Effects of topography on dispersal of black-billed magpie Pica pica sericea revealed by population genetic analysis

This study was conducted using random amplified polymorphic DNA analysis to examine whether the effects of topographical structure on the dispersal of black-billed magpie Pica pica sericea are reflected in its population genetic structure. The black-billed magpie is typically seen in the lowlands and is remarkably sedentary in Korea and Japan. The unweighted pair-group method of clustering analysis showed two main clusters: five populations in the western region of the Bekdudegan mountains (WRBM) in one cluster and five populations in the eastern region of the Bekdudegan mountains (ERBM), including the Japanese population in the other cluster. The populations in WRBM appeared to be diverged from the populations in ERBM. Analysis of molecular variance revealed that the populations in ERBM were more genetically divergent from each other than were those in WRBM. The high-rising mountains, very rugged topographical features and the sea in ERBM may have resulted in a lower dispersal rate and larger genetic variation among populations in ERBM compared to those in WRBM. These results suggest that the topographical structure may have an influence on the dispersal and population genetic structure of the black-billed magpie. Electronic Publication     

Intranuclear and cytoplasmic hemoglobin in human erythroblasts during maturation. Electron microscopic immunocytochemistry

Changes in the hemoglobin level in human bone marrow erythroblasts associated with cell maturation were studied by the electron microscopic immunocytochemical technique using protein A-gold. Intense reaction of gold to hemoglobin was observed diffusely in the cytoplasm, but the reaction was weak in the Golgi zone. No reaction was observed in mitochondria or granules. Cytoplasmic hemoglobin was noted in basophilic erythroblasts and increased with maturation. Hemoglobin was also noted in the nucleus, especially in the euchromatin, though in smaller amounts than in the cytoplasm. Since intranuclear hemoglobin tended to increase in the euchromatin but to decrease in the heterochromatin with erythroblast maturation, the ratio of the amount of hemoglobin in the euchromatin to that in the heterochromatin increased with maturation.     

Genetic variants of protease inhibitors against fungal protease and α-chymotrypsin from hemolymph of the silkworm,Bombyx mori

Many electrophoretic variants of hemolymph inhibitors of proteases from Aspergillus melleus and pancreatic alpha-chymotrypsin were found using 126 silkworm strains. Six inhibitors of the fungal protease were detected and eight of chymotrypsin; the distribution of inhibitors among Japanese, Chinese, and European races was investigated. Comparison of electrophoretic patterns from F1 hybrids and parents showed that the offspring produce inhibitors of both parental types. Segregation in F2 and backcrossing suggest that the expression of each inhibitor is controlled in most cases by a pair of alleles which are responsible for strong and null bands. Two bands of fungal protease inhibitors C and D were controlled by codominant alleles. These results suggest that polymorphism of hemolymph protease inhibitors in the silkworm would be a useful experimental system for the study of the genetic control of protease inhibitors.     

Synthesis of 1-(5'-O-benzoyl-3'-deoxy-beta-D-glycero-pentofuran-2'-ulosyl)uracil and its alpha-anomer by [1,2]-hydride shift

In contrast with direct tosylation of 5'-O-benzoyl- (1d) or 5'-O-pivaloyl-1-beta-D-lyxofuranosyl-uracil (1e) with TsCl/pyridine, tosylation of the 2', 3'-O-dibutylstannylene derivatives (4d,e) of these compounds proved to give the 3'-O-tosyl derivatives 2d, e selectively. Coversion of 2d as a model to 1-(5'-O-benzoyl-3'-deoxy-beta-D-glycero-pentofuran-2'-ulosyl )uracil (5-beta) by base-induced [1,2]-hydride shift was examined under various reaction conditions, and the alpha/beta ratio of the product mixture (5-alpha, beta) determined by 1H NMR spectroscopy in each case. The BzOLi/DMF combination has proved to be most profitable for obtaining 5-beta.     

Affinity labeling of adenine nucleotide-related enzymes with reactive adenine nucleotide analogs. I. Affinity labeling of glyceraldehyde 3-phosphate dehydrogenase and myokinase with a reactive AMP analog.

Rabbit muscle glyceraldehyde 3-phosphate dehydrogenase (GPD) and myokinase (MK) were rapidly inactivated by a reactive AMP analog, N6-(p-bromoacetaminobenzyl)-AMP, under mild conditions. Complete inactivation was observed when 4 and 0.3 mol of the reagent with respect to enzyme were reacted with GPD and MK, respectively. The inactivation of both enzymes were favored at higher pH and the enzymes were protected by addition of adenine nucleotide substrate. Modified GPD or MK had no affinity for AMP-Sepharose, in contrast to the native enzymes. From these results, the inactivation of GPD and MK by the reactive AMP analog can be regarded as an affinity labeling. The posibility that the present AMP analog may be used as a general affinity labeling reagent for various adenine nucleotide-related enzymes is discussed based on the results obtained.     

Zinc uptake by cultured human lymphoblasts

Biological Trace Element Research - At physiological plasma concentrations (12–20 μM), zinc uptake by cultured human B lymphoblasts is biphasic with an early, rapid, saturable phase,...     

Studies on aspartase. IV. Reversible denaturation of Escherichia coli aspartase.

Aspartase (L-aspartate ammonia lyase, EC 4.3.1.1) of Escherichia coli, denatured in 4 M guanidine-HCl, was renatured in vitro by simple dilution with a concomitant restoration of the activity. While the native enzyme exhibited a marked negative Cotton effect centered at 233 +/- 1 nm in optical rotatory dispersion, the enzyme denatured in 4 M guanidine-HCl retained little optical activity. Upon dilution of the denatured enzyme, however, more than 90% of the ordered structure was recovered in 1 min, while the restoration of the activity proceeded much more slowly. Estimation of molecular weights by gel permeation chromatography indicated that the tetrameric enzyme is subject to reversible dissociation into monomeric subunits under the experimental conditions. Various environmental factors such as temperature, pH and protein concentration exhibited profound influence on the rate and extent of the reactivation. In order to examine the correlation between the restoration of the activity and the quaternary structure, electron microscopic inspection of the kinetic processes of reversible denaturation was attempted. Upon dilution of the denatured enzyme at 4 degrees C, neither the activity nor tetrameric images were detected over several min. Upon the temperature shift up to 25 degrees C, however, the activity regain was rapidly proceeded concomitant with the appearance of tetrameric molecules. These results are compatible with the possibility that the subunit assembly is an essential prerequisite, thought not sufficient, for enzyme activity.