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1.
New Phytol ; 238(3): 971-976, 2023 05.
Article in English | MEDLINE | ID: mdl-36721296

ABSTRACT

Auxin has long been known as an important regulator of plant growth and development. Classical studies in auxin biology have uncovered a 'canonical' transcriptional auxin-signalling pathway involving the TRANSPORT INHIBITOR RESPONSE1/AUXIN SIGNALING F-BOX (TIR1/AFB) receptors. TIR1/AFB perception of auxin triggers the degradation of repressors and the derepression of auxin-responsive genes. Nevertheless, the canonical pathway cannot account for all aspects of auxin biology, such as physiological responses that are too rapid for transcriptional regulation. This Tansley insight will explore several 'non-canonical' pathways that have been described in recent years mediating fast auxin responses. We focus on the interplay between a nontranscriptional branch of TIR1/AFB signalling and a TRANSMEMBRANE KINASE1 (TMK1)-mediated pathway in root acid growth. Other developmental aspects involving the TMKs and their association with the controversial AUXIN-BINDING PROTEIN 1 (ABP1) will be discussed. Finally, we provide an updated overview of the ETTIN (ETT)-mediated pathway in contexts outside of gynoecium development.


Subject(s)
Arabidopsis Proteins , Arabidopsis , F-Box Proteins , Indoleacetic Acids/metabolism , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Plant Growth Regulators/metabolism , Arabidopsis/metabolism , F-Box Proteins/genetics , Gene Expression Regulation, Plant
2.
Article in English | MEDLINE | ID: mdl-33431583

ABSTRACT

Auxin influences all aspects of plant growth and development and exerts its function at scales ranging from the subcellular to the whole-organism level. A canonical mechanism for auxin signaling has been elucidated, which is based on derepression of downstream genes via ubiquitin-mediated degradation of transcriptional repressors. While the combinatorial nature of this canonical pathway provides great potential for specificity in the auxin response, alternative noncanonical signaling pathways required to mediate certain processes have been identified. One such pathway affects gene regulation in a manner that is reminiscent of mechanisms employed in animal hormone signaling, while another triggers transcriptional changes through auxin perception at the plasma membrane and the stabilization of transcriptional repressors. In some cases, the exact perception mechanisms and the nature of the receptors involved are yet to be revealed. In this review, we describe and discuss current knowledge on noncanonical auxin signaling and highlight unresolved questions surrounding auxin biology.


Subject(s)
Indoleacetic Acids/metabolism , Plant Development , Plants/metabolism , Signal Transduction , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Plants/genetics , Protein Kinases/metabolism
3.
Curr Biol ; 30(22): R1380-R1382, 2020 11 16.
Article in English | MEDLINE | ID: mdl-33202240

ABSTRACT

Ovules are initiated in a highly regular pattern along the placenta inside the gynoecia of flowering plants. New research reveals that two separate EPFL peptide-mediated pathways functioning through a set of ERECTA-family receptors coordinate ovule patterning with fruit growth.


Subject(s)
Fruit , Ovule , Gene Expression Regulation, Plant , Ligands , Peptides , Seeds
4.
Singapore Med J ; 60(11): 590-595, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31197378

ABSTRACT

INTRODUCTION: The use of electroconvulsive therapy (ECT) in Singapore dates back to 1947. However, there is little local information on the clinical practice of ECT and its standards. We aimed to conduct a comprehensive national survey of ECT practice in Singapore. METHODS: A cross-sectional structured questionnaire assessing the types of ECT (e.g. electrode placement, stimulus parameters), indications, anaesthetic technique, dosing methods, monitoring of outcomes and credentialing was sent in 2015 to all ECT centres in Singapore via email to collect qualitative and quantitative data regarding ECT. RESULTS: Data was obtained from all ECT centres (n = 6), which represented that ECT was available in 23.1% of all hospitals and 50.0% of all psychiatric specialist centres. The rate of ECT was 5.89 treatments per 10,000 residents per year, and each patient received an average of 5.4 ECT per course. Only 7.0% of ECT was administered for continuation/maintenance ECT. The most common indication for ECT was depression in 5 (83.3%) out of six centres, with schizophrenia being the second most common. In 5 (83.3%) out of six centres, ECT was brief (0.5 ms) bitemporal ECT with age-based dosing, and 93.0% of the sessions were conducted in an inpatient setting. All ECT was conducted under general anaesthesia, with propofol (66.7%) being the most common type of anaesthetic used. CONCLUSION: The practice of ECT in Singapore was highly uniform. The rates and indications for ECT were consistent with those of other developed countries, with greater use of ECT for schizophrenia. Future advances for ECT in Singapore include the use of individualised dosing based on empirical seizure threshold titration, expanded electrode placements and increased utilisation of continuation/maintenance ECT.


Subject(s)
Depressive Disorder, Major/therapy , Electroconvulsive Therapy/statistics & numerical data , Electroconvulsive Therapy/trends , Practice Patterns, Physicians'/statistics & numerical data , Cross-Sectional Studies , Electrodes , Hospitals , Humans , Mood Disorders/therapy , Schizophrenia/therapy , Singapore , Surveys and Questionnaires
5.
Methods Mol Biol ; 1768: 531-554, 2018.
Article in English | MEDLINE | ID: mdl-29717463

ABSTRACT

In addition to its growing use in detecting and quantifying genes and larger genomic events, the partitioning used in digital PCR can serve as a powerful tool for high-fidelity amplification of synthetic combinatorial libraries of single-stranded DNA. Sequence-diverse libraries of this type are used as a basis for selecting tight-binding aptamers against a specific target. Here we provide a detailed description of the Hi-Fi SELEX protocol for rapid and efficient DNA aptamer selection. As part of that methodology, we describe how Hi-Fi SELEX gains advantages over other aptamer selection methods in part through the use of the massive partitioning capability of digital PCR.


Subject(s)
Aptamers, Nucleotide/isolation & purification , DNA, Single-Stranded/isolation & purification , Gene Library , Polymerase Chain Reaction/methods , SELEX Aptamer Technique/methods , Aptamers, Nucleotide/genetics , DNA, Single-Stranded/genetics , Polymerase Chain Reaction/instrumentation , Reproducibility of Results , SELEX Aptamer Technique/instrumentation
6.
Ann Acad Med Singap ; 38(4): 370-4, 2009 Apr.
Article in English | MEDLINE | ID: mdl-19434342

ABSTRACT

Medical co-morbidities are very common in patients with psychiatric conditions. Although respecting one's autonomy to make treatment decisions is the ethical default position, the capacity to make such decisions may need to be assessed, especially when patients are in relapse of their psychiatric condition, and/or when the decisions made are high-risk and possibly fatal. This case report highlights the ethical issues of refusing potential life-saving treatment in a patient who is in relapse of her schizoaffective disorder. In particular, the assessment of decisional capacity and the role of the doctors (if the patient lacks capacity) are discussed. Recommendations are also made on how to better manage such situations.


Subject(s)
Kidney Failure, Chronic/therapy , Mental Competency , Patient Care/ethics , Patient Participation/psychology , Schizophrenia , Adult , Female , Humans , Personal Autonomy
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