scholarly journals Biochemical Differences Between Alcohol Debydrogenases of Drosophila Melanogaster

1976 ◽  
Vol 29 (4) ◽  
pp. 365 ◽  
Author(s):  
JG Oakeshott
Keyword(s):  
Drosophila Melanogaster ◽  
The Other ◽  
Developmental Changes ◽  
Substrate Specificities ◽  
Ph Values ◽  
Ph Profiles

This paper describes substrate specificities, developmental changes in activity, pH profiles, and heat stabilities of isozymes produced by four Adh genotypes in D. melanogaster. No differences are found in the substrate specificities of isozymes from the different genotypes but studies of the other three properties reveal significant differences between the isozymes. Thus relatively low activities are found among extracts of AdhF Adhn2 larvae and among extracts of AdhF AdhF adults aged 44 days. Also AdhF Adhs and Adhs Adhs extracts have relatively high activities at pH 6� 5, and AdhF Adhn2 extracts have relatively low activities at pH values above 10�0. Finally, extracts of AdhF AdhF and AdhF Adhs are more stable at 40�C than are those of Adhs Adhs and AdhF Adhn2 ?

scholarly journals Purification and Substrate Specificities of Two α-l-Arabinofuranosidases from Aspergillus awamori IFO 4033

1998 ◽  
Vol 64 (10) ◽  
pp. 4021-4027 ◽  
Author(s):  
Satoshi Kaneko ◽  
Mitsue Arimoto ◽  
Misako Ohba ◽  
Hideyuki Kobayashi ◽  
Tadashi Ishii ◽  
...  
Keyword(s):  
Culture Filtrate ◽  
The Other ◽  
Hydrolysis Reaction ◽  
Aspergillus Awamori ◽  
Side Chain ◽  
Optimum Temperature ◽  
Substrate Specificities ◽  
Molecular Weights ◽  
Ph Values ◽  
Optimum Ph

ABSTRACT α-l-Arabinofuranosidases I and II were purified from the culture filtrate of Aspergillus awamori IFO 4033 and had molecular weights of 81,000 and 62,000 and pIs of 3.3 and 3.6, respectively. Both enzymes had an optimum pH of 4.0 and an optimum temperature of 60°C and exhibited stability at pH values from 3 to 7 and at temperatures up to 60°C. The enzymes released arabinose from p-nitrophenyl-α-l-arabinofuranoside,O-α-l-arabinofuranosyl-(1→3)-O-β-d-xylopyranosyl-(1→4)-d-xylopyranose, and arabinose-containing polysaccharides but not fromO-β-d-xylopyranosyl-(1→2)-O-α-l-arabinofuranosyl-(1→3)-O-β-d-xylopyranosyl-(1→4)-O-β-d-xylopyranosyl-(1→4)-d-xylopyranose. α-l-Arabinofuranosidase I also released arabinose fromO-β-d-xylopy-ranosyl-(1→4)-[O-α-l-arabinofuranosyl-(1→3)]-O-β-d-xylopyranosyl-(1→4)-d-xylopyranose. However, α-l-arabinofuranosidase II did not readily catalyze this hydrolysis reaction. α-l-Arabinofuranosidase I hydrolyzed all linkages that can occur between two α-l-arabinofuranosyl residues in the following order: (1→5) linkage > (1→3) linkage > (1→2) linkage. α-l-Arabinofuranosidase II hydrolyzed the linkages in the following order: (1→5) linkage > (1→2) linkage > (1→3) linkage. α-l-Arabinofuranosidase I preferentially hydrolyzed the (1→5) linkage of branched arabinotrisaccharide. On the other hand, α-l-arabinofuranosidase II preferentially hydrolyzed the (1→3) linkage in the same substrate. α-l-Arabinofuranosidase I released arabinose from the nonreducing terminus of arabinan, whereas α-l-arabinofuranosidase II preferentially hydrolyzed the arabinosyl side chain linkage of arabinan.

