The promoter of a Brassica napus lipid transfer protein gene is active in a range of tissues and stimulated by light and viral infection in transgenic Arabidopsis.

cDNA and genomic clones encoding Brassica napus non-specific lipid transfer proteins (LTP) were isolated and sequenced. The encoded amino acid sequences were very similar to those reported previously for LTPs from B. napus and other species. Sequence information indicates that B. napus contains an LTP gene family. The 5'-flanking region of one gene, designated BnLTP, was fused to GUS and the fusion introduced into Arabidopsis. LTP transcripts and BnLTP-Gus expression were present predominantly in the epidermis of leaf and stem, consistent with the hypothesised function of LTPs in the deposition of cuticular or epicuticular waxes. However, GUS activity was detected in other tissues, including lateral root initials, anthers, stigmas and vascular tissues, which may suggest additional functions. LTP transcript levels in B. napus and Arabidopsis and BnLTP-GUS expression in transgenic Arabidopsis were stimulated by blue and red light but not UV-B. BnLTP promoter activity was also stimulated upon viral infection, at a time when the virus had spread systemically. No increase in expression was observed in response to cold or wounding.

Nucleotide sequence of the canine rod-opsin-encoding gene.

The major parts of two canine rod-specific opsin (Ops) transcripts have been cloned by polymerase chain reaction from retinal mRNA. Both transcripts are derived from the same gene. The 5' leader sequence of the transcripts was cloned from canine peripheral blood DNA. The transcripts code for a protein of 348 amino acids (aa), M(r) 38,962 (prior to any protein modification). The aa sequence suggests that in common with other sequenced Ops, canine rod Ops contains seven transmembrane domains, and residues believed essential for retinal pigment binding and for palmitate binding are conserved in the canine protein. Northern blotting using the central part of the ops gene as probe suggested that mature transcripts of three different sizes (about 1900, 2600 and 5500 bases) were found in retina. Of these, the 2600-base transcript was the most abundant. RACE cloning of the 3' end of ops showed that at least two of these size classes originate from differential transcript termination.

Drug response and genetic characterization of Plasmodium falciparum clones recently isolated from a Sudanese village.

We have isolated 20 clones of Plasmodium falciparum from isolates from patients attending a village clinic in Sudan during 10 d in October-November 1989. The clones were genetically diverse, having highly variable molecular karyotypes and a wide range of drug responses. Chloroquine-sensitive (50% inhibitory concentration [IC50] in the 4-15 nM range) and chloroquine-resistant clones (IC50 in the 40-95 nM range) co-existed in the population, but no obvious amplification of the P-glycoprotein homologue gene, Pgh1 (previously known as the multi-drug resistance gene, mdr1) marked the chloroquine-resistant clones. Chloroquine resistance was reversible by verapamil in these clones, although they varied in their susceptibility to verapamil alone. These observations indicate that the biochemical characteristics of the Sudanese chloroquine-resistant P. falciparum are similar to those reported from south-east Asian and Latin American isolates, which is consistent with there being a similar molecular basis for this phenomenon.