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1.
The molecular events associated with decondensation of human sperm nuclei were analyzed by incubating sperm with egg extracts from an amphibian, Bufo japonicus . Acid-urea-Triton polyacrylamide gel electrophoresis (AUT-PAGE) showed that the nuclear basic proteins of human sperm consist mainly of protamines (HPI, HPII) with minor amounts of nucleosomal histones. On incubation of lysolecithin (LC)- and dithiothreitol (DTT)-treated human sperm with the egg extract, the nuclei lost HPI and HPII within 15 min in association with extensive nuclear decondensation, and the acquirement of a whole set of nucleosomal histones. Incubation of LC-DTT-sperm with nucleoplasmin purified from Bufo eggs also induced nuclear decondensation and loss of protamines within 30 min. Native-PAGE and Western blot analyses of incubation medium indicated tight association of the released protamines to nucleoplasmin, strongly suggesting that protamines are removed from sperm nuclei not enzymatically but by their specific binding to nucleoplasmin. On incubation of LC-DTT-sperm with nucleoplasmin and exogenous nucleosomal core histones, micrococcal nuclease-protected DNA fragments were released, although their unit repeat length was slightly less than that of somatic nucleosomes. Thus remodeling of human sperm during fertilization can be mimicked under defined conditions with nucleoplasmin and exogenous histones.  相似文献   
2.
Immunological Studies of Betaine Aldehyde Dehydrogenase in Barley   总被引:2,自引:0,他引:2  
The changes in the level of the protein for betaine aldehydedehydrogenase, which catalyzes the last step in the synthesisof glycinebetaine, were analyzed with antiserum raised againstSDS-denatured betaine aldehyde dehydrogenase from spinach. Inbarley leaves, the levels of betaine aldehyde dehydrogenaseprotein were found to be enhanced by the addition of 200 mMNaCl to the growth medium. These changes in the level of theenzyme protein corresponded to those in the activity of theenzyme, as described in our previous study (Arakawa et al. 1990).The extent of this enhancement was reduced when barley plantswere relieved from salt stress. An increase in the level ofthe protein was also induced by water stress, such as the withholdingof water or the addition of polyethylene glycol 6000. Betainealdehyde dehydrogenase protein was detected in etiolated leavesand roots, as well as in green leaves. In etiolated leaves,the level of betaine aldehyde dehydrogenase protein was notaffected by salt stress. 1 This work was supported by a grant from the Bio-Media Projectof the Japanese Ministry of Agriculture, Forestry and Fisheries(BMP92-III-l-1).  相似文献   
3.
Summary: Targeted mutagenesis of genes‐of‐interest, or gene‐knockout, is a powerful method to address the functions of genes. Engineered nucleases have enabled this approach in various organisms because of their ease of use. The ascidian Ciona intestinalis is an excellent organism to analyze gene functions by means of genetic technologies. In our previous study, we reported mutagenesis of Ciona somatic cells with TALE nucleases (TALENs) by electroporating expression constructs. In this study, we report germ cell mutagenesis of Ciona by microinjecting mRNAs encoding TALENs. TALEN mRNAs introduced mutations to target genes in both somatic and germ cells. TALEN‐mediated mutations in the germ cell genome were inherited by the next generation. We conclude that knockout lines of Ciona that have disrupted target genes can be established through TALEN‐mediated germ cell mutagenesis. genesis 52:431–439, 2014. © 2014 Wiley Periodicals, Inc.  相似文献   
4.
Previously we found that the organic components in scallop shell promote lipolysis in differentiated 3T3-L1 and C3H10T1/2 adipocyte cells, and that incorporating scallop shell powder into the diet of rats reduced the amount of white adipose tissue. In this study, we used RT-PCR to investigate the effect of ingesting scallop shell powder on the gene expression profile of uncoupling proteins (UCPs) regulating energy metabolism in rats.Feeding of scallop shell powder increased mRNA levels of UCP1 and UCP2 in white adipose tissue. By contrast, scallop shell powder had no effect on the expression of UCP1 in brown adipose tissue, although the expression level of UCP2 mRNA decreased significantly. These results suggest that feeding scallop shell powder increases gene expression of UCP1 that may regulate energy metabolism in white adipose tissue, resulting in the observed reduction in weight of white adipose tissue.  相似文献   
5.