scholarly journals Transvection at the End of the Truncated Chromosome in Drosophila melanogaster

Genetics ◽  
2003 ◽  
Vol 163 (4) ◽  
pp. 1375-1387
Author(s):  
Mikhail Savitsky ◽  
Tatyana Kahn ◽  
Ekaterina Pomerantseva ◽  
Pavel Georgiev
Keyword(s):  
Drosophila Melanogaster ◽  
Homologous Chromosome ◽  
Regulatory Region ◽  
Proximal Region ◽  
The Other ◽  
Upstream Region ◽  
Upstream Sequence ◽  
Transcription Start ◽  
Promoter Proximal Region

Abstract The phenomenon of transvection is well known for the Drosophila yellow locus. Thus enhancers of a promoterless yellow locus in one homologous chromosome can activate the yellow promoter in the other chromosome where the enhancers are inactive or deleted. In this report, we examined the requirements for trans-activation of the yellow promoter at the end of the deficient chromosome. A number of truncated chromosomes ending in different areas of the yellow regulatory region were examined in combination with the promoterless y alleles. We found that trans-activation of the yellow promoter at the end of a deficient chromosome required ∼6 kb of an additional upstream sequence. The nature of upstream sequences affected the strength of transvection: addition of gypsy sequences induced stronger trans-activation than addition of HeT-A or yellow sequences. Only the promoter proximal region (within -158 bp of the yellow transcription start) was essential for trans-activation; i.e., transvection did not require extensive homology in the yellow upstream region. Finally, the yellow enhancers located on the two pairing chromosomes could cooperatively activate one yellow promoter.

scholarly journals Purification, properties and comparative specificities of the enzyme prolyl-transfer ribonucleic acid synthetase from Phaseolus aureus and Polygonatum multiflorum

1965 ◽  
Vol 97 (1) ◽  
pp. 112-124 ◽  
Author(s):  
PJ Peterson ◽  
L Fowden
Keyword(s):  
Carboxylic Acid ◽  
Enzyme Preparation ◽  
Enzymic Activity ◽  
The Other ◽  
Asparagus Officinalis ◽  
Acid Activation ◽  
Phaseolus Aureus ◽  
Substrate Specificities ◽  
Imino Acids ◽  
Ammonium Sulphate Fractionation

1. A prolyl-s-RNA synthetase (prolyl-transfer RNA synthetase) has been purified about 250-fold from seed of Phaseolus aureus (mung bean), a species not producing azetidine-2-carboxylic acid, and more than 10-fold from rhizome apices of Polygonatum multiflorum, a liliaceous species containing azetidine-2-carboxylic acid. The latter enzyme was unstable during ammonium sulphate fractionation. 2. The enzymes exhibited different substrate specificities towards the analogue. That from Phaseolus, when assayed by the ATP-PP(i) exchange, showed azetidine-2-carboxylic acid activation at about one-third the rate with proline. Both labelled imino acids gave rise to a labelled aminoacyl-s-RNA. The enzyme from Polygonatum, however, activated only proline. 3. The enzyme from Polygonatum also formed a labelled prolyl-s-RNA with Phaseolus s-RNA but at a lower rate than when the Phaseolus enzyme was used. No reaction occurred when the Phaseolus enzyme was coupled with Polygonatum s-RNA, and only a very slight one was observed when both enzyme and s-RNA came from Polygonatum. 4. Protein preparations from seeds of Pisum sativum, another species not producing azetidine-2-carboxylic acid, also activated the analogue in addition to proline, whereas those from rhizome and seeds of Convallaria, the species from which the analogue was originally isolated, failed to activate it. However, a liliaceous species not producing the analogue, Asparagus officinalis, activated it. 5. Of the other proline analogues investigated, only 3,4-dehydro-dl-proline and l-thiazolidine-4-carboxylic acid were active with the enzyme preparation from Phaseolus. 6. pH optima of 7.9 and 8.4 were established for the enzymes from Phaseolus and Polygonatum respectively. 7. The Phaseolus enzyme was specific for ATP and PP(i). Mn(2+) partially replaced the requirement for Mg(2+) as cofactor. Preincubation with p-chloromercuribenzoate at a concentration of 0.5mm or higher produced over 99% inhibition of the Phaseolus enzyme. One-half the enzymic activity was destroyed by preheating for 5min. at 62 degrees in tris-hydrochloric acid buffer, pH7.9. 8. All experimental evidence supports the hypothesis that azetidine-2-carboxylic acid and proline are activated by the same enzyme in Phaseolus preparations, whereas the analogue was inactive in all Polygonatum preparations. The possible nature of this different substrate behaviour is discussed.

