Morphological Responses of Wheat to Changes in Phytochrome Photoequilibrium

Wheat plants (Triticum aestivum L.) were grown at the same photosynthetic photon flux (PPF), 200 micromoles per square meter per second, but with phytochrome photoequilibrium ([unk]) values of 0.81, 0.55, and 0.33. Plants grown at [unk] values of 0.55 and 0.33 tillered 43 and 56%, less compared with plants grown at [unk] of 0.81. Main culm development (Haun stage) was slightly more advanced at lower values of [unk], and leaf sheaths, but not leaf lamina, were longer at lower [unk]. Dry-mass accumulation was not affected by different levels of [unk]. Three levels of PPF (100, 200, and 400 micromoles per square meter per second) and two lamp types, metal halide and high pressure sodium, were also tested. Higher levels of PPF resulted in more dry mass, more tillering, and a more advanced Haun stage. There was no difference in plant dry mass or development under metal halide versus high pressure sodium lamps, except for total leaf length, which was greater under high pressure sodium lamps (49.5 versus 44.9 centimeters, P < 0.01).     

Binding of polonium-210 to liver metallothionein

The interactions of 210Po at the molecular level in biological systems have received little study even though this alpha-emitting radionuclide occurs widely in nature. Polonium-210 was given subcutaneously to rats and found to be incorporated into liver metallothionein as judged by a number of criteria including heat stability, acetone precipitation, and chromatography. In vitro studies confirmed this binding. The binding of 210Po to metallothionein has implications that may help explain some of the radiation damage 210Po causes intracellularly.     

Low genetic variability in a Utah cherry-infesting population of the apple maggot, Rhagoletis pomonella

The apple maggot fly, Rhagoletis pomonella (Walsh), has only recently been found in Utah infesting sour cherry, Prunus cerasus L. An electrophoretic comparison of flies from Utah cherries with flies from Illinois hawthorns, Crataegus mollis (T. & G.) Scheele (a native host within the native range of the fly), show a marked reduction of genetic variability in the Utah sample. This result is indicative of a genetic bottleneck associated with the establishment of the apple maggot population in Utah cherries.

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Résumé R. pomonella (Walsh), est originaire de Crataegus dans l'Amérique du N.E. Il attaque de nombreux autres fruits, y compris les pommes et les cerises aigres (Prunus cerasus). La mouche a été récemment signalée en Utah, à la fois sur cerises et sur Crataegus douglasii. Nous avons comparé les niveaux de variabilité génétique d'une population de l'Utah contaminant les cerises et d'une population de l'Illinois contaminant C. mollis (la population de l'Illinois est représentative des niveaux de variabilité génétique dans l'aire d'origine de la mouche).La variabilité génétique à 17 loci a été évaluée par électrophorèse sur gel d'amidon. 10 de ces loci sont polymorphes dans la population d'Illinois, mais seulement 4 dans la population de l'Utah. Les fréquences alléliques de ces 4 loci de R. pomonella diffèrent significativement en Utah et en Illinois. La population de l'Utah présente nettement moins d'allèles par locus, un plus faible pourcentage de loci polymorphes et une hétérozygotie moyenne plus faible que la population de l'Illinois. Tous ces résultats sont conformes aux conséquences prévisibles d'un goulot d'étranglement.Deux explications existent pour cette perte de variabilité, toutes les deux liées à la combinaison de la faible taille de la population et de la dérive génétique ultérieure. Pour la première, la colonisation du cerisier par les mouches venant de Crataegus peut avoir provoqué un goulot d'étranglement génétique. Au contraire, la réduction de la variabilité peut avoir été la conséquence de la colonisation de l'Utah par R. pomonella. Nous retenons cette dernière comme la cause la plus vraisemblable de la variabilité génétique de la population de R. pomonella contaminant les cerises de l'Utah.

     

Studies on the genus Fontinalis (Musci: Fontinalaceae)

Fontinalis welchiana, a new species in the concave-leaved group ofFontinalis restricted to Arkansas, Missouri, and Illinois, differs fromF. novaeangliae by its slender size, dimorphic leaves, erect and strongly concave branch leaves, and lightly papillose exostome with ventral lamellae that are strongly rounded at the corners.Fontinalis allenii is a synonym ofF. antipyretica var.oreganensis.     

