Antisense technology is based on the ability to design potent, sequence-specific inhibitors. The G-clamp heterocycle modification, a cytosine analog that clamps on to guanine by forming an additional hydrogen bond, was rationally designed to enhance oligonucleotide/RNA hybrid affinity. A single, context-dependent substitution of a G-clamp heterocycle into a 15-mer phosphorothioate oligodeoxynuc...

Previous studies suggest that the CCAAT/enhancer-binding protein (C/EBP) functions in the coordinate expression of adipocyte genes during differentiation of 3T3-L1 preadipocytes. We sought to block expression of C/EBP selectively using a bovine papilloma virus (BPV) vector to direct transcription of a approximately 0.4-kb segment of C/EBP cDNA (in antisense orientation) containing translated se...

A surprise that has emerged from transcriptomics is the prevalence of genomic antisense transcription, which occurs counter to gene orientation. While frequent, the roles of antisense transcription in regulation are poorly understood. We built a synthetic system in Escherichia coli to study how antisense transcription can change the expression of a gene and tune the response characteristics of ...

The aim of the present study was to identify functional antisense oligodeoxynucleotides (ODNs) against the rat glutathione S-transferase Mu (GSTM) isoforms, GSTM1 and GSTM2. These antisense ODNs would enable the study of the physiological consequences of GSTM deficiency. Because it has been suggested that the effectiveness of antisense ODNs is dependent on the secondary mRNA structures of their...

In chloroplasts, the control of mRNA stability is of critical importance for proper regulation of gene expression. The Chlamydomonas reinhardtii strain Delta26pAtE is engineered such that the atpB mRNA terminates with an mRNA destabilizing polyadenylate tract, resulting in this strain being unable to conduct photosynthesis. A collection of photosynthetic revertants was obtained from Delta26pAtE...

Transfection of a neuroblastoma cell line with expression vectors containing two different segments of human c-mybcomplementary DNA in antisense orientation yielded far fewer transfectant clones than did the transaction with the identical segments in sense orientation. In cell clones expressing c-myb antisense RNA, levels of the c-myb protein were down-regulated and the proliferation rate was s...

Pervasive transcription of eukaryotic genomes stems to a large extent from bidirectional promoters that synthesize mRNA and divergent noncoding RNA (ncRNA). Here, we show that ncRNA transcription in the yeast S. cerevisiae is globally restricted by early termination that relies on the essential RNA-binding factor Nrd1. Depletion of Nrd1 from the nucleus results in 1,526 Nrd1-unterminated transc...

Antisense inhibition of gene expression during Xenopus development was obtained by injecting, into the zygote, an expression vector carrying the adenovirus VAI gene read by RNA polymerase III. This vector yields high levels of antisense RNA in most embryonic cells between mid-blastula transition and tailbud stage. As a target we chose the Xenopus homeobox gene Xhox1A. A 26 bp long oligonucleoti...

In this study, we employ antisense RNA technology to block Hepatitis B Virus (HBV) gene expression in cell culture by gene transfer as an approach to block immune recognition and pathogenic sequelae. Retroviral vectors encoding antisense and sense copies of the HBV surface antigen gene (HBsAg) were constructed, respectively. To assay the inhibition of HBV gene expression by antisense RNA, the a...