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121.
中国稻蝗属细胞分类学研究(英文) 总被引:4,自引:0,他引:4
本文对分布于中国境内11省区,27个采集地点的八种稻蝗进行了染色体C带核型比较研究。结果表明:中华稻蝗Oxya chinensis,上海稻蝗O.shanghaiensis,无齿稻蝗O.adentata C带分布型式相似,但染色体分组型式、交叉定位数据以及异染色质含量具有差异;山稻蝗O.agauisa具有本身独特的带纹结构,与本属其它种类迥异;双带稻蝗O.bicingula染色体带型结构相似于山稻蝗及中华稻蝗类群,表明三者在进化历程中有一定联系。小稻蝗O.hyla intricata中一个亲缘种团(Sibling species group),体现在种内的形态差异及染色体带型结构的不同。显示该种近期内分化速率较高。据此,本文讨论了稻蝗属内八个种相互间的亲缘关系和分类地位,本文认为稻蝗属内务物种进化速率是不均衡的,这种状态应归因于各物种的遗传背景和环境因素的影响。 相似文献
122.
Transcription-Independent Activation of Ornithine Decarboxylase Activity by Heparin in Cloned Cerebral Endothelial Cells 总被引:1,自引:1,他引:0
H. Bauer A. Amberger H. C. Bauer G. Webersinke O. Zach J. W. Olson† B. Hennig† 《Journal of neurochemistry》1993,60(4):1520-1524
Abstract: Heparin, a highly sulfated glycosaminoglycan, is known to be obligatory for long-term endothelial cell cultures; it potentiates the mitogenic activities of endothelial cell growth factors and prolongs the replicative life span of the cells. Here we have shown that besides its growth factor-supportive role, heparin exerts a specific action on cerebral capillary endothelial cells (cECs), unrelated to serum or growth factors, by increasing activity of ornithine decarboxylase (ODC; EC 4.1.1.17) in these cells. For our experiments we have used two different types of cloned cECs: type I cECs, grown in the presence of endothelial cell growth factor and heparin, and type II cECs, usually cultivated without growth factors. Heparin action on ODC activity was shown to be dose dependent within the range of 1–100 μg/ml. Increasing concentrations of or depletion of endothelial cell growth factor from type I cultures had no effect on ODC activity. The increase in enzyme activity was highest after 30 min to 1 h of heparin treatment. As evidenced by northern analysis, the heparin-mediated enhancement of ODC activity was not accompanied by changes of ODC mRNA levels. Studies of DNA replication revealed that in the absence of heparin-binding growth factors, heparin did not affect the proliferative activity of cloned cECs. 相似文献
123.
Jeffrey S. Chamberlain Michael Boehnke Thomas S. Frank Sam Kiousis Junxhe Xu Sun-Wei Guo Elizabeth R. Hauser Robert A. Norum Elizabeth A. Helmbold Dorene S. Markel Sima M. Keshavarzi C. Eugene Jackson Kathleen Calzone Judy Garber Francis S. Collins Barbara L. Weber 《American journal of human genetics》1993,52(4):792-798
Previous studies have demonstrated linkage between early-onset breast cancer and ovarian cancer and genetic markers on chromosome 17q21. These markers define the location of a gene (BRCA1) which appears to be inherited as an autosomal dominant susceptibility allele. We analyzed five families with multiple affected individuals for evidence of linkage to the BRCA1 region. Two of the five families appear to be linked to BRCA1. One apparently linked family contains critical recombinants, suggesting that the gene is proximal to the marker D17S579 (Mfd188). These findings are consistent with the maximum-likelihood position estimated by the Breast Cancer Linkage Consortium and with recombination events detected in other linked families. Linkage analysis was greatly aided by PCR-based analysis of paraffin-embedded normal breast tissue from deceased family members, demonstrating the feasibility and importance of this approach. One of the two families with evidence of linkage between breast cancer and genetic markers flanking BRCA1 represents the first such family of African-American descent to be reported in detail. 相似文献
124.
用快中子照射红粒济宁3号小麦干种子,后代获得白粒植株,经选育而成白粒济宁3号。白粒济宁3号与红粒济宁3号比,除籽粒颜色差别外,籽粒蛋白含量显著高于红粒济宁3号,而落黄性、籽粒饱满度、千粒重、产量均略低于红粒济宁3号,该品种累计种植面积10余万亩。 相似文献
125.
