Genetics of Gracilaria tikvahiae (Rhodophyceae). VIII. Phenotypic and genetic characterization of some selected morphological mutants

1982 ◽  
Vol 60 (12) ◽  
pp. 2556-2564 ◽  
Author(s):  
Mohsin U. Patwary ◽  
John P. van der Meer
Keyword(s):  
Wild Type ◽  
Initial Attempt ◽  
Gracilaria Tikvahiae ◽  
Induced Mutants ◽  
Morphological Mutants ◽  
Phenotypic And Genetic Characterization ◽  
Growth Habits ◽  
Selection Of ◽  
Better Than

Morphological mutants of the marine red alga Gracilaria tikvahiae have been isolated in an initial attempt to develop improved strains for mariculture by selection of plants with altered growth habits. Both spontaneous and ethylmethanesulphonate-induced mutants were collected for this study. The phenotypes of the mutants range from plants with extremely fine, highly branched fronds to plants with thick puffy fronds. Among 10 mutants selected for more detailed study, 9 have distinctly different phenotypes. Genetic results identify nine mutant cistrons corresponding to the nine phenotypes. All the phenotypes are transmitted as single, mostly recessive, Mendelian mutations, with possible linkage appearing in two combinations of mutants. Growth trials in culture indicate that at least some of the mutants grow better than a genetically related wild type. In general, plants with increased branching showed the greatest promise.

scholarly journals Nutrição enteral em sistema fechado para pediatria: escolha com base na disponibilidade no comércio brasileiro e na rotulagem

2020 ◽  
Vol 35 (1) ◽  
pp. 70-76
Author(s):  
Anelise Pigatto Bissacotti ◽  
Franceliane Jobim Benedetti
Keyword(s):  
Enteral Nutrition ◽  
Closed System ◽  
Clinical Situation ◽  
Nutritional Composition ◽  
Enteral Diet ◽  
Pediatric Nutrition ◽  
Age Range ◽  
Selection Of ◽  
Better Than

Introduction: The enteral diet (ED) for pediatric nutrition should ensure the appropriate nutritional intake for the child and/or adolescent. Therefore, during the selection of ED, in addition to the patient’s needs, the characteristics and nutritional composition of the patients should be taken into account. Thus, the objective was to identify and characterize the diets for pediatric enteral nutrition, in a closed system, currently available in the Brazilian market, in order to assist nutritionists and doctors in prescription. Methods: The descriptive and documental research consisted in the identification of the diets for pediatric enteral nutrition, in a closed system, currently available in the Brazilian market and characterization of the diets, based on labeling data. The data of interest for the development of this study were collected in catalogs and official websites of the manufacturers and suppliers and books of enteral nutrition and nutrition in pediatrics. Results: In Brazil, nine pediatric enteral nutrition diets are available in a closed system, marketed by three manufacturers. It was found that the diets for pediatric enteral nutrition can be indicated for a wide age range, from one to 10 years and patients in different pathophysiological states. There is little variation in the levels and sources of macronutrients. Four enteral diets present fibers in their composition and 5 are hypotonic. Conclusions: The Brazilian market has a limited number of diets for pediatric enteral nutrition in a closed system, which makes prescribing a challenge for nutritionists and doctors. It can not be said that a particular pediatric enteral diet in closed system is better than another, each one has specific characteristics. This makes it necessary for to carefully evaluate the professionals adequacy of the diet to the patient’s clinical situation and individuality.

Effects of temperature and tissue age on gel strength and composition of agar from Gracilaria tikvahiae (Rhodophyceae)

1984 ◽  
Vol 62 (8) ◽  
pp. 1665-1670 ◽  
Author(s):  
James S. Craigie ◽  
Zong C. Wen
Keyword(s):  
Gel Strength ◽  
Wild Type ◽  
Gracilaria Tikvahiae ◽  
Morphological Mutants ◽  
Wild Type Clone ◽  
Effects Of Temperature ◽  
Lateral Branches ◽  
Increasing Temperature ◽  
Strong Inverse Relationship ◽  
Galactose Content

