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1.
The gene responsible for Duchenne muscular dystrophy (DMD) and Becker muscular dystrophy (BMD) maps to the X chromosome short arm, band Xp21. In a few females with DMD or BMD, the Xp21 region is disrupted by an X-autosome translocation. Accumulating evidence suggests that the exchange has physically disrupted the DMD/BMD locus to cause the disease. One affected female with a t(X;21)(p21;p12) translocation was studied in detail. The exchange points from both translocation chromosomes were cloned, restriction-mapped, and sequenced. The translocation is reciprocal, but not conservative. A small amount of DNA is missing from the translocated chromosomes; 71 to 72 base pairs from the X chromosome and 16 to 23 base pairs from the 28S ribosomal gene on chromosome 21.  相似文献   

2.
A probe for the 5' end of the Duchenne muscular dystrophy (DMD) gene was used to study expression of the gene in normal human muscle, myogenic cell cultures, and muscle from patients with DMD. Expression was found in RNA from normal fetal muscle, adult cardiac and skeletal muscle, and cultured muscle after myoblast fusion. In DMD muscle, expression of this portion of the gene was also revealed by in situ RNA hybridization, particularly in regenerating muscle fibers.  相似文献   

3.
Expression of the murine Duchenne muscular dystrophy gene in muscle and brain   总被引:18,自引:0,他引:18  
Complementary DNA clones were isolated that represent the 5' terminal 2.5 kilobases of the murine Duchenne muscular dystrophy (Dmd) messenger RNA (mRNA). Mouse Dmd mRNA was detectable in skeletal and cardiac muscle and at a level approximately 90 percent lower in brain. Dmd mRNA is also present, but at much lower than normal levels, in both the muscle and brain of three different strains of dystrophic mdx mice. The identification of Dmd mRNA in brain raises the possibility of a relation between human Duchenne muscular dystrophy (DMD) gene expression and the mental retardation found in some DMD males. These results also provide evidence that the mdx mutations are allelic variants of mouse Dmd gene mutations.  相似文献   

4.
5.
Duchenne muscular dystrophy (DMD) is a severe X-linked disorder leading to early death of affected males. Females with the disease are rare, but seven are known to be affected because of a chromosomal rearrangement involving a site at or near the dmd gene on the X chromosome. One of the seven has a translocation between the X and chromosome 21. The translocation-derived chromosomes from this patient have been isolated, and the translocation is shown to have split the block of genes encoding ribosomal RNA on the short arm of chromosome 21. Thus ribosomal RNA gene probes may be used to identify a junction fragment from the translocation site, allowing access to cloned segments of the X at or near the dmd gene and presenting a new approach to the study of this disease.  相似文献   

6.
Most mutations in the dystrophin gene create a frameshift or a stop in the mRNA and are associated with severe Duchenne muscular dystrophy. Exon skipping that naturally occurs at low frequency sometimes eliminates the mutation and leads to the production of a rescued protein. We have achieved persistent exon skipping that removes the mutated exon on the dystrophin messenger mRNA of the mdx mouse, by a single administration of an AAV vector expressing antisense sequences linked to a modified U7 small nuclear RNA. We report the sustained production of functional dystrophin at physiological levels in entire groups of muscles and the correction of the muscular dystrophy.  相似文献   

7.
8.
The imprinted regulation of H19 and Insulin-like growth factor 2 expression involves binding of the vertebrate insulator protein, CCCTC binding factor (CTCF), to the maternally hypomethylated differentially methylated domain (DMD). How this hypomethylated state is maintained during oogenesis and the role of CTCF, if any, in this process are not understood. With the use of a transgenic RNA interference (RNAi)-based approach to generate oocytes with reduced amounts of CTCF protein, we found increased methylation of the H19 DMD and decreased developmental competence of CTCF-deficient oocytes. Our results suggest that CTCF protects the H19 DMD from de novo methylation during oocyte growth and is required for normal preimplantation development.  相似文献   

9.
Myotonic dystrophy (DM), the most common form of muscular dystrophy in adults, can be caused by a mutation on either chromosome 19q13 (DM1) or 3q21 (DM2/PROMM). DM1 is caused by a CTG expansion in the 3' untranslated region of the dystrophia myotonica-protein kinase gene (DMPK). Several mechanisms have been invoked to explain how this mutation, which does not alter the protein-coding portion of a gene, causes the specific constellation of clinical features characteristic of DM. We now report that DM2 is caused by a CCTG expansion (mean approximately 5000 repeats) located in intron 1 of the zinc finger protein 9 (ZNF9) gene. Parallels between these mutations indicate that microsatellite expansions in RNA can be pathogenic and cause the multisystemic features of DM1 and DM2.  相似文献   

