Genetic Map of Bacteriophage phiX174

Bacteriophage X174 temperature-sensitive and nonsense mutations in eight cistrons were mapped by using two-, three-, and four-factor genetic crosses. The genetic map is circular with a total length of 24 × 10⁻⁴wt recombinants per progeny phage. The cistron order is D-E-F-G-H-A-B-C. High negative interference is seen, consistent with a small closed circular deoxyribonucleic acid molecule as a genome.     

Genetic Map of Bacteriophage T3

About 200 amber mutants of phage T3 were found to lie in 14 different genes. These genes are homologous to known T7 genes. The genetic map of T3 is very similar to that of T7.     

A Genetic Linkage Map for Cattle

We report the most extensive physically anchored linkage map for cattle produced to date. Three-hundred thirteen genetic markers ordered in 30 linkage groups, anchored to 24 autosomal chromosomes (n = 29), the X and Y chromosomes, four unanchored syntenic groups and two unassigned linkage groups spanning 2464 cM of the bovine genome are summarized. The map also assigns 19 type I loci to specific chromosomes and/or syntenic groups and four cosmid clones containing informative microsatellites to chromosomes 13, 25 and 29 anchoring syntenic groups U11, U7 and U8, respectively. This map provides the skeletal framework prerequisite to development of a comprehensive genetic map for cattle and analysis of economic trait loci (ETL).     

Zebrafish Genetic Map with 2000 Microsatellite Markers

The zebrafish is the first vertebrate organism used for large-scale genetic screens seeking genes critical to development. These screens have been quite successful, with more than 1800 recessive mutations discovered that speak to morphogenesis of the vertebrate embryo. The cloning of the mutant genes depends on a dense genetic map. The 2000 markers we present here, using microsatellite (CA) repeats, provides 1.2-cM average resolution. One centimorgan in zebrafish is about 0. 74 megabase, so, for many mutations, these markers are close enough to begin positional cloning by YAC walks.     

大豆遗传图谱的构建和分析

分子标记连锁图的构建为植物基因组的结构和功能分析提供了有力的工具。较高密度的遗传图谱在数量性状基因定位、图位克隆重要农艺性状基因等研究中发挥了巨大作用。应用栽培大豆长农４和半野生大豆新民６杂交得到的Ｆ８代重组自交系,构建了一张较高密度的遗传图谱。该图谱共有２４０个标记,其中包括２个形态标记、１００个ＲＦＬＰ标记、３３个ＳＳＲ标记、４２个ＡＦＬＰ标记、６２个ＲＡＰＤ标记和１个ＳＣＡＲ标记,分布在２２     

A PCR-Based Genetic Map for Human Chromosome 3

Oligonucleotide primers for 125 simple sequence repeat microsatellite-based genetic markers have been assayed by polymerase chain reaction (PCR) in the CEPH reference family panel. These microsatellites include 101 dinucleotide repeats as well as 24 new tetranucleotide repeats. The average heterozygosity of this marker set was 72.4%. Genetic data were analyzed with the genetic mapping package LINKAGE. A subset of these microsatellite markers define a set of 56 uniquely ordered loci (>1000:1 against local inversion) that span 271 cM. Sixty-seven additional loci were tightly linked to markers on the uniquely ordered map, but could not be ordered with such high precision. These markers were positioned by CMAP into confidence intervals. One hundred thirteen of the microsatellite markers were also tested on a chromosome 3 framework somatic cell hybrid panel that divides this chromosome into 23 cytogenetically defined regions, integrating the genetic and physical maps of this chromosome. The high density, high heterozygosity, and PCR format of this genetically and physically mapped set of markers will accelerate the mapping and positional cloning of new chromosome 3 genes.     

Linkage and Genetic Map Length in TETRAHYMENA THERMOPHILA

The genetic map of T. thermophila has been extended with tests of over 170 marker combinations. Three linkage groups have been identified, in addition to several apparent linkages which are seen only when certain strains are used. A sampling argument was developed to estimate the total genetic map length from the observed fraction of marker combinations showing linkage. If the strain-dependent linkages are actually due to structural heterozygosity, the total map length is estimated at about 1,200 cM.     

