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1.
YASUYOSHI TORII KIYOTAKA HITOMI YASUKO YAMAGISHI NORIHIRO TSUKAGOSHI 《Cell biology international》1996,20(7):459-464
MC3T3-E1 cells grown with ascorbic acid express sequentially osteoblastic marker proteins such as alkaline phosphatase (ALPase) and then form a mineralized extracellular matrix (ECM) as a consequence of osteoblastic differentiation. To explore the functional roles of ALPase in the process of osteoblastic maturation, an inducible expression vector for antisense ALPase RNA was constructed and stably transfected into MC3T3-E1 cells. The expression of antisense ALPase RNA in the differentiated MC3T3-E1 transfectants reduced markedly the ALPase activity, which resulted in a significant decrease in the deposition of minerals upon prolonged culture. These findings demonstrated directly that ALPase participated in the mineralizationof ECM. 相似文献
2.
Mesophyll conductance decreases in the wild type but not in an ABA‐deficient mutant (aba1) of Nicotiana plumbaginifolia under drought conditions 下载免费PDF全文
YUSUKE MIZOKAMI KO NOGUCHI MIKIKO KOJIMA HITOSHI SAKAKIBARA ICHIRO TERASHIMA 《Plant, cell & environment》2015,38(3):388-398
Under drought conditions, leaf photosynthesis is limited by the supply of CO2. Drought induces production of abscisic acid (ABA), and ABA decreases stomatal conductance (gs). Previous papers reported that the drought stress also causes the decrease in mesophyll conductance (gm). However, the relationships between ABA content and gm are unclear. We investigated the responses of gm to the leaf ABA content [(ABA)L] using an ABA‐deficient mutant, aba1, and the wild type (WT) of Nicotiana plumbaginifolia. We also measured leaf water potential (ΨL) because leaf hydraulics may be related to gm. Under drought conditions, gm decreased with the increase in (ABA)L in WT, whereas both (ABA)L and gm were unchanged by the drought treatment in aba1. Exogenously applied ABA decreased gm in both WT and aba1 in a dose‐dependent manner. ΨL in WT was decreased by the drought treatment to ?0.7 MPa, whereas ΨL in aba1 was around ?0.8 MPa even under the well‐watered conditions and unchanged by the drought treatment. From these results, we conclude that the increase in (ABA)L is crucial for the decrease in gm under drought conditions. We discuss possible relationships between the decrease in gm and changes in the leaf hydraulics. 相似文献
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4.
Comparative foraging ecology of Madagascar vangids (Vangidae) 总被引:1,自引:0,他引:1
The Vangidae, an endemic family in Madagascar, contains 14 species in 11 genera. The foraging behaviour of 13 species of vangids was investigated during the periods August-November 1989 and September-November 1990. These vangids are grouped into six bill types according to their bill shape, using the analogy of gripping tools: (1) forceps. (2) radio pliers, (3) strong pinchers, (4) pliers, (5) standard and (6) flat forceps types. We recognized seven foraging niches: (A) canopy-gleaning, (B) general, (C) ground-snatching, (D) trunk/ branch-probing, (E) leaf and twig/branch-gleaning/probing, (F) leaf and twig/branch-gleaning and (G) trunk-gleaning niches. Two or more coexisting species with the same foraging niche differed in their bill types. Those vangids that exploited similar resources segregated in their bill types, geographic ranges and/or foraging niches, presumably to avoid severe competition. Several vangid species partially occupied the ecological niche that would be filled by woodpeckers elsewhere. 相似文献
5.
Tomoko GANAHA Machiko NOHARA Shinsuke SATO Nami UECHI Kenzou YAMAGISHI Satoshi YAMAUCHI Junichi YUKAWA 《Entomological Science》2007,10(2):157-169
In the past, Rhopalomyia longitubifex, Rhopalomyia shinjii, and Rhopalomyia sp. (Diptera: Cecidomyiidae) have been regarded as independent species based on differences in the sizes and shapes of axillary bud galls induced on Artemisia montana (Asteraceae) in Japan and A. princeps in Japan and Korea. However, comparison of morphological features and molecular sequencing data indicate that these Rhopalomyia gall midges are identical and that the differences in gall shape are polymorphisms, although the measurements of gall height and diameter overlap slightly. This finding suggests that although galls have frequently been regarded as extensions of the phenotype of a species, differences in gall shape may not always be reliable for identifying gall‐inducing cecidomyiids. The older name, R. longitubifex, is applied to these gall midges, and the names that were applied to this species on later occasions are revised or synonymized. The mature and immature stages of R. longitubifex are redescribed and information on the distribution, host range, and gall size of this species is provided. We also discuss the role of gall polymorphism in the early stages of speciation. 相似文献
6.
