scholarly journals Activation tagging of the LEAFY PETIOLE gene affects leaf petiole development in Arabidopsis thaliana

Development ◽  
2000 ◽  
Vol 127 (22) ◽  
pp. 4971-4980 ◽  
Author(s):  
E. van der Graaff ◽  
A.D. Dulk-Ras ◽  
P.J. Hooykaas ◽  
B. Keller
Keyword(s):  
Leaf Development ◽  
Leaf Blade ◽  
Proximal Part ◽  
Dna Binding Domain ◽  
Wild Type ◽  
Leaf Petiole ◽  
Right Border ◽  
Lep Gene ◽  
The Right ◽  
Marginal Meristem

In a screen for leaf developmental mutants we have isolated an activator T-DNA-tagged mutant that produces leaves without a petiole. In addition to that leafy petiole phenotype this lettuce (let) mutant shows aberrant inflorescence branching and silique shape. The LEAFY PETIOLE (LEP) gene is located close to the right border of the T-DNA insert linked with these dominant phenotypes and encodes a protein with a domain with similarity to the DNA binding domain of members of the AP2/EREBP family of transcription factors. Introduction of the activation-tagged LEP gene in wild-type plants conferred all the phenotypic aberrations mentioned above. The leafy petiole phenotype consists of a conversion of the proximal part of the leaf from petiole into leaf blade, which means that leaf development in let is disturbed along the proximodistal axis. Therefore, LEP is involved in either cell division activity in the marginal meristem or patterning along the proximodistal axis.

scholarly journals Perturbation of GABA Biosynthesis Links Cell Cycle to Control Arabidopsis thaliana Leaf Development

2020 ◽  
Author(s):  
Yaxin Gong ◽  
Han Yue ◽  
Yu Xiang ◽  
Guanghui Yu
Keyword(s):  
Reactive Oxygen Species ◽  
Leaf Development ◽  
Cell Expansion ◽  
Leaf Blade ◽  
Aminobutyric Acid ◽  
Oxygen Species ◽  
Gaba Level ◽  
Wild Type ◽  
Blade Area ◽  
In The Wild

AbstractTo investigate the molecular mechanism underlying increasing leaf area in γ-Aminobutyric acid (GABA) biosynthetic mutants, the first pair of true leaves of GABA biosynthetic mutants was measured. The results showed that the leaf blade area in GABA biosynthetic mutants was larger than that of the wild type to different extents, and the area of the leaf epidermal cells in mutants was larger than that of the wild type. DNA polyploid analysis showed that polyploid cells in GABA biosynthetic mutants were appearing earlier and more abundant than in the wild type. To check the correlation between cell size and endoreplication, the expression of factors involving endocycles, including D-type cyclin gene (CYCD3;1, CYCD3;2, CYCD3;3, and CYCD4;1) and kinase CKDA;1, were analysed by qRT-PCR. The results showed that CKDA;1 in GABA biosynthetic mutants was downregulated, and four types of CYCDs showed different expression patterns in different GABA biosynthetic mutants. Inconsistent with this result, for CCS52A (CELL CYCLE SWITCH 52A) (controlling the endocycle entry) in gad2 and gad1/gad2 mutants, the expression of CCS52A2 was significantly higher than that in the wild type. The expression of SIM (SIAMESE) and SMR (SIAMESE-RELATED), which inhibit kinase activity, were also upregulated compared with the control. To further study the possible potential relationship between GABA metabolism and endoreplication, we analysed the reactive oxygen species (ROS) levels in guard cells using ROS fluorescent probes. ROS levels were significantly higher in GABA biosynthetic mutants than the control. All results indicated that cyclin, the cyclin-dependent kinase, and its inhibitory protein were coordinated to participate in endoreplication control at the transcription level in the leaves of GABA biosynthetic mutant Arabidopsis.Contribution to the field statementγ-Aminobutyric acid (GABA) metabolic pathway plays a dual role in plant development. This research investigated the perturbation of GABA biosynthesis on Arabidopsis leave endoreplication for the first time. In the GABA biosynthetic mutants, many genes, participating in cell division regulation, are coordinately transcriptionally expressed to trigger the onset and maintenance of endoreplication, and this led to the cell expansion and the increase leaf blade area. However, this initiation of endoreplication links with the decrease of endogenous GABA level and the increase Reactive oxygen species (ROS). This may be a compensation mechanism to adapt to abnormal GABA level in plant leaf development. Present evidence provided hypothesized that the normal GABA level in plant leaf development plays a brake to inhibit the immature cell expansion and differentiation, and this negative regulation functions a guarantee mechanism to watchdog the normal leaf development. In all, this contribution provides an updated perspective on the role of GABA in plant development.