scholarly journals Genetics of Differences in Pheromonal Hydrocarbons Between Drosophila melanogaster and D. simulans

Genetics ◽  
1996 ◽  
Vol 143 (1) ◽  
pp. 353-364 ◽  
Author(s):  
Jerry A Coyne
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Dimorphism ◽  
Genetic Analysis ◽  
Species Difference ◽  
The Other ◽  
Chromosome 3 ◽  
Apparent Effect ◽  
The Third ◽  
Hydrocarbon Profile ◽  
The Right

Abstract Females of Drosophila melanogaster and its sibling species D. simulans have very different cuticular hydrocarbons, with the former bearing predominantly 7,11-heptacosadiene and the latter 7-tricosene. This difference contributes to reproductive isolation between the species. Genetic analysis shows that this difference maps to only the third chromosome, with the other three chromosomes having no apparent effect. The D. simulans alleles on the left arm of chromosome 3 are largely recessive, allowing us to search for the relevant regions using D. melanogaster deficiencies. At least four nonoverlapping regions of this arm have large effects on the hydrocarbon profile, implying that several genes on this arm are responsible for the species difference. Because the right arm of chromosome 3 also affects the hydrocarbon profile, a minimum of five genes appear to be involved. The large effect of the third chromosome on hydrocarbons has also been reported in the hybridization between D. simulans and its closer relative D. sechellia, implying either an evolutionaly convergence or the retention in D. sechllia of an ancestral sexual dimorphism.

AGGRESSION IN PRESCHOOLERS: ITS RELATION TO SOCIALIZATION

PEDIATRICS ◽  
1994 ◽  
Vol 93 (2) ◽  
pp. 163-163
Author(s):  
Klaus Minde
Keyword(s):  
Aggressive Behavior ◽  
Perspective Taking ◽  
Normal Control Group ◽  
The Other ◽  
Developmental Changes ◽  
Control Group ◽  
Clinical Implications ◽  
Significant Delay ◽  
Short Term ◽  
Aggressive Children

The present article discusses developmental changes of aggression seen in preschool children and reports on an 18-month short-term prospective study of three preschool populations: a group referred for aggressive behavior problems, a normal control group, and a group of youngsters who had lived in violent homes, but showed no aggressive behaviors. Results indicate that the aggressive children, in comparison with the other two groups at age 4, showed a significant delay in their interpersonal awareness and perspective taking ability. However, although the aggressive children caught up with their peers in the course of the study period, there was no accompanying decrease in their aggressive behavior. The theoretical and clinical implications of these findings are discussed.

scholarly journals Aferição do pH de diferentes agentes clareadores indicados para o clareamento intracoronário

2018 ◽  
Author(s):  
João Felipe Besegato ◽  
Gabriela Dos Santos Ribeiro Rocha ◽  
Marlene De Sousa Amorim ◽  
Fabio Martins Salomão ◽  
Daniel Poletto ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Statistical Analysis ◽  
Multiple Comparisons ◽  
The Other ◽  
Sodium Perborate ◽  
Distilled Water ◽  
Friedman Test ◽  
Time Intervals ◽  
Ph Values ◽  
Evaluation Time

