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遗传漂变教学方法刍议 被引量:2
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作者 王春明 林昌俊 冯虎元 《遗传》 CAS CSCD 北大核心 2020年第12期1211-1220,共10页
遗传漂变是影响群体遗传平衡的4个重要因素之一。因为它的作用形式不如突变、选择、迁移这3个因素那么直观易懂,所以在理解和掌握上存在较大的困难。尤其目前国内外教材中关于遗传漂变内容的介绍系统性不足,要么过于粗略,要么完全忽视... 遗传漂变是影响群体遗传平衡的4个重要因素之一。因为它的作用形式不如突变、选择、迁移这3个因素那么直观易懂,所以在理解和掌握上存在较大的困难。尤其目前国内外教材中关于遗传漂变内容的介绍系统性不足,要么过于粗略,要么完全忽视了二项式定理这样的数学基础,造成了遗传漂变学习长期不到位的困难局面。本文总结得出遗传漂变的5个基本属性,即固有性、普遍性、随机性、无方向性、有规律性。进而从遗传漂变的遗传基础是雌雄配子的自由组合出发,指出抽样误差属性是遗传漂变固有的本质特征,并循序渐进地从N=1这样仅仅由1个个体组成的极端小群体出发,推演出遗传漂变随着群体变大而影响减弱的性质,通过二项式定理数学模型、二项分布的特点、以及计算机模拟结果,形象直观地展示遗传漂变的作用,助力遗传漂变教学。 展开更多
关键词 遗传漂变 群体 遗传平衡 二项式定理 二项分布 抽样误差
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粗糙脉孢菌7种子囊型归类教学探究 被引量:1
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作者 王春明 孙英莉 +4 位作者 林昌俊 王铭裕 牛月 李晓峰 冯虎元 《遗传》 CAS CSCD 北大核心 2019年第11期1067-1072,共6页
遗传分析是本科遗传学教学的重要内容,四分子分析是真菌类遗传分析的独特方式,其中的粗糙脉孢菌顺序四分子分析不仅可以研究基因与着丝粒间的重组、基因间的重组,而且还可以精细研究同源染色体非姊妹染色单体之间的交换形式,是深入理解... 遗传分析是本科遗传学教学的重要内容,四分子分析是真菌类遗传分析的独特方式,其中的粗糙脉孢菌顺序四分子分析不仅可以研究基因与着丝粒间的重组、基因间的重组,而且还可以精细研究同源染色体非姊妹染色单体之间的交换形式,是深入理解交换重组分子机制的重要遗传学研究材料。对此,教材中已有详尽的介绍。美中不足的是,中外教科书和相关专业期刊中缺乏对顺序四分子两基因连锁分析中7种基本子囊型归纳方法的具体介绍,令相关内容的学习留下疑惑。本文从顺序四分子两基因连锁遗传分析过程中涉及的3种四分子类型(PD、NPD和T)与两基因4种分离时期组合(ⅠⅠ,ⅡⅡ,ⅠⅡ,ⅡⅠ)的相互关系入手,设计表格,直观展现了二者的12种可能组合结果(3×4=12),并应用直观的对错符号(√、×),同时结合表后的3项分析,排除了其中的5种组合形式,最终归纳得到7种基本子囊型。本文提供了7种基本子囊型具体的归纳分析方法,解决了相关教学内容的论述不足问题,以期为真菌类顺序四分子遗传分析的教学提供帮助。 展开更多
关键词 真菌 顺序四分子 基本子囊型 四分子分析 遗传分析
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Bioaccumulative Characteristics of Polybrominated Diphenyl Ethers in Channel Catfish and Fish Feeds from China
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作者 Xiaozhong Hu Decong Hu +1 位作者 Bin Wu changjun lin 《Journal of Environmental Protection》 2014年第11期936-948,共13页
PBDEs are widely used brominated flame retardant, which are increasingly reported in the environment. Concentrations of thirteen PBDEs in a large number of channel catfish and fish feeds collected from Hubei province ... PBDEs are widely used brominated flame retardant, which are increasingly reported in the environment. Concentrations of thirteen PBDEs in a large number of channel catfish and fish feeds collected from Hubei province of China were investigated in this study. A fast isotopic dilution GC-MS method was firstly developed to simultaneously determine thirteen PBDEs in channel catfish and fish feeds in this study, and especially for the first time PBDEs in fish feeds. Pressurized liquid extraction and multi-layer silica gel column chromatography cleanup were used, some important steps and crucial parameters were modified and intensified compared with other literatures, and GC and MS conditions were optimized. The limits of quantitation values of 0.25 - 5 μg·kg-1 wet weight in channel catfish were calculated for PBDEs;so did 1 - 20 μg·kg-1 wet weight in fish feeds. In addition, good repeatability and accuracy of the whole method were achieved. The established methods were therefore suitable for the simultaneous determinations of thirteen PBDEs in these samples at trace contamination levels. Using the established methods, PBDEs emerged in 10 of 180 channel catfish and 13 of 115 fish feeds, and the dominant PBDEs homologues were PBDE-28, PBDE-47, PBDE-100, PBDE-99, PBDE-154, PBDE-153 and PBDE-183. The detection rates of seven PBDEs congeners were in turn respectively 1.74%, 7.83%, 4.35%, 5.22%, 3.48%, 2.61% and 2.61% in fish feeds, and detection rates of seven PBDEs congeners were in turn respectively 1.11%, 3.89%, 2.22%, 1.67%, 1.11%, 1.11% and 1.11% in channel catfish. There was significant correlation in PBDEs between matching channel catfish and fish feeds (R2 = 0.742, P < 0.001, n = 30), suggesting that fish feeds contaminated with PBDEs possibly resulted in PBDEs residual in channel catfish through biological transfer. 展开更多
关键词 Polybrominated DIPHENYL ETHERS (PBDEs) Channel CATFISH FISH Feeds Bioaccumulative CHARACTERISTICS GC-MS
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