scholarly journals Role of the Agrobacterium tumefaciens VirD2 Protein in T-DNA Transfer and Integration

1998 ◽  
Vol 11 (7) ◽  
pp. 668-683 ◽  
Author(s):  
Kirankumar S. Mysore ◽  
Burgund Bassuner ◽  
Xiao-bing Deng ◽  
Nune S. Darbinian ◽  
Andrei Motchoulski ◽  
...  
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Fusion Protein ◽  
Binary Vector ◽  
Type A ◽  
Blue Staining ◽  
Wild Type ◽  
Dna Integration ◽  
Right Border ◽  
The Right

VirD2 is one of the key Agrobacterium tumefaciens proteins involved in T-DNA processing and transfer. In addition to its endonuclease domain, VirD2 contains a bipartite C-terminal nuclear localization sequence (NLS) and a conserved region called ω that is important for virulence. Previous results from our laboratory indicated that the C-terminal, bipartite NLS and the ω region are not essential for nuclear uptake of T-DNA, and further suggested that the ω domain may be required for efficient integration of T-DNA into the plant genome. In this study, we took two approaches to investigate the importance of the ω domain in T-DNA integration. Using the first approach, we constructed a T-DNA binary vector containing a promoterless gusA-intron gene just inside the right T-DNA border. The expression of β-glucuronidase (GUS) activity in plant cells transformed by this T-DNA would indicate that the T-DNA integrated downstream of a plant promoter. Approximately 0.4% of the tobacco cell clusters infected by a wild-type A. tumefaciens strain harboring this vector stained blue with 5-bromo-4-chloro-3-indolyl β-d-glucuronic acid (X-gluc). However, using an ω-mutant A. tumefaciens strain harboring the same binary vector, we did not detect any blue staining. Using the second approach, we directly demonstrated that more T-DNA is integrated into high-molecular-weight plant DNA after infection of Arabidopsis thaliana cells with a wild-type A. tumefaciens strain than with a strain containing a VirD2 ω deletion/substitution. Taken together, these data indicate that the VirD2 ω domain is important for efficient T-DNA integration. To determine whether the use of the T-DNA right border is altered in those few tumors generated by A. tumefaciens strains harboring the ω mutation, we analyzed DNA extracted from these tumors. Our data indicate that the right border was used to integrate the T-DNA in a similar manner regardless of whether the VirD2 protein encoded by the inciting A. tumefaciens was wild-type or contained an ω mutation. In addition, a mutant VirD2 protein lacking the ω domain was as least as active in cleaving a T-DNA border in vitro as was the wild-type protein. Finally, we investigated the role of various amino acids of the ω and bipartite NLS domains in the targeting of a GUS-VirD2 fusion protein to the nucleus of electroporated tobacco protoplasts. Deletion of the ω domain, or mutation of the 10-amino-acid region between the two components of the bipartite NLS, had little effect upon the nuclear targeting of the GUS-VirD2 fusion protein. Mutation of both components of the NLS reduced, but did not eliminate, targeting of the fusion protein to the nucleus.

scholarly journals Natural Zeitgebers Under Temperate Conditions Cannot Compensate for the Loss of a Functional Circadian Clock in Timing of a Vital Behavior in Drosophila

2021 ◽  
pp. 074873042199811
Author(s):  
Franziska Ruf ◽  
Oliver Mitesser ◽  
Simon Tii Mungwa ◽  
Melanie Horn ◽  
Dirk Rieger ◽  
...  
Keyword(s):  
Molecular Clock ◽  
Time Window ◽  
Fruit Fly ◽  
Diel Activity ◽  
Wild Type ◽  
Statistical Measures ◽  
Clock Mutant ◽  
Full Complement ◽  
The Right