Huili Feng Jiahuan Guo Changhui Peng Daniel Kneeshaw Gabrielle Roberge Chang Pan Xuehong Ma Dan Zhou Weifeng Wang 《Global Change Biology》2023,29(14):3970-3989
A significant increase in reactive nitrogen (N) added to terrestrial ecosystems through agricultural fertilization or atmospheric deposition is considered to be one of the most widespread drivers of global change. Modifying biomass allocation is one primary strategy for maximizing plant growth rate, survival, and adaptability to various biotic and abiotic stresses. However, there is much uncertainty as to whether and how plant biomass allocation strategies change in response to increased N inputs in terrestrial ecosystems. Here, we synthesized 3516 paired observations of plant biomass and their components related to N additions across terrestrial ecosystems worldwide. Our meta-analysis reveals that N addition (ranging from 1.08 to 113.81 g m−2 year−1) increased terrestrial plant biomass by 55.6% on average. N addition has increased plant stem mass fraction, shoot mass fraction, and leaf mass fraction by 13.8%, 12.9%, and 13.4%, respectively, but with an associated decrease in plant reproductive mass (including flower and fruit biomass) fraction by 3.4%. We further documented a reduction in plant root-shoot ratio and root mass fraction by 27% (21.8%–32.1%) and 14.7% (11.6%–17.8%), respectively, in response to N addition. Meta-regression results showed that N addition effects on plant biomass were positively correlated with mean annual temperature, soil available phosphorus, soil total potassium, specific leaf area, and leaf area per plant. Nevertheless, they were negatively correlated with soil total N, leaf carbon/N ratio, leaf carbon and N content per leaf area, as well as the amount and duration of N addition. In summary, our meta-analysis suggests that N addition may alter terrestrial plant biomass allocation strategies, leading to more biomass being allocated to aboveground organs than belowground organs and growth versus reproductive trade-offs. At the global scale, leaf functional traits may dictate how plant species change their biomass allocation pattern in response to N addition. 相似文献
126.
药用寄生植物菟丝子属,列当属和无根藤属氨基酸的分析 总被引:1,自引:0,他引:1
本文测定了菟丝子属、列当属和无根藤属某些种的种子和植株氨基酸的种类组成和含量。结果表明,3个属种子和植株氨基酸均在15种以上,且含量丰富,特别是必需氨基酸的含量较高。文中讨论了氨基酸的药用和在种子鉴定与化学分类上的作用,探讨了开发应用的前景。 相似文献
127.
黑木耳8808菌株,是笔者几年来,从黑龙江省15个地区,采集的32个样本中,分离的59个野生菌株中,经多次培养、比较,栽培试验选出的一株优质、高产菌株。该菌株1992年,在本省五常县长山乡生产150万袋,全省生产近1000万段,均获丰收,产量、质量均明显优于原生产菌株。为更好的为生产提供科学依据,本文研究了该木耳孢子弹射及萌发特征,菌丝、子实体、孢子形态,不同温度、pH、氮碳源浓度,不同培养料配方对该木耳菌丝生长及产实影响。 相似文献
128.
129.
本文报道了在国内首次用转移因子制剂治疗奶牛隐性乳房炎的效果。我们采用的转移因子制剂是本单位从健康猪脾细胞提取的,经按人用转移因子制检规程检测达到要求后,用于本省西部、东部和郊区三个奶牛场计159头患隐性乳房炎的奶牛,每天一次肌注,连续用药5次,测定用药前后的客观指标(CMT、BTB、苛性钠及氯化物凝乳试验等),以痊愈、显效、好转及无效等判定标准,经统计学处理后看出,用药后与用药前比较,差异非常显著(P<0.01),治疗组的有效率为91.2%,看出了应用转移因子治疗奶牛隐性乳房炎具有明显的治疗效果。 相似文献
130.
Qihe Tang Wanli Li Zhengwei Wang Zhixiang Dong Xijie Li Jiali Li Qi Huang Zhe Cao Wei Gong Yazhou Zhao Minzeng Wang Jun Guo 《Environmental microbiology》2023,25(10):2020-2031
Honeybee (Apis mellifera) ingestion of toxic nectar plants can threaten their health and survival. However, little is known about how to help honeybees mitigate the effects of toxic nectar plant poisoning. We exposed honeybees to different concentrations of Bidens pilosa flower extracts and found that B. pilosa exposure significantly reduced honeybee survival in a dose-dependent manner. By measuring changes in detoxification and antioxidant enzymes and the gut microbiome, we found that superoxide dismutase, glutathione-S-transferase and carboxylesterase activities were significantly activated with increasing concentrations of B. pilosa and that different concentrations of B. pilosa exposure changed the structure of the honeybee gut microbiome, causing a significant reduction in the abundance of Bartonella (p < 0.001) and an increase in Lactobacillus. Importantly, by using Germ-Free bees, we found that colonization by the gut microbes Bartonella apis and Apilactobacillus kunkeei (original classification as Lactobacillus kunkeei) significantly increased the resistance of honeybees to B. pilosa and significantly upregulated bee-associated immune genes. These results suggest that honeybee detoxification systems possess a level of resistance to the toxic nectar plant B. pilosa and that the gut microbes B. apis and A. kunkeei may augment resistance to B. pilosa stress by improving host immunity. 相似文献