The aim of this study was to assess the adhesion of Bifidobacterium strains to acidic carbohydrate moieties of porcine colonic mucin. Mucins were extracted and purified via gel filtration chromatography followed by density-gradient ultracentrifugation. The presence of sulfated and sialylated carbohydrates in mucins was shown by enzyme-linked immunosorbent assays using PGM34 and HMC31 monoclonal antibodies (mAbs), respectively. Adhesion of Bifidobacterium strains to mucin preparations was markedly affected by the degree of purification. In eight of 22 strains, we observed increased adhesion to mucin preparations purified by ultracentrifugation. Moreover, in some of these eight strains, adhesion to mucin was reduced by pretreatment with sulfatase and/or sialidase, and competitively inhibited by pretreatment with PGM34 and/or HCM31 mAbs. Our results showed that some Bifidobacterium strains adhered to sulfo- and/or sialomucin and were able to recognize carbohydrate structures of the mAbs epitopes.  相似文献   
6.
Muscarinic receptors are expressed in the adrenal medullary (AM) cells of various mammals, but their physiological roles are controversial. Therefore, the ionic mechanism for muscarinic receptor-mediated depolarization and the role of muscarinic receptors in neuronal transmission were investigated in dissociated guinea-pig AM cells and in the perfused guinea-pig adrenal gland. Bath application of muscarine induced an inward current at -60 mV. This inward current was partially suppressed by quinine with an IC(50) of 6.1 μM. The quinine-insensitive component of muscarine-induced currents changed the polarity at -78 mV and was inhibited by bupivacaine, a TWIK-related acid-sensitive K(+) (TASK) channel inhibitor. Conversely, the current-voltage relationship for the bupivacaine-insensitive component of muscarine currents showed a reversal potential of -5 mV and a negative slope below -40 mV. External application of La(3+) had a double action on muscarine currents of both enhancement and suppression. Immunoblotting and immunocytochemistry revealed expression of TASK1 channels and cononical transient receptor potential channels 1, 4, 5, and 7 in guinea-pig AM cells. Retrograde application of atropine reversibly suppressed transsynaptically evoked catecholamine secretion from the adrenal gland. The results indicate that muscarinic receptor stimulation in guinea-pig AM cells induces depolarization through inhibition of TASK channels and activation of nonselective cation channels and that muscarinic receptors are involved in neuronal transmission from the splanchnic nerve.  相似文献   
7.
Recent studies in streams and ponds have demonstrated that the distribution and biomass of aquatic organisms can be estimated by detection and quantification of environmental DNA (eDNA). In more open systems such as seas, it is not evident whether eDNA can represent the distribution and biomass of aquatic organisms because various environmental factors (e.g., water flow) are expected to affect eDNA distribution and concentration. To test the relationships between the distribution of fish and eDNA, we conducted a grid survey in Maizuru Bay, Sea of Japan, and sampled surface and bottom waters while monitoring biomass of the Japanese jack mackerel (Trachurus japonicus) using echo sounder technology. A linear model showed a high R2 value (0.665) without outlier data points, and the association between estimated eDNA concentrations from the surface water samples and echo intensity was significantly positive, suggesting that the estimated spatial variation in eDNA concentration can reflect the local biomass of the jack mackerel. We also found that a best-fit model included echo intensity obtained within 10–150 m from water sampling sites, indicating that the estimated eDNA concentration most likely reflects fish biomass within 150 m in the bay. Although eDNA from a wholesale fish market partially affected eDNA concentration, we conclude that eDNA generally provides a ‘snapshot’ of fish distribution and biomass in a large area. Further studies in which dynamics of eDNA under field conditions (e.g., patterns of release, degradation, and diffusion of eDNA) are taken into account will provide a better estimate of fish distribution and biomass based on eDNA.  相似文献   
8.
