scholarly journals Control of Drosophila deoxyuridine triphosphatase. Existence of a developmentally expressed protein inhibitor

1989 ◽  
Vol 259 (2) ◽  
pp. 593-596 ◽  
Author(s):  
M D Nation ◽  
S N Guzder ◽  
L E Giroir ◽  
W A Deutsch
Keyword(s):  
Drosophila Melanogaster ◽  
Molecular Mass ◽  
Sedimentation Coefficient ◽  
The Other ◽  
Proteinase K ◽  
Protein Inhibitor ◽  
Stages Of Development ◽  
Early Stages ◽  
A Subunit ◽  
Rnase Treatment

An activity that inhibits deoxyuridine triphosphatase (dUTPase) has been partially purified from Drosophila melanogaster. The inhibitor has a sedimentation coefficient of 4.1 S and a subunit molecular mass of 61 kDa. Its expression is limited to early stages of development, similar to the pattern previously found for dUTPase. The inhibitor is unusually stable to heating and is insensitive to DNAse and RNAse treatment. On the other hand, inhibition is sensitive to digestion with proteinase K, indicating that a protein is required for activity. These results suggest that at least one form of regulation is exerted on Drosophila dUTPase that could allow a greater opportunity for the incorporation of uracil into DNA.

Comparative leaf development of aerial and aquatic growth forms of Myriophyllum aquaticum

Botany ◽  
2013 ◽  
Vol 91 (7) ◽  
pp. 421-430 ◽  
Author(s):  
M.D. Shafiullah ◽  
Christian R. Lacroix
Keyword(s):  
Apical Meristem ◽  
Epidermal Cells ◽  
The Other ◽  
Developmental Study ◽  
Growth Forms ◽  
Myriophyllum Aquaticum ◽  
Stages Of Development ◽  
Qualitative And Quantitative ◽  
Early Stages ◽  
Other Hand

Myriophyllum aquaticum (Vell.) Verdc. produces two morphologically different forms of leaves based on whether they are aerial or aquatic. The objective of this study was to determine whether there are any similarities or differences between these two growth forms during their early stages of development. A comparative developmental study of aerial and aquatic growth forms of M. aquaticum was conducted from a qualitative and quantitative perspective using a scanning electron microscope. The pattern of leaf and lobe initiation such as their origin and shape were similar in both growth forms until the fourth plastochron (stage P4). Differences between the two growth forms became evident from stage P5 onward, where a larger shoot apical meristem (SAM), elongated epidermal cells, shorter and slightly more numerous lobes, as well as the presence of appendage-like structures characterized aquatic growth forms. On the other hand, aerial growth forms had smaller SAM, bulb-like epidermal cells, and longer and slightly less numerous leaf lobes. Significant differences between growth forms were noted for parameters such as volume of SAM, length of terminal, first, and middle lobes, as well as the length from first to last lobes. The volume of the SAM of aquatic shoot tips was always greater than aerial forms. On the other hand, lobes of aerial forms were always longer than the aquatic counterpart during early stages of development. This study on the development of M. aquaticum shows that the aerial and aquatic growth forms diverge from their early stages of development.

XV. On the development of the parasitic isopoda

1878 ◽  
Vol 169 ◽  
pp. 505-521 ◽  
Keyword(s):  
The Body ◽  
The Other ◽  
Stages Of Development ◽  
Early Stages ◽  
Abdominal Appendages ◽  
Pair Of Antennae

The following paper contains an account of observations on the development of the species Cymothoa œstroides and C . parallela of Milne Edwards; but the forms of the young seem to show that several species are really included under these two names. In the early stages of development the only observable difference that exists between the embryos is one of size, but in the later stages they differ very markedly from each other in their external characters. From adult individuals answering the description of C . œstroides I have obtained four varieties of embryos: two with long antennae and two with short.* In the two former the first pair of antennae are but slightly longer than the head, while the second pair are longer than the body; the eyes are small. In one of the varieties thus characterised the abdominal appendages are fringed with long hairs (fig. 20), and in the other they are smooth.

scholarly journals Purification and some properties of an IMP-specific 5′-nucleotidase from yeast