Agars were prepared from a wild type and two morphological mutants of Gracilaria tikvahiae grown at 17, 22, and 27 °C, and from apical segments, main axis segments, and lateral branches of the wild type clone MP-2 grown at 17 and 27 °C. The yield of native agar was 9–11% from the young parts and 19–23% from the most mature parts of the MP-2 thallus. The gel strengths of alkali-modified agars showed a strong inverse relationship with increasing temperature of growth in each of the three clones examined. The modified agar produced from plants grown at high temperature contained more sulfate and less 3,6-anhydro-L-galactose than agars produced at lower temperatures. The increase in 4-O-methyl-L-galactose content of the agars as the growth temperature increased was especially marked. Dissection experiments on clone MP-2 showed that agar with the maximum gel strength and 3,6-anhydro-L-galactose content and the minimum sulfate and 4-O-methyl-L-galactose content was produced at low temperature by apical segments and young lateral branches. The poorest quality agar was prepared from mature segments of the thallus, especially those grown at high temperatures. Agars prepared from mature parts of the thallus were greatly enriched in 4-O-methyl-L-galactose, which reached 8.8% of the weight of the agar at 27 °C. Changes in 6-O-methyl-D-galactose were smaller, but this sugar was lowest in agar prepared from young tissues of plants grown at 17 °C.

Growth experiments on morphological mutants of Gracilaria tikvahiae (Rhodophyceae)

1983 ◽  
Vol 61 (6) ◽  
pp. 1654-1659 ◽  
Author(s):  
Mohsin U. Patwary ◽  
John P. van der Meer
Keyword(s):  
Growth Rate ◽  
High Density ◽  
Low Density ◽  
Wild Type ◽  
Gracilaria Tikvahiae ◽  
Morphological Mutants ◽  
Growth Experiments

The growth of morphological mutants of Gracilaria tikvahiae was compared with that of wild-type clones in tanks of flowing seawater in a greenhouse. At low density four mutants grew faster than a related wild type, and two, MP-40 and MP-44, grew faster than any of the wild clones tested. Of the mutants, MP-40 consistently had the fastest growth rate at low density. At high density MP-40 and MP-44 again grew faster than wild type; however, MP-44 had the faster growth rate and gave the higher yields. Both of these mutants removed nitrogen (NH4+) from seawater faster than the wild types and both proved to be much more epiphyte resistant, with MP-40 scoring highest for both of these characteristics.

scholarly journals spe-43 is required for sperm activation in C. elegans

2017 ◽  
Author(s):  
Amber R. Krauchunas ◽  
Ernesto Mendez ◽  
Julie Zhouli Ni ◽  
Marina Druzhinina ◽  
Amanda Mulia ◽  
...  
Keyword(s):  
Transmembrane Protein ◽  
Activation Process ◽  
Deletion Mapping ◽  
Cell Periphery ◽  
Wild Type ◽  
Sperm Activation ◽  
C Elegans ◽  
Phenotypic And Genetic Characterization

ABSTRACTSuccessful fertilization requires that sperm are activated prior to contacting an oocyte. In C. elegans, this activation process, called spermiogenesis, transforms round immobile spermatids into motile, fertilization-competent spermatozoa. We describe the phenotypic and genetic characterization of spe-43, a new component of the spe-8 pathway, which is required for spermiogenesis in hermaphrodites; spe-43 hermaphrodites are self-sterile, while spe-43 males show wild-type fertility. When exposed to Pronase to activate sperm in vitro, spe-43 spermatids form long rigid spikes radiating outward from the cell periphery instead of forming a motile pseudopod, indicating that spermiogenesis initiates but is not completed. Using a combination of recombinant and deletion mapping and whole genome sequencing, we identified F09E8.1 as spe-43. SPE-43 is predicted to exist in two isoforms; one isoform appears to be a single-pass transmembrane protein while the other is predicted to be a secreted protein. SPE-43 can bind to other known sperm proteins, including SPE-4 and SPE-29, which are known to impact spermiogenesis. In summary, we have identified a membrane protein that is present in C. elegans sperm and is required for sperm activation via the hermaphrodite activation signal.