Screening of faecal bacteria for glycyrrhetic acid (GA) production by hydrolysing of glycyrrhizin (GL) resulted in the isolation of two strains, designated ZM35T and ZM38. Strains ZM35T and ZM38 were Gram-positive, obligate anaerobic, non-spore-forming and rod-shaped bacteria. Analysis of the 16S rRNA gene sequences indicated that strains ZM35T and ZM38 belonged to cluster XIVa of the genus Clostridium. The 16S rRNA gene sequences of strains ZM35T and ZM38 were identical. Strain ZM35T exhibited approximately 94% to 95% identity with the validly described species, Clostridium oroticum(94.5%), Eubacterium contortum(93.8%), Ruminococcus gnavus(94.5%) and R. torques(95.1%). In an experiment of DNA-DNA hybridization, it was confirmed that strains ZM35T and ZM38 were the same species. The guanine-plus-cytosine (G+C) content of strain ZM35T is 45.7 mol%. Based on the phylogenetic and phenotypic findings, we propose that strains ZM35T and ZM38 be assigned to a novel species named Clostridium glycyrrhizinilyticum. The type strain is ZM35T (=JCM 13368T=DSM 17593T).  相似文献   
9.
Predation and brood parasitism are common reasons for nesting failure in passerine species and the additive impact by invasive species is a major conservation concern, particularly on tropical islands. Recognising the relative contribution of the different components of nesting failure rates is important to understand co-evolutionary interactions within brood parasite–host systems. In the remote archipelago of New Caledonia, the fan-tailed gerygone Gerygone flavolateralis is the exclusive host of the brood-parasitic shining bronze-cuckoo Chalcites lucidus. Additionally, invasive rodents also possibly have an impact on breeding success. To estimate the impact of potential nest predators, we 1) video monitored nests to identify predators, 2) estimated the probability of predation based on nest visibility and predator abundance and 3) tested the possibility that the location of experimental nests and lack of odour cues decrease the predation by rodents. In addition, we estimated nest survival rates using data collected in different habitats over the course of eight breeding seasons. Nesting success of fan-tailed gerygones was relatively low and predation was the main cause of nesting failure. We recorded mainly predation by native birds, including the shining bronze-cuckoo, whereas predation by rats was rare. In open habitats predation by cuckoos was much lower than predation by other avian predators. Neither predator activity around nests nor nest visibility influenced the probability of predation. Experimental nests in more accessible locations and containing an odorous bait were more exposed to rodent predation. Apparently, the fan-tailed gerygone has either never been specifically vulnerable to predation by rats or has developed anti-predator adaptations.  相似文献   
10.
Electronegative LDL, a charge-modified LDL (cm-LDL) subfraction that is more negatively charged than normal LDL, has been shown to be inflammatory. We previously showed that pravastatin and simvastatin reduced the electronegative LDL subfraction, fast-migrating LDL (fLDL), as analyzed by capillary isotachophoresis (cITP). The present study examined the effects of rosuvastatin on the more electronegative LDL subfraction, very-fast-migrating LDL (vfLDL), and small, dense charge-modified LDL (sd-cm-LDL) subfractions. Patients with hypercholesterolemia or those who were being treated with statins (n = 81) were treated with or switched to 2.5 mg/d rosuvastatin for 3 months. Rosuvastatin treatment effectively reduced cITP cm-LDL subfractions of LDL (vfLDL and fLDL) or sdLDL (sd-vfLDL and sd-fLDL), which were closely related to each other but were different from the normal subfraction of LDL [slow-migrating LDL (sLDL)] or sdLDL (sd-sLDL) in their relation to the levels of remnant-like particle cholesterol (RLP-C), apolipoprotein (apo) C-II, and apoE. The percent changes in cm-LDL or sd-cm-LDL caused by rosuvastatin were correlated with those in the particle concentrations of LDL or sdLDL measured as LDL-apoB or sdLDL-apoB and the levels of HDL-C, RLP-C, apoC-II, and apoE. In conclusion, rosuvastatin effectively reduced both the vfLDL subfraction and sd-cm-LDL subfractions as analyzed by cITP.  相似文献   
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