1994 ◽  
Vol 298 (3) ◽  
pp. 593-598 ◽  
Author(s):  
R Itoh
Keyword(s):  
Molecular Mass ◽  
Substrate Concentration ◽  
Soluble Protein ◽  
The Other ◽  
Metal Salts ◽  
Bivalent Metal ◽  
Pyrimidine Nucleotides ◽  
Ph Optimum ◽  
A Subunit ◽  
Purine And Pyrimidine Nucleotides

An IMP-hydrolysing enzyme was purified to homogeneity from yeast extract. It was a soluble protein with an apparent molecular mass of 220 kDa, with a subunit molecular mass of 55 kDa. It was highly specific for IMP, and there was virtually no detectable activity with the other purine and pyrimidine nucleotides tested, including AMP and dIMP. The enzyme had a pH optimum of 6.0-6.5. Its activity was absolutely dependent on bivalent metal salts: Mg2+ was most potent, followed by Co2+ and Mn2+. The velocity/substrate-concentration plot of the enzyme was slightly sigmoidal (h = 1.7) and the s0.5 was 0.4 mM. ATP stimulated the enzyme by decreasing both h and s0.5. Diadenosine tetraphosphate stimulated the enzyme as effectively as ATP. Although the properties of the enzyme are similar to those of the IMP/GMP 5′-nucleotidase identified in various animals [Itoh (1993) Comp. Biochem. Physiol. 105B, 13-19], the substrate specificity of the former was much more strict than the latter.

scholarly journals Demonstration of chromatinic structures in avian tubercle bacilli in the early stages of development

1947 ◽  
Vol 45 (4) ◽  
pp. 413-416 ◽  
Author(s):  
E. M. Brieger ◽  
C. F. Robinow
Keyword(s):  
Hydrochloric Acid ◽  
Early Development ◽  
The Other ◽  
Feulgen Reaction ◽  
Cytological Investigation ◽  
Stages Of Development ◽  
The Third ◽  
Early Stages ◽  
Other Hand ◽  
The Masses

In a cytological investigation of three branching and two non-branching strains grown on Loewenstein medium, it was found that avian tubercle bacilli contain chromatinic material which gives a positive Feulgen reaction and is readily stainable with Giemsa's solution after treatment of the fixed bacteria with hydrochloric acid.Growing filamentous forms of both ‘bacterial’ and ‘mycelial’ strains from 1 to 2 day old cultures contain variable numbers of irregularly spaced, more or less spherical chromatinic bodies which vary in staining in the same bacillus, some being red, others purple. During the third or fourth day the chromatinic material in the bacteria increases very much until most of it is fused into an almost homogeneous deeply stained column. In thenon-branchingstrains the filamentous forms with high chromatin content soon break up into small mono-or binucleate elements, and the same holds true for the ‘straight’ filamentous forms which are also present in cultures of branching strains. The ‘mycelial’ forms, on the other hand, disintegrate at this time (fourth or fifth day of cultivation), and it is uncertain whether they contribute (by partial fragmentation) to the masses of small mono- or binucleate forms which are the predominant element in old cultures of all the strains investigated.The chromatinic structures of avian tubercle bacilli have the same staining properties as those of ordinary non-acid-fast bacteria but differ from them in their behaviour during the early development of the bacilli.

scholarly journals Sucrose Breakdown and Synthesis in the Ripening Grape Berry

1967 ◽  
Vol 20 (2) ◽  
pp. 465 ◽  
Author(s):  
PJ Hardy
Keyword(s):  
Sugar Content ◽  
Grape Berry ◽  
The Other ◽  
Berry Development ◽  
Stages Of Development ◽  
Early Stages

Sucrose is the major translocated sugar in the grapevine (Swanson and EIShishiny 1958), but in the berry glucose and fructose together make up the bulk of the sugar content at all stages of development (Kliewer 1965a). The inversion of sucrose to glucose and fructose in ripening berries is suggested by the presence of invertase (Arnold 1965) and by the occurrence of approximately equal amounts of glucose and fructose (Kliewer 1965a). During the early stages of berry development, glucose and fructose concentrations are low, but at the onset of ripening there begins a phase of rapid glucose and fructose accumulation (Kliewer 1965a). Besides sugar, the other major soluble constituents of grapes are malate and tartrate. The concentrations of both substances increase rapidly in the immature berry, but when ripening commences sharp decreases occur, particularly in the concentration of malate (Kliewer 1965b). Some workers believe that malate and tartrate are translocated from the leaves (Amerine 1956; Peynaud and Maurie 1958) but there is evidence that some at least of the malate and tartrate is synthesized in the berry (Hale 1962). The mechanisms of the syntheses of malate and tartrate in the berry are not known.