10.
A new probe for the diagnosis of myotonic muscular dystrophy   总被引:11,自引:0,他引:11  
Myotonic muscular dystrophy (DM) is the most common muscular dystrophy, affecting adults as well as children. It is inherited as an autosomal dominant trait and is characterized by variable expressivity and late age-of-onset. Linkage studies have established the locus on chromosome 19. In order to identify tightly linked probes for diagnosis as well as to define in detail the DM gene region, chromosome 19 libraries were constructed and screened for restriction fragment length polymorphisms tightly linked to DM. A genomic clone, LDR152 (D19S19), was isolated that is tightly linked to DM; recombination fraction = 0.0 (95% confidence limits 0.0-0.03); lod score, 15.4.  相似文献   

11.
Human metmyoglobin was separated electrophoretically into four subfractions: Mb(1), Mb(2), Mb(3), and Mb(4), which divide into at least two biochemically independent groups: Mb(1) and Mb(2), and Mb(3), and Mb(4). In normal subjects, Mb(1) constituted the predominant component; Mb(2), Mb(3), and Mb(4) were the minor components in this descending order. In the Duchenne type of progressive muscular dystrophy, on the contrary, a remarkable decrease in Mb(1) and a concomitant increase in Mb(3) were observed. This unique abnormality in the relative distribution of myoglobin subfractions was recognized only in the Duchenne type and not in other types of progressive muscular dystrophy or in other myopathies.  相似文献   

12.
Several of the endothelial cell polypeptide mitogens that have been described probably play a role in blood vessel homeostasis. Two overlapping complementary DNA clones encoding human endothelial cell growth factor (ECGF) were isolated from a human brain stem complementary DNA library. Southern blot analysis suggested that there is a single copy of the ECGF gene and that it maps to human chromosome 5 at bands 5q31.3 to 33.2 A 4.8-kilobase messenger RNA was present in human brain stem messenger RNA. The complete amino acid sequence of human ECGF was deduced from the nucleic acid sequence of these clones; it encompasses all the well-characterized acidic endothelial cell polypeptide mitogens described by several laboratories. The ECGF-encoding open reading frame is flanked by translation stop codons and provides no signal peptide or internal hydrophobic domain for the secretion of ECGF. This property is shared by human interleukin-1, which is approximately 30 percent homologous to ECGF.  相似文献   

13.
The sequence of the entire RNA genome of the type flavivirus, yellow fever virus, has been obtained. Inspection of this sequence reveals a single long open reading frame of 10,233 nucleotides, which could encode a polypeptide of 3411 amino acids. The structural proteins are found within the amino-terminal 780 residues of this polyprotein; the remainder of the open reading frame consists of nonstructural viral polypeptides. This genome organization implies that mature viral proteins are produced by posttranslational cleavage of a polyprotein precursor and has implications for flavivirus RNA replication and for the evolutionary relation of this virus family to other RNA viruses.  相似文献   

14.
利用反转录-聚合酶链式反应(RT-PCR)方法,从新疆阿勒泰×中国美利奴杂交F1代绵羊脑垂体总RNA扩增出编码绵羊生长激素(oGH)基因序列,T-A克隆入载体质粒pT-Adv.测序结果表明所克隆的oGH cDNA在重组质粒的阅读框架是正确的,共含有654个碱基,其核苷酸序列与已知的3条绵羊序列相比共有7个碱基的差异,除第472位和529位的碱基差异能够引起氨基酸序列的变化外,其余均为无义突变,说明从新疆阿勒泰×中国美利奴杂交绵羊中获得的羊生长激素存在有不同品系间的基因多态性变化.将重组质粒pT-Adv/oGH cDNA定向克隆入真核表达载体质粒pcDNA3.1/myc-HisA,构建成重组oGH基因的真核表达载体pcDNA3.1A/oGH.利用脂质体转染法,将重组质粒导入到小鼠骨髓瘤(SP2/0)细胞中,经间接ELISA检测,证明在转染细胞的上清中存在有目的基因产物的外泌表达.  相似文献   

15.
鱼油在鲤饲料中的适宜用量   总被引:7,自引:0,他引:7  
在高蛋白半纯化饲料中分别添加0,30,50,70,90g/kg的未加抗氧化剂的新鲜鱼油,投喂58g左右2龄鲤(Cyprinus carpio)鱼种46d , 结果表明,添加新鲜鱼油量为30g/kg时,鲤生产性能最佳,鲤肝体比(HSI),肝胰脏脂肪含量,肌肉营养不良症和肌肉渗出性损失随着钎油添加量的增加而持续上升,而肌肉和肾脏氧化稳定性则随着鱼油添加量的增中而持续下降,当添加鱼油量升至30,70,70,50,70,70g/kg时,上述6项指标与对照组差异显著(P<0.05),综合各项指标,未添加抗氧化剂的新鲜鱼油在高蛋白质鲤饲料中适宜用量以不超过30g/kg为宜。  相似文献   

16.
Met-myoglobin isolated from gluteal muscle of cases with Duchenne type of progressive muscular dystrophy showed an abnormal ultraviolet spectrum. The maximum of the spectrum at pH 7.0 was at 275 mmicro, in contrast to that at 281 m/ A in normal met-myoglobin. Such an abnormality was not found in the limb-girdle type of dystrophy and in progressive spinal muscular atrophy. The results indicate the presence of an abnormal myoglobin in the Duchenne type of progressive muscular dystrophy.  相似文献   

17.
Human T-cell lymphotropic virus type III (HTLV-III), the causative agent of the acquired immune deficiency syndrome (AIDS), was recently isolated and its genomic structure analyzed by DNA cloning methods. In the studies reported here a combined cloning and expression system was used to identify HTLV-III encoded peptides that react immunologically with antibodies in sera from AIDS patients. Cloned HTLV-III DNA was sheared into approximately 500-base-pair fragments and inserted into an "open reading frame" expression vector, pMR100. The inserted DNA was expressed in Escherichia coli transformants as a polypeptide fused to the lambda CI protein at its amino terminus and to beta-galactosidase at its carboxyl terminus. Sera from AIDS patients containing antibodies to HTLV-III were then used to screen for immunoreactive fusion proteins. Twenty clones, each specifying a fusion protein strongly reactive with AIDS serum, were identified. DNA sequence analysis indicated that the HTLV-III fragments were derived from the open reading frame DNA segments corresponding to the gag and pol gene coding regions and also the large open reading frame region (env-lor) located near the 3' end of the viral genome.  相似文献   

18.
A novel gene of HIV-1, vpu, and its 16-kilodalton product   总被引:51,自引:0,他引:51  
A 16-kilodalton protein expressed in cells producing the human immunodeficiency virus (HIV-1) was identified as the gene product of the vpu open reading frame. When expressed in vitro, the 81-amino acid vpu protein reacted with about one-third of the serum samples from AIDS patients that were tested, indicating that the vpu open reading frame is expressed in vivo as well. Introduction of a frame-shift mutation into the vpu open reading frame did not significantly interfere with expression of the major viral proteins in a transient expression system. However, a five- to tenfold reduction in progeny virions was observed after the infection of T lymphocytes with the mutant virus. These data suggest that the vpu gene product is required for efficient virus replication and may have a role in assembly or maturation of progeny virions.  相似文献   

19.
以G6型牛轮状病毒总RNA为模板,应用RT-PCR技术扩增牛轮状病毒VP4开放性阅读框,通过T-A克隆技术,将PCR产物克隆至pEASy-T3载体中,成功构建出克隆质粒pEASY-T3-VP4.经双酶切后再将该基因重组于原核表达载体pET32a(+)中,构建出原核表达质粒pET32a-VP4.将pET32a-VP4转化至大肠杆菌BL21(DE3)中,经IPTG诱导和SDS-PAGE分析,可见约108 KD的融合蛋白带,成功构建了能够稳定表达VP4蛋白的基因工程菌株,为进一步研制牛轮状病毒基因工程疫苗奠定了基础.  相似文献   

20.
根据GenBank中欧洲兔ZP3 mRNA序列设计特异性引物, 以草兔卵巢组织总RNA为模板, 通过RT-PCR技术首次克隆得到草兔ZP3 cDNA编码区,命名为hZP3( GenBank登录号:KC447289)。生物信息学分析表明:扩增出的hZP3基因编码序列长1 260 bp, 编码419个氨基酸,包含一个完整的开放阅读框(ORF)。与欧洲兔ZP3基因核苷酸一致性高达96%。预测的ZP3蛋白具有ZP家族典型特征。系统进化树显示其与欧洲兔亲缘关系最近,其次是啮齿目动物,符合物种进化规律。hZP3基因编码区的成功克隆, 为进一步利用该基因通过免疫不育手段防治森林草兔危害提供了基础。  相似文献   

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