Mixed-species flocks of forest living birds were investigated in a rainforest at Perinet/ Analamazaotra (Andasibe), Madagascar. Most insectivorous birds in the area participated in mixed-species flocks. Flocks were composed of foliage gleaners, foliage-branch gleaners, trunk gleaners and flycatchers. Species whose foraging techniques and foraging locations in vegetation were similar were different from each other in foraging heights. The nuclear species often occurred in small conspecific flocks in and out of mixed-species flocks. 相似文献
7.
Akira ISHIKAWA Makoto SUGIYAMA Eiichi HONDO Keiji KINOSHITA Yuki YAMAGISHI 《Experimental Animals》2015,64(2):207-220
Oca2p-cas (oculocutaneous albinism II; pink-eyed dilution
castaneus) is a coat color mutant gene on mouse chromosome 7 that arose spontaneously in
wild Mus musculus castaneus mice. Mice homozygous for
Oca2p-cas usually exhibit pink eyes and gray coat hair on
the non-agouti genetic background, and this ordinary phenotype remains unchanged
throughout life. During breeding of a mixed strain carrying this gene on the C57BL/6J
background, we discovered a novel spontaneous mutation that causes darkening of the eyes
and coat hair with aging. In this study, we developed a novel mouse model showing this
unique phenotype. Gross observations revealed that the pink eyes and gray coat hair of the
novel mutant young mice became progressively darker in color by approximately 3 months
after birth. Light and transmission-electron microscopic observations revealed a marked
increase in melanin pigmentation of coat hair shafts and choroid of the eye in the novel
mice compared to that in the ordinary mice. Sequence analysis of
Oca2p-cas revealed a 4.1-kb deletion involving exons 15
and 16 of its wild-type gene. However, there was no sequence difference between the two
types of mutant mice. Mating experiments suggested that the novel mutant phenotype was not
inherited in a simple fashion, due to incomplete penetrance. The novel spontaneous mutant
mouse is the first example of progressive hair darkening animals and is an essential
animal model for understanding of the regulation mechanisms of melanin biosynthesis with
aging. 相似文献
8.
HIDEO YAMAGISHI TAKAHIRO KUNISADA YOICHIRO IWAKURA YOSHITAKE NISHIMUNE YOKO OGISO AIZO MATSUSHIRO 《Development, growth & differentiation》1983,25(6):563-569
A small number of mouse embryos and embryonal carcinoma cells were pressed by mica sheet; then the extruded DNA complexes were adsorbed to mica and processed for electron microscopy. Extrachromosomal circular DNA complexes longer than 1 μm emerged during the compaction process of mouse embryos and during the differentiation of embryonal carcinoma cells induced with retinoic acid. These DNA molecules are discussed as possible products of developmental gene rearrangements occurring in the chromosomal DNA. 相似文献
9.
Transcriptomic analysis of metabolic changes by phosphorus stress in rice plant roots 总被引:15,自引:0,他引:15
10.
AKIHIRO SAITO MISA SAITO YUSUKE ICHIKAWA MASAAKI YOSHIBA TOSHIAKI TADANO EITARO MIWA KYOKO HIGUCHI 《Plant, cell & environment》2010,33(2):174-187
To evaluate Ni dynamics at the subcellular level, the distribution and speciation of Ni were determined in wild‐type (WT) and Ni‐tolerant (NIT) tobacco BY‐2 cell lines. When exposed to low but toxic levels of Ni, NIT cells were found to contain 2.5‐fold more Ni (14% of whole‐cell Ni values) in their cell walls than WT cells (6% of whole‐cell Ni values). In addition to higher levels of Ni in the apoplast, a higher proportion (94%) of symplastic Ni was localized in the vacuoles of NIT cells than in the vacuoles of WT cells (81%). The concentration of cytosolic Ni in the NIT cells was significantly lower (18 nmol g?1 FW) than that in the WT cells (85 nmol g?1 FW). In silico simulation showed that 95% of vacuolar Ni was in the form of Ni‐citrate complexes, and that free Ni2+ was virtually absent in the NIT cells. On the other hand, the amount of free metal ions was markedly increased in WT cells because free citrate was depleted by chelation of Ni. A protoplast viability assay using BCECF‐AM further demonstrated that the main mechanism that confers strong Ni tolerance was present in the symplast as opposed to the cell wall. 相似文献