scholarly journals Pharmacogenomics characterization of the MDM2 inhibitor MI-773 reveals candidate tumours and predictive biomarkers

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Vincent Vuaroqueaux ◽  
Hans R. Hendriks ◽  
Hoor Al-Hasani ◽  
Anne-Lise Peille ◽  
Samayita Das ◽  
...  
Keyword(s):  
Therapeutic Potential ◽  
Predictive Biomarkers ◽  
Wild Type ◽  
Mutation Status ◽  
Anti Tumour Activity ◽  
Molecule Inhibitor ◽  
Tumour Activity ◽  
Selection Of

AbstractMI-773 is a recently developed small-molecule inhibitor of the mouse double minute 2 (MDM2) proto-oncogene. Preclinical data on the anti-tumour activity of MI-773 are limited and indicate that tumour cell lines (CLs) with mutated TP53 are more resistant to MI-773 than wild type TP53. Here, we explored the compound’s therapeutic potential in vitro using a panel of 274 annotated CLs derived from a diversity of tumours. MI-773 exhibited a pronounced selectivity and moderate potency, with anti-tumour activity in the sub-micromolar range in about 15% of the CLs. The most sensitive tumour types were melanoma, sarcoma, renal and gastric cancers, leukaemia, and lymphoma. A COMPARE analysis showed that the profile of MI-773 was similar to that of Nutlin-3a, the first potent inhibitor of p53–MDM2 interactions, and, in addition, had a superior potency. In contrast, it poorly correlates with profiles of compounds targeting the p53 pathway with another mechanism of action. OMICS analyses confirmed that MI-773 was primarily active in CLs with wild type TP53. In silico biomarker investigations revealed that the TP53 mutation status plus the aggregated expression levels of 11 genes involved in the p53 signalling pathway predicted sensitivity or resistance of CLs to inhibitors of p53–MDM2 interactions reliably. The results obtained for MI-773 could help to refine the selection of cancer patients for therapy.

Phenotypic and genetic characterization of Paecilomyces lilacinus strains with biocontrol activity against root-knot nematodes

2000 ◽  
Vol 46 (9) ◽  
pp. 775-783 ◽  
Author(s):  
T S Gunasekera ◽  
R J Holland ◽  
M R Gillings ◽  
D A Briscoe ◽  
D C Neethling ◽  
...  
Keyword(s):  
Uv Radiation ◽  
Nematophagous Fungus ◽  
Paecilomyces Lilacinus ◽  
Candidate Species ◽  
Genetic Clusters ◽  
Screening Assays ◽  
Phenotypic And Genetic Characterization ◽  
Efficient Selection ◽  
Selection Of

Efficient selection of fungi for biological control of nematodes requires a series of screening assays. Assessment of genetic diversity in the candidate species maximizes the variety of the isolates tested and permits the assignment of a particular genotype with high nematophagous potential using a rapid novel assay. Molecular analyses also facilitate separation between isolates, allowing the identification of proprietary strains and trace biocontrol strains in the environment. The resistance of propagules to UV radiation is an important factor in the survival of a biocontrol agent. We have analyzed 15 strains of the nematophagous fungus Paecilomyces lilacinus using these principles. Arbitrarily primed DNA and allozyme assays were applied to place the isolates into genetic clusters, and demonstrated that some genetically related P. lilacinus strains exhibit widespread geographic distributions. When exposed to UV radiation, some weakly nematophagous strains were generally more susceptible than effective isolates. A microtitre tray-based assay used to screen the pathogenic activity of each isolate to Meloidogyne javanica egg masses revealed that the nematophagous ability varied between 37%-100%. However, there was no clear relationship between nematophagous ability and genetic clusters. Molecular characterizations revealed sufficient diversity to allow tracking of strains released into the environment.Key words: Paecilomyces lilacinus, LP-RAPD analysis, allozymes, UV sensitivity.

scholarly journals Development of Improved Cellulase Variants for the Conversion of Spent Mushroom Substrate Supplemented with Wheat Straw by Directed Evolution