Objective: to measure pH values of bleaching agents that are indicated to intracoronal bleaching technique in different time intervals. Methods: Each group (G) received five samples (n=5): G1 – distilled water (AD); G2 – hydrogen peroxide (H2O2) 30%; G3 – sodium perborate (PbS) + AD; G4 – PbS + H2O2 30%; G5 – sodium percarbonate (PcS) + AD; and G6 – PcS + H2O2 30%. pH values were stated using a digital pHmeter, in different time intervals: immediately after handling (T0), 24 hours (T1) and 168 hours after handling (T2). The results were submitted to statistical analysis through Kruskal-Wallis and Mann Whitney tests, in this order, allowing multiple comparisons among the groups. To verify the effect of time in each group, Friedman test was applied. Results: In the evaluation of the effect of time in each group, it was observed that G2 presented acid behavior, while the other groups exhibited values close to neutrality or alkaline. Conclusions: H2O2 30% was the only agent that showed acidic behavior in every evaluation time. Meanwhile, PcS + H2O had the highest pH values.

GROWTH OF STAPHYLOCOCCUS AUREUS IN ACIDIFIED PASTEURIZED MILK1

1970 ◽  
Vol 33 (11) ◽  
pp. 516-520 ◽  
Author(s):  
T. E. Minor ◽  
E. H. Marth
Keyword(s):  
Staphylococcus Aureus ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Hydrochloric Acid ◽  
Ph Value ◽  
The Other ◽  
Antagonistic Effects ◽  
Pasteurized Milk ◽  
Ph Values ◽  
Effect On Growth

The effect of gradually reducing the pH of pasteurized milk with acetic, citric, hydrochloric, lactic, and phosphoric acids over periods of 4, 8, and 12 hr on growth of Staphylococcus aureus 100 in this substrate was determined. In addition, 1: 1 mixtures of lactic acid and each of the other acids, and of acetic and citric acids were evaluated for their effect on growth of this organism. To achieve a 90% reduction in growth over a 12 hr period, a final pH value of 5.2 was required for acetic, 4.9 for lactic, 4.7 for phosphoric and citric, and 4.6 for hydrochloric acid. A 99% reduction during a 12 hr period was obtained with a final pH value of 5.0 for acetic, 4.6 for lactic, 4.5 for citric, 4.1 for phosphoric, and 4.0 for hydrochloric acid. A pH value of 3.3 was required for a 99.9% reduction with hydrochloric acid, whereas the same effect was produced at a pH value of 4.9 with acetic acid. Correspondingly lower pH values were required to inhibit growth within 8 and 4 hr periods. Mixtures of acids adjusted to pH values at the borderline for growth (12 hr period) exhibited neither synergistic nor antagonistic effects between two acids.

scholarly journals Effect of Different Antimicrobial Applications on Color Stability of Ground Pork

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
H. D. Garnica ◽  
M. F. Miller ◽  
D. A. Vargas ◽  
A. R. English ◽  
K. E. Hanlon ◽  
...  
Keyword(s):  
Peracetic Acid ◽  
Storage Period ◽  
Color Stability ◽  
The Other ◽  
Color Analysis ◽  
B Values ◽  
Positive Effects ◽  
Ph Values ◽  
Ground Pork ◽  
Hue Angle

