Evolution in inbred strains of mice appears rapid

Genetic variation at 97 loci in ten commonly used inbred strains of mice is greatly in excess of that expected under current assumptions. Evidence against all of the readily apparent explanations is presented and the possibility of early selection for heterozygosity or of conversion is suggested. The common ancestor of these strains is estimated to have occurred about 150 years ago.     

Correlation between mean litter size and mean life span among 12 inbred strains of mice

In 12 inbred strains of mice there was no general correlation between litter size and parental life span within strains, although a significant between-strain correlation of +0.69 was found between mean life span of the dams and the mean size of their litters. When data for AKR/J mice, which characteristically die early from leukemia, were excluded, the correlation was increased to +0.90 for the remaining 11 strains. These findings indicate that the correlation is of genetic origin-that is, that genes affecting a dam's life span also affect the size of her litters.     

Gene trees and the origins of inbred strains of mice

Extensive data on genetic divergence among 24 inbred strains of mice provide an opportunity to examine the concordance of gene trees and species trees, especially whether structured subsamples of loci give congruent estimates of phylogenetic relationships. Phylogenetic analyses of 144 separate loci reproduce almost exactly the known genealogical relationships among these 24 strains. Partitioning these loci into structured subsets representing loci coding for proteins, the immune system and endogenous viruses give incongruent phylogenetic results. The gene tree based on protein loci provides an accurate picture of the genealogical relationships among strains; however, gene trees based upon immune and viral data show significant deviations from known genealogical affinities.     

大蒜体细胞无性系的电泳图谱分析

利用电泳技术对改良蒜的10个体细胞无性系(F0代)酯酶同工酶、过氧化物酶同工酶和醇溶蛋白进行了研究，电泳图谱分析表明，受检的10个体细胞无性系，其酯酶同工酶和过氧化物酶同工酶均出现了酶活性的变化和酶带条数的减少。对照植株的酯酶同工酶在13区有4条酶带，而G0。、G04、G07、G11、G15、G16、G17、G22、G23等9个无性系只有1～3条酶带，均少于对照，变异率达90％；醇溶蛋白在图谱上也表现出不同无性系之间条带数量的不同及迁移率相同的条带而颜色差异明显。     

Heritability of plasma cholinesterase activity in inbred mouse strains

The activity of cholinesterase was measured in the plasma of 543 mice of both sexes from 23 inbred mouse strains. Differences between strains were highly significant. The heritability of this characteristic was 0.70 in females and 0.67 in males.     

近交系小鼠微卫星位点遗传检测方法的建立

笔者设计了 3 4对特异性引物 ,以 PCR方法对部分近交系小鼠基因组微卫星多态性进行了检测和分析 ,在所有 3 4条引物扩增带中 ,有 2 5个微卫星位点的长度在不同品系小鼠中存在差异 ,不同品系小鼠之间微卫星长度多态性差异在3 8.3 %～ 5 8.8%之间。微卫星多态性分析是一种快速、经济的遗传监测近交系动物的方法 ,微卫星位点提供了检测近交系小鼠遗传特性的又一种新的方法     

Deficiency of a kidney metalloproteinase activity in inbred mouse strains

Kidneys from BALB/c mice contain a potent metalloendoproteinase, termed meprin, that is active against large proteins as well as small peptides. The enzyme is present in mouse strains C57BR/cdJ, C57BL/6J, BALB/cJ, A/J, DBA/IJ, CD/l, Swiss, and ICR. Three related inbred strains, CBA/J, CBA/CaJ, and C3H/He, are markedly deficient in this enzymatic activity. This is the first report of a heritable deficiency of an intracellular proteinase in mammalian tissues. Meprin deficiency appears to have arisen as an early event in the development of the C stock. Furthermore, meprin is present in the progeny of a cross between a meprin-sufficient female (C57BL/6) and a meprin-deficient male (C3H/HeN), an indication that the trait for the deficiency is recessive.     

Synthesis of functional human hemoglobin in transgenic mice

Human alpha- and beta-globin genes were separately fused downstream of two erythroid-specific deoxyribonuclease (DNase) I super-hypersensitive sites that are normally located 50 kilobases upstream of the human beta-globin gene. These two constructs were coinjected into fertilized mouse eggs, and expression was analyzed in transgenic animals that developed. Mice that had intact copies of the transgenes expressed high levels of correctly initiated human alpha- and beta-globin messenger RNA specifically in erythroid tissue. An authentic human hemoglobin was formed in adult erythrocytes that when purified had an oxygen equilibrium curve identical to the curve of native human hemoglobin A (Hb A). Thus, functional human hemoglobin can be synthesized in transgenic mice. This provides a foundation for production of mouse models of human hemoglobinopathies such as sickle cell disease.     

Rapid increase of phenylethanolamine N-methyltransferase by environmental stress in an inbred mouse strains

The activity of-phenylethanolamine N-methyltransferase in mice of the C57Bl/Ka strain was determined after a 4 degrees C stress. The enzyme activity increased 1.2-fold at the end of 3 hours and by 1.4-fold by the end of 6 hours of the stress. The results are in contrast to those from other species with intact animals in which the enzyme changes only after several days of chronic stress. Cycloheximide prevents the rise in enzyme activity, suggesting the increase may be due to protein synthesis. The increase may provide a model system for studying regulation of catecholamine biosynthetic enzymes.     

DNA指纹技术在近交系小鼠遗传检测中的应用研究

采用生物素标记的(GGAT)4寡核苷酸探针对C57BL/6J、BALB/c和DBA/2三种近交系小鼠进行了DNA指纹图分析.结果表明:(GGAT)4寡核苷酸探针对上述3种近交系小鼠产生的DNA指纹图的图带数均为10-12条,具有良好的多态性,品系内平均DNA指纹图的相似系数在0.92~1.00的范围内,具有相同指纹图的概率均在0.40以上,极显著地高于品系间的相似系数(0.21~0.39)和相同指纹图的概率(P<3.10×10-7),说明(GGAT)4寡核苷酸探针可用于制作近交系小鼠的DNA指纹图,以对其进行遗传检测.     

20个骨干玉米自交系的SSR指纹图谱构建

本实验利用80对SSR引物对20个玉米自交系进行扩增,综合考虑扩增带的清晰度及多态性、条带多少、引物重复性高低,筛选出Phi080,Phi123,Umc1061,Phi126,Phi065,Dupssr13,Phi102228,bnlg240,Phi083等9对引物,构建了20个玉米自交系的指纹图谱。其中有7个材料各用1对引物就可确定其特征性谱带,有3个材料各需用2对引物组合就能区分,有2个材料需4对引物组合方能予以有效区分,其余材料则需8对引物组合才可区分。本实验还对这9对引物的重复性作了验证,再次证明利用SSR标记构建玉米自交系指纹图谱是可行的,也是可靠的。     

甘蓝“129”自交不亲和系种子生长发育规律研究

通过对甘蓝"129"自交不亲和系角果和种子生长发育测定研究,结果表明,种荚长和种荚直径在授粉后第30d达最大;种子直径、种荚及种子鲜重在授粉30d后达最大值;种子干重在授粉40d后达最大值;种子发芽率及活力指数在授粉50d后最高.     

玉米自交系苞叶表型可塑性差异分析

为确定玉米5大杂优群苞叶表型可塑性在异地引种的稳定性和敏感性,收集了我国玉米5大杂优群50份自交系,2014年在海南省三亚市、2015年在北京市和2017年在辽宁省铁岭市3种环境下测定各杂优群的自交系在不同环境的苞叶性状,计算苞叶性状的变异系数,分析杂优群间苞叶长度可塑性(phenotypic plasticity of husk length, PHL)、宽度可塑性(phenotypic plasticity of husk width, PHW)和层数可塑性(phenotypic plasticity of husk layer number, PHN)的差异和杂优群内的相关性,比较不同环境和生长时期各气象因子的变化。结果显示:苞叶性状受环境影响显著;在全部测定群体、旅大红骨和唐四平头群中PHL与PHW呈显著正相关,在瑞德群中PHL与PHN呈极显著负相关;不同血缘玉米种质的苞叶表型可塑性存在明显差异,PHL与PHW表现出协同调控的特点;旅大红骨群的苞叶长度和PB群的苞叶长度、宽度对环境不敏感,这2个性状异地引种时会保持稳定;兰卡斯特群PHL较大,且符合苞叶性状南长北短的要求,这类育种材料适合南北方异地引种;气象因子中平均温度和湿度在玉米生长前期差异较大,日照时间在玉米生长的前、中和后期都有一个差异较大的时段。因此,高温区适时早播,低温区适时晚播,有利于减少环境间的苞叶差异。     

玉米四类种质与自330杂交模式的分析

以四类种质的12个代表自交系及自330按完全双列杂交组成的78个组合为材料，对四类种质与自330杂交模式进行综合分析，结果表明，在夏播条件下，唐四平头系统、Mo17亚群与自330杂交模式，生育期和株高适中，具有长穗、大粒、高产的特点，是筛选夏播玉米品种较为理想的模式。     

白菜型油菜品种间和自交系间杂种优势效应分析

本试验主要研究了白菜型油菜品种间和自交系间的杂种优势效应。６个白菜型油菜品种间的１５个组合产量测定结果。除３个组合具有正向超亲优势外（优势率为１．４％、６．０％和８．４％）,其余给合均表现为负向超亲优势。４个自交系间１２个杂交组合产量测定结果,９个组合具有正向超亲优势,其中５个组合的超亲优势达２５．０％～９６．４％,它们中有３个组合具有超标准品种优势（优势率在１３．５８％～３５．８０％之间）。表明     

中国鲫与日本鲫几个群体肌浆蛋白的电泳分析

以中国二倍体和三倍体鲫Carassius(黑龙江流域鲫、九江彭泽鲫、宁河彭泽鲫、海河流域鲫、金鱼)以及日本二倍体、三倍体鲫为试验材料,应用水平式淀粉凝胶电泳法对其肌浆蛋白进行了检测分析。结果表明:在中国二倍体鲫中共检测出4种类型(BB、BC、CC和BD),其中BB为主要类型,并且4种类型均不同于日本的二倍体鲫;在中国三倍体鲫中也检测出4种类型(BBB、BBC、BCC、ABB),方正银鲫中的两种类型(BBC、BCC)均不同于九江彭泽鲫、宁河彭泽鲫、于桥水库鲫和日本三倍体鲫,九江彭泽鲫、宁河彭泽鲫以及95.1%的于桥水库鲫为BBB类型,其电泳带组成与谷口顺彦报道的日本银鲫中的Ⅱ-1型相同。     

Tetraploid wheats: seed protein electrophoretic patterns of the Emmer and Timopheevi groups

Crude protein extracts were subjected to disk electrophoresis on polyacrylamide gel. The pattern obtained showed a fast and slow series of bands. In the fast series, the eight species of wheat of the Emmer group gave virtually identical eight-band patterns, and the four species of the Timopheevi group gave nearly identical six- or seven-band patterns. The groups consistently differed with respect to four bands. Two of these differences were attributable to the A genome.