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951.
952.
Mutations in the helix termination motif of mouse type I IRS keratin genes impair the assembly of keratin intermediate filament 总被引:1,自引:0,他引:1
Tanaka S Miura I Yoshiki A Kato Y Yokoyama H Shinogi A Masuya H Wakana S Tamura M Shiroishi T 《Genomics》2007,90(6):703-711
Two classical mouse hair coat mutations, Rex (Re) and Rex wavy coat (Re(wc)), are linked to the type I inner root sheath (IRS) keratin genes of chromosome 11. An N-ethyl-N-nitrosourea-induced mutation, M100573, also maps close to the type I IRS keratin genes. In this study, we demonstrate that Re and M100573 mice bear mutations in the type I IRS gene Krt25; Re(wc) mice bear an additional mutation in the type I IRS gene Krt27. These three mutations are located in the helix termination motif of the 2B alpha-helical rod domain of a type I IRS keratin protein. Immunohistological analysis revealed abnormal foam-like immunoreactivity with an antibody raised to type II IRS keratin K71 in the IRS of Re/+ mice. These results suggest that the helix termination motif is essential for the proper assembly of types I and II IRS keratin protein complexes and the formation of keratin intermediate filaments. 相似文献
953.
We report here the results of an 8-year study of the growth and population dynamics of Quercus mongolica ssp. crispula in a Pinus densiflora stand in a state of succession. In 1998, there were 169 Q. mongolica ssp. crispula individuals in a 400-m2 plot under the P. densiflora canopy. This number remained nearly constant between 1998 and 2005. Mean recruitment of new individuals was 11 year−1, while mean mortality was 12 year−1. Of the 35 individuals ≥60 cm in height existing in 1998, 30 were still surviving in 2005. We were able to represent the
height growth of Q. mongolica ssp. crispula individuals as H=30 [1+21.96 exp(−0.0839t)]−1, with t = years since 1998 and H = height in meters. Using this equation we predict that by 2015 the mean height of Q. mongolica ssp. crispula trees in the stand will exceed those of understory trees, such as Rhus trichocarpa and Prunus
maximowiczii. Once above the understory stratum, the Q. mongolica ssp. crispula trees can be expected to grow more rapidly due to the better light conditions, thereby rapidly reaching the canopy stratum
of the P. densiflora stand. 相似文献
954.
Kato S Shimizu-Ibuka A Mura K Takeuchi A Tokue C Arai S 《Bioscience, biotechnology, and biochemistry》2007,71(12):3007-3013
An alpha-amylase secreted by Pichia burtonii 15-1 isolated from a traditional starter murcha of Nepal, named Pichia burtonii alpha-amylase (PBA), was studied. The gene was cloned and its nucleotide sequence was determined. PBA was deduced to consist of 494 amino acid residues. It shared certain degrees of amino acid sequence identity with other homologous proteins: 60% with Schwanniomyces occidentalis alpha-amylase, 58% with Saccharomycopsis sp. alpha-amylase, and 47% with Taka-amylase A from Aspergillus oryzae. A three-dimensional structural model of PBA generated using the known three-dimensional structure of Taka-amylase A as a template suggested high structural similarity between them. Kinetic analysis revealed that the K(m) values of PBA were lower than those of Taka-amylase A for the oligosaccharides. Although the k(cat) values of PBA were lower than those of Taka-amylase A for the oligosaccharide substrates, the k(cat)/K(m) values of PBA were higher. 相似文献
955.
Saito N Konishi K Ohta S Kondo T Kato M Hashino S Takeda H Asaka M Ooi HK 《Human cell》2007,20(1):10-14
A 44-year-old man was found to have M-proteins of IgG consisting of kappa- and lambda-chains in serum without lymphadenopathy or splenomegaly. The serum concentrations of IgG, IgA and IgM were within normal limits. Bone marrow examination showed normal cellular marrow containing 6.3% of plasma cells with no abnormal features. No chromosomal abnormality was observed at all. The patient was diagnosed as having monoclonal gammopathy of undetermined significance. The bone marrow plasma cells possessed free kappa- and lambda-chains in Golgi apparatus, rough endoplasmic reticula and cytoplasmic matrices. Plural light chains were simultaneously produced with the same heavy chain in a plasma cell by immunoelectron microscopy. This is the first report in the world of a monoclonal gammopathy of undetermined significance producing plural light chains with the same heavy chain. 相似文献
956.
957.
Female Cycnotrachelus roelofsi (Coleoptera: Attelabidae) construct two types of leaf roll, i.e., cut-off cradles (CCs) and suspended cradles (SCs), in which
to lay eggs; these cradles are generally constructed using older and younger leaves, respectively. We conducted two experiments
to determine whether the quality of cradle leaves affects egg and larval survival. In the first experiment, we severed all
SCs from a tree and placed them on the ground with unmanipulated CCs in the early breeding season. In the second experiment,
we resuspended all CCs in a tree with unmanipulated SCs in the late breeding season. We also compared leaf mass per area (LMA),
polyphenol content, and nitrogen content between the two cradle types to determine whether there were any differences in leaf
quality. Larval mortality, probably caused by cradle herbivory, was significantly greater in severed SCs than in intact CCs
in the early season, suggesting that leaf quality had a profound effect on larval mortality in the terrestrial microhabitat.
In contrast, larval mortality did not differ between resuspended CCs and intact SCs in the late season, suggesting that leaf
quality had little effect on larval mortality in the arboreal microhabitat. LMA was higher in CCs than in SCs, but there were
no differences in the nitrogen and polyphenol contents. These results suggest that cradles constructed using mature, tough
leaves were more effective against terrestrial cradle herbivores than those constructed using new, soft leaves. 相似文献
958.
959.
Hagiwara D Matsubayashi Y Marui J Furukawa K Yamashino T Kanamaru K Kato M Abe K Kobayashi T Mizuno T 《Bioscience, biotechnology, and biochemistry》2007,71(3):844-847
We recently compiled a complete list of phosphorelay signal transduction components in the model filamentous fungus Aspergillus nidulans. In this study, we characterized a histidine protein kinase (designated NikA) that is found in many fungi, with special reference to responses to potent fungicides (iprodione and fludioxonil). We provided evidence that not only NikA, but also two downstream response regulators (SskA and SrrA) are crucially implicated in the mode of action of these fungicides, and also that the further downstream HogA-MAPK cascade is exaggerated abnormally (or ectopically) in hyphae by the fungicides in a manner dependent on the NikA-SskA phosphorelay. 相似文献
960.
Haploid sporophytes of Osmunda claytoniana (2n = x = 22) were apogamously produced from calli when cultivated on a hormone-free medium. Flow cytometric analysis showed that
ploidy chimeras were spontaneously produced in a haploid sporophyte of O. claytoniana and those of O. japonica that were obtained in the previous study. In the haploid sporophyte of O. claytoniana, a diploid pinnule and a partially diploid terminal segment were produced in a haploid pinna. In O. japonica, a haploid sporophyte yielded a diploid pinna in a haploid frond, and another haploid sporophyte yielded a diploid pinnule
in a haploid pinna. Diploid chimeras were large in size and could be readily distinguished from other haploid parts of the
fronds. It is likely that the chimeras were produced clonally from a single diploid cell that established chromosome doubling. 相似文献