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121.
122.
以栽培稻的8个籼-粳测验种为对照,采用39对SSR引物检测了江永野生稻居群在1982年、2008年、2017年的遗传多样性,采用38对In Del引物检测了江永野生稻居群在1982年、2008年、2017年的籼-粳基因频率。结果表明:在1982年取样保存在异位圃的40份样本的遗传多样性稍高于2008年、2017年原位保护区样本的遗传多样性;2008年取的样本数虽然比2017年多,但两次取的样本之间遗传多样性几乎没差异。不同年份取的样本之间的遗传分化系数Fst都很小,基因流Nm都较大,分化不明显。通过聚类分析和主坐标分析(PCo A),发现野生稻居群与4份栽培粳稻聚为一类,4份栽培籼稻单独聚成一类,显示江永野生稻与粳稻的血缘近于籼稻;籼-粳基因频率的分析表明,野生稻样本多属粳稻型,少数属偏粳稻型,原位保护区的偏粳稻类型单株数占取样单株总数的比例,2008年比1982年的增加了10.0%,2017年比2008年的增加了1.6%,显示江永野生稻原位保护区生境条件有利野生稻从粳稻型向偏粳稻型变异,随着野生稻产生环境适应性变异,籼型基因频率在提高。  相似文献   
123.
Previous studies show that the proliferation of human mesangial cells (HMCs) played a significant part in the pathogenesis of Henoch‐Schönlein purpura nephritis (HSPN). The aim of this study was to explore the proliferation of HMCs induced by IgA1 isolated from the sera of HSP patients. HMCs were cultured in three different types of media, including IgA1 from patients with HSP (HSP IgA1 group), healthy children (healthy IgA1 group) and medium (control group). The proliferation of HMCs incubated with IgA1 was determined by cell counting kit‐8 assay and bromodeoxyuridine incorporation. The expression of ERK1/2 and phosphatidylinositol 3 kinase/protein kinase B/mammalian targets of the rapamycin (PI3K/AKt/mTOR) signals and transferrin receptor (TfR/CD71) was detected with the methods of immunoblotting. The results indicated that the proliferation of HMCs significantly increased in the HSP IgA1 group compared with that in the control group or the healthy IgA1 group (P < 0.001). Moreover, we found that IgA1 isolated from HSP patients activated ERK and PI3K/AKt/mTOR signals, and markedly increased TfR/CD71 expression in HMCs. These effects induced by IgA1 isolated from patients with HSP were inhibited by human TfR polyclonal antibody (hTfR pAb) and soluble human transferrin receptor (sTfR), indicating that IgA1‐induced HMC proliferation and ERK1/2 and PI3K/AKt/mTOR activation were dependent on TfR/CD71 engagement. Altogether, these data suggested that TfR/CD71 overexpression and ERK1/2 and PI3K/AKt/mTOR activation were engaged in HMC proliferation induced by IgA1 from HSP patients, which might be related to the mesangial injury of HSPN.  相似文献   
124.
The paper reports 13 species from Yaoluoping National Nature Reserve,Anhui,China,including a new species and a new subspecies,Tipula (Emodotipula) alexanderi Men,sp.nov.and Nephrotoma impigra anqingensis Men,subsp.nov.The female of Libnotes (Libnotes) pseudonohirai Men,2015 is described and illustrated for the first time.The males of Holorusia henana Yang,1999 and Tipula (Vestiplex)jiangi Yang & Yang,1991 are redescribed and illustrated with new morphological characters.A key to all species is provided.  相似文献   
125.
A so-called "green protein" has been purified from a moderate halophilic eubacterium, Bacillus halodenitrificans (ATCC 49067), under anaerobic conditions. The protein, which might play an important role in denitrification, dissociates mainly into two components after exposure to air: a manganese superoxide dismutase (GP-MnSOD) and a nucleoside diphosphate kinase. As a first step in elucidating the overall structure of the green protein and the role of each component, the 2.8-A resolution crystal structure of GP-MnSOD was determined. Compared with other manganese dismutases, GP-MnSOD shows two significant characteristics. The first is that the entrance to its substrate channel has an additional basic residue-Lys38. The second is that its surface is decorated with an excess of acidic over basic residues. All these structural features may be related to GP-MnSOD's high catalytic activity and its endurance against the special cytoplasm of B. halodenitrificans. The structure of GP-MnSOD provides the basis for recognizing its possible role and assembly state in the green protein.  相似文献   
126.
石刁柏已形成细胞的幼嫩胚乳,接种在附加有不同浓度的生长素(NAA)和细胞分裂素(BA)的 MS 培养基上,获得了愈伤组织。愈伤组织的诱导频率随生长素的浓度不同而异,可达65.9—83.1%。将胚乳愈伤组织转移到降低了生长素浓度或只含有低浓度生长素的分化培养基上,可陆续分化芽、根、芽丛和少量胚状体,个别的芽和胚状体能发育成小植株。切取1.5—5cm 长的芽,接种在诱导根的培养基上,或在 IBA50ppm 溶液中浸泡2小时,转移到 MS 基本培养基上,部分芽能生根形成完整植株。  相似文献   
127.
用Ca2+ 和胰酶处理大叶藻(Zostera m arina)叶绿体膜研究了其类囊体膜多肽成分与Mg2+ 诱导其Chla荧光和类囊体膜表面电荷变化之间的相互关系,观察到:1.在正常的叶绿体膜中,Mg2+ 诱导PSⅡ荧光强度的增高与其诱导类囊体膜表面电荷密度的降低密切相关;2.用Ca2+ 处理这种叶绿体膜,除去类囊体膜表面的32~34 kD多肽对Mg2+ 诱导的上述现象无影响;3.如果用胰酶消化Ca2+ 处理过的叶绿体膜,进一步除去膜表面的26 kD多肽,Mg2+诱导的这些现象则全部消失。这些实验结果清楚地表明,在大叶藻的叶绿体膜中,类囊体膜表面的26 kD 多肽是阳离子诱导这两种相关现象的特异性作用部位。对阳离子调节激发能在PSⅡ和PSⅠ之间分配的机理进行了讨论  相似文献   
128.
Gui C  Hagenbuch B 《Biochemistry》2008,47(35):9090-9097
Human organic anion transporting polypeptides (OATP) 1B1 and 1B3 are multispecific transporters that mediate uptake of amphipathic organic compounds into hepatocytes. The two OATPs contain 12 transmembrane domains (TMs) and share 80% amino acid sequence identity. Besides common substrates with OATP1B1, OATP1B3 specifically transports cholecystokinin octapeptide (CCK-8). To determine which structural domains and/or residues are important for the substrate selectivity of OATP1B3, we constructed a series of chimeric proteins between OATP1B3 and 1B1, expressed them in HEK293 cells, and determined rates of uptake of CCK-8 along with surface expression of the proteins. Replacing TM10 in OATP1B3 with TM10 of OATP1B1 resulted in a dramatically reduced degree of CCK-8 transport, indicating that TM10 is crucial for recognition and/or translocation of CCK-8. Using site-directed mutagenesis, we identified three key residues within TM10, namely, Y537, S545, and T550. When we replaced these residues with the corresponding amino acid residues found in OATP1B1, the level of CCK-8 transport was similarly low as for the replacement of the whole TM10. Kinetic experiments showed that the K m values for CCK-8 transport in the TM10 replacement and triple mutant were only 1.3 and 1.1 microM, respectively, as compared to 16.3 microM for wild-type OATP1B3. Similarly, the V max values dropped from 495.5 pmol (normalized mg) (-1) min (-1) for wild-type OATP1B3 to 13.3 and 19.0 pmol (normalized mg) (-1) min (-1) for the TM10 replacement and triple mutant, respectively. Molecular modeling indicated that two of the three identified residues might form hydrogen bonds with CCK-8. In conclusion, we have identified three amino acid residues (Y537, S545, and T550) in TM10 of OATP1B3 that are important for CCK-8 transport.  相似文献   
129.
Due to increasing applications of lanthanides (Ln) in industry and daily life, numerous studies confirmed that Ln exposure may result in organ damages in mice and rats, while very few studies focused on several organs damages simultaneously. In order to compare the toxicity of Ln on organs, mice were exposed to LaCl(3), CeCl(3), and NdCl(3) of a dose of 20 mg/kg body weight for consecutive 60 days, respectively, then histopathological changes of liver, kidney, and heart, and their function were investigated. The results showed that long-term exposure to Ln caused cell necrosis and basophilia of liver, ambiguity of renal tubule architecture, congestion of blood vessel and capillary of kidney, and heart hemorrhage. The histopathological changes of liver, kidney, and heart in mice caused by Ce(3+) was most severe; the effect by Nd(3+) was slighter than Ce(3+) but more severe than La(3+). The assay of serum biochemical parameters suggested that Ln exposure severely impaired the functions of liver, kidney, and myocardium in mice. These findings suggested that long-term exposure to Ln resulted in histopathological changes of liver, kidney, and heart, and their function damages. Therefore, we thought that long-term application of the products containing Ln on human should be cautious.  相似文献   
130.
Chang J  Wang M  Gui W  Zhao Y  Yu L  Zhu G 《Zoological science》2012,29(3):181-184
The zebrafish (Danio rerio) has been used as a model for the study of endocrine disrupting chemicals. This study set out to determine the profiles of whole-body thyroxine (T4) and 3,5,3'-triiodothyronine (T3) levels during the development of zebrafish from embryo to adult. Enzyme-linked immunoassay was used to analyze whole-body T4 and T3 contents. The results showed that whole-body T4 and T3 levels remained stable during the pre-hatching period (0-3 d) and increased significantly during early development after hatching. The T3 level peaked at 0.28 ± 0.01 ng g(-1) body weight at 10 days post-fertilization (dpf), and T4 peaked at 0.58 ± 0.09 ng g(-1) body weight at 21 dpf. Both thyroid hormones subsequently declined during later development. This study establishes a baseline for thyroid hormones in zebrafish, which will be vital for the understanding of thyroid hormone functions and in future studies of thyroid toxicants in this species.  相似文献   
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