A and alpha supernatant pretreatment of Saccharomyces cerevisiae cells affects both the kinetics and efficiency of mating

1982 ◽  
Vol 2 (8) ◽  
pp. 897-903
Author(s):  
E P Sena
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Fusion ◽  
Large Scale ◽  
Culture Supernatant ◽  
Treatment Procedure ◽  
Logarithmic Growth Phase ◽  
Future Studies ◽  
Mating Efficiency ◽  
Potential Applications ◽  
Logarithmic Growth

The effects of culture supernatant treatment on subsequent matings between pretreated a and alpha Saccharomyces cerevisiae cells were studied. For each experiment, pairs of a and alpha [rho+] or [rho- rho0] cells in the logarithmic growth phase in defined minimal medium were pretreated for a total of 15 min (by exchanging their cell-free supernatants or by mixing samples of a and alpha cell cultures) and then mated in defined minimal (YNB) or enriched (YEP) liquid medium. All pretreated cells, regardless of treatment procedure, initiated cell fusion 15 to 35 min faster than did their nontreated counterparts. In all cases, pretreated cells mated 8 to 20% more efficiently than did nonpretreated ones. Regardless of the strains, the hierarchy of mating efficiency was always treated YEP greater than untreated YEP greater than treated YNB greater than untreated YNB. The cell fusion kinetics in alpha [rho+] X a [rho-] crosses were most affected by pretreatment (delta 30 to 35 min), whereas [rho+] X [rho+] crosses were least affected (delta 15 min). These results are discussed in relation to the functions known for a and alpha pheromones. The successful pretreatment regimes were used to design new rapid and efficient techniques for mating YNB-grown log-phase cells in either YNB or YEP liquid media. These techniques can be used for small- or large-scale mating, and because of their inherent media flexibility, they have many potential applications to future studies on mating-specific or intrazygotic phenomena.

scholarly journals A and alpha supernatant pretreatment of Saccharomyces cerevisiae cells affects both the kinetics and efficiency of mating.

1982 ◽  
Vol 2 (8) ◽  
pp. 897-903 ◽  
Author(s):  
E P Sena
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Fusion ◽  
Large Scale ◽  
Culture Supernatant ◽  
Treatment Procedure ◽  
Logarithmic Growth Phase ◽  
Future Studies ◽  
Mating Efficiency ◽  
Potential Applications ◽  
Logarithmic Growth

The effects of culture supernatant treatment on subsequent matings between pretreated a and alpha Saccharomyces cerevisiae cells were studied. For each experiment, pairs of a and alpha [rho+] or [rho- rho0] cells in the logarithmic growth phase in defined minimal medium were pretreated for a total of 15 min (by exchanging their cell-free supernatants or by mixing samples of a and alpha cell cultures) and then mated in defined minimal (YNB) or enriched (YEP) liquid medium. All pretreated cells, regardless of treatment procedure, initiated cell fusion 15 to 35 min faster than did their nontreated counterparts. In all cases, pretreated cells mated 8 to 20% more efficiently than did nonpretreated ones. Regardless of the strains, the hierarchy of mating efficiency was always treated YEP greater than untreated YEP greater than treated YNB greater than untreated YNB. The cell fusion kinetics in alpha [rho+] X a [rho-] crosses were most affected by pretreatment (delta 30 to 35 min), whereas [rho+] X [rho+] crosses were least affected (delta 15 min). These results are discussed in relation to the functions known for a and alpha pheromones. The successful pretreatment regimes were used to design new rapid and efficient techniques for mating YNB-grown log-phase cells in either YNB or YEP liquid media. These techniques can be used for small- or large-scale mating, and because of their inherent media flexibility, they have many potential applications to future studies on mating-specific or intrazygotic phenomena.

