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A SteMNess perspective of survival motor neuron function： splicing factors in stem cell biology and disease

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Frontiers in Biology 2015年第4期10卷 297-309页

作者： stuart j. grice j.-long liu MRC Functional Genomics Unit Department of Physiology Anatomy and Genetics University of Oxford South Parks RoadOxford OX1 3PT UK

Genome-wide analyses of metazoan messenger RNA （mRNA） species are unveiling the extensive transcriptional diversity generated by alternative splicing （AS）. Research is also beginning to identify the splicing factors and AS events required to maintain the balance between stem cell renewal （i.e stemness properties） and differentiation. One set of proteins at the center of spliceosome biogenesis are the survival motor neuron （SMN） complex constituents, which have a critical role in the assembly of spliceosomal small nuclear ribonucleoproteins （snRNPs） in all cells. In this review we discuss what is currently known about how AS controls pluripotency and cell fate and consider how an increased requirement for splicing factors, including SMN, helps to maintain an enrichment of stem cell-specific AS events. Furthermore, we highlight studies showing that mutations in specific splicing factors can lead to the aberrant development, and cause targeted degeneration of the nervous system. Using SMN as an example, we discuss the perspective of how stem cell-specific changes in splicing factors can lead to developmental defects and the selective degeneration of particular tissues. Finally we consider the expanding role of SMN, and other splicing factors, in the regulation of gene expression in stem cell biology, thereby providing insight into a number of debilitating diseases.

关键词： stem cells splicing survival motor neuron (SMN) spinal muscular atrophy (SMA)

Neurodevelopmental defects as a primer of neurodegeneration:lessons from spinal muscular atrophy and Huntington's disease

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Neural Regeneration Research 2023年第9期18卷 1952-1953页

作者： stuart j.grice j.-long liu Medical Research Council Functional Genomics Unit Department of PhysiologyAnatomy and GeneticsUniversity of OxfordOxfordUK School of Life Science and Technology ShanghaiTech UniversityShanghaiChina

Developmental motifs in neurodegeneration:Neurodegeneration,the prominent feature of neurodegenerative disease,is characterized by the progressive and selective loss of neuronal *** some of the pathologies caused by neurodegeneration may be irreversible,early intervention will be required for the treatments that aim to slow or halt the manifestation of these ***,neurodegeneration evokes the idea of a progressive decline of brain function.

关键词： neurodegeneration Huntington function

Further Studies of the Cap Pushing Response in Honey Bees (Apis mellifera)

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Natural Science 2024年第5期16卷 45-64页

作者： Riley j. Wincheski Kiri Li N. Stauch Laura M. Grossner Maya B. Zepeda j.mes W. grice Charles I. Abramson Department of Psychology Oklahoma State University Stillwater USA Laboratory of Comparative Psychology and Behavioral Biology Oklahoma State University Stillwater USA Department of Earth and Environmental Sciences California State University Fresno USA

The Cap Pushing Response (CPR) is a free-flying technique used to study learning and memory in honey bees (Apis mellifera). The series of experiments outlined in this paper aimed to test whether honey bees exhibit the cognitive concept of “expectancy” utilizing the CPR in a weight differentiation paradigm. Five previous experiments in our laboratory have explored whether the concept of expectancy can account for honey bee performance and have all failed to support the cognitive interpretation. The first experiment examined if bees could differentiate between the two caps in the amount of force they used to push the cap and the distance the cap was pushed when the caps were presented one at a time. The second experiment explored cap weight preference by presenting bees with a choice between the two caps. The third and fourth experiments tested the bee’s ability to expect reward or punishment based on cap weight. Results revealed that bees were found to have a strong preference for the light cap and therefore were not able to expect reward or punishment based on cap weight. These experiments contribute to the debate on whether bees have “cognitive” representations and continue to support the behaviorist interpretation.

关键词： Apis mellifera Cap Pushing Response Cognition Learning

The impact of macroalgae on mean and turbulent flow fields

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j.urnal of Hydrodynamics 2015年第3期27卷 427-435页

作者： THOMAS Robert E. MCLELLAND stuart j. Department of Geography Environment and Earth Sciences University of Hull

In this paper, we attempt to quantify the mean and turbulent flow fields around live macroalgae within a tidal inlet in Norway. Two Laminaria digitata specimens - 0.50 m apart were selected for detailed study and a profiling ADV was used to collect 45 velocity profiles, each composed of up to seven 0.035 m-high profiles collected for 240 s at 100 Hz, at a streamwise spacing of 0.25 m and cross-stream spacing of 0.20 m. To quantify the impact of the macroalgae, measurements were repeated over a sparser grid after the region had been completely cleared of algae and maj.r roughness elements.

关键词： dealiasing laminaria digitata turbulence vectrino profiler velocity profile

The effects of gonadal hormones on learning and memory in male mammals： A review

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Current Zoology 2011年第4期57卷 543-558页

作者： stuart T. LEONARD Peter j. WINSAUER Department of Pharmacology and Experimental Therapeutics Louisiana State University Health Sciences Center 1901 Perdido Street New Orleans LA 70112-1393

The primary role of the gonadal steroid hormones in mammals is to regulate reproduction and related behaviors; however, both androgens and estrogens are also integrally involved in mediating higher brain function and processes including cognition, neural development, and neural plasticity. In particular, a number of studies show that estradiol modulates dendritic spine growth and synapse density （synaptic plasticity） in the hippocampus of females, and that increased estradiol levels are generally associated with improvements on a variety of learning and memory tasks. While the maj.rity of research has focused on the beneficial effects of estradiol in females, much less attention has been given to testosterone and its effects on learning and memory in males. Similar to estradiol titers in females, testosterone titers in males decline with age, albeit more gradually, and this decline has been correlated with impairment of certain cognitive tasks. Moreover, studies involving both humans and animals indicate that testosterone and its metabolites can augment responding on certain behavioral tasks, depending on the subj.ct＇s current hormonal state, the response required, and the stimuli involved （e.g., those involving spatial or nonspatial stimuli）. While the exact mechanisms by which testosterone exerts its effects on learning and memory are not fully understood, recent findings suggest that testosterone modulates learning and memory in males through an interaction with the cholinergic system. The overall obj.ctive of this review is to discuss studies investigating the role of the gonadal hormones in mediating learning and memory processes in male mammals [Current Zoology 57 （4）： 543-558, 2011].

关键词： Testosterone Learning and memory Cholinergic system Mammals Cognition Androgens

Vocal repertoire of the New Zealand kea parrot Nestor notabilis

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Current Zoology 2012年第5期58卷 727-740页

作者： Raoul SCHWING stuart PARSONS Ximena j. NELSON School of Biological Sciences University of Auckland Private Bag 92019 Auckland New Zealand School of Biological Sciences University of Canterbury Private Bag 4800 Christchurch New Zealand

The unique alpine-living kea parrot Nestor notabilis has been the focus of numerous cognitive studies, but its com- munication system has so far been largely neglected. We examined 2,884 calls recorded in New Zealand＇s Southern Alps. Based on audio and visual spectrographic differences, these calls were categorised into seven distinct call types： the non-oscillating ＇screech＇ contact call and ＇mew＇; and the oscillating ＇trill＇, ＇chatter＇, ＇warble＇ and ＇whistle＇; and a hybrid ＇screech-trill＇. Most of these calls contained aspects that were individually unique, in addition to potentially encoding for an individual＇s sex and age. Additionally, for each recording, the sender＇s previous and next calls were noted, as well as any response given by conspecifics. We found that the previous and next calls made by the sender were most often of the same type, and that the next most likely pre- ceding and/or following call type was the screech call, a contact call which sounds like the ＇kee-ah＇ from which the bird＇s name derives. As a social bird capable of covering large distances over visually obstructive terrain, long distance contact calls may be of considerable importance for social cohesion. Contact calls allow kea to locate conspecifics and congregate in temporary groups for social activities. The most likely response to any given call was a screech, usually followed by the same type of call as the ini- tial call made by the sender, although responses differed depending on the age of the caller. The exception was the warble, the kea＇s play call, to which the most likely response was another warble. Being the most common call type, as well as the default response to another call, it appears that the ＇contagious＇ screech contact call plays a central role in kea vocal communication and social cohesion [Current Zoology 58 （5）： 727-740, 2012].

关键词： Acoustic signals Communication Kea Psittacidae Social behaviour Habitat

In Vivo Phosphorylation Site Mapping and Functional Characterization of Arabidopsis Phototropin 1

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Molecular Plant 2008年第1期1卷 178-194页

作者： stuart Sullivan Catriona E. Thomson Douglas j. Lamont Matthew A. j.nes j.hn M. Christie Plant Science Group Division of Biochemistry and Molecular Biology. Institute of Biomedical and Life Sciences University of Glasgow. University Avenue. Glasgow Scotland UK FingerPrints Proteomics Facility Post-Genomics and Molecular Interactions Centre. School of Life Sciences MSI/WTB/CIR Complex University of Dundee. Dundee Scotland UK

Phototropins （phot1 and phot2） are blue-light receptor kinases controlling a range of responses that optimize the photosynthetic efficiency of plants. Light sensing is mediated by two flavin-binding motifs, known as LOVl and LOV2, located within the N-terminal region of the protein. Photoexcitation via LOV2 leads to activation of the C-terminal kinase domain and consequently receptor autophosphorylation. However, knowledge of the in-vivo phosphorylation sites for Arabidopsis phototropins is lacking and has impeded progress in elucidating the functional significance of receptor phos- phorylation. We have purified photl from Arabidopsis and identified the in-vivo sites of receptor phosphorylation by liquid chromatography tandem mass spectrometry. Arabidopsis-derived photl binds flavin mononucleotide as chromophore and is phosphorylated at four maj.r sites located upstream of LOV2 （Ser^58, Ser^85, Ser^350, and Ser^410）, three of which are induced by blue light. Nevertheless, structure-function analysis indicates that the biological activity of photl can be attributed to a modular unit comprising the LOV2-kinase region of the protein. Thus, peptide regions upstream of LOV2, including the sites of receptor phosphorylation identified here, do not appear to be important for receptor signaling. By contrast, these regions may be necessary for maximizing stomatal performance and possibly light-induced relocalization of photl.

关键词： Phototropins (phot1 and phot2) lavin-binding motifs

Radiofrequency electric-field heating behaviors of highly enriched semiconducting and metallic single-walled carbon nanotubes

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Nano Research 2015年第9期8卷 2859-2870页

作者： stuart j. Corr Mustafa Raoof Brandon T. Cisneros Alvin W. Orbaek Matthew A. Cheney j.stin j. Law Nadia C. Lara Andrew R. Barron Lon j. Wilsor Steven A. Curley Division of Surgery Baylor College of Medicine Houston TX 77030 USA Department of Surgical Oncology University of Texas M.D. Anderson Cancer Center Houston TX 77030 USA Department of Chemistry and the Richard E. Smalley Institute for Nanoscale Science and Technology Rice University Houston TX 77005 USA Department of Surgery The University of Arizona College of Medicine Tucson AZ 85724 USA Department of Chemistry and Biochemistry University of California San Diego La Jolla CA 92093 USA College of Engineering Swansea University Singleton Park Swansea SA2 8PP Wales UK Department of Mechanical Engineering and Materials Science Rice University Houston TX 77005 USA

It is theorized that enhanced thermal heating may result from exposing single-walled carbon nanotubes （SWNTs） embedded in a conductive host to radiofrequency （RF） electric fields. We examine the RF-induced （13.56 MHz） heating behaviors of 95% metallic- and semiconducting-enriched SWNTs （m-/s-SWNTs） suspended in aqueous solutions with varying NaC1 molarity （0.001 mM-1 M）. The heating effects were only evident for host molarities below 1 mM （equivalent to 0.1 S/m） at which the s-SWNT heating rates dominated those of the m-SWNTs. The heating effects were localized to aligned and aggregated ＂SWNT ropes＂ -1 cm in length that formed in suspension, parallel to the electric-field vector, during the RF exposure. For molarities above 1 mM, no enhancements were evident, owing to the large heating effects of the bulk ionic NaC1 suspensions, which were observed in previous studies. Although larger enhancement effects proportional to the host conductivity have been theoretically predicted for m-/s-SWNT suspensions, this was not observed most likely because of the aggregation and screening effects, which diminished the scattered electric field near the m-/s-SWNTs. Our research may further the development of better nanoparticle heating agents for applications such as non-invasive RF-induced cancer hyperthermia.

关键词： rad.iofrequency,carbon nanotubes,metallic,semiconducting,hyperthermia

Endoscopic ultrasound-guided elastography in the nodal staging of oesophageal cancer

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World j.urnal of Gastroenterology 2012年第9期18卷 889-895页

作者： stuart Paterson Fraser Duthie Adrian j.Stanley Department of Gastroenterology Forth Valley Royal Hospital Department of Pathology Glasgow Royal Infirmary Department of Gastroenterology Glasgow Royal Infirmary

AIM： To assess quantitative endoscopic ultrasound （EUS）- guided elastography in the nodal staging of oesophago- gastric cancers.METHODS： This was a single tertiary centre study as- sessing 50 patients with established oesophago-gastric cancer undergoing EUS-guided fine needle aspiration biopsy （FNAB） of lymph nodes between j.ly 2007 and j.ly 2009. EUS-guided elastography of lymph nodes was performed before EUS-FNAB. Standard EUS charac- teristics were also described. Cytological determination of whether a lymph node was malignant or benign was used as the gold standard for this study. Comparisons of elastography and standard EUS characteristics were made between the cytologically benign and malignant nodes. The main outcome measure was the accuracy of elastography in differentiating between benign and malignant lymph nodes in oesophageal cancers.

关键词： Endoscopic ultrasound Oesophageal cancerLymph nodes Elastography Tumour staging