Isolation and interrelationships of the multiple molecular tissue-type and urokinase-type plasminogen activator forms produced by cultured human umbilical vein endothelial cells

Primary and early subcultures (1st- to 3rd passage) of human umbilical vein endothelial cells produce tissue-type plasminogen activator (t-PA) antigen, consisting only of a major Mr 110,000 t-PA form. Later subcultures (greater than 4th passage) produce increasing amounts of t-PA antigen, consisting of a major Mr 110,000 and a minor Mr 68,000 form as well as increasing amounts of urokinase-type plasminogen activator (u-PA) antigen, consisting of a minor Mr 95,000 and major Mr 54,000 form. All of the major plasminogen activator forms were purified to homogeneity from 72 h serum-free conditioned media (3 liters, 1-1.8 x 10(9) cells) by a combination of immunoaffinity and gel filtration chromatography. Typically, 4th to 6th passage cultures produced/secreted t-PA-type proteins consisting of an inactive Mr 110,000 (220 IU/mg) and active Mr 68,000 (76,500 IU/mg) form representing about 39 and 8%, respectively, of the total starting sodium dodecyl sulfate stable t-PA activity, and u-PA-type proteins consisting of an inactive Mr 95,000 (700 IU/mg) and active Mr 54,000 (81,000 IU/mg) form representing about 9 and 38%, respectively, of the total starting sodium dodecyl sulfate stable u-PA activity. The isolated Mr 68,000 t-PA and Mr 54,000 u-PA proteins, exist only as two-chain forms in the absence of aprotinin and as mixtures of single- and two-chain proteins in the presence of aprotinin. Treatment with nucleophilic agents completely dissociated the Mr 110,000 t-PA and Mr 95,000 u-PA proteins into their respective Mr 68,000 t-PA and Mr 54,000 u-PA activity forms and a common Mr 46,000 protein, confirming the enzyme-inhibitor complex nature of these inactive plasminogen activator forms.     

Dopamine Metabolism in Hypoxanthine-Guanine Phosphoribosyltransferase-Deficient Variants of PC12 Cells

Lesch-Nyhan syndrome results from a deficiency of hypoxanthine-guanine phosphoribosyltransferase (HPRT). It is manifest by behavioral abnormalities, including self-mutilation, and evidence of abnormal 3,4-dihydroxyphenylethylamine (dopamine) metabolism. To assess whether an HPRT deficiency in a dopaminergic cell can adversely affect dopamine metabolism in that cell, dopamine metabolism was examined in HPRT-deficient variants of PC12 pheochromocytoma cells and in cells that had regained HPRT activity by virtue of transformation with a recombinant retrovirus containing the human gene for HPRT. There was no correlation between HPRT activity and endogenous dopamine levels, dopamine uptake, dopamine release, or monoamine oxidase activity. Transformation with the HPRT retrovirus did not adversely affect dopamine metabolism.     

Transformation of the basidiomycete, Schizophyllum commune

Summary Protoplasts of aSchizophyllum commune tryptophan auxotroph (trp1), deficient in indole-3-glycerol phosphate synthetase (IGPS), were transformed to trp⁺ with plasmid DNA containing the SchizophyllumTRP1 sequence. Efficiencies up to 30 transformants per microgram of plasmid DNA were obtained. Southern blots reveal that the transforming DNA is integrated in chromosomal DNA. The trp⁺ phenotype of transformants is stable in meiosis and mitosis. Transformants possess IGPS activity comparable to wild-type cells.     

A Method for Combined Gross Skeletal Staining and Feulgen Staining of Embryonic Chick Tissues

This paper describes a combined technique for gross skeletal staining and Feulgen staining of avian embryonic limbs. The gross skeletal stain uses Victoria blue B, and the Feulgen stain is done en bloc before the skeletal stain is applied. The method has been useful in determining the cellular origins of supernumerary structures arising from experiments in which quail wing mesoderm is grafted into chick wing buds.