The chemotaxis study of adipose derived stem cells (ADSCs) to adenoid cystic carcinoma (ACC) cells.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e17000-e17000
Author(s):  
Li Hua ◽  
Han Zhengxue
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Adenoid Cystic Carcinoma ◽  
Culture Supernatant ◽  
Adipose Derived Stem Cells ◽  
Logarithmic Growth Phase ◽  
Cell Microenvironment ◽  
Adenoid Cystic ◽  
Lower Chamber ◽  
Logarithmic Growth

e17000 Background: Adenoid cystic carcinoma (ACC) has some properties such as neurotropic, angiotropic and early metastasis, recurrence and metastasis is the leading cause of poor prognosis in sACC. The current theory is that the invasion and metastasis were related to tumor stem cells, and the stem cell microenvironment play an important role in this process. According to the stem cell theory, we hypothesized that normal tissue stem cells may also produce chemotactic migration to tumor stem cell microenvironment, therefore this research was to explore the possibility of adipose derived stem cells as a therapy vector targeted to the microenvironment of ACC. Methods: Conventionally culture ACC cells to logarithmic growth phase, then collected them and cultured in serum-free medium. After 48 h, the culture supernatant was collected, filtered and prewarmed, and then added to each well (24-well plate, the lower chamber of the transwell chamber), 600-800 ul for each. Using the same method, the culture supernatant of T293 cells were joined into the lower chamber as a control. Then, the transwell membrane was gently placed into the well, and 100 ~ 150μl suspension of adipose derived stem cells in the logarithmic growth phase (serum-free media) were added into the upper chamber. After cultured under routine conditions for 24 hours, the transwell chamber were removed , fixed and stained. Under bright field microscope, cells invasived and attached to the transwell membrane were observed and counted, results were statistically analyzed by student test. Results: Selecte five high-power microscopic field randomly, counted the number of adipose derived stem cells migrated to transwell membrane of different cell lines. Results showed that migrated cell number of SACC-LM group was 64.3 ± 7.6, the number of SACC-83 group was 52.3 ± 6.1, both higher than the T293 group (31.8 ± 6.3), and the difference between them was statistically significant (p <0.05). Conclusions: Adipose derived stem cells have obvious chemotaxis to adenoid cystic carcinoma cell culture supernatants, so we can propose that adipose derived stem cells has the possibility and feasibiliy of being used as a targeted therapy vectors for ACC.

scholarly journals Genetic Analysis of Default Mating Behavior in Saccharomyces cerevisiae

Genetics ◽  
1997 ◽  
Vol 146 (1) ◽  
pp. 39-55 ◽  
Author(s):  
Russell Dorer ◽  
Charles Boone ◽  
Tyler Kimbrough ◽  
Joshua Kim ◽  
Leland H Hartwell
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Genetic Analysis ◽  
Mating Behavior ◽  
Cell Fusion ◽  
Yeast Cells ◽  
Stringent Requirement ◽  
Mating Partner ◽  
Mating Efficiency ◽  
Multiple Copies ◽  
Mating Pathway

Haploid Saccharomyces cerevisiae cells find each other during conjugation by orienting their growth toward each other along pheromone gradients (chemotropism). However, when their receptors are saturated for pheromone binding, yeast cells must select a mate by executing a default pathway in which they choose a mating partner at random. We previously demonstrated that this default pathway requires the SPA2 gene. In this report we show that the default mating pathway also requires the AXL1, FUS1, FUS2, FUS3, PEAZ, RVS161, and BNI1 genes. These genes, including SPA2, are also important for efficient cell fusion during chemotropic mating. Cells containing null mutations in these genes display defects in cell fusion that subtly affect mating efficiency. In addition, we found that the defect in default mating caused by mutations in SPA2 is partially suppressed by multiple copies of two genes, FUS2 and MFA2. These findings uncover a molecular relationship between default mating and cell fusion. Moreover, because axl1 mutants secrete reduced levels of a-factor and are defective at both cell fusion and default mating, these results reveal an important role for a-factor in cell fusion and default mating. We suggest that default mating places a more stringent requirement on some aspects of cell fusion than does chemotropic mating.

scholarly journals CHS5, a gene involved in chitin synthesis and mating in Saccharomyces cerevisiae.

