A A Hoffmann — Page 4 | PubMed Health

PubMed1975

Studies on the nature of circulating DNA in systemic lupus erythematosus (SLE).

The isolation and purification of DNA from the sera of patients with SLE is described. Buoyant density determinations of this DNA using CsCl gradients suggest in some cases that it may be of endogenous origin. DNA from the synovial fluid of an SLE patