Fruit color and fruit size of bird-disseminated plants in Japan

Fruit color, fruit size and phenology of bird-disseminated plants were examined in different climatic zones of Japan and the relationships between the plants and frugivorous birds were disscussed.Black fruit was the most common in warm-temperate areas and red was the most common in cool-temperate and subarctic zones. Red was more dominant in the lower layer of the forests in all climatic zones. Bicolor fruits were frequent in trees and were not found in herbs. Both in warm- and cool-temperate zones conspicuous fruits which are red and bicolored display were more frequent in summer than in winter.The diameter of most fruits were 4–11 mm. Fruits in warm-temperate were somewhat bigger than those in cooltemperate zone. In forest strata the fruits of shrubs were smaller than those of trees and herbs in width. However I found no relationships between fruit size and fruit color.The frugivorous birds could have influenced not only the evolution of seasonal differences in the proportion of fruit color between warm-temperate and cool-temperate region, but also affect the fruit size.     

Competitive habitat utilization in the damselfly,Mnais nawai (Zygoptera: Calopterygidae) coexisting with a related species,Mnais pruinosa

Reproductive behaviors related to habitat utilization were studied in males of the damsefly,Mnais nawai, which has two male forms, territorial orange-winged males (nawai) and non-territorial pale-orange-winged males (sahoi), at the upper part of a mountain stream where they partiallycoexist with a related species,Mnais pruinosa, which also has two male forms, territorial orange-winged males (esakii) and non-territorial hyaline-winged males (strigata). These two species showed parapatric distribution; the lower part of the stream was occupied byM. nawai, and the upper part byM. pruinosa. In the present study, cross-matings occurred between bothMnais species, although normal intraspecific matings occurred more frequently than cross-matings. Territorial males of both species copulated with conspecific females that entered their territory and guarded the ovipositing females, probably to avoid sperm displacement resulting from subsequent copulations. Severe competition for oviposition sites by territorial males even occurred between the two species. On the other hand, non-territorial males of both species have alternative mating strategies (including several tactics such as sneaking, takeover and interception). The possible benefits from conflict among territorial males of both species is discussed.     

Immunocytochemical localization of 5α-reductase type 1 in the prostate of normal and castrated rats

We immunohistochemically studied the localization of 5-reductase type 1 in combination with androgen receptor (AR) expression in individual lobes of the prostates of intact and castrated rats. In the normal rat prostate, 5-reductase was localized in the cytoplasm of most epithelial cells in the ventral, dorsal, and lateral type 1 (L1) lobes. Epithelial cells of lateral type 2 (L2) lobes were negative for 5-reductase. AR was present in the nuclei of all epithelial and stromal cells throughout the prostate. The number of 5-reductase-immunoreactive cells rapidly decreased in the ventral and L1 lobes after castration, whereas many positive cells remained in the dorsal lobe even at 4 weeks after castration. AR immunostaining was lost in the ventral, dorsal, and L1 lobes at 1 week after castration, but remained in the L2 lobe of 4-week-castrated rats. Electron microscopic immunocytochemistry showed that 5-reductase was exclusively localized in the rough endoplasmic reticulum membranes and that there were no distinct structural differences between the positively and negatively stained epithelial cells. These findings suggested that the expression of 5-reductase type 1 in the epithelial cell is heterogeneous within and among the individual lobes of the rat prostate, and does not correspond to AR expression.     

Photo-induced activation of cytochrome P450/reductase fusion enzyme coupled with spinach chloroplasts

Summary Photoactivation of cytochrome P450 monooxygenase was studied using a combination of spinach chloroplasts and yeast microsomes containing rat P4501A1/yeast reductase fusion enzyme. Under illumination, in the reaction mixture, NADP was reduced, transferring electrons to the P450/reductase fusion enzyme to convert 7-ethoxycoumarin to 7-hydroxycoumarin.     

