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71.
SHAHID Muhammad Qasim 《科学通报(英文版)》2010,55(13):1255-1262
Oryza rufipogon exhibits abundant genetic diversity and contains many elite genes. In this work, a total of 441 accessions of O. rufipogon were genetically examined using the functional marker S5n, revealing that 18 accessions carried the S5n allele with a heterozygous genotype (S5nS5i/j). Of these accessions, 14 were from Guangdong Province, 2 from Guangxi Zhuang Autonomous Region, 1 from Hainan Province and 1 from Jiangxi Province. Further sequence analysis spanning both sides of the deletion in S5n allel... 相似文献
72.
73.
An inflammatory drug prospect. 总被引:2,自引:0,他引:2
74.
电梯上高峰模式下动态分区算法的研究 总被引:1,自引:0,他引:1
研究了电梯群控系统(EGCS)上行高峰时期的动态分区群控方法.动态分区是根据大楼乘客流量的大小和分布情况动态地调整楼层区域的划分;同时提出了一致的UPPINT的目标函数,将动态分区问题归结为一个最优化问题,用直接搜索法对其进行求解;并对群控的几种算法进行了仿真比较,验证了动态分区算法的良好效果. 相似文献
75.
76.
Microautophagy: lesser-known self-eating 总被引:1,自引:1,他引:0
Microautophagy, the non-selective lysosomal degradative process, involves direct engulfment of cytoplasmic cargo at a boundary
membrane by autophagic tubes, which mediate both invagination and vesicle scission into the lumen. With its constitutive characteristics,
microautophagy of soluble substrates can be induced by nitrogen starvation or rapamycin via regulatory signaling complex pathways.
The maintenance of organellar size, membrane homeostasis, and cell survival under nitrogen restriction are the main functions
of microautophagy. In addition, microautophagy is coordinated with and complements macroautophagy, chaperone-mediated autophagy,
and other self-eating pathways. Three forms of selective microautophagy, including micropexophagy, piecemeal microautophagy
of the nucleus, and micromitophagy, share common ground with microautophagy to some degree. As the accumulation of experimental
data, the precise mechanisms that govern microautophagy are becoming more appreciated. Here, we review the microautophagic
molecular machinery, its physiological functions, and relevance to human diseases, especially in diseases involving multivesicular
bodies and multivesicular lysosomes. 相似文献
77.
Angela M. Ortega-León Maricela Villagrán-Santa Cruz J. Jamie Zú?iga-Vega Raúl Cueva-del Castillo Fausto R. Méndez-de la Cruz 《西北部美国博物学家》2011,69(1)
Asynchronous reproduction is a common phenomenon in high-elevation populations of lizards from Central México. Sperm storage in the reproductive tract of females is the mechanism for making oocyte fertilization possible. Our study addresses questions related to functional oviductal sperm storage of females mating on different dates throughout the reproductive season. A population of Sceloporus mucronatus with copulation in the summer and ovulation in the fall was chosen for this experiment. Eleven females that copulated in the field during June and 13 females that copulated in captivity during August were maintained in the laboratory until parturition. The number of pregnant females and the litter sizes produced in each experimental group were indicative of the viability of the stored sperm. Sperm stored in the reproductive tract of females were able to fertilize eggs after 4 months. No significant differences were found in the number of pregnant females between the 2 experimental groups nor in the litter sizes that they produced. We found that the amount of time sperm were held in the female reproductive tract (ca. 3 months) had no effect on the capacity of sperm to fertilize eggs. Histological examination of 8 oviducts collected before the mating season eliminated the possibility of sperm storage from one year to the next. In this system, sperm retention could have evolved as a response mechanism to deal with the asynchrony between sexes in the reproductive cycles. However, we cannot rule out alternative hypotheses. 相似文献
78.
Important to the function of calpains is temporal and spatial regulation of their proteolytic activity. Here, we demonstrate
that cytoplasm-resident calpain 2 cleaves human nuclear topoisomerase I (hTOP1) via Ca2+-activated proteolysis and nucleoplasmic shuttling of proteases. This proteolysis of hTOP1 was induced by either ionomycin-caused
Ca2+ influx or addition of Ca2+ in cellular extracts. Ca2+ failed to induce hTOP1 proteolysis in calpain 2-knockdown cells. Moreover, calpain 2 cleaved hTOP1 in vitro. Furthermore,
calpain 2 entered the nucleus upon Ca2+ influx, and calpastatin interfered with this process. Calpain 2 cleavage sites were mapped at K158 and K183 of hTOP1. Calpain 2-truncated hTOP1 exhibited greater relaxation activity but remained able to interact with nucleolin and
to form cleavable complexes. Interestingly, calpain 2 appears to be involved in ionomycin-induced protection from camptothecin-induced
cytotoxicity. Thus, our data suggest that nucleocytoplasmic shuttling may serve as a novel type of regulation for calpain
2-mediated nuclear proteolysis. 相似文献
79.
The apicomplexan plastid and its evolution 总被引:1,自引:0,他引:1
Sato S 《Cellular and molecular life sciences : CMLS》2011,68(8):1285-1296
Protistan species belonging to the phylum Apicomplexa have a non-photosynthetic secondary plastid—the apicoplast. Although
its tiny genome and even the entire nuclear genome has been sequenced for several organisms bearing the organelle, the reason
for its existence remains largely obscure. Some of the functions of the apicoplast, including housekeeping ones, are significantly
different from those of other plastids, possibly due to the organelle’s unique symbiotic origin. 相似文献
80.
Rai A Nöthe H Tzvetkov N Korenbaum E Manstein DJ 《Cellular and molecular life sciences : CMLS》2011,68(16):2751-2767
Dictyostelium discoideum cells produce five dynamin family proteins. Here, we show that dynamin B is the only member of this group of proteins that
is initially produced as a preprotein and requires processing by mitochondrial proteases for formation of the mature protein.
Our results show that dynamin B-depletion affects many aspects of cell motility, cell-cell and cell-surface adhesion, resistance
to osmotic shock, and fatty acid metabolism. The mature form of dynamin B mediates a wide range and unique combination of
functions. Dynamin B affects events at the plasma membrane, peroxisomes, the contractile vacuole system, components of the
actin-based cytoskeleton, and cell adhesion sites. The modulating effect of dynamin B on the activity of the contractile vacuole
system is unique for the Dictyostelium system. Other functions displayed by dynamin B are commonly associated with either classical dynamins or dynamin-related
proteins. 相似文献