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111.
Hui Wang Michinari Matsushita Nobuhiro Tomaru Michiko Nakagawa 《Ecology and evolution》2017,7(7):2340-2345
Sex change affects the sex ratios of plant populations and may play an essential role in the evolutionary shift of sexual systems. Sex change can be a strategy for increasing fitness over the lifetime of a plant, and plant size, environmental factors, and growth rate may affect sex change. We described frequent, repeated sex changes following various patterns in a subdioecious Eurya japonica population over five successive years. Of the individuals, 27.5% changed their sex at least once, and these changes were unidirectional or bidirectional. The sex ratio (females/males/all hermaphrodite types) did not fluctuate over the 5 years. In our study plots, although the current sex ratio among the sexes appears to be stable, the change in sex ratio may be slowly progressing toward increasing females and decreasing males. Sex was more likely to change with higher growth rates and more exposure to light throughout the year. Among individuals that changed sex, those that were less exposed to light in the leafy season and had less diameter growth tended to shift from hermaphrodite to a single sex. Therefore, sex change in E. japonica seemed to be explained by a response to the internal physiological condition of an individual mediated by intrinsic and abiotic environmental factors. 相似文献
112.
Electron microscopic examination of the orexin immunoreactivity in the dorsal raphe nucleus 总被引:1,自引:0,他引:1
The ultrastructure and the synaptic relationships of the orexin-A-like immunoreactive fibers in the dorsal raphe nucleus were examined with an immunoelectron microscopic method. At the electron microscopic level, most of the immunoreactive fibers, a varicosity appearance at the light microscopic level, were found as axon terminals. The large dense-cored vesicles contained in the immunoreactive axon terminals were the most intensely immunostained organellae. These axon terminals were often found to make synapses. While the axo-dendritic synapses were usually asymmetric in appearance, the axo-somatic synapses were symmetric. Orexin-A-like immunoreactive processes with no synaptic vesicles were also found. These processes often received asymmetric synapses. With less frequency, the synapses were found between the orexin-like immunoreactive processes. The results suggest that the orexin peptides are stored in the large dense-cored vesicles; the orexin-containing fibers may have influences on the physiological activities of the dorsal raphe nucleus through direct synaptic relationships. 相似文献
113.
Seiji Hayashizaki Shinobu Hirai Yumi Ito Yoshiko Honda Yosefu Arime Ichiro Sora Haruo Okado Tohru Kodama Masahiko Takada 《PloS one》2013,8(10)
Dopamine regulates the psychomotor stimulant activities of amphetamine-like substances in the brain. The effects of dopamine are mediated through five known dopamine receptor subtypes in mammals. The functional relevance of D5 dopamine receptors in the central nervous system is not well understood. To determine the functional relevance of D5 dopamine receptors, we created D5 dopamine receptor-deficient mice and then used these mice to assess the roles of D5 dopamine receptors in the behavioral response to methamphetamine. Interestingly, D5 dopamine receptor-deficient mice displayed increased ambulation in response to methamphetamine. Furthermore, dopamine transporter threonine phosphorylation levels, which regulate amphetamine-induced dopamine release, were elevated in D5 dopamine receptor-deficient mice. The increase in methamphetamine-induced locomotor activity was eliminated by pretreatment with the dopamine transporter blocker GBR12909. Taken together, these results suggest that dopamine transporter activity and threonine phosphorylation levels are regulated by D5 dopamine receptors. 相似文献
114.
115.
Setsuro Matsushita Fumio Ibuki Tomohiko Mori Tadao Hata 《Bioscience, biotechnology, and biochemistry》2013,77(5):436-446
Phosphodiesterase was solubilized from bovine milk microsomes and partially purified. The purified enzyme showed 20-fold specific activity compared with that of microsomes, and 1,500-fold with that of the original milk.The properties of the enzyme were investigated by using NpT. The pH optimum was at 9.5. The enzyme was inhibited with EDT A and reactivated with the addition of magnesium or calcium ions. This enzyme was strongly inhibited with reducing reagents. Km, value was 7.4 x 10-4 M for NpT at pH 9.5.RNA was hydrolyzed completely to 5′-mononucleotides, and this enzyme may be considered to show the exonucleolytic action for RNA. 相似文献
116.
Minenosuke Matsutani Kota Fukushima Chiho Kayama Misato Arimitsu Hideki Hirakawa Hirohide Toyama Osao Adachi Toshiharu Yakushi Kazunobu Matsushita 《BBA》2014
The bacterial aerobic respiratory chain has a terminal oxidase of the heme-copper oxidase superfamily, comprised of cytochrome c oxidase (COX) and ubiquinol oxidase (UOX); UOX evolved from COX. Acetobacter pasteurianus, an α-Proteobacterial acetic acid bacterium (AAB), produces UOX but not COX, although it has a partial COX gene cluster, ctaBD and ctaA, in addition to the UOX operon cyaBACD. We expressed ctaB and ctaA genes of A. pasteurianus in Escherichia coli and demonstrated their function as heme O and heme A synthases. We also found that the absence of ctaD function is likely due to accumulated mutations. These COX genes are closely related to other α-Proteobacterial COX proteins. However, the UOX operons of AAB are closely related to those of the β/γ-Proteobacteria (γ-type UOX), distinct from the α/β-Proteobacterial proteins (α-type UOX), but different from the other γ-type UOX proteins by the absence of the cyoE heme O synthase. Thus, we suggest that A. pasteurianus has a functional γ-type UOX but has lost the COX genes, with the exception of ctaB and ctaA, which supply the heme O and A moieties for UOX. Our results suggest that, in AAB, COX was replaced by β/γ-Proteobacterial UOX via horizontal gene transfer, while the COX genes, except for the heme O/A synthase genes, were lost. 相似文献
117.