Tissue distribution of messenger RNAs coding for opioid peptide precursors and related RNA

All of the endogenous opioid peptides thus far identified are derived from three types of precursors, i.e. the corticotropin/beta-lipotropin precursor, preproenkephalin A and preproenkephalin B. Poly(A)-containing RNA from various bovine and porcine tissues has been subjected to blot hybridization analysis with the use of cDNA probes specific for the three opioid peptide precursors. Analysis with a corticotropin/beta-lipotropin precursor cDNA probe has revealed, in addition to the pituitary mRNA, a smaller hybridizable RNA species present in bovine extrapituitary tissues, such as the adrenal medulla, thyroid, thymus, duodenum and lung. The hypothalamus contains both these RNA species. DNA complementary to the smaller RNA species from the bovine adrenal medulla has been cloned. Analysis of the cloned cDNA, in conjunction with endonuclease S1 mapping of poly(A)-rich RNA from the adrenal medulla, has indicated that the smaller RNA species represents the 3'-terminal 712-729 nucleotides, excluding the poly(A) tail, of the pituitary corticotropin/beta-lipotropin precursor mRNA, having heterogeneous start sites. Analysis with a preproenkephalin A cDNA probe has shown the presence of hybridizable RNA in the bovine hypothalamus, duodenum and pituitary neurointermediate lobe in addition to the adrenal medulla. The hybridizable RNA species from all these tissues are indistinguishable in size. RNA hybridizable with a preproenkephalin B cDNA probe has been found in the porcine spinal cord and ileum besides the hypothalamus, and these RNA species exhibit an indistinguishable size. The results presented indicate that each opioid peptide precursor is synthesized in different tissues.     

A cold-labile acetyl-coenzyme-A hydrolase from the supernatant fraction of rat liver. Reactivation and reconstitution of the active species from the inactive monomer

An acetyl-coenzyme-A hydrolase from the supernatant fraction of rat liver is known to be rapidly inactivated at low temperature. Loss of catalytic activity is accompanied by apparent dissociation of tetrameric and dimeric forms of the enzyme into monomers. It was found that rewarming under appropriate conditions almost completely reversed the cold-induced inactivation and dissociation of the enzyme: At a protein concentration of 14 micrograms/ml, simple rewarming only partially restored the enzyme activity (less than 3% of the original activity), but at a higher concentration of the enzyme or in the presence of 1 mg/ml bovine serum albumin, the reactivation by warming was greater. Warming at 37 degrees C appeared to be optimal for reactivation; warming at 25 degrees C or at 43 degrees C was less effective. Longer exposure to cold did not affect reactivation on rewarming, but on repeated inactivation and reactivation the reactivation decreased to some extent, especially at lower concentrations of enzyme protein. Among various nucleotides tested, ATP greatly enhanced the restoration of the activity, while ITP, UTP and ADP were less effective and AMP, GTP, TTP and CTP had little effect. At an enzyme-protein concentration of 14 micrograms/ml, 2 mM ATP restored the enzyme activity to about 70% of that before cold treatment, while acetyl-CoA (0.5 mM) restored the activity about 50%. High concentrations of phosphate (0.92 M) and pyrophosphate (0.45 M) restored about 80% and 95%, respectively, of the original activity. Sucrose density gradient centrifugation of the active dimer at high enzyme concentration at 4 degrees C for 20 h produced a monomeric form without catalytic activity. Gel filtration showed that simple rewarming mostly converted the monomeric enzyme obtained in this way to the dimeric form, whereas on rewarming with ATP the monomer was mostly converted to a tetrameric form. The dimeric and tetrameric forms both had catalytic activity.     

1H NMR of glycosaminoglycans and hyaluronic acid oligosaccharides in aqueous solution: the amide proton environment

