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81.
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
82.
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
83.
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
84.
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
85.
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
86.
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
87.
Yong Qian Wu Timothy Lawrence Jun Qing Guo Patrick M. Woster 《Bioorganic & medicinal chemistry letters》1993,3(12):2811-2816
A pair of -cyano analogues of decarboxylated S-adenosylmethionine (2a and 2b) were synthesized as potential enzyme activated, irreversible inhibitors of the[pyruvoyl enzyme S-adenosylmethionine decarboxylase (AdoMet-DC). Each of these analogues acts as an irreversible inactivator for ADoMet-DC from Escherichia coli (IC50 values of 9 and 50 μM, respectively). These analogues also inactivate human AdoMet-DC, with KI values of 246.6 and 7.2 μM, and kinact values of 0.29 and 0.03 min−1, respectively. 相似文献
88.
为比较山美水库两种入侵齐氏罗非鱼(Coptodon zillii)和伽利略罗非鱼(Sarotherodon galilaeus)种群的繁殖生物学特征,于2021年3—10月份在山美水库逐月采样,分析了繁殖时间、性比、绝对繁殖力、相对繁殖力和成熟卵径等特征。结果表明,两种罗非鱼均于4月份开始繁殖,齐氏罗非鱼繁殖高峰为7月, 10月结束繁殖;伽利略罗非鱼繁殖高峰为6月, 9月结束繁殖。齐氏罗非鱼平均绝对繁殖力为(4009.85±1305.69)粒、平均体重相对繁殖力为(67.32±15.63)粒/g、平均体长相对繁殖力为(31.31±5.03)粒/mm;伽利略罗非鱼平均绝对繁殖力为(1701.85±591.29)粒、平均体重相对繁殖力为(6.46±0.87)粒/g、平均体长相对繁殖力为(8.22±2.33)粒/mm;齐氏罗非鱼的绝对繁殖力、体重相对繁殖力和体长相对繁殖力均显著高于伽利略罗非鱼,平均成熟卵径则显著小于伽利略罗非鱼。齐氏罗非鱼和伽利略罗非鱼繁殖群体的雌雄性比分别为1.59和1.83,两个种群的雌雄性比无显著差异,但均显著偏离1﹕1。研究表明两种共同入侵的罗非鱼种群具有不同的繁殖... 相似文献
89.
90.
甘蓝型油菜子叶和下胚轴再生植株无性系建立 总被引:4,自引:1,他引:3
以甘蓝型油菜(Brassica napus L.)豫油2号和6257的子叶和下胚轴为材料,在不同激素配比的MS培养基上诱导出了愈伤组织。将经过继代的部分愈伤转入分化培养基,分化结果表明:除基因型、外植体和分化培养基的激素配比对分化率有影响外,诱导愈伤培养基的激素配比对分化率也至关重要。豫油2号的子叶和下胚轴在最适诱导培养基(ZT 1+NAA0.5+2,4-D 0.2 mg/L)和最适分化培养基(ZT4+IAA 0.2 mg/L)组合中的愈伤分化率分别为12.5%和75%;6257的子叶和下胚轴在其最适诱导培养基(KT 2+NAA1+2,4-D 0.2 mg/L)和最适分化培养基(6-BA 4+IAA 0.02 mg/L)组合中的愈伤分化率分别为50%和37.5%。将其最适诱导培养基中的愈伤组织继代达8个月以上,建立了不同继代愈伤的再生植株无性系。 相似文献