ISSN:1044-5498    

DOI:10.1089/dna.1.1984.3.1

年代:1984

数据来源: MAL

摘要:

ABSTRACTThe repair activity ofEscherichia coliDNA polymerase I (Klenow fragment) was used to prepare nonadecanucleotide hybridization probes which were complementary either to the normal human β-globin (βA) or to the sickle cell human β-globin (βS) gene. Template-directed polymerization of highly radiolabeled α[32P]deoxyribonucleoside triphosphates (dNTPs) onto nonamer and decamer primers produced probes with specific activities ranging from 1.0 × 1010to 2.0 × 1010dpm/μg. The extremely high specific activities of these probes made it possible to detect the βAand βSsingle-copy gene sequences in as little as 1 μg of total human genomic DNA as well as to discriminate between the homozygous and heterozyg

ISSN:1044-5498    

DOI:10.1089/dna.1.1984.3.7

年代:1984

数据来源: MAL

摘要:

ABSTRACTA series of plasmids was constructed differing only in the sequence of the Shine-Dalgarno region preceding the leukocyte interferon-A gene. This series of plasmids was used to test the efficiency of interferon expression in bothBacillus subtilisandEscherichia coli. InB. subtilis, interferon expression was much more sensitive to changes in the sequence of the Shine-Dalgarno region than inE. coliand it appeared to require more homology to the 3′ end of 16S ribosomal RN

ISSN:1044-5498    

DOI:10.1089/dna.1.1984.3.17

年代:1984

数据来源: MAL

摘要:

ABSTRACTThe DNA sequences for the coding and flanking regions of the type-common glycoprotein-D (gD) genes of herpes simplex virus (HSV) types 1 and 2 have been determined. The resultant protein sequences are approximately 80% homologous. Both gD proteins are 393 amino acids long and both have maintained three identical potential glycosylation sites. Amino acid changes are found throughout the proteins, with the majority of changes located in the amino and carboxyl/termini. Most of the amino acid differences were found to be conservative. Hydropathy analysis, which determines hydrophobic and hydrophilic regions, reveals a remarkable structural similarity between the proteins. Examination of 5′ flanking sequences demonstrates extensive DNA sequence homology adjacent to the start of gD gene transcription. In addition, another homologous noncoding region was found 3′ to the gD gene. This second homologous sequence is 5′ to a 1.6-kb transcription

ISSN:1044-5498    

DOI:10.1089/dna.1.1984.3.23

年代:1984

数据来源: MAL

摘要:

ABSTRACTThe maize genes for the 17S, 5.8S, and 26S ribosomal RNAs (rRNAs) are located on chromosome 6 and consist of 9-kb sequences repeated about 5,000–10,000 times per 2C. One of these sequences was isolated from a λ library containing maizeEcoRI genomic segments. The sequence of the small-subunit (17S) RNA was determined using the M13 shotgun-dideoxy sequencing approach. The maize sequence was compared with nuclear rRNAs from yeast,Xenopus, and rat. Using these sequences, it is possible to identify tentatively the start and the end points of the sequence of the maize nuclear small subunit rRNA. This RNA has a length of 1809 nucleotides. The alignment of all four sequences for maximal homology allows us to identify regions within the rRNA that have been conserved during eukaryotic evoluti

ISSN:1044-5498    

DOI:10.1089/dna.1.1984.3.31

年代:1984

数据来源: MAL

摘要:

ABSTRACTExtinction of rat growth hormone (rGH) gene expression occurs in somatic cell hybrids of GH3 cells (rat pituitary adenoma) and L cells (mouse transformed fibroblast). We have suggested that this is due totransacting factors contributed directly or indirectly by the L cells. To study this in more detail, the cloned rGH gene was introduced into clones of these hybrid cells by microinjection or calcium phosphate transfection. GH peptides were detected 24 hr later in the microinjected cells by immunofluorescence. Production of rGH gene transcripts in the stably transformed hybrid cells was also detected by Northern hybridization. Although the overall patterns of transcripts differed from those present in GH3cells, normal-sized rGH mRNA species were detected, whereas these had not been observed in previous studies in which the GH gene was transfected into L cells and other mouse fibroblasts. No more than one or two extra GH gene copies per cell were required to restore GH gene expression in the hybrids. Whereas GH gene expression in the hybrid cells transfected with the GH gene might reflect activation of the endogenous GH gene, this was not the case in at least one transfected hybrid cell line which had lost the endogenous gene. These results suggest: (i) the putativetransactive repressors of GH gene expression in the hybrid cells do not recognize the transfected genes; and (ii) elements in the hybrid cells, unlike the case with L cells, allow for the production of normal-sized GH mRNA that can also produce GH peptides. Somatic cell hybrids therefore seem to offer several advantages as recipients for gene-transfer studies, particularly of genes whose expression is limited to specialized cell types.

ISSN:1044-5498    

DOI:10.1089/dna.1.1984.3.41

年代:1984

数据来源: MAL

ISSN:1044-5498    

DOI:10.1089/dna.1.1984.3.51

年代:1984

数据来源: MAL

ISSN:1044-5498    

DOI:10.1089/dna.1.1984.3.75

年代:1984

数据来源: MAL