scholarly journals Dormancy‐to‐death transition in yeast spores occurs due to gradual loss of gene‐expressing ability

2020 ◽  
Vol 16 (11) ◽  
Author(s):  
Théo Maire ◽  
Tim Allertz ◽  
Max A Betjes ◽  
Hyun Youk
Keyword(s):  
Gradual Loss ◽  
Gene Expressing

scholarly journals Dormancy-to-death transition in yeast spores occurs due to gradual loss of gene-expressing ability

2019 ◽  
Author(s):  
Théo Maire ◽  
Tim Allertz ◽  
Max A. Betjes ◽  
Hyun Youk
Keyword(s):  
Gene Expression ◽  
List Type ◽  
Cell Level ◽  
Open Questions ◽  
Germination Ability ◽  
Gradual Loss ◽  
Inhibit Gene Expression ◽  
Synthetic Circuit ◽  
Dormant Spore ◽  
Gene Expressing

ABSTRACTDormancy is colloquially considered as extending lifespan by being still. Starved yeasts form dormant spores that wake-up (germinate) when nutrients reappear but cannot germinate (die) after some time. What sets their lifespans and how they age are open questions because what processes occur - and by how much - within each dormant spore remains unclear. With single-cell-level measurements, we discovered how dormant yeast spores age and die: spores have a quantifiable gene-expressing ability during dormancy that decreases over days to months until it vanishes, causing death. Specifically, each spore has a different probability of germinating that decreases because its ability to - without nutrients - express genes decreases, as revealed by a synthetic circuit that forces GFP expression during dormancy. Decreasing amounts of molecules required for gene expression - including RNA polymerases - decreases gene-expressing ability which then decreases chances of germinating. Spores gradually lose these molecules because they are produced too slowly compared to their degradations, causing gene-expressing ability to eventually vanish and, thus, death. Our work provides a systems-level view of dormancy-to-death transition.Short summaryThis study identifies systems-level quantities that decay during dormancy in Saccharomyces cerevisiae spores and thereby reveals the meaning of ageing for dormant yeast spores and shows that they die when their gene-expressing ability is irreversibly lost.HighlightsFor a given glucose concentration, a dormant yeast spore has a well-defined probability of germinating (“germination ability”).A spore’s germination ability positively correlates with its RNAP I-III levels and the gene-expression (GFP) level it can realize when the expression is forced without nutrients.Ageing during dormancy means gradual decreases in germination ability, RNAP levels, and GFP-level realizable when expression is forced.Spores die after sufficiently losing gene-expressing ability and drugs that inhibit gene expression during dormancy shorten spores’ lifespans (e.g., from months to a day).

scholarly journals Nostoc commune UTEX 584 gene expressing indole phosphate hydrolase activity in Escherichia coli.

1989 ◽  
Vol 171 (2) ◽  
pp. 708-713 ◽  
Author(s):  
W Q Xie ◽  
B A Whitton ◽  
J W Simon ◽  
K Jäger ◽  
D Reed ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Hydrolase Activity ◽  
Nostoc Commune ◽  
Gene Expressing

scholarly journals The structure of Brazilian Amazonian gut microbiomes in the process of urbanisation

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Ana Paula Schaan ◽  
Dionison Sarquis ◽  
Giovanna C. Cavalcante ◽  
Leandro Magalhães ◽  
Eliene R. P. Sacuena ◽  
...  
Keyword(s):  
Native American ◽  
Ribosomal Rna ◽  
Gut Microbiome ◽  
Brazilian Amazon ◽  
American People ◽  
South American ◽  
Subsistence Strategy ◽  
Urban Populations ◽  
Gradual Loss ◽  
Agricultural Societies

AbstractShifts in subsistence strategy among Native American people of the Amazon may be the cause of typically western diseases previously linked to modifications of gut microbial communities. Here, we used 16S ribosomal RNA sequencing to characterise the gut microbiome of 114 rural individuals, namely Xikrin, Suruí and Tupaiú, and urban individuals from Belém city, in the Brazilian Amazon. Our findings show the degree of potential urbanisation occurring in the gut microbiome of rural Amazonian communities characterised by the gradual loss and substitution of taxa associated with rural lifestyles, such as Treponema. Comparisons to worldwide populations indicated that Native American groups are similar to South American agricultural societies and urban groups are comparable to African urban and semi-urban populations. The transitioning profile observed among traditional populations is concerning in light of increasingly urban lifestyles. Lastly, we propose the term “tropical urban” to classify the microbiome of urban populations living in tropical zones.

scholarly journals Gradual Loss of a DNA-Inducible Protein Kinase Activity From the Cytoplasmic Extracts of Arbacia Embryos

1996 ◽  
Vol 191 (2) ◽  
pp. 281-282 ◽  
Author(s):  
J. Kanungo ◽  
B. Calhoun ◽  
Y. Takeda ◽  
J. A. Hardin ◽  
H. Rasmussen
Keyword(s):  
Protein Kinase ◽  
Kinase Activity ◽  
Protein Kinase Activity ◽  
Gradual Loss ◽  
Inducible Protein

Retrograde effects of target atrophy on submandibular ganglion neurons

1987 ◽  
Vol 58 (2) ◽  
pp. 276-287 ◽  
Author(s):  
M. D. Womble ◽  
S. Roper
Keyword(s):  
Cell Loss ◽  
Salivary Gland Cell ◽  
Target Tissue ◽  
Nerve Supply ◽  
Neuron Number ◽  
Adult Rat ◽  
Gradual Loss ◽  
Duct Ligation ◽  
Direct Injury ◽  
Ganglion Neurons

1. To study the retrograde effects of changes in target tissue upon the innervating nerve supply, we have examined the parasympathetic submandibular ganglion of the adult rat. Neurons of this ganglion innervate the submandibular and sublingual salivary glands. 2. Ligating the salivary ducts leads to rapid and prolonged salivary gland cell atrophy. 3. Duct ligations, without direct injury to the glandular nerve supply, initially produced few alterations in the ganglion. After 8 wk, however, neuron number was reduced by 50%. The numbers of presynaptic inputs/neuron and synapses/neuron perimeter were not affected by the cell loss. 4. After 1 wk of duct ligation in which the glandular nerve supply was intentionally damaged, some ganglionic neurons have lost all presynaptic inputs, suggesting synaptic disjunction. This is followed at 3 wk by a 40% decrease in neuron number and an increase in the number of inputs per (remaining) ganglion cell. However, the number of synapses/neuronal profile was unchanged. 5. Thus axotomy plus target atrophy causes synaptic disjunction, neuron cell death, and input rearrangement, presumably due to a combination of direct injury effects and an abrupt loss of peripheral trophic supplies. 6. In contrast, target atrophy alone produced more gradual changes in submandibular ganglion neurons. Only prolonged target atrophy leads to a decrease in the number of ganglionic neurons, perhaps due to the gradual loss of peripheral trophic supplies. However, other features, such as the number of inputs/cell and the number of synapses/neuron perimeter, remain unaltered. Evidently, the gradual loss of trophic support does not result in synaptic disjunction to the degree needed to produce presynaptic input rearrangement.

In vivo comparison of IVDU and IVFRU in HSV1-TK gene expressing tumor bearing rats

2004 ◽  
Vol 60 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Tae Hyun Choi ◽  
Soon Hyuk Ahn ◽  
Hee-Chung Kwon ◽  
Chang Woon Choi ◽  
Ok Doo Awh ◽  
...  
Keyword(s):  
Tumor Bearing ◽  
Gene Expressing

CHANGES IN THE THERMAL STABILITY AND ACIDIC CHARACTERISTICS OF HYDROXY-Al-MONTMORILLONITE COMPLEXES FORMED IN THE PRESENCE OF CITRIC ACID

1985 ◽  
Vol 65 (3) ◽  
pp. 519-522 ◽  
Author(s):  
TEE BOON GOH ◽  
P. M. HUANG
Keyword(s):  
Thermal Stability ◽  
Citric Acid ◽  
Organic Carbon ◽  
Organic Acid ◽  
Key Words ◽  
Titratable Acidity ◽  
Structural Water ◽  
Molar Ratios ◽  
Gradual Loss

The thermal stability and acidic characteristics of Al interlayered montmorillonite were affected by citric acid which was present during its formation. Perturbation to the formation of Al interlayers by citric acid resulted in more gradual loss of their structural water in the 430 °C to 520 °C region at initial citric acid/Al molar ratios of 0.1 and 0.5. The data clearly reveal that, besides hydroxy-Al polymers, hydroxy-Al-citrate complexes adsorbed on the surfaces of montmorillonite very substantially contribute to the total and third buffer range titratable acidity of the clay. Key words: Hydroxy-Al-citrate interlayers, smectite, organic acid, DTA, third buffer range, organic carbon

The Influence of the Addition of Ti on the Mechanical Properties of W-S-Ti Coatings

2006 ◽  
Vol 514-516 ◽  
pp. 687-691 ◽  
Author(s):  
Manuel Evaristo ◽  
Ana Nossa ◽  
Albano Cavaleiro
Keyword(s):  
Mechanical Properties ◽  
Friction Coefficient ◽  
Tribological Performance ◽  
The Self ◽  
Wear Coefficient ◽  
Gradual Loss ◽  
Order Of Magnitude ◽  
Amorphous Structures ◽  
Ti Content ◽  
Ti Films

In this work, W-S-Ti films were deposited by r.f. magnetron sputtering, using simultaneously WS2 and Ti targets. The atomic percentage of Ti in the coating was varied from 0 at.% up to 28 at.%. No significant variations in the S/W ratio with the increase of Ti content were observed. The increasing Ti contents in the films led to a gradual loss of crystallinity. Coatings with contents greater than ≈ 16 at.% only presents a broad peak characteristic of amorphous structures. Alloying the films with Ti led to significant improvements in the hardness (from 0.3 to 8.9 GPa). Also, the adhesive critical load continuously grew with the increase of the Ti content in the films. The wear coefficient of the films dropped more than one order of magnitude with the increase of Ti content whereas the friction coefficient was kept fairly constant with just a small increase in relation to single W-S film. In conclusion, to have a good tribological performance, the addition of Ti to the films should be balanced in order that the increase of the mechanical properties does not lead to severe loss of the self-lubricant properties.

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