scholarly journals RNA-Seeded Functional Amyloids Balance Growth and Survival

2016 ◽  
Vol 39 (2) ◽  
pp. 131-132 ◽  
Author(s):  
Shawn M. Lyons ◽  
Paul Anderson
2013 ◽  
Vol 24 (12) ◽  
pp. 2045-2057 ◽  
Author(s):  
Natalia Petrenko ◽  
Raˇzvan V. Chereji ◽  
Megan N. McClean ◽  
Alexandre V. Morozov ◽  
James R. Broach

All cells perceive and respond to environmental stresses through elaborate stress-sensing networks. Yeast cells sense stress through diverse signaling pathways that converge on the transcription factors Msn2 and Msn4, which respond by initiating rapid, idiosyncratic cycles into and out of the nucleus. To understand the role of Msn2/4 nuclear localization dynamics, we combined time-lapse studies of Msn2-GFP localization in living cells with computational modeling of stress-sensing signaling networks. We find that several signaling pathways, including Ras/protein kinase A, AMP-activated kinase, the high-osmolarity response mitogen-activated protein kinase pathway, and protein phosphatase 1, regulate activation of Msn2 in distinct ways in response to different stresses. Moreover, we find that bursts of nuclear localization elicit a more robust transcriptional response than does sustained nuclear localization. Using stochastic modeling, we reproduce in silico the responses of Msn2 to different stresses, and demonstrate that bursts of localization arise from noise in the signaling pathways amplified by the small number of Msn2 molecules in the cell. This noise imparts diverse behaviors to genetically identical cells, allowing cell populations to “hedge their bets” in responding to an uncertain future, and to balance growth and survival in an unpredictable environment.


2014 ◽  
Vol 56 ◽  
pp. 207-219 ◽  
Author(s):  
Chi L.L. Pham ◽  
Ann H. Kwan ◽  
Margaret Sunde

Amyloids are insoluble fibrillar protein deposits with an underlying cross-β structure initially discovered in the context of human diseases. However, it is now clear that the same fibrillar structure is used by many organisms, from bacteria to humans, in order to achieve a diverse range of biological functions. These functions include structure and protection (e.g. curli and chorion proteins, and insect and spider silk proteins), aiding interface transitions and cell–cell recognition (e.g. chaplins, rodlins and hydrophobins), protein control and storage (e.g. Microcin E492, modulins and PMEL), and epigenetic inheritance and memory [e.g. Sup35, Ure2p, HET-s and CPEB (cytoplasmic polyadenylation element-binding protein)]. As more examples of functional amyloid come to light, the list of roles associated with functional amyloids has continued to expand. More recently, amyloids have also been implicated in signal transduction [e.g. RIP1/RIP3 (receptor-interacting protein)] and perhaps in host defence [e.g. aDrs (anionic dermaseptin) peptide]. The present chapter discusses in detail functional amyloids that are used in Nature by micro-organisms, non-mammalian animals and mammals, including the biological roles that they play, their molecular composition and how they assemble, as well as the coping strategies that organisms have evolved to avoid the potential toxicity of functional amyloid.


2017 ◽  
Vol 11 (3) ◽  
pp. 249
Author(s):  
Lisa Fajar Indriana ◽  
Yuli Afrianti ◽  
Sitti Hilyana ◽  
Muhammad Firdaus Firdaus

Teripang pasir, Holothuria scabra merupakan komoditas hasil laut yang bernilai ekonomis tinggi. Penangkapan berlebihan stok di alam mendorong berkembangnya kegiatan budidaya. Penempelan merupakan fase kritis pada larva teripang karena terjadi peralihan sifat planktonis ke bentik yang memerlukan substrat. Penelitian ini bertujuan untuk mengetahui preferensi penempelan, pertumbuhan, dan sintasan larva H. scabra fase penempelan pada substrat lamun yang berbeda. Penelitian menggunakan metode rancangan acak lengkap dengan perlakuan empat jenis daun lamun berbeda dan lima ulangan. Perlakuan terdiri atas Enhalus acoroides (L-1), Syringodium isoetifolium (L-2), Cymodocea serrulata (L-3), dan Cymodocea rotundata (L-4). Jumlah awal larva sebanyak 1.000 individu dan substrat dirangkai dengan luasan yang sama sebesar 12 cm x 17 cm untuk setiap unit penelitian. Hasil penelitian menunjukkan jenis lamun yang digunakan sebagai substrat berpengaruh secara nyata terhadap preferensi penempelan dan sintasan larva teripang pasir, namun tidak berpengaruh terhadap pertumbuhan. E. acoroides menunjukkan hasil terbaik dengan preferensi penempelan 0,26 ind. cm-2 dan sintasan 10,66%; sehingga layak digunakan sebagai substrat penempelan dalam pembenihan teripang pasir, H. scabra.Holothuria scabra larvae on different seagrass substrates. By: Lisa Fajar Indriana, Yuli Afrianti, Sitti Hilyana, and Muhammad FirdausSandfish Holothuria scabra is marine commodities with a high economic value. Overfishing of natural stocks has compelled an interest to begin aquaculture practice. Settlement is a critical phase for the planktonic larvae as they will transform to benthic form in the presence of substrate. This study aims to evaluate the settlement preferences, growth, and survival rate of H. scabra larvae settled on different seagrass leaves. The research was conducted using the Completely randomized design with four different species of seagrass leaves and five replications. The treatments consist of Enhalus acoroides (L-1), Syringodium isoetifolium (L-2), Cymodocea serrulata (L-3), and Cymodocea rotundata (L-4). Initial number of larvae was 1,000 individuals and the substrate was set with same widthof 12 cm x 17 cm for each unit. Results of the experiment indicated that settlement preference and survival rate of H. scabra larvae was significantly affected by seagrass used as substrate while no significantly differences was observed for growth of larvae. E. acoroides showed the best result with 0.26 ind. cm-2 settelement preference and 10.66% survival rate, so that suitable to be used as settlement substrate in H. scabra hatchery.


2019 ◽  
Vol 118 (8) ◽  
pp. 172-189
Author(s):  
Magreth B Tjizumaue ◽  
Krishna Govender

Due to the absence of appropriate Consumer Protection legislation in Namibia, there seems to be a lack of consumer protection, which may result in consumers being exploited. Since the literature reveals that Consumer Awareness, Consumer Protection, Service Quality and Customer Satisfaction influence Customer Loyalty, the aforementioned relationship was explored among consumers of long-term insurance products in Namibia. The researcher embedded the study in the Services Marketing and User’s Satisfaction/Dissatisfaction theory and developed a framework for creating a more aware consumer and thus contribute to the growth and survival of the long-term insurance industry in Namibia.  A survey was conducted using a questionnaire, among a judgmental sample of 407 long-term insurance consumers in Namibia and Structural Equation Modelling was used to analyse (eight) hypothesized relationships among the research constructs alluded to in the title of this study. In summary, it was ascertained that if the customers are fully aware (have sufficient knowledge of the products and their consumer rights), they will feel protected against unfair business practices. Furthermore, if they perceive having received quality services, they are more likely to be satisfied with the service provider and will therefore, remain loyal.


2019 ◽  
Vol 5 (2) ◽  
Author(s):  
Muhammad Atilah Setiawan ◽  
Muarif Muarif ◽  
Fia Sri Mumpuni

The aim of this study was to determine the growth and survival rate of Ctenopoma fish seeds. This study used a completely randomized design with 3 treatments and 3 replications. The treatment in this study was a different feeding rate using natural feed of Tubifex sp  namely A (8%), B (10%), and C (12%) ). The test fish used was Ctenopoma fish seeds with an initial length of 2.40 ± 0.10 cm and an initial weight of 0.32 ± 0.05 g. Fish seeds are cultivated  for 28 days with feeding frequency twice a day. The results of research showed that the use of different feeding rate had an significantly different (P<0.05) on the specific growth  rate and absolute length growth with the best results in the treatment C. The survival rate was not significantly different between treatments (P>0.05). Key Words: Ctenopoma, feeding rate, growth, survival rate 


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