No abstract

The entire genomic RNA of clover yellow mosaic virus was sequenced from cDNA clones and run-off cDNA transcripts.

A full-length cDNA copy of clover yellow mosaic virus (CYMV) RNA was constructed from two smaller cDNA clones. In vitro transcription of linearized plasmid with T7 RNA polymerase produced genomic-sized RNA. These transcripts caused symptoms typical of CYMV infection when used to inoculate both a systemic host (Viciafaba) and a local lesion host (Gomphrena globosa).Electron microscopy of extracts from individual local lesions revealed virus particles identical to native CYMV. Increasing the length of the poly(A) tail from 23 residues to 80 or to 135 residues increased the infectivity rate from 12 % to 17 % or to 35 % that of native CYMV RNA, respectively.

Endothelin receptors bind peptides of the endothelin family, the most potent vasoconstrictors known, and have been implicated in hypertension. To begin to define DNA sequences necessary for the transcriptional regulation of the rat endothelin type A receptor (ETA), we have sequenced the 5'-untranslated region (UTR) and part of the 5'-flanking region, a total of 1153 nucleotides. Comparison of the rat and human sequences revealed a 57% similarity in the 5'-flanking sequences, and a 63% similarity in the 5'-UTRs. Several conserved sequences were identified, including GATA and E-boxes, which may be important for the regulation of ETA gene expression. Primer extension analysis identified two transcription initiation sites within the rat gene.