1997 ◽  
Vol 17 (5) ◽  
pp. 2485-2496 ◽  
Author(s):  
B Santos ◽  
A Duran ◽  
M H Valdivieso
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Fusion ◽  
Chitin Synthase ◽  
Activity Levels ◽  
Wild Type ◽  
Neurofilament Proteins ◽  
Chitin Synthesis ◽  
Mating Efficiency ◽  
Carboxy Terminal

The CHS5 locus of Saccharomyces cerevisiae is important for wild-type levels of chitin synthase III activity. chs5 cells have reduced levels of this activity. To further understand the role of CHS5 in yeast, the CHS5 gene was cloned by complementation of the Calcofluor resistance phenotype of a chs5 mutant. Transformation of the mutant with a plasmid carrying CHS5 restored Calcofluor sensitivity, wild-type cell wall chitin levels, and chitin synthase III activity levels. DNA sequence analysis reveals that CHS5 encodes a unique polypeptide of 671 amino acids with a molecular mass of 73,642 Da. The predicted sequence shows a heptapeptide repeated 10 times, a carboxy-terminal lysine-rich tail, and some similarity to neurofilament proteins. The effects of deletion of CHS5 indicate that it is not essential for yeast cell growth; however, it is important for mating. Deletion of CHS3, the presumptive structural gene for chitin synthase III activity, results in a modest decrease in mating efficiency, whereas chs5delta cells exhibit a much stronger mating defect. However, chs5 cells produce more chitin than chs3 mutants, indicating that CHS5 plays a role in other processes besides chitin synthesis. Analysis of mating mixtures of chs5 cells reveals that cells agglutinate and make contact but fail to undergo cell fusion. The chs5 mating defect can be partially rescued by FUS1 and/or FUS2, two genes which have been implicated previously in cell fusion, but not by FUS3. In addition, mating efficiency is much lower in fus1 fus2 x chs5 than in fus1 fus2 x wild type crosses. Our results indicate that Chs5p plays an important role in the cell fusion step of mating.

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

scholarly journals Development and Characterization of Two Types of Surface Displayed Levansucrases for Levan Biosynthesis

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 757
Author(s):  
Huiyi Shang ◽  
Danni Yang ◽  
Dairong Qiao ◽  
Hui Xu ◽  
Yi Cao
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Weight ◽  
Large Scale ◽  
Surface Display ◽  
Yeast Surface Display ◽  
Fusion Partner ◽  
Whole Cell ◽  
Food Industries ◽  
Yeast Surface ◽  
The Stability

Levan has wide applications in chemical, cosmetic, pharmaceutical and food industries. The free levansucrase is usually used in the biosynthesis of levan, but the poor reusability and low stability of free levansucrase have limited its large-scale use. To address this problem, the surface-displayed levansucrase in Saccharomyces cerevisiae were generated and evaluated in this study. The levansucrase from Zymomonas mobilis was displayed on the cell surface of Saccharomyces cerevisiae EBY100 using a various yeast surface display platform. The N-terminal fusion partner is based on a-agglutinin, and the C-terminal one is Flo1p. The yield of levan produced by these two whole-cell biocatalysts reaches 26 g/L and 34 g/L in 24 h, respectively. Meanwhile, the stability of the surface-displayed levansucrases is significantly enhanced. After six reuses, these two biocatalysts retained over 50% and 60% of their initial activities, respectively. Furthermore, the molecular weight and polydispersity test of the products suggested that the whole-cell biocatalyst of levansucrase displayed by Flo1p has more potentials in the production of levan with low molecular weight which is critical in certain applications. In conclusion, our method not only enable the possibility to reuse the enzyme, but also improves the stability of the enzyme.