The exchangeable amide protons of hyaluronic acid (HA) oligosaccharides and a higher-molecular-weight segment dissolved in H2O at pH 2.5 or 5.5 were examined by H NMR spectroscopy at 250 MHz. The HA segment preparation showed a single amide resonance, near the chemical shift for the amide proton of the monosaccharide 2-acetamido-2-deoxy-beta-D-glucopyranose (beta-GlcNAc). Smaller HA oligosaccharides showed two or three separate amide proton resonances, corresponding in relative peak area to interior or end GlcNAc residues. The interior GlcNAc amide resonance occurred at the same chemical shift as the single resonance of the HA segment. For the end GlcNAc residues, linkage to D-glucuronopyranose (GlcUA) through C1 resulted in an upfield shift relative to the beta-anomer of GlcNAc, whereas linkage through C3 resulted in a downfield shift relative to the corresponding anomer of GlcNAc. These chemical-shift perturbations appeared to be approximately offsetting in the case of linkage at both positions. The amide proton vicinal coupling constant (ca. 9 Hz) was found to be essentially independent of chain length, residue position, or solution pH. These data favor a nearly perpendicular orientation for the acetamido group with respect to the sugar ring, little affected by linkage of GlcNAc to GlcUA. No evidence for the existence of a stable hydrogen bond linking the amide proton with the carboxyl(ate) oxygen of the adjacent uronic acid residue was found. The amide proton resonances for chondroitin, chondroitin 4-sulfate, and dermatan sulfate were compared to that of HA. The chemical shifts of these resonances deviated no more than 0.1 ppm from that of HA. A small dependence on the identity of the adjacent uronic acid residue was noted, based on the observation of two resonances for dermatan sulfate.     

Effects of taurine and γ-aminobutyric acid on akinesia and analgesia induced by D-Ala2-Met-enkephalinamide in rats

Effects of taurine or γ-aminobutyric acid (GABA) on akinesia and analgesia induced by D-Ala²-Met-enkephalinamide were investigated in rats. Administration of taurine (dose range: 2.375×10^?2 M–9.5×10^?2 M/10 μl) into the left lateral ventricle 10 min prior to the injection of D-Ala²-Met-enkephalinamide (50 μg/10 μl) produced a dose-dependent reduction in the duration of akinesia and to some extent of analgesia, as estimated at 30 min and 60 min following the enkephalinamide injection; at the first estimation-time (10 min), taurine did not alter the duration of akinesia or that of analgesia. The median effective dose (ED₅₀) for akinesia determined at 60 min after D-Ala²-Met-enkephalinamide was 5 times greater and that for analgesia assessed at the same time was 1.7 times greater in taurine-treated rats than the respective doses in control animals. Administration of GABA under similar experimental conditions produced a dose-dependent reduction in the duration of analgesia from the initial estimation time (10 min) following the injection of D-Ala²-Met-enkephalinamide. The ED₅₀ for analgesia determined at 30 min after D-Ala²-Met-enkephalinamide was 3 times greater in GABA-treated rats than in control animals. Unlike the effects of taurine, GABA did not alter the duration of akinesia. Neither the duration of akinesia nor that of analgesia was modified by taurine or GABA alone in rats tested 9 min after the injection of each amino acid. These findings suggest that taurine may promote a recovery from both akinesia and analgesia, while GABA decreases only the analgesia induced by D-Ala²-Met-enkephalinamide.     

Separation and properties of five glycosaminoglycan sulfatases from rat skin.

Chondroitin sulfates, dermatan sulfate, heparan sulfate, heparin, keratan sulfate, and oligosaccharides derived from these sulfated glycosaminoglycans have been used for the measurement of sulfatase activity of rat skin extracts. Chromatographic fractionation of the extracts followed by specificity studies demonstrated the existence of five different sulfatases, specific for 1) the nonreducing N-acetylglucosamine 6-sulfate end groups of heparin sulfate and keratan sulfate, 2) the nonreducing N-acetylgalactosamine (or galactose) 6-sulfate end groups of chondroitin sulfate (or keratan sulfate), 3) the nonreducing N-acetylgalactosamine 4-sulfate end groups of chondroitin sulfate and dermatan sulfate, 4) certain suitably located glucosamine N-sulfate groups of heparin and heparan sulfate, or 5) certain suitably located iduronate sulfate groups of heparan sulfate and dermatan sulfate. Two arylsulfatases, one of which was identical in its chromatographic behaviors with the third enzyme described above, were also demonstrated in the extracts. These results taken together with those previously obtained from studies on human fibroblast cultures suggest that normal skin fibroblasts contain at least five specific sulfatases and diminished activity of any one may result in a specific storage disease.