The origin of Cotyledon and Epicotyl in Elettaria cardamomum Maton

1968 ◽  
Vol 16 (3) ◽  
pp. 427 ◽  
Author(s):  
VJ Philip
Keyword(s):  
Embryo Development ◽  
The Other ◽  
Terminal Cell ◽  
Stages Of Development ◽  
Elettaria Cardamomum ◽  
Early Stages ◽  
Derivatives Of ◽  
Two Sectors

A reinvestigation of embryo development in Elettaria cardamomum reveals that from the very early stages of development both the cotyledonary and epicotylary sectors are aligned adjacent to each other and are engendered by the derivatives of the terminal cell q. Thus the two sectors are topographically terminal on the proembryonal axis. One half of the working sphere is involved in the organization of the cotyledon and the other half in that of the epicotyl.

scholarly journals Physiology of Pea Fruits IV. Changes in Sugars in the Developing Seed

1957 ◽  
Vol 10 (4) ◽  
pp. 407 ◽  
Author(s):  
JF Turner ◽  
Donella H Turner ◽  
JB Lee
Keyword(s):  
Starch Synthesis ◽  
The Other ◽  
Plant Tissues ◽  
Stages Of Development ◽  
Early Stages ◽  
Chromatographic Methods ◽  
Developing Seed ◽  
Pea Seed ◽  
Galactose Content

Paper chromatographic methods were developed for the estimation of sugars in plant tissues and were used to follow changes in some individual sugars during the development of the pea seed. Sucrose was the predominant sugar present in the seeds and there were smaller quantities of fructose, glucose, and galactose. The amounts of fructose and glucose were approximately equal at all stages of develop. ment. The sucrose, fructose, and glucose contents of the seed increased in the early stages of development but decreased during the phase of rapid starch synthesis. The galactose content increased to a maximum at a later state than the other sugars estimated. The concentrations of sucrose, fructose, and glucose in the seeds were compared with the concentrations in the leaves, stems, and hulls. The possible significance of the changes in sugars in relation to the metabolism of the pea seed is discussed.

Aramid, Carbon, and PBO Fibers/Yarns in Engineered Fabrics or Membranes

2000 ◽  
Vol 30 (1) ◽  
pp. 42-49 ◽  
Author(s):  
Brian Doyle
Keyword(s):  
High Strength ◽  
The Other ◽  
Great Promise ◽  
Stages Of Development ◽  
Early Stages ◽  
The Future ◽  
Near Future

PBO delivers low stretch, high strength, but degrades rapidly in outdoor light. Carbon also has low stretch and high strength but not quite as high as PBO. Carbon does not degrade in UV but is more brittle in flexing than PBO. Both of these fibers are in the early stages of development as sail materials. Both show great promise for the future if development continues. For a number of reasons, some racing classes and organizations have restricted the use of one or both of these fibers in sails. While restricting both may be appropriate in some classes, picking one in favor of the other seems inappropriate and surely will stifle development that could lead to better sail materials in the near future.

Vico’s New Science

1998 ◽  
pp. 16-19
Author(s):  
Joseph P. Vincenzo
Keyword(s):  
The Other ◽  
Stages Of Development ◽  
Universal History ◽  
New Science ◽  
Early Stages ◽  
Other Hand ◽  
The One

In Vico’s New Science wisdom is understood in a double sense. On the one hand, wisdom means the poetic wisdom that provides intelligibility for the peoples of the nations during their early stages of development. On the other hand, wisdom means the noetic knowledge gained by the Vichian scientist who contemplates concrete historicity in the light of the New Science. By means of an examination of three principle aspects of Vico’s science, and by looking to his conception of the origin of the most rudimentary institutions of humanity, primordial piety— fear of the mythic other— is shown to be the origin of poetic wisdom. And, by focusing on the necessity of surmounting the conceit of scholars and the conceit of nations for a science of universal history, philosophical piety— openness to the wholly Other— is revealed as the ground of philosophical wisdom. This paper sets out to show how Vico’s science of the principles of humanity is, at the same time, a science of the unity of piety and wisdom.

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