scholarly journals C4 Bacterial Volatiles Improve Plant Health

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 682
Author(s):  
Bruno Henrique Silva Dias ◽  
Sung-Hee Jung ◽  
Juliana Velasco de Castro Oliveira ◽  
Choong-Min Ryu
Keyword(s):  
Plant Growth ◽  
Volatile Compounds ◽  
Large Scale ◽  
Growth Promotion ◽  
Plant Growth Promoting Rhizobacteria ◽  
Plant Health ◽  
Systemic Resistance ◽  
Potential Applications ◽  
Plant Growth Promoting ◽  
Bacterial Volatiles

Plant growth-promoting rhizobacteria (PGPR) associated with plant roots can trigger plant growth promotion and induced systemic resistance. Several bacterial determinants including cell-wall components and secreted compounds have been identified to date. Here, we review a group of low-molecular-weight volatile compounds released by PGPR, which improve plant health, mostly by protecting plants against pathogen attack under greenhouse and field conditions. We particularly focus on C4 bacterial volatile compounds (BVCs), such as 2,3-butanediol and acetoin, which have been shown to activate the plant immune response and to promote plant growth at the molecular level as well as in large-scale field applications. We also disc/ uss the potential applications, metabolic engineering, and large-scale fermentation of C4 BVCs. The C4 bacterial volatiles act as airborne signals and therefore represent a new type of biocontrol agent. Further advances in the encapsulation procedure, together with the development of standards and guidelines, will promote the application of C4 volatiles in the field.

scholarly journals In Vivo Production of RNA Aptamers and Nanoparticles: Problems and Prospects

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1422
Author(s):  
Ousama Al Shanaa ◽  
Andrey Rumyantsev ◽  
Elena Sambuk ◽  
Marina Padkina
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Large Scale ◽  
Potential Model ◽  
Model Organism ◽  
Rna Aptamers ◽  
Early Stages ◽  
Near Future

RNA aptamers are becoming increasingly attractive due to their superior properties. This review discusses the early stages of aptamer research, the main developments in this area, and the latest technologies being developed. The review also highlights the advantages of RNA aptamers in comparison to antibodies, considering the great potential of RNA aptamers and their applications in the near future. In addition, it is shown how RNA aptamers can form endless 3-D structures, giving rise to various structural and functional possibilities. Special attention is paid to the Mango, Spinach and Broccoli fluorescent RNA aptamers, and the advantages of split RNA aptamers are discussed. The review focuses on the importance of creating a platform for the synthesis of RNA nanoparticles in vivo and examines yeast, namely Saccharomyces cerevisiae, as a potential model organism for the production of RNA nanoparticles on a large scale.

scholarly journals Reanalysis of an Allocentric Navigation Strategy Scale based on Item Response Theory

2020 ◽  
Vol 2 (1) ◽  
pp. 90-105
Author(s):  
Jimmy Y. Zhong
Keyword(s):  
Item Response Theory ◽  
Item Response ◽  
Large Scale ◽  
Relative Magnitude ◽  
Latent Structure ◽  
Response Theory ◽  
Future Studies ◽  
Bidimensional Model ◽  
Navigation Strategy ◽  
Component Loading

AbstractFocusing on 12 allocentric/survey-based strategy items of the Navigation Strategy Questionnaire (Zhong & Kozhevnikov, 2016), the current study applied item response theory-based analysis to determine whether a bidimensional model could better describe the latent structure of the survey-based strategy. Results from item and model fit diagnostics, categorical response and item information curves showed that an item with the lowest rotated component loading (.27) [SURVEY12], could be considered for exclusion in future studies; and that a bidimensional model with three preference-related items constituting a content factor offered a better representation of the latent structure than a unidimensional model per se. Mean scores from these three items also correlated significantly with a pointing-to-landmarks task to the same relative magnitude as the mean scores from all items, and all items excluding SURVEY12. These findings gave early evidence suggesting that the three preference-related items could constitute a subscale for deriving quick estimates of large-scale allocentric spatial processing in healthy adults in both experimental and clinical settings. Potential cognitive and brain mechanisms were discussed, followed by calls for future studies to gather greater evidence confirming the predictive validity of the full and sub scales, along with the design of new items focusing on environmental familiarity.

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