The adaptive significance of adjusting behavioral activities to the right time of the day seems obvious. Laboratory studies implicated an important role of circadian clocks in behavioral timing and rhythmicity. Yet, recent studies on clock-mutant animals questioned this importance under more naturalistic settings, as various clock mutants showed nearly normal diel activity rhythms under seminatural zeitgeber conditions. We here report evidence that proper timing of eclosion, a vital behavior of the fruit fly Drosophila melanogaster, requires a functional molecular clock under quasi-natural conditions. In contrast to wild-type flies, period01 mutants with a defective molecular clock showed impaired rhythmicity and gating in a temperate environment even in the presence of a full complement of abiotic zeitgebers. Although period01 mutants still eclosed during a certain time window during the day, this time window was much broader and loosely defined, and rhythmicity was lower or lost as classified by various statistical measures. Moreover, peak eclosion time became more susceptible to variable day-to-day changes of light. In contrast, flies with impaired peptidergic interclock signaling ( Pdf01 and han5304 PDF receptor mutants) eclosed mostly rhythmically with normal gate sizes, similar to wild-type controls. Our results suggest that the presence of natural zeitgebers is not sufficient, and a functional molecular clock is required to induce stable temporal eclosion patterns in flies under temperate conditions with considerable day-to-day variation in light intensity and temperature. Temperate zeitgebers are, however, sufficient to functionally rescue a loss of PDF-mediated clock-internal and -output signaling

scholarly journals COMPLEMENTATION ANALYSIS OF LINKED CIRCADIAN CLOCK MUTANTS OF NEUROSPORA CRASSA

Genetics ◽  
1976 ◽  
Vol 82 (1) ◽  
pp. 9-17 ◽  
Author(s):  
Jerry F Feldman ◽  
Marian N Hoyle
Keyword(s):  
Linkage Group ◽  
Circadian Clock ◽  
Neurospora Crassa ◽  
Period Length ◽  
Complementation Analysis ◽  
Wild Type ◽  
The Right

ABSTRACT A fourth mutant of Neurospora crassa, designated frq-4, has been isolated in which the period length of the circadian conidiation rhythm is shortened to 19.3 ± 0.3 hours. This mutant is tightly linked to the three previously isolated frq mutants, and all four map to the right arm of linkage group VII about 10 map units from the centromere. Complementation tests suggest, but do not prove, that all four mutations are allelic, since each of the four mutants is co-dominant with the frq  + allele—i.e., heterokaryons have period lengths intermediate between the mutant and wild-type—and since heterokaryons between pairs of mutants also have period lengths intermediate between those of the two mutants.

scholarly journals Focused Genetic Recombination of Bacteriophage T4 Initiated by Double-Strand Breaks

Genetics ◽  
2002 ◽  
Vol 162 (2) ◽  
pp. 543-556
Author(s):  
Victor Shcherbakov ◽  
Igor Granovsky ◽  
Lidiya Plugina ◽  
Tamara Shcherbakova ◽  
Svetlana Sizova ◽  
...  
Keyword(s):  
Genetic Recombination ◽  
Bacteriophage T4 ◽  
Proximal Part ◽  
Coupling Model ◽  
Strand Break ◽  
Double Strand Breaks ◽  
Strand Breaks ◽  
The Right ◽  
Frequency Distance

Abstract A model system for studying double-strand-break (DSB)-induced genetic recombination in vivo based on the ets1 segCΔ strain of bacteriophage T4 was developed. The ets1, a 66-bp DNA fragment of phage T2L containing the cleavage site for the T4 SegC site-specific endonuclease, was inserted into the proximal part of the T4 rIIB gene. Under segC+ conditions, the ets1 behaves as a recombination hotspot. Crosses of the ets1 against rII markers located to the left and to the right of ets1 gave similar results, thus demonstrating the equal and symmetrical initiation of recombination by either part of the broken chromosome. Frequency/distance relationships were studied in a series of two- and three-factor crosses with other rIIB and rIIA mutants (all segC+) separated from ets1 by 12-2100 bp. The observed relationships were readily interpretable in terms of the modified splice/patch coupling model. The advantages of this localized or focused recombination over that distributed along the chromosome, as a model for studying the recombination-replication pathway in T4 in vivo, are discussed.

