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A tip-focused Ca^2+ gradient is tightly coupled to polarized pollen tube growth, and tip-localized influxes of extracellular Ca^2+ are required for this process. However the molecular identity and regulation of the potential Ca^2+ channels remains elusive. The present study has implicated CNGC18 (cyclic nucleotide-gated channel 18) in polarized pollen tube growth, because its overexpression induced wider and shorter pollen tubes. Moreover, CNGC18 overexpression induced depolarization of pollen tube growth was suppressed by lower extracellular calcium ([Ca^2+]ex). CNGC18-yellow fluorescence protein (YFP) was preferentially localized to the apparent post-Golgi vesicles and the plasma membrane (PM) in the apex of pollen tubes. The PM localization was affected by tip-localized ROP1 signaling. Expression of wild type ROP1 or an active form of ROP1 enhanced CNGC18-YFP localization to the apical region of the PM, whereas expression of RopGAP1 (a ROP1 deactivator) blocked the PM localization. These results support a role for PM-Iocalized CNGC18 in the regulation of polarized pollen tube growth through its potential function in the modulation of calcium influxes.  相似文献   
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Bone and tooth, fundamental parts of the craniofacial skeleton, are anatomically and developmentally interconnected structures. Notably, pathological processes in these tissues underwent together and progressed in multilevels. Extracellular vesicles (EVs) are cell-released small organelles and transfer proteins and genetic information into cells and tissues. Although EVs have been identified in bone and tooth, particularly EVs have been identified in the bone formation and resorption, the concrete roles of EVs in bone and tooth development and diseases remain elusive. As such, we review the recent progress of EVs in bone and tooth to highlight the novel findings of EVs in cellular communication, tissue homeostasis, and interventions. This will enhance our comprehension on the skeletal biology and shed new light on the modulation of skeletal disorders and the potential of genetic treatment.  相似文献   
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slyD encodes a 196 amino acid polypeptide that is a member of the FKBP family of cis–trans peptidyl–prolyl isomerases (PPIases). slyD mutations affect plaque formation by the phage φX174 by blocking the action of the phage lysis protein E. Here we describe the selection of a set of spontaneous slyD mutations conferring resistance to the expression of gene E from a plasmid. These mutations occur disproportionately in residues of SlyD that, based on the structure of the prototype mammalian FKBP12, make ligand contacts with immunosuppressing drug molecules or are conserved in other FKBP proteins. A wide variation in the plating efficiency of φX174 on these E  R strains is observed, relative to the parental, indicating that these alleles differ widely in residual SlyD activity. Moreover, it is found that slyD mutations cause significant growth rate defects in Escherichia coli B and C backgrounds. Finally, overexpression of slyD causes filamentation of the host. Thus, among the FKBP genes found in organisms across the evolutionary spectrum, slyD is unique in having three distinct drug-independent phenotypes.  相似文献   
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本文描述了发现于福建的冬青科冬青属2新种——泰宁冬青Ilex tainingensis G. S. He和南平冬青I. nanpingensis G. S. He,并分别说明两者与其他近缘种的区别要点。泰宁冬青与太平山冬青I. sugerokii Maxim.的区别在于前种小枝被毛,无棱槽,叶片宽卵圆形,花淡紫色,分核表面具细条纹,背后中部有一凹槽。南平冬青与拟榕叶冬青I. subficoidea S. Y. Hu区别在于前种果为椭圆形,较大,表面光滑无腺点,果梗长于1 cm,每分核上端有2尖角,均可以区别。  相似文献   
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Abstract Morphological features of mature larvae of Petelia rivulosa (Butler), Exangerona prattiaria (Leech) and Culcula panterinaria (Bremer & Grey) of Ennominae are described and illustrated. All specimens examined are deposited in the Insect Collection of Department of Forest Resources Protection, Kangwon National University, Korea.  相似文献   
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