2021 ◽  
Author(s):  
Valentina Mauriello ◽  
Anna Pennacchio ◽  
Irantzu Alegria Dallo ◽  
Laura Garcia Saez ◽  
Petri Ihalainen ◽  
...  
Keyword(s):  
Directed Evolution ◽  
Wheat Straw ◽  
Recombinant Expression ◽  
Scale Up ◽  
Wild Type ◽  
Spent Mushroom Substrate ◽  
Glucose Yield ◽  
Hydrolysis Of ◽  
Selection Of

Abstract To improve the Spent mushroom substrate (SMS) saccharification, cloning, recombinant expression in Escherichia coli and characterization of two new GH5 family cellulases (Cel1 and Cel2) were performed. Based on enzymes properties, Cel2 was selected for the generation of 30,000 random mutants by directed evolution in order to develop improved biocatalysts. Error-prone Polymerase Chain Reaction was used for diversity generation in cel2 gene and the screening for activity of mutants allowed selection of 63 improved variants that were subjected to a scale up production. Among these, 13 clones exhibited two-fold higher activity than Cel2 and a higher thermoresistance after 72h. The performances of these mutants in the hydrolysis of pretreated SMS/ wheat straw (40/60) were compared to the wild type Cel2 in conjunction with a commercial enzymatic mixture (MetZyme® SUNO™ BOOSTER 144). All the mutants exhibited a glucose yield two-fold or four fold higher than wild-type Cel2 after 72h of incubation.

Applications of Transmission Electron Microscopy in the Characterization of Metal Machinability

1968 ◽  
Vol 26 ◽  
pp. 442-443 ◽  
Author(s):  
L.E. Murr ◽  
A.B. Draper
Keyword(s):  
Electron Microscopy ◽  
State Physics ◽  
Test Material ◽  
Milling Machine ◽  
Rotary Table ◽  
Solid State Physics ◽  
Materials Properties ◽  
Transmission Electron ◽  
Selection Of

The industrial characterization of the machinability of metals and alloys has always been a very arbitrarily defined property, subject to the selection of various reference or test materials; and the adoption of rather naive and misleading interpretations and standards. However, it seems reasonable to assume that with the present state of knowledge of materials properties, and the current theories of solid state physics, more basic guidelines for machinability characterization might be established on the basis of the residual machined microstructures. This approach was originally pursued by Draper; and our presentation here will simply reflect an exposition and extension of this research.The technique consists initially in the production of machined chips of a desired test material on a horizontal milling machine with the workpiece (specimen) mounted on a rotary table vice. A single cut of a specified depth is taken from the workpiece (0.25 in. wide) each at a new tool location.

Characterization of Rh/Si multilayer structure by HREM and HAADF

1992 ◽  
Vol 50 (1) ◽  
pp. 122-123
Author(s):  
Y. Cheng ◽  
J. Liu ◽  
M.B. Stearns ◽  
D.G. Steams
Keyword(s):  
Normal Incidence ◽  
High Resolution Electron Microscopy ◽  
X Rays ◽  
Beam Direction ◽  
Cross Sectional ◽  
Optical Elements ◽  
Resolution Electron ◽  
Point To Point ◽  
Better Than

The Rh/Si multilayer (ML) thin films are promising optical elements for soft x-rays since they have a calculated normal incidence reflectivity of ∼60% at a x-ray wavelength of ∼13 nm. However, a reflectivity of only 28% has been attained to date for ML fabricated by dc magnetron sputtering. In order to determine the cause of this degraded reflectivity the microstructure of this ML was examined on cross-sectional specimens with two high-resolution electron microscopy (HREM and HAADF) techniques.Cross-sectional specimens were made from an as-prepared ML sample and from the same ML annealed at 298 °C for 1 and 100 hours. The specimens were imaged using a JEM-4000EX TEM operating at 400 kV with a point-to-point resolution of better than 0.17 nm. The specimens were viewed along Si [110] projection of the substrate, with the (001) Si surface plane parallel to the beam direction.

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