Hiraku Takei Soji Morishita Marito Araki Yoko Edahiro Yoshitaka Sunami Yumi Hironaka Naohiro Noda Yuji Sekiguchi Satoshi Tsuneda Akimichi Ohsaka Norio Komatsu 《PloS one》2014,9(8)
A gain-of-function mutation in the myeloproliferative leukemia virus (MPL) gene, which encodes the thrombopoietin receptor, has been identified in patients with essential thrombocythemia and primary myelofibrosis, subgroups of classic myeloproliferative neoplasms (MPNs). The presence of MPL gene mutations is a critical diagnostic criterion for these diseases. Here, we developed a rapid, simple, and cost-effective method of detecting two major MPL mutations, MPLW515L/K, in a single PCR assay; we termed this method DARMS (dual amplification refractory mutation system)-PCR. DARMS-PCR is designed to produce three different PCR products corresponding to MPLW515L, MPLW515K, and all MPL alleles. The amplicons are later detected and quantified using a capillary sequencer to determine the relative frequencies of the mutant and wild-type alleles. Applying DARMS-PCR to human specimens, we successfully identified MPL mutations in MPN patients, with the exception of patients bearing mutant allele frequencies below the detection limit (5%) of this method. The MPL mutant allele frequencies determined using DARMS-PCR correlated strongly with the values determined using deep sequencing. Thus, we demonstrated the potential of DARMS-PCR to detect MPL mutations and determine the allele frequencies in a timely and cost-effective manner. 相似文献
118.
119.
Generation of neutralization-resistant HIV-1 in vitro due to amino acid interchanges of third hypervariable env region. 总被引:5,自引:0,他引:5
T Masuda S Matsushita M J Kuroda M Kannagi K Takatsuki S Harada 《Journal of immunology (Baltimore, Md. : 1950)》1990,145(10):3240-3246
Antigenic mutants of HIV-1 were isolated from three plaque-cloned viruses by the resistance of the virus to neutralizing mAb 0.5 beta against V3 domain of viral gp120, when the viruses were passaged in the presence of the antibody. However, when chronically infected MOLT-4 cells were treated with 0.5 beta mAb, recovered viruses from the 0.5 beta-treated cells showed no antigenic changes. The extent of genomic variation among antigenically distinct isolates was examined by nucleotide sequencing, which revealed a few base substitutions in 0.5 beta-binding site of all mutants isolated. The predicted amino acid replacements within 0.5 beta reacting epitope (V3 domain) causing the altered antigenicity were also identified for each of three isolates. Particularly, in one of the mutants, the most conserved Gly-Pro-Gly-Arg region located at the center of the V3 domain was changed to Gly-Gln-Gly-Arg. The radioimmunoprecipitation and synthetic peptide analyses revealed that this Pro320----Gln substitution reduced the binding affinity with 0.5 beta, although other mutations observed in the other mutants did not affect the binding affinity in radioimmunoprecipitation. We also observed that nucleic acid substitutions in the V3 domain occurred frequently in the absence of 0.5 beta mAb during our in vitro acute infection system using MT-4 cells. 相似文献
120.
The biosynthetic relationship between the two norlignans agatharesinol and trans-hinokiresinol was investigated. Fresh sapwood sticks of Cryptomeria japonica were fed with stable isotope-labeled compounds, namely p-coumaryl alcohol-[9,9-2H], p-coumaryl alcohol-[9-18O] and trans-hinokiresinol-[1-2H], and then incubated under high-humidity for approximately 20 days, during which the two norlignans were produced simultaneously. While trans-hinokiresinol was strongly deuterium-labeled after feeding with p-coumaryl alcohol-[9,9-2H], agatharesinol was only lightly labeled after feeding with either p-coumaryl alcohol-[9,9-2H] or -[9-18O]. These results suggest that p-coumaryl alcohol, which is a precursor of hinokiresinol, is not involved in the biosynthesis of agatharesinol. Therefore, the norlignan carbon skeleton of agatharesinol must be framed from different types of phenylpropanoid monomers compared to those utilized by the trans-hinokiresinol pathway. The biosynthesis of these two norlignans seems to branch at an early stage, i.e., before the framing of the norlignan carbon skeleton. Furthermore, agatharesinol was not labeled with deuterium after feeding with 2H-labeled trans-hinokiresinol, which has the simplest norlignan structure. This result strongly supports the suggestion that the conversion of trans-hinokiresinol to agatharesinol is not part of the biosynthesis of norlignans and that early branching occurs instead. 相似文献