Genetic Analysis of a Mouse t Complex Locus That Is Homologous to a Kidney Cdna Clone

A mouse kidney cDNA clone, pMK174, identifies restriction fragment length polymorphisms (RFLPs) that map to two unlinked loci. One, designated D17Rp17, has been mapped near quaking, (qk), on chromosome 17 using three sets of recombinant inbred (RI) strains. A study of several t haplotypes resulted in the identification of t-specific alleles of D17Rp17 that map to the proximal half of the t complex. Neither t-specific nor wild-type D17Rp17 alleles are present in chromosomes carrying either the T Orleans (TtOrl) or the T hairpin tail (Thp) deletions. Comparison with other molecular markers indicates that pMK174 identifies a new proximal t complex locus, Rp17. The second locus identified by pMK174, termed D4Rp18, is tentatively assigned to chromosome 4 by mouse-Chinese hamster somatic cell hybrid analysis.     

伊犁鲈微卫星位点的筛选及近缘物种通用性

为开发伊犁鲈(Perca schrenkii)分子标记用于鲈属鱼类种质资源保护,以伊犁鲈为材料,应用磁珠富集法进行了微卫星标记的筛选.从伊犁鲈尾鳍提取总DNA,进行酶切、接头连接、PCR扩增,再采用生物素标记(CA)15探针及生物素标记(TG)15探针对扩增产物进行杂交富集,经再次PCR扩增及T-A克隆,成功构建了伊犁鲈基因组微卫星富集文库.采用重复序列引物筛选获得阳性克隆,随机选取48个阳性克隆进行测序,测得序列46个,其中38个克隆含有微卫星序列,41个位点的微卫星重复数在8次以上.根据测得序列设计17对微卫星引物,均能在伊犁鲈群体中扩增获得目的条带.采用该17对引物对河鲈(P.fluviatilis)及黄金鲈(P.flavescens)群体样本进行扩增,10对引物具有通用性,其中6对在河鲈中具有高度多态性(PIC>0.5),5对在黄金鲈中具有高度多态性.     

中国13个民族7个Y-STR基因座遗传关系的研究

选择具有高度遗传多态性与稳定性的7个Y-STR位点分析宁夏回族与国内17个群体之间的群体遗传关系。采用Y-STR复合扩增、ABI全自动测序仪测序方法,结合基因扫描和自动分型技术获得150名宁夏回族个体DYS19、DYS389Ⅰ、DYS389Ⅱ、DYS390、DYS391、DYS392和DYS393七个基因座的基因频率,同时还收集国内17个群体这7个基因座的基因频率数据,计算他们间的遗传距离,进行聚类分析。结果显示:宁夏回族与北京汉族、云南汉族、安徽汉族、天津汉族、湖南汉族先聚为一类,然后与福建汉族相聚,最后与其他少数民族相聚,揭示回族与汉族在遗传结构上具有很大的相似性,为回族起源和发展过程中融入了大量汉族血缘的论点提供了遗传学证据。     

Structural Analysis of the dur Loci in S. CEREVISIAE: Two Domains of a Single Multifunctional Gene

In Saccharomyces cerevisiae, the degradation of urea to carbon dioxide and ammonia is catalyzed by urea carboxylase and allophanate hydrolase. The loci coding for these enzymes (dur1 and dur2) are very tightly linked on the right arm of chromosome II between pet11 and met8. Pleiotropic mutations that fail to complement mutations in either of the dur loci were found to be predominantly located in or near the dur2 locus. We interpret these data as suggesting that the two dur loci might in reality be domains of a single gene that codes for a multifunctional polypeptide. In view of this conclusion, we have renamed the dur loci as the dur1,2 locus.     

Isolation and Genetic Analysis of Mutations at the SerH Immobilization Antigen Locus of TETRAHYMENA THERMOPHILA

Multiple alleles at the SerH locus specify the major cell surface protein (immobilization antigen) of the ciliate Tetrahymena thermophila. Following mutagenesis of SerH1 homozygotes, two mutations, H1-1 and H1-2, were recovered in heterozygous form. Mutant homozygotes do not express H1 antigen, nor is H1 expressed in F1 progeny of crosses to wild-type strains homozygous for SerH2 or SerH3. H1-1 and H1-2 segregate without recombination from these wild-type alleles in expected F2 and testcross Mendelian ratios. H1-1 and H1-2 do, however, complement each other to express H1 antigen. Experiments suggest this complementation is due neither to recombination during macronuclear development nor to interallelic complementation of defective SerH1 gene products. These results suggest that SerH1 is intact in one mutant, and possibly both, although no such allele has been segregated in testcross progeny (N = 205). The hypothesis is presented that complementation between H1-1 and H1-2 is due to interaction between allele-specific regulators closely linked to the SerH1 gene.     

西藏和埃塞俄比亚大麦6个同工酶位点遗传变异的对比分析

我们对比分析了埃塞俄比亚(简称埃)和西藏共777份栽培大麦材料在6个同工酶位点(Est1、Est2、Kst3、Est4、Acp1和Got1)的遗传变异。结果表明,无论是从单个位点上分析还是在多位点基因组合形式上评价,埃大麦与西藏大麦群体在遗传组成和多位点基因结构上都有着很大的差异。遗传多样性对比分析表明,从单个位点基因类型看,西藏大麦与埃大麦遗传变异程度大致相当,但从多位点基因组合形式看,西藏大麦遗传多样性程度极显著地高于埃大麦。     

Evidence That the Saethre-Chotzen Syndrome Locus Lies between D7S664 and D7S507, by Genetic Analysis and Detection of a Microdeletion in a Patient

The locus for Saethre-Chotzen syndrome, a common autosomal dominant disorder of craniosynostosis and digital anomalies, was previously mapped to chromosome 7p between D7S513 and D7S516. We used linkage and haplotype analyses to narrow the disease locus to an 8-cM region between D7S664 and D7S507. The tightest linkage was to locus D7S664 ( = 7.16, θ = .00). Chromosomes from a Saethre-Chotzen syndrome patient with t(2;7) (p23;p22) were used for in situ hybridization with YAC clones containing D7S664 and D7S507. The D7S664 locus was found to lie distal to the 7p22 breakpoint, and the D7S507 locus was deleted from the translocation chromosomes. These genetic and physical mapping data independently show that the disease locus resides in this interval.     

大白菜一个冷相关基因的分离与逆境诱导表达(英文)

以冷处理的大白菜幼叶为材料,采用RT-PCR技术获得1条新的冷相关基因序列(BpCOR,GenBank登录号DQ491005)。该基因编码129个氨基酸的亲水多肽,预测其N端含有叶绿体转运肽序列。多序列比对显示,Bc-COR蛋白与拟南芥及其它植物COR具有较高的相似性。Northern杂交结果显示BcCOR基因能被冷处理强烈诱导表达,而被脱水和盐处理弱诱导;在冷处理下,BcCORmRNA在根中的积累量低于叶片,光照能显著加强该基因在叶片中的表达。研究表明,BcCOR基因可能在大白菜抵抗冷胁迫和其它非生物胁迫的过程中具有重要的作用。     

Molecular Genetic Characterization of a Locus That Contains Duplicate Adh Genes in DROSOPHILA MOJAVENSIS and Related Species

Drosophila mojavensis and other species of the mulleri subgroup contain a duplicate gene encoding the enzyme alcohol dehydrogenase (ADH). Studies on the genetic relationship of the two genes using electrophoretic variants show them to be closely linked. We have cloned a 13.5-kb fragment of D. mojavensis DNA into the lambda vector, Charon 30. This fragment contains both Adh genes separated by approximately 2 kb of DNA. The clone hybridized to a single position on chromosome 3 in D. mojavensis following in situ hybridization. It is likely that the genes are tandemly arranged in the genome. One of the two genes shows a complexity in its structure that suggests the close linkage of a pseudogene or part of a gene. The structure of the Adh locus in five species of the mulleri subgroup have been compared by constructing restriction maps of genomic DNA. Two of these species D. arizonensis and D. mojavensis express Adh-1 in the ovaries; the others do not. In comparing these species it is evident that there has been one or two insertions into the region between the Adh genes. It is possible that one of these structural changes is related to the change in Adh tissue-specific expression that has occurred during the evolution of these species.     

Genetic Control of Pheromones in Drosophila Simulans. I. Ngbo, a Locus on the Second Chromosome

7-Tricosene and 7-pentacosene are predominant hydrocarbons on the cuticle of both sexes in Drosophila simulans. The pheromonal role of 7-tricosene has been clearly established for conspecific males, while a synergistic effect for 7-pentacosene has been postulated. Interstrain variation for the production of both compounds is very marked, but similar for both sexes. The genetic basis of this polymorphism was investigated. A major role was found for the second chromosome, which controls the 7-tricosene:7-pentacosene ratio. The main locus involved in controlling this variation, Ngbo, was mapped to position 65.3 on the second chromosome. The production of 7-pentacosene is directly related to the Ngbo genotype, which is additively expressed with two known alleles, Seychelles and Cameroon. These alleles act codominantly and are, respectively, hypomorphic and hypermorphic with regard to their effect on 7-pentacosene production. The production of 7-tricosene, which is partially inversely related to that of 7-pentacosene, is also affected by secondary interactions with the second chromosome and with the autosomal background.     

Use of Genetic and Physical Mapping to Locate the Spinal Muscular Atrophy Locus between Two New Highly Polymorphic DNA Markers

The gene for autosomal recessive forms of spinal muscular atrophy (SMA) has recently been mapped to chromosome 5ql3, within a 4-cM region between the blocks D5S465/D5S125 and MAP-1B/D5S112. We identified two new highly polymorphic microsatellite DNA markers—namely, AFM265wf5 (D5S629) and AFM281yh9 (D5S637)—which are the closest markers to the SMA locus. Multilocus analysis by the location-score method was used to establish the best estimate of the SMA gene location. Our data suggest that the most likely location for SMA is between locus D5S629 and the block D5S637/D5S351/MAP-1B/D5S112/D5S357. Genetic analysis of inbred SMA families, based on homozygosity by descent and physical mapping using mega-YACs, gave additional information for the loci order as follows: cen–D5S6–D5S125/D5S465–D5S435–D5S629–SMA–D5S637–D5S351–MAP–1B/D5S112–D5S357–D5S39–tel. These data give the direction for bidirectional walking in order to clone this interval and isolate the SMA gene.     

Commonality of self-recognition specificity of S haplotypes between Brassica oleracea and Brassica rapa

We have identified several interspecific pairs of S haplotypes having highly similar SRK and SP11/SCR sequences between Brassica oleracea and Brassica rapa. The recognition specificities of S haplotypes in these pairs were examined with three different methods. Stigmas of interspecific hybrids between an S-32 homozygote in B. oleracea and an S-60 homozygote in B. rapa, which were produced to avoid the interspecific incompatibility between the two species, showed incompatibility to the pollen of an S-8 homozygote in B. rapa and to the pollen of an S-15 homozygote in B. oleracea, while it showed compatibility to the pollen of other S haplotypes, suggesting B. oleracea S-32 and B. rapa S-60 have the same recognition specificity as B. rapa S-8 and B. oleracea S-15. Pollen grains of transgenic S-60 homozygous plants in B. rapa carrying a transgene of SP11-24 from B. oleracea were incompatible to B. rapa S-36 stigma, indicating that B. oleracea S-24 and B. rapa S-36 have the same recognition specificity. Application of the SP11 protein of B. rapa S-41 and S-47 onto the surface of B. oleracea S-64 stigmas and S-12 stigmas, respectively, resulted in the incompatibility reaction to pollen grains of another S haplotype, but application onto the stigmas of other S haplotypes did not, suggesting that B. oleracea S-64 stigmas and S-12 stigmas recognized the B. rapa SP11-41 and SP11-47 proteins as self SP11 proteins, respectively. Besides having evolutionary implications, finding of many interspecific pairs of S haplotypes can provide insight into the molecular mechanism of self-recognition. Comparing deduced amino-acid sequences of SP11 proteins and SRK proteins in the pairs, regions of SP11 and SRK important for self-recognition are discussed.     

水稻双链RNA结合蛋白同源基因OsRBP的克隆及其表达的分析

在基因数据库中发现两个水稻EST片段与大白菜BcpLH基因的双链RNA结合结构域 (dsRBD)有同源的区域 ,根据同源片段的位置特征设计引物 ,用RT-RCR扩增粳稻 (Oryzasativasubsp .japonica)愈伤组织的cDNA ,得到大小为 1.8kb的DNA片段。该cDNA片段含完整的编码区 ,有两个典型的dsRBD ,分别与BcpLH的dsRBD在氨基酸水平上同源性为 75 %左右 ,故将其命名为OsRBP。RT -PCR表达分析显示该基因在未成熟的种子和愈伤组织中表达 ,在根、茎、叶、穗、成熟种子及胚芽鞘中没有表达信号 ,由此推测该基因的表达可能与种子和胚的早期发育相关。该研究首次从水稻中分离到双链RNA结合蛋白基因 ,并初步研究了其表达方式 ,为进一步探讨水稻重要器官的发育和植物中双链RNA结合蛋白的调节作用奠定了基础     

Isolation and characterization of a homologous to lipase gene from Brassica napus

Lipase is an important lipolytic enzyme involved in plant lipid metabolism. To analyze its function and roles during seed germination and growth, a full-length cDNA encoding a homologous to lipase gene named BnLIP1 was cloned from Brassica napus, cv. Huyou 15, by rapid amplification of cDNA ends. The BnLIP1 gene had a total length of 1318 bp, with an open reading frame of 1170 bp encoding 389 amino acid residues. Sequence analysis revealed that BnLIP1 protein belonged to the GDSL family of serine esterases/lipases. In B. napus genome, BnLIP1 is represented by several copies with the length of 1601 bp, the gene comprises five exons and four introns. RT-PCR analysis indicated that BnLIP1 showed no tissue-specific expression during reproductive growth and is strongly expressed during seed germination. No expression could be detected until three days after germination, and its peak was registered at the fifth day after germination. In conclusion, BnLIP1-encoded protein is predicted to be a lipolytic enzyme widely expressed at various stages of oilseed rape germination and development. Published in Russian in Fiziologiya Rastenii, 2006, Vol. 53, No. 3, pp. 410–417. The text was submitted by the authors in English.     

Isolation and Characterization of the Bovine Microsatellite Loci

Microsatellite loci were isolated using five repetitive probes for Korean native cattle. Eleven microsatellite loci were developed based on a biotin hybrid capture method, and enrichment of the genomic libraries (AAAT, TG, AG, T, and TGC repeats) was performed using Sau3AI adapters. The isolated markers were tested in two half-sib Korean cattle families and four imported breeds (Angus, Limousine, Holstein, and Shorthorn). Nine informative microsatellite loci were observed, and two microsatellite loci were revealed as monomorphic in Korean cattle. In the imported breeds, however, all of the markers were informative. In total, 213 alleles were obtained at the 11 loci across five breeds, and the average number of alleles found per locus, considering all populations, was 4.26. Heterozygosity was 0.71 (expected) and 0.57 (observed). The range of the polymorphic information content for the markers in all cattle populations was 0.43-0.69. Eleven percent of genetic variation was attributed to differentiation between populations as determined by the mean F (ST) values. The remaining 89% corresponded to differences among individuals. The isolated markers may be used to identify and classify the local breeds on a molecular basis.     

Isolation and Partial Characterization of Temperature-Sensitive Mutants in Ten Loci That Affect Cell Membrane Synthesis in Escherichia coli: Isolation and Genetic Sorting

Four hundred temperature-sensitive (ts) mutants were isolated by the (3)H-glycerol-3-phosphate membrane suicide procedure of Cronan, Ray, and Vagelos and were sorted into 13 groups by the rapid mapping procedures of Low. Recombination and complementation studies on representative members of each group suggested that the ts mutations of all 13 groups are present in genetically different complementation groups. Biochemical studies suggested that 10 of these ts mutations affected cell membrane synthesis. In this paper, the genetic data are presented in detail so that the limits of the Low rapid mapping procedures can be assessed, and in an accompanying paper the partial biochemical characterization of the ts mutations is described.