ObjectivesThe purpose of the study was to evaluate color changes during dark storage of ground pork following application with one of three different antimicrobial interventions to pork trim.Materials and MethodsTreatments included a control (no antimicrobial), lactic acid (LA; 3%), PAA+Titon [sulfuric acid and sodium sulfate (pH 1.3) combined with peracetic acid (350 ppm)], PAA+Acetic [peracetic acid (400 ppm) with 2% acetic acid]. Four 22.7-kg batches of pork trim were treated with one intervention, ground [coarse (3/16’’) followed by a fine (1/8”) grind] and packaged in 454-g rollstock vacuum packaging (n = 40/treatment). After random assignment to an aging time (0, 7, 14, 21, or 28 d), product was held under dark storage at 2–4°C. On each storage day, samples (n = 8/treatment) were opened and L*, a*, and b* values were taken using a HunterLab Miniscan XE spectrophotometer at 0 min, 10 min, and 20 min for bloom color analysis, with hue angle [arctangent (b*/a*)] and chroma [ (a* + b*)1/2 ] calculated from a* and b* values. For pH, 5 g of sample and 90 mL of distillated water were homogenized and analyzed with a bench top pH probe. Finally, fat, moisture, and protein percentage were determined using a FOSS FoodScan. Statistical analysis was conducted using the GLM procedure of SAS with a means separation using the Tukey adjustment and significance set at P < 0.05.ResultsProximate analysis of the ground pork in this study showed 20.04 ± 1.13% for fat, 61.15 ± 1.11% for moisture, and 16.83 ± 0.39% for protein content. For initial pork color, at 0 min, LA had greater L* values compared to PAA+Titon at 0d, 7d and 14d (P < 0.05), but no treatment differences were detected in L* values at 21d and 28d (P > 0.05). After 10 min of bloom time, PAA+Titon maintained the highest chroma value throughout all aging days (P < 0.05) demonstrating the most color intensity. At 21d PAA+Titon increased blooming properties through 20min (P < 0.05), based on a*, while control samples had no bloom development (P > 0.05). At 21d and 28d aging LA hue angle was highest (P < 0.05) indicating more potential metmyoglobin discoloration. PAA+Titon presented the highest pH values compared to all the other treatments for each day during the storage period except for Day 14, while LA presented lower values compared to all the other treatments for each day (P < 0.05).ConclusionAs an organic acid application on pork trim prior to grinding, PAA+Titon demonstrates positive effects on color of ground pork based on color and pH values, after post-grinding storage.

scholarly journals Rex-induced recombination implies bipolar organization of the ribosomal RNA genes of Drosophila melanogaster.

Genetics ◽  
1988 ◽  
Vol 120 (4) ◽  
pp. 1053-1059
Author(s):  
L G Robbins ◽  
E E Swanson
Keyword(s):  
Drosophila Melanogaster ◽  
Ribosomal Rna ◽  
Mitotic Recombination ◽  
Ribosomal Rna Genes ◽  
The Other ◽  
Other Orientation ◽  
Rna Genes ◽  
Nucleolus Organizers

Abstract Rex-induced mitotic recombination was used to determine whether nucleolus organizers can pair in both inverted and noninverted orientations. Two target chromosomes, each duplicated for the rDNA region, were exposed to maternal Rex activity. Recombination in one orientation should yield deletion of the material between the two nucleolus organizers, recombination in the other orientation should yield inversion of the same material. Both products were recovered from both target chromosomes. The generality of using Rex-mediated recombination for analysis of the rDNA is considered.

scholarly journals MULTIPLE MEIOTIC DRIVE SYSTEMS IN THE DROSOPHILA MELANOGASTER MALE

Genetics ◽  
1972 ◽  
Vol 72 (1) ◽  
pp. 105-115
Author(s):  
George L Gabor Miklos ◽  
Armon F Yanders ◽  
W J Peacock
Keyword(s):  
Drosophila Melanogaster ◽  
Survival Probability ◽  
Sex Chromosome ◽  
Meiotic Drive ◽  
The Other ◽  
Segregation Distorter ◽  
Two Systems ◽  
Combined Action ◽  
Drive Systems

ABSTRACT The behaviour of two "meiotic drive" systems, Segregation-Distorter (SD) and the sex chromosome sc4sc8 has been examined in the same meiocyte. It has been found that the two systems interact in a specific way. When the distorting effects of SD and sc4sc8 are against each other, there is no detectable interaction. Each system is apparently oblivious to the presence of the other, gametes being produced according to independence expectations. However when the affected chromosomes are at the same meiotic pole an interaction occurs; the survival probability of the gamete containing both distorted chromosomal products is increased, rather than being decreased by the combined action of two systems.

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