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1.
谭信TAN  Xin 《遗传》1993,15(6):5-8
本文应用数量遗传学方法,结合概率运算,从理论上分析了由X连锁基因控制的性状在雌雄群体中的变异情况。表明雄(男)性群体的这类性状遗传变异范围有大于雌(女)性群体的倾向。对这一问题的探讨,将有助于对X连锁基因及所决定性状的遗传特性、进化特点及基因定位等的研究提供新的思路。  相似文献   
2.
一种简单、经济的植物RNA抽提方法   总被引:3,自引:0,他引:3  
一种简单、经济的植物RNA抽提方法孟玲谭德勇王焕效吕朝晖王晓燕周翔(云南大学生物系,昆明650091)ASimpleEconomicalMethodfortheIsolationofPlantRNAMENGLingTANDeyongWANGHuanx...  相似文献   
3.
对取自MAPMAKER软件小鼠F2群体(含333个体)的5个RFLP连锁标记数据作了共显性分子标记偏分离的分析。先确定选择类型的方程组(配子或合子),随后采用Newton-Raphson迭代法估算标记间的重组值。在构建分子标记遗传图谱时,如果两个相邻标记均存在偏分离,最好采用纳入偏分离因子的估算方法。在估计F2群体标记间偏分离重组距离上,用连续χ2检测方法比传统χ2检测更为准确。Abstract The comparative analysis of segregation distortions of the codominant markers data presented in software MAPMAKER are made, where five RFLPs markers involve in a mouse F2 population with 333 individuals. The successive χ2 test begins with the determinations of gametic or zygotic selection types, followed by the estimation of recombination fractions between two markers with the Newton-Raphson iteration method. It is better to use the molecular marker showing segregation distortion for constructing a genetic map, in the case of seriously skew segregation between both the adjoining markers. The successive χ2 test provides better accuracy than that of classical χ2 test for the estimation of the recombination values in F2 population with segregation distortion.  相似文献   
4.
秦岭川金丝猴的一次家庭雄性替代   总被引:3,自引:2,他引:1  
家庭雄性替代已在亚洲叶猴的许多种类中有所报道。 2 0 0 3年 ,我们在一种亚洲叶猴———秦岭的川金丝猴 (Rhinopithecusroxellana)的一个单雄家庭中观察到一次完整的家庭雄性替代过程。此次替代发生于 4月 2 8日 - 5月 2日的五天时间内。在家庭雄性发生替代后的第六个月 ,该家庭中的婴猴消失。本文是首次对野生川金丝猴家庭雄性替代进行详细的报道。通过本次观察证明野生川金丝猴的确存在家庭雄性替代的现象。且像亚洲叶猴的许多种类一样 ,野生川金丝猴的家庭雄性替代同样发生于产仔季节和交配季节之间。但我们仍无法确定在本次雄性替代中婴猴最终的消失是否是雄性杀婴的结果  相似文献   
5.
肠道微生物与寄主具有复杂的、多方面的相互依存效应,这种依存效应所产生的共生关系或协同进化关系既可反映寄主间的系统演化关系,也可显示肠道微生物间的系统演化关系,共生关系或协同进化关系是由于寄主与肠道微生物两者之间存在着相互自然选择作用所形成的,在长期的进化历程中逐步发生的共生关系信息很可能被记录在DNA序列中。本文通过检测鲤鱼科8种鱼中9种肠道菌群的分布含量对这9种菌群进行分析,且利用从GenBank调取这9种肠道细菌菌属的43个种或亚种的16S DNA序列的构建NJ树和MP树,将这6个科9个属43个种或亚种分为革兰氏阴性和革兰氏阳性两大类群(一级分枝)。在这两类群中,又以科为单位分为6个亚类群(二级分枝),而肠杆菌科中则以属为单位分为4个小类群(三级分枝),此外球状菌与杆状菌也能截然分开。将16S DNA的NJ树隐去所有的种,以属为单位所得到的以分枝形式的无根树在拓扑结构上与菌群分布含量(寄主范围)所构建的无根树相近,但芽孢杆菌在两种无根树的位置中有较大的差异。如果提高检测水平,扩大所检测的寄主对象,这种差异有可能消除。 Abstract:There is a complex- and multi-effect for interdependent survival between intestinal- microorganisms and hosts.The symbiosis or coevolution that results from this effect for interdependent survival is used to reveal the phylogenies of hosts as well as intestinal microorganisms.The symbiosis or coevolution between intestinal microorganisms and hosts has been generated by interactive natural selection occurred between them.The symbiosis information that has been formed by interactive natural selection during a long evolutionary process must be recorded in DNA sequences.According to this point of view,we analyzed the phylogeny of 9 intestinal bacteria genera using their contents in intestines of 8 Cyrinidate species.At the same time,we fetched the 16S rRNA gene DNA sequences of 43 intestinal bacteria species being included in these nine genera of six intestinal families from GeneBank and constructed phylogenetic trees by NJ and MP methods.The NJ tree and MP tree have the same topologic configuration and are identical with the classical phylogenetic tree.Both the trees of 16S rRNA gene separated 43 bacteria species into gram-negative bacteria group and the gram-positive bacteria group,which are the first branches.Each of the first branches (groups) made again 6 subbranches (subgroups) where each subbranch is a family.Especially,the subbranch (subgroup) of enterobacteriaceace made again four small branches as genus taxon.This tree also shows that bacilliform bacterium is distinct from each other in the NJ and MP trees.After all species on the tree are merged,the topological configuration of the unrooted tree of 16S gene is closed to that of the host range unrooted tree.However,the position of bacillus is greatly changed on both the unrooted trees.The difference can be found if we increase the examination level and extend the hosts examed.  相似文献   
6.
Many studies have shown that the ubiq-uitin-proteasome pathway (UPP) for the degradation of short-lived proteins plays a key role in regulating cell cycle progression[1—3]. At least two distinct prote-olytic pathways are required for cell cycle process. The first pathway promotes transition from G1 to S phase, and the second initiates the onset of anaphase and exit from mitosis. The inhibition of UPP will re-sult in the blockage of cell cycle process. The knowl-edge of the role of UPP in…  相似文献   
7.
福建卷柏属植物的物种多样性述评   总被引:3,自引:0,他引:3  
卷柏属Selaginella Beauv.是一个在分类上较困难的类群,种类多,形态变化大。全世界有卷柏属植物750种以上,可以分为5个亚属。2002年10月我们对武夷山脉及周边地区的卷柏种类进行了调查,采集的标本存放于新加坡国立大学标本馆(SINU)和厦门大学标本馆(AU)。此外,我们还认真观察了来自福建师范大学标本馆(FNU)和AU的卷柏标本。结果表明,在福建,卷柏有18种1变种。其中,缘毛卷柏S. ciliaris、白毛卷柏S. albociliata和布朗卷柏S. braunii是福建分布的3个新记录。  相似文献   
8.
The discovery of antibiotics is the miracle of modern medicine,which has contributed greatly to the protection of human health.However,in despite of medical advances to date,some quite inexplicable modern diseases are still haunting us.These chronic diseases are less fierce in fatality,but more permanently compromise the quality of patients′lives.In this paper,the relevant background knowledge about antibiotics were introduced and the relationship between antibiotics and several common chronic diseases was analyzed,in order to promote the rational use of antibiotics and the correct view on antibiotics.  相似文献   
9.
水稻白叶枯病广谱抗性基因Xa21导入两用不育系培矮64S   总被引:17,自引:0,他引:17  
以克隆的Xa21基因为外源基因,成熟胚愈伤组织为转化受体,应用农杆菌介导法对水稻两用型核不育系培矮64S进行转化,获46株转基因植株。PCR和Southern分析结果表明,Xa21已整合到受体基因组。用稻白叶枯病病原菌(Xanthomonasoryzaepv.oryzae)菲律宾小种6号接种鉴定,结果表明大多数转基因植株获得了抗病性。已整合的Xa21基因能够稳定地遗传,在所检测转基因株系的T1代中,Xa21基因显示3:1的分离。  相似文献   
10.
雄性不育嵌合基因的构建及番茄转化研究   总被引:19,自引:1,他引:18  
用从烟草里克隆的TA29启动子分离自Bacillus amyloliquefaciens的核糖核酸酶基因barnase,构建成雄性不育嵌合基因。再用农杆菌介导法转化番茄子叶,获得了具有雄性不育特征的转基因植株。 Abstract:The utilization of heterosis based on male sterility has great significance in raising crop yeld and improving quality.A tapetum-specific promoter TA29 from tobacco young leaves,and a Rnase gene-barnase from Bacillus amyloliquefaciens have been cloned for the construction of male sterile chimeric gene.Transgenic tomato plants with male sterile property have been obtained after transformation with this gene.  相似文献   
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