL motors are less proficient in navigating microtubules coated with microtubule-associated proteins. Taken together, these results support a model in which KIF18A's neck linker length permits efficient navigation of obstacles to reach K-fiber ends during mitosis.

scholarly journals Identification of different putative outer membrane electron conduits necessary for Fe(III) citrate, Fe(III)-oxide, Mn(IV)-oxide, or electrode reduction by Geobacter sulfurreducens .

2018 ◽  
Author(s):  
Fernanda Jiménez Otero ◽  
Chi Ho Chan ◽  
Daniel R Bond
Keyword(s):  
Electron Transfer ◽  
Outer Membrane ◽  
Electron Acceptor ◽  
Single Gene ◽  
Gene Clusters ◽  
Geobacter Sulfurreducens ◽  
Transcriptional Analysis ◽  
Growth Defect ◽  
Redox Potentials ◽  
Wild Type

At least five gene clusters in the Geobacter sulfurreducens genome encode putative ‘electron conduits’ implicated in electron transfer across the outer membrane, each containing a periplasmic multiheme c -type cytochrome, integral outer membrane anchor, and outer membrane redox lipoprotein(s). Markerless single gene cluster deletions and all possible multiple deletion combinations were constructed and grown with soluble Fe(III) citrate, Fe(III)- and Mn(IV)-oxides, and graphite electrodes poised at +0.24 V and -0.1 V vs. SHE. Different gene clusters were necessary for reduction of each electron acceptor. During metal oxide reduction, deletion of the previously described omcBC cluster caused defects, but deletion of additional components in an Δ omcBC background, such as extEFG , were needed to produce defects greater than 50% compared to wild type. Deletion of all five gene clusters abolished all metal reduction. During electrode reduction, only the Δ extABCD mutant had a severe growth defect at both redox potentials, while this mutation did not affect Fe(III)-oxide, Mn(IV)-oxide, or Fe(III) citrate reduction. Some mutants containing only one cluster were able to reduce particular terminal electron acceptors better than wild type, suggesting routes for improvement by targeting specific electron transfer pathways. Transcriptomic comparisons between fumarate and electrode-based growth showed all of these ext clusters to be constitutive, and transcriptional analysis of the triple-deletion strain containing only extABCD detected no significant changes in expression of known redox proteins or pili components. These genetic experiments reveal new outer membrane conduit complexes necessary for growth of G. sulfurreducens , depending on the available extracellular electron acceptor.

scholarly journals Analysis of Cytadherence-Deficient, GapA-NegativeMycoplasma gallisepticum Strain R

2000 ◽  
Vol 68 (12) ◽  
pp. 6643-6649 ◽  
Author(s):  
L. Papazisi ◽  
K. E. Troy ◽  
T. S. Gorton ◽  
X. Liao ◽  
S. J. Geary
Keyword(s):  
Shuttle Vector ◽  
Phenotypic Expression ◽  
Mycoplasma Genitalium ◽  
Transcriptional Analysis ◽  
Start Codon ◽  
Wild Type ◽  
Gene Encoding ◽  
Genes Encoding ◽  
Low Passage ◽  
Translational Start

ABSTRACT Comparison of the phenotypic expression of Mycoplasma gallisepticum strain R low (passage 15) to that of strain R high (passage 164) revealed that three proteins, i.e., the cytadhesin molecule GapA, a 116-kDa protein (p116), and a 45-kDa protein (p45), are missing in strain R high. Sequence analysis confirmed that the insertion of an adenine 105 bp downstream of the gapAtranslational start codon resulted in premature termination of translation in R high. A second adenine insertion had also occurred at position 907. Restoration of expression of wild-type gapAin R high (clone designated GT5) allowed us to evaluate the extent to which the diminished cytadherence capacity could be attributed to GapA alone. The results indicated that GT5 attached to the same limited extent as the parental R high, from which it was derived. The cytadherence capability of the parental R high was not restored solely by gapA complementation alone, indicating that either p116 or p45 or both may play a role in the overall cytadherence process. The gene encoding p116 was found to be immediately downstream ofgapA in the same operon and was designatedcrmA. This gene exhibited striking homology to genes encoding molecules with cytadhesin-related functions in bothMycoplasma pneumoniae and Mycoplasma genitalium. Transcriptional analysis revealed thatcrmA is not transcribed in R high. We are currently constructing a shuttle vector containing both the wild-typegapA and crmA for transformation into R high to assess the role of CrmA in the cytadherence process.

Abstract 308: Cardiac Cycle Affects Ultrasound Measurements of Ascending Aortic Diameter in a Marfan Mouse Model

2017 ◽  
Vol 37 (suppl_1) ◽  
Author(s):  
Zheying Chen ◽  
Hisashi Sawada ◽  
Debra Rateri ◽  
Alan Daugherty ◽  
Mary Sheppard
Keyword(s):  
Cardiac Cycle ◽  
Interobserver Variability ◽  
Innominate Artery ◽  
Aortic Diameter ◽  
Ultrasound Images ◽  
Anatomical Landmarks ◽  
Wild Type ◽  
Ultrasound Measurements ◽  
Fibrillin 1 ◽  
Ascending Aortic Diameter

Objective: Ultrasound measurements of aortic diameter are a common endpoint in preclinical studies. However, there is a lack of standardization in both image capture and analysis. For our study, we developed a standardized protocol for measuring ascending aortic diameter and examined effects of cardiac cycle in wild type and fibrillin-1 hypomorphic (FBN mgR/mgR ) mice. Methods and Results: Twelve week old male and female FBN mgR/mgR mice were anesthetized and maintained at a heart rate of 450-550 beats per minute. Ultrasound images were captured using a Vevo 2100 system with a 40MHz tranducer. Images captured were standardized according to two anatomical landmarks: the innominate artery branchpoint and aortic valves. The largest luminal ascending aortic diameter between the sinotubular junction and the innominate artery were measured in mid-systole and end-diastole by two blinded, independent observers. Aortic diameters were significantly different (p<0.05) when comparing systole and diastole within gender and genotype. Interestingly, wild-type male (n=4) and female (n=3) mice exhibited a 19% and 15% expansion of the ascending aorta respectively during systole compared to diastole. This difference was not recapitulated in either male (n=6) or female (n=5) FBN mgR/mgR mice (4% expansion in both; p<0.05 vs wild-type). Agreement between observers was excellent (R^2 = 0.99) but interobserver variability was a mean of .09 mm (%CV = 5%) Conclusion: As expected, there is a difference in aortic diameters between wild-type and FBN mgR/mgR mice. Luminal aortic diameters in FBN mgR/mgR vs wild-type mice of both genders are affected by cardiac cycle. Mid-systolic aortic expansion in wild-type vs FBN mgR/mgR mice were different. Error introduced by interobserver variability impacts ascending aortic measurements. Altogether, these phenomena may confound analyses of aortic dilation in FBN mgR/mgR mice, especially when studying interventions with modest effect sizes.

scholarly journals Heteromeric Interactions among Nucleoid-Associated Bacterial Proteins: Localization of StpA-Stabilizing Regions in H-NS of Escherichia coli

2001 ◽  
Vol 183 (7) ◽  
pp. 2343-2347 ◽  
Author(s):  
Jörgen Johansson ◽  
Sven Eriksson ◽  
Berit Sondén ◽  
Sun Nyunt Wai ◽  
Bernt Eric Uhlin
Keyword(s):  
Escherichia Coli ◽  
Stable Form ◽  
Lon Protease ◽  
Wild Type ◽  
Bacterial Proteins ◽  
Regulatory Systems ◽  
Associated Proteins ◽  
Gene Regulatory

ABSTRACT The nucleoid-associated proteins H-NS and StpA inEscherichia coli bind DNA as oligomers and are implicated in gene regulatory systems. There is evidence for both homomeric and heteromeric H-NS–StpA complexes. The two proteins show differential turnover, and StpA was previously found to be subject to protease-mediated degradation by the Lon protease. We investigated which regions of the H-NS protein are able to prevent degradation of StpA. A set of truncated H-NS derivatives was tested for their ability to mediate StpA stability and to form heteromers in vitro. The data indicate that H-NS interacts with StpA at two regions and that the presence of at least one of the H-NS regions is necessary for StpA stability. Our results also suggest that a proteolytically stable form of StpA, StpAF21C, forms dimers, whereas wild-type StpA in the absence of H-NS predominantly forms tetramers or oligomers, which are more susceptible to proteolysis.

Nanomechanics of Knockout Mouse Bones

2006 ◽  
Vol 975 ◽  
Author(s):  
N Beril Kavukcuoglu ◽  
Adrian B. Mann
Keyword(s):  
Mechanical Properties ◽  
Knockout Mice ◽  
Bone Mineralization ◽  
Bone Matrix ◽  
Wild Type ◽  
Knock Out ◽  
Bone Matrix Proteins ◽  
Fibrillin 1 ◽  
Deficient Mice ◽  
Radial Axis

ABSTRACTOsteocalcin (OC) and osteopontin (OPN) are among the most abundant non-collagenous bone matrix proteins. Both have drawn interest from investigators studying their function in osteoporosis and it is known that mutations of these proteins can also have dramatic effects on the properties of bone. Other proteins including fibrillin 1 and 2 (FBN2) have been less widely studied, but can be mutated in some individuals resulting in connective tissue disorders. It has been reported that abnormal fibrillin may play a role in decreased bone mass. In this study bones from osteopontin (OPN), osteocalcin (OC) and fibrillin-2 (FBN2) knockout mice have been investigated. The study has identified how these proteins affect the bone's nanomechanical properties (hardness and elastic modulus). Nanoindentation tests were performed on the radial axis of cortical femora bones from the knockout mice and their wildtype controls. The results showed that young (age< 12 weeks) OPN knock-out bones have significantly lower mechanical properties than wild-type bones indicate a crucial role for OPN in early bone mineralization. After 12 weeks of age, the OPN knockout and wild-type control bones did not show any statistical difference. In OC deficient mice the mechanical properties were found to increase in the cortical mid-shaft of femora from 1 year old mice, suggesting an increase in bone mineralization, but 3 month old FBN2 deficient mice bones showed a decrease in mechanical properties across the cortical radial axis of the mid- femora.

scholarly journals CO-Dependent H2Production by Genetically Engineered Thermococcus onnurineus NA1

2013 ◽  
Vol 79 (6) ◽  
pp. 2048-2053 ◽  
Author(s):  
Min-Sik Kim ◽  
Seung Seob Bae ◽  
Yun Jae Kim ◽  
Tae Wan Kim ◽  
Jae Kyu Lim ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Type Strain ◽  
Wild Type Strain ◽  
Specific Activity ◽  
Steel Production ◽  
Transcriptional Analysis ◽  
Bioreactor Culture ◽  
Wild Type ◽  
Steel Mill ◽  
Engineered Strain

ABSTRACTHydrogenogenic CO oxidation (CO + H2O → CO2+ H2) has the potential for H2production as a clean renewable fuel.Thermococcus onnurineusNA1, which grows on CO and produces H2, has a unique gene cluster encoding the carbon monoxide dehydrogenase (CODH) and the hydrogenase. The gene cluster was identified as essential for carboxydotrophic hydrogenogenic metabolism by gene disruption and transcriptional analysis. To develop a strain producing high levels of H2, the gene cluster was placed under the control of a strong promoter. The resulting mutant, MC01, showed 30-fold-higher transcription of the mRNA encoding CODH, hydrogenase, and Na+/H+antiporter and a 1.8-fold-higher specific activity for CO-dependent H2production than did the wild-type strain. The H2production potential of the MC01 mutant in a bioreactor culture was 3.8-fold higher than that of the wild-type strain. The H2production rate of the engineered strain was severalfold higher than those of any other CO-dependent H2-producing prokaryotes studied to date. The engineered strain also possessed high activity for the bioconversion of industrial waste gases created as a by-product during steel production. This work represents the first demonstration of H2production from steel mill waste gas using a carboxydotrophic hydrogenogenic microbe.

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