谷子SSR分子图谱的构建及主要农艺性状QTL定位

试验拟对谷子重要农艺性状进行数量性状位点QTL分析。以表型差异较大的沈3/晋谷20F2作图群体为材料,观测其株高、穗长等性状,选用SSR做分子标记,利用完备区间作图法(BASTEN C J)进行QTL分析。结果显示,表型数据在作图群体中呈现连续分布,表现为多基因控制的数量性状,被整合的54个SSR标记构建10个连锁群,LOD阈值设置为2.0,检测到与株高相关的主效QTL2个,联合贡献率45.9637%,穗长主效QTL1个,贡献率14.9647%,与穗重、粒重相关的主效QTL为同一位点,贡献率分别为11.9601%和10.1879%。有6组QTL位点之间存在基因互作效应,大小范围为-0.4986-16.6407,对性状的贡献率在2.2716％至6.7478％之间。谷子表型控制复杂,相关QTL的检测受环境影响较大,不同连锁群QTL间互作明显。     

梨遗传连锁图谱的构建及其与苹果图谱的比较

以‘丰水’为母本、‘砀山酥梨’为父本杂交所得的F1代104株单体为作图群体,利用SSR分子标记进行遗传连锁分析,应用Jionmap 3.0作图软件,构建了一张包含104个SSR分子标记,分属于18个连锁群的梨遗传连锁图谱,覆盖梨基因组总长831.8cM,平均图距为8.0cM。根据定位到该图谱上的SSR标记与苹果‘Fiesta’图谱进行比较,25个共有的SSR标记将该图谱和苹果图谱各连锁群连接起来,这些标记不仅呈现良好的共线性而且它们之间的相对遗传距离也很相近。研究认为,SSR标记作为锚定引物,可以与不同物种的遗传图谱相比较整合,为不同物种之间遗传信息的转移提供参考依据;同时该研究为梨树相关性状的基因定位、分离以及克隆奠定了基础。     

Construction of a Genetic Map of Bacteria Pseudomonas mendocina

Based on the results of matings with interrupted conjugation and analysis of marker joint inheritance frequencies, distances between 26 genetic determinants were estimated and a genetic map of Pseudomonas mendocina bacteria was constructed.     

A Genetic Linkage Map of the Male Goat Genome

This paper presents a first genetic linkage map of the goat genome. Primers derived from the flanking sequences of 612 bovine, ovine and goat microsatellite markers were gathered and tested for amplification with goat DNA under standardized PCR conditions. This screen made it possible to choose a set of 55 polymorphic markers that can be used in the three species and to define a panel of 223 microsatellites suitable for the goat. Twelve half-sib paternal goat families were then used to build a linkage map of the goat genome. The linkage analysis made it possible to construct a meiotic map covering 2300 cM, i.e., >80% of the total estimated length of the goat genome. Moreover, eight cosmids containing microsatellites were mapped by fluorescence in situ hybridization in goat and sheep. Together with 11 microsatellite-containing cosmids previously mapped in cattle (and supposing conservation of the banding pattern between this species and the goat) and data from the sheep map, these results made the orientation of 15 linkage groups possible. Furthermore, 12 coding sequences were mapped either genetically or physically, providing useful data for comparative mapping.     

中国白菜RAPD分子遗传图谱的构建

以芜菁（Ｂｒａｓｓｉｃａ ｃａｍｐｅｓｔｒｉｓ Ｌ．ｓｓｐ．ｒａｐｉｆｅｒａ Ｍｅｔｚｇ）和结球白菜（Ｂ．ｃａｒｎｐｅｓｔｒｉｓ Ｌ．ｓｓｐ ．Ｐｌｋｉｎｅｎｓｉｓ（Ｌｏｕｒ．）Ｏｉｓｓｏｎ）杂交的Ｆ２群体为试材,采用ＲＡＰＤ标记,用８４个１０核苷酸随机引物构建了白菜的ＲＡＰＤ遗传图谱。该图谱覆盖基因组的１６３２．４ｃＭ（ｃｅｒｔｉ Ｍｏｒｇａｎ）标记间的平均间隔为１６．５ｃＭ。其中最长的连锁群为     

An Autosomal Genetic Linkage Map of the Sheep Genome

We report the first extensive ovine genetic linkage map covering 2070 cM of the sheep genome. The map was generated from the linkage analysis of 246 polymorphic markers, in nine three-generation fullsib pedigrees, which make up the AgResearch International Mapping Flock. We have exploited many markers from cattle so that valuable comparisons between these two ruminant linkage maps can be made. The markers, used in the segregation analyses, comprised 86 anonymous microsatellite markers derived from the sheep genome, 126 anonymous microsatellites from cattle, one from deer, and 33 polymorphic markers of various types associated with known genes. The maximum number of informative meioses within the mapping flock was 222. The average number of informative meioses per marker was 140 (range 18-209). Linkage groups have been assigned to all 26 sheep autosomes.     

不结球白菜分子遗传图谱的构建及分析

以不结球白菜'常州乌塌菜'和'二青'杂交产生的181株F2代分离材料为作图群体,利用ISSR、RAPD、SSR、SRAP等分子标记来构建不结球白菜分子遗传连锁图谱.结果表明,构建的连锁图谱包含11个连锁群,由139个标记组成,其中包括4个ISSR标记、19个RAPD标记、22个SSR标记和94个SRAP标记.其中偏分离标记37个,占26.6%;每条连锁群上的标记数在4～33个之间,连锁群长度在61～164 cM的范围,覆盖基因组950 cM,总平均图距6.8 cM.     

山羊基因组与遗传变异图谱研究进展

高通量测序技术和生物信息学的发展极大的促进了山羊分子生物学研究。山羊参考基因组的不断完善以及基因组重测序技术的应用,在全基因组水平上发现了大量的遗传变异信息(SNP、Indel和CNV),丰富了山羊分子群体遗传学研究利用的分子标记。综述了山羊参考基因组组装和全基因组变异图谱的构建及其在山羊上的研究进展,以期为进一步利用分子遗传标记进行山羊的各种性状的遗传基础研究和遗传资源保护利用提供科学依据和参考。     

Centromere-Linkage Analysis and Consolidation of the Zebrafish Genetic Map

The ease of isolating mutations in zebrafish will contribute to an understanding of a variety of processes common to all vertebrates. To facilitate genetic analysis of such mutations, we have identified DNA polymorphisms closely linked to each of the 25 centromeres of zebrafish, placed centromeres on the linkage map, increased the number of mapped PCR-based markers to 652, and consolidated the number of linkage groups to the number of chromosomes. This work makes possible centromere-linkage analysis, a novel, rapid method to assign mutations to a specific linkage group using half-tetrads.     

中国白菜RAPD分子遗传图谱的构建

A molecular genetic map of Brassica campestris L. (syn. B. rapa) was constructed based on the segregation of 99 RAPDs (random amplified polymorphic DNAs) markers from eighty-four 10-base random primers using DNA samples extracted from F2 population of turnip (B． campestris L. ssp. rapifera Metzg) × Chinese cabbage (B． campestris L. ssp. pekinensis Lour. Olsson). This genetic map covered 1 632.4 cM (centiMorgan) genome (Kosambi Function) with 16.5 cM mean intervals between flanking markers and defined thirteen linkage groups, in which the longest linkage group is 267.5 cM with 20.6 cM mean interval and the shortest linkage group is 62.2 cM with 15.6 cM mean interval. The size and distribution of linkage groups in this map is similar to other RFLP maps and karyotype data in B. campestris.     

Genetic Linkage Map of the Edible Basidiomycete Pleurotus ostreatus

We have constructed a genetic linkage map of the edible basidiomycete Pleurotus ostreatus (var. Florida). The map is based on the segregation of 178 random amplified polymorphic DNA and 23 restriction fragment length polymorphism markers; four hydrophobin, two laccase, and two manganese peroxidase genes; both mating type loci; one isozyme locus (est1); the rRNA gene sequence; and a repetitive DNA sequence in a population of 80 sibling monokaryons. The map identifies 11 linkage groups corresponding to the chromosomes of P. ostreatus, and it has a total length of 1,000.7 centimorgans (cM) with an average of 35.1 kbp/cM. The map shows a high correlation (0.76) between physical and genetic chromosome sizes. The number of crossovers observed per chromosome per individual cell is 0.89. This map covers nearly the whole genome of P. ostreatus.