Brodie’s Abscess of the Proximal Humerus Metaphysis: A Case Report

2021 ◽  
Vol 11 (9) ◽  
Author(s):  
Nilesh Vishwakarma ◽  
Shaival Chauhan ◽  
Shrey S Binyala ◽  
Sanjeev K Singh
Keyword(s):  
Case Report ◽  
Shoulder Joint ◽  
Proximal Part ◽  
Focal Lesion ◽  
Posterior View ◽  
Brodie’S Abscess ◽  
Magnetic Resonance Imaging Mri ◽  
The Right ◽  
Pyogenic Osteomyelitis ◽  
Metaphyseal Region

Introduction:Primary subacute pyogenic osteomyelitis, or Brodie’s abscess was initially documented by Sir Benjamin Brodie in 1832. We present a case report with a 6-months follow-up period, demonstrating the successful diagnosis and surgical treatment of a focal lesion of the proximal metaphysis of the right humerus in a 21-years-old female. The pathology of hematologic osteomyelitis and its role in the development of a subacute abscess along with a review of literature and an in detail description of the pathogenesis of Brodie’s abscess is discussed and submitted. Case Report:A 21- years -old healthy female with a history of fall sustaining injury to the right shoulder one 1 year back followed by which she presented to the outpatient clinic with a swelling over her right shoulder. The patient was managed conservatively with analgesics and was relieved of pain over a course of one 1 week of medications, the patient now presents with pain and swelling in the right shoulder joint on and off since the episode of fall one 1 year back, which had increased over a period of past one 1 week. A week before the most recent presentation she started experiencing some discomfort and pain in her right shoulder. No recent trauma was reported. A mild swelling appeared over the proximal part of the humerus. There were no constitutional symptoms of fever or any illness reported. On examination, there was noted a painful restriction of ROM at the right shoulder joint with no rotator cuff injury. Laboratory investigations were suggestive of raised inflammatory markers. Radiograph of the right shoulder taken in the true antero-posterior view with the shoulder in the neutral rotation was suggestive of an oval lucency with surrounding sclerosis in the proximal metaphyseal region of the humerus. Magnetic resonance imaging MRI of the right shoulder joint showed features consistent with Brodie’s abscess in the proximal metaphyseal region of the humerus. Surgical debridement of the abscess w

scholarly journals Agrobacterium-Mediated Transformation of Aspergillus awamori in the Absence of Full-Length VirD2, VirC2, or VirE2 Leads to Insertion of Aberrant T-DNA Structures

2004 ◽  
Vol 186 (7) ◽  
pp. 2038-2045 ◽  
Author(s):  
Caroline B. Michielse ◽  
Arthur F. J. Ram ◽  
Paul J. J. Hooykaas ◽  
Cees A. M. J. J. van den Hondel
Keyword(s):  
Single Copy ◽  
Full Length ◽  
Aspergillus Awamori ◽  
Wild Type ◽  
Dna Structures ◽  
Dna Integration ◽  
Virulence Proteins ◽  
Type Transformation ◽  
The Right ◽  
Transposon Insertions

ABSTRACT Reductions to 2, 5, and 42% of the wild-type transformation efficiency were found when Agrobacterium mutants carrying transposon insertions in virD2, virC2, and virE2, respectively, were used to transform Aspergillus awamori. The structures of the T-DNAs integrated into the host genome by these mutants were analyzed by Southern and sequence analyses. The T-DNAs of transformants obtained with the virE2 mutant had left-border truncations, whereas those obtained with the virD2 mutant had truncated right ends. From this analysis, it was concluded that the virulence proteins VirD2 and VirE2 are required for full-length T-DNA integration and that these proteins play a role in protecting the right and left T-DNA borders, respectively. Multicopy and truncated T-DNA structures were detected in the majority of the transformants obtained with the virC2 mutant, indicating that VirC2 plays a role in correct T-DNA processing and is required for single-copy T-DNA integration.

Analysing CYP2D6*4 Allele frequency in Patients with Schizophrenia

2017 ◽  
Vol 41 (S1) ◽  
pp. S101-S102
Author(s):  
V. Djordjevic ◽  
T. Jevtovic Stoimenov
Keyword(s):  
Allele Frequency ◽  
Plasma Concentrations ◽  
Clinical Severity ◽  
Genotype Distribution ◽  
Healthy Individuals ◽  
Wild Type ◽  
Specific Pcr ◽  
Significant Difference ◽  
Schizophrenic Patients ◽  
The Right

IntroductionSchizophrenia is treated with antipsychotics and other psychotropic medications, many of which are substrates for the highly polymorphic CYP2D6 enzyme. The most frequent variant allele is CYP2D6*4- leading cause of poor metabolism (PM) phenotype. PM causes the reduction of therapeutic response, increase the risk of adverse drug reactions and increase the plasma concentration of both drug and its metabolites above the levels of toxicity.The AimAnalysing CYP2D6*4 allele frequency among schizophrenic patients for further individualisation and rationalisation of therapy.Patients and methodsResearch was conducted on 38 schizophrenic patients and 110 healthy individuals. CYP2D6*4 allele was detected with allele specific PCR.ResultsBoth wild type allele carriers are 55% of the schizophrenic patients, 45% are wild type/*4heterozygous, and *4/*4 homozygous are not identified. There is a statistically significant difference in the genotype distribution (P < 0.05) between schizophrenic patients and healthy individuals. Significantly higher *4 allele frequency (37%) comparing to healthy individuals (P < 0.0001) indicates the necessary caution in administration of CYP2D6 substrates. A lower frequency of PMs in schizophrenic patients than in healthy individuals could be explained with CYP2D6 neuroactive substrate metabolism. Forty-five percent of the schizophrenic patients are intermediate metabolisers carrying the higher risk of adverse response to CYP2D6 substrates comparing to wild type homozygous. As none of the analyzed patients was PM, exceeded plasma concentrations of medications above toxic levels are not expected when administrating the right dosage.ConclusionAltered CYP2D6 metabolism may contribute to the vulnerability, clinical severity and treatment outcome of schizophrenia.Disclosure of interestThe authors have not supplied their declaration of competing interest.

scholarly journals Foamy Virus Integration

2004 ◽  
Vol 78 (5) ◽  
pp. 2472-2477 ◽  
Author(s):  
Thomas Juretzek ◽  
Teresa Holm ◽  
Kathleen Gärtner ◽  
Sylvia Kanzler ◽  
Dirk Lindemann ◽  
...  
Keyword(s):  
Infectious Virus ◽  
High Titer ◽  
Foamy Virus ◽  
Wild Type ◽  
Foamy Viruses ◽  
Unintegrated Dna ◽  
Particle Export ◽  
The Right ◽  
Virus Integration ◽  
Transcription And Replication

ABSTRACT It had been suggested that during integration of spumaretroviruses (foamy viruses) the right (U5) end of the cDNA is processed, while the left (U3) remains uncleaved. We confirmed this hypothesis by sequencing two-long terminal repeat (LTR) circle junctions of unintegrated DNA. Based on an infectious foamy virus molecular clone, a set of constructs harboring mutations at the 5′ end of the U3 region in the 3′ LTR was analyzed for particle export, reverse transcription, and replication. Following transient transfection some mutants were severely impaired in generating infectious virus, while others replicated almost like the wild type. The replication competence of the mutants was unrelated to the cleavability of the newly created U3 end. This became obvious with two mutants both belonging to the high-titer type. One mutant containing a dinucleotide artificially transferred from the right to the left end was trimmed upon integration, while another one with an unrelated dinucleotide in that place was not. The latter construct in particular showed that the canonical TG motif at the beginning of the provirus is not essential for foamy virus integration.

scholarly journals Persistent sciatic artery: A case report

2008 ◽  
Vol 136 (11-12) ◽  
pp. 654-657
Author(s):  
Dragan Sagic ◽  
Zelimir Antonic ◽  
Stevo Duvnjak ◽  
Miodrag Peric ◽  
Branko Petrovic ◽  
...  
Keyword(s):  
Femoral Artery ◽  
Common Femoral Artery ◽  
Proximal Part ◽  
Persistent Sciatic Artery ◽  
Usual Manner ◽  
Therapeutic Decisions ◽  
Inferior Extremity ◽  
Internal Iliac ◽  
Embryologic Development ◽  
The Right

INTRODUCTION The sciatic artery represents the earliest embryological blood supply to the lower extremity. It regresses after the 3rd month of embryologic development. The proximal part of the sciatic artery eventually persists as the inferior gluteal artery. Rarely, however, it persists into adulthood when it is frequently associated with numerous possible complications (aneurysm formation, embolism, nerve compression, rupture, thrombosis). CASE OUTLINE In March 1996, a 48-year-old male was admitted for angiography of the blood vessels of the right inferior extremity, before an elective orthopaedic procedure. Arteriography of the right leg was done in a usual manner through the right common femoral artery in order to get an angiogram of the popliteal trifurcation and crural arteries. However, on the first field we noticed a hypoplastic superficial femoral artery, as well as a huge persistent sciatic artery (PSA) originating from the internal iliac artery running distally and overlapping the deep femoral artery. There were no aneurysm and stenotic changes of PSA. CONCLUSION If clinical condition is stable, follow-ups at 12 months intervals should be done by means of ultrasound. The therapeutic decisions also depend on complete or incomplete PSA.

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