Genomic Structure and Chromosomal Localization of Mouse Cyclin G1 Gene

Mouse genomic DNA harboring the full coding sequence of cyclin G1 was cloned and analyzed. The locations of five coding exons and the intron–exon boundary sequences were found to be conserved between the mouse and the human genes. Two putative binding sites for thep53tumor suppressor gene product were found around the first exon: one was located in the 5′ regulatory region, and the other was in the first intron. The mouse cyclin G1 gene was mapped to bands A5 to B1 of chromosomes 11 (11A5–B1) by FISH using genomic DNA clone as a biotinylated probe. The location of mouse cyclin G1 is syntenic to that of its human homologue, which we previously mapped to 5q32–q34 of chromosome 5. An additional faint signal was detected on chromosome 4 (4B1–C2), probably indicating the presence of a cyclin G1-related gene or pseudogene in the mouse genome.     

S-扁桃酸脱氢酶基因的克隆及表达

S-扁桃酸脱氢酶能够选择性催化S-扁桃酸生成苯甲酰甲酸。通过PCR扩增获得Pseudomonas p utida NUST的S-扁桃酸脱氢酶全长基因(mdlA),并构建了表达载体pET30a(+)-mdlA,转化大肠杆菌E.coli BL21(DE3)后,经异丙基-β-D-硫代吡喃半乳糖苷(IPTG)诱导获得表达,SDS-PAGE结果显示表达蛋白为43kDa。所以工程菌细胞具有转化S-扁桃酸生成苯甲酰甲酸能力。     

Genomic Structure, Sub-Cellular Localization, and Promoter Analysis of the Gene Encoding Sorbitol-6-Phosphate Dehydrogenase from Apple

Sorbitol is the primary photosynthetic product and the translocatable and storage carbohydrate in apple (Malus domestica) and other fruit tree species within the Rosaceae family. Sorbitol-6-phosphate dehydrogenase (S6PDH, EC 1.1.1.200) is the key enzyme in the biosynthesis of sorbitol. In this study, we isolated two full-length genomic sequences for S6PDH from ??Gala?? apple. The two sequences have same six exons and first two introns, but the sizes of their last three introns are different. The two sequences were mapped to the same loci on chromosome 10. Immunogold electron microscopy analysis demonstrates that the S6PDH is localized mainly in leaf cytosol and chloroplasts. We also isolated and analyzed the promoter region of S6PDH and constructed a series of promoter deletion derivatives with ??-glucuronidase (GUS) gene to identify the upstream region of the S6PDH gene required for promoter activity. The GUS activity in Agrobacterium-mediated transient transformation of tobacco leaves reveals that the -1719 region is more important for gene expression contrasting with other regions in the S6PDH promoter. The promoter region can be induced by cold, dark, and abscisic acid treatment.     

小鼠一个新基因mLPTS的克隆、表达及亚细胞定位

利用EST拼接技术,RT－PCR及DNA序列测定,首次成功克隆了小鼠新基因mLPTS。获得的mLPTS基因片段长1244bp,编剧了一个由332个氨基酸组成的蛋白质。该蛋白质与人的LPTS蛋白有78％的同源性,LPTS基因是本实验室通过定位候选克隆策略获得的一个新的肝癌相关基因。它在肝癌组织中不表达或低表达,并参与细胞生长的负调控。小鼠mLPTS基因在小鼠的各个组织中都有表达,与人LPTS基因的表达组织分布相同。分析比较了LPTS蛋白在不同物种间的序列同源性,发现LPTS在进化上是高度保守的,是一个具有重要功能的基因。将mLPTS基因与绿色荧光蛋白EGFP融合构建真核表达载体,在中国仓鼠卵CHO细胞中表达,发现mLPTS基因表达产物位于细胞核仁中,为进一步研究该基因的功能及作用途径提供了重要信息。     

组织凝集素在人染色体上的基因定位

本文用非放射性DIG标记组织凝集素基因探针研究其在人染色体上的基因定 位,首先对基因原位杂交条件进行了一系列研究。结果表明采用染色体温和变性、基因 片段探针等为较好的基因原位杂交条件,通过135个细胞中期相的分析结果显示, 杂交阳 性率为20%,本底为2.81,杂交点分布峰位于3q12-13。 Abstract:The localization of sarcolectin gene on human chromosome is studied.A modified system of in situ hybridization was developed.A specific signal was generated by employing a nonradioactive DIG-labelled gene fragment as a probe in combination with the hybridization buffer containing no dextran sulphate and softly denatured chromosomes.Using this system,unique sequence for sarcolectin as small as 0.65kb was detectable and observed at 3q12-13.Of 135 metaphases examined,27(20%) had at least one grain deposited on 3q12-13,and the backgrand was 2.81.     

Partial Structure, Chromosome Localization, and Expression of the MouseIclnGene

The molecular identities of most volume-regulated ion channel proteins and putative regulatory elements are currently unknown. Recently, a role for a nucleotide-sensitive chloride conductance regulator, ICln, in the function of a ubiquitous volume-regulated chloride channel has been suggested. Here, we report the cloning of a fragment of the mouseIclngene and identification of probableIclnpseudogenes. The functionalIclngene was mapped independently to human chromosome 11q13.5–q14 and mouse chromosome 7 (50.3 cM). ICln mRNA was shown to be abundantly expressed and evenly distributed in all mouse tissues examined and at four stages of embryonic development, consistent with the proposed role of ICln in the regulation of a ubiquitous chloride channel.     

Primary Structure of Human 11-cisRetinol Dehydrogenase and Organization and Chromosomal Localization of the Corresponding Gene

The universal chromophore of visual pigments in higher animals is 11-cisretinaldehyde. The final step in the biosynthetic pathway generating this compound is catalyzed by 11-cisretinol dehydrogenase, a membrane-bound enzyme abundantly expressed in the retinal pigment epithelium of the eye. In this work we demonstrate that the primary structure of human 11-cisretinol dehydrogenase is highly conserved with 91% identity to the bovine enzyme. The gene encoding 11-cisretinol dehydrogenase spans over ≈4.1 kb of DNA and is divided into four translated exons. Analysis of a panel of somatic cells hybrids and fluorescencein situhybridization on metaphase chromosomes revealed that the gene is located on chromosome 12q13–q14. Due to the unique role of 11-cisretinol dehydrogenase in the generation of visual pigments, it is a candidate gene for involvement in hereditary eye disease.     

猕猴桃L-艾杜糖脱氢酶基因的克隆及转化

以猕猴桃果实为材料,利用电子克隆技术获得了L-艾杜糖脱氢酶(L-Idonate dehydrogenase,IDH)基因,然后将其转入番茄中,为了解猕猴桃IDH基因如何调控AsA的降解奠定基础。结果表明,获得的猕猴桃IDH基因cDNA全长为1 239bp,含有一个1 080bp的开放阅读框,编码359个氨基酸;成功构建了IDH基因植物表达载体pWR-IDH及工程农杆菌,以番茄叶片及茎段为受体,通过农杆菌介导法进行转化,获得了4株经PCR和RT-PCR检测呈阳性的转基因植株。     

Cloning of cDNA and Genomic DNA Encoding Human Type XVIII Collagen and Localization of the α1(XVIII) Collagen Gene to Mouse Chromosome 10 and Human Chromosome 21

Types XV and XVIII collagen belong to a unique and novel subclass of the collagen superfamily for which we have proposed the name the MULTIPLEXIN family. Members of this class contain polypeptides with multiple triple-helical domains separated and flanked by non-triple-helical regions. In this paper, we report the isolation of human cDNAs and genomic DNAs encoding the α1(XVIII) collagen chain. Utilizing a genomic clone as probe, we have mapped the COL18A1 gene to chromosome 21q22.3 by fluorescence in situ hybridization. In addition, using an interspecific backcross panel, we have shown that the murine Col18a1 locus is on chromosome 10, close to the loci for Col6a1 and Col6a2.     

Isolation, Mapping, and Functional Expression of the Mouse X Chromosome Glycerol Kinase Gene

Glycerol kinase (Gyk) participates in the metabolism of endogenously derived and dietary glycerol. Deficiency of the human enzyme activity is an X-linked recessive disorder with a clinical picture varying from childhood metabolic crisis to asymptomatic adults incidentally identified by hyperlipidemia screening (pseudohypertriglyceridemia). Gyk is a member of a small group of kinases termed ambiquitous enzymes that are found in the cytosol or as membrane-bound enzymes associated with the voltage-dependent anion channel of the mitochondrial outer membrane. It was recently reported that in humans there are X-linked and autosomal copies of Gyk sequences, both apparently functional genes and processed pseudogenes. To understand the role of Gyk in normal metabolism and the variable clinical features seen with Gyk deficiency, we have characterized the mouse Gyk gene. We present the sequence of a full-length mouse Gyk cDNA that is alternatively spliced in brain. The Gyk gene was mapped to the mouse X chromosome by both fluorescencein situhybridization and an interspecies backcross panel, demonstrating conservation of synteny withdmd.To confirm the functional identity of the cDNA, transient transfection of the cDNA into COS7 cells was shown to cause a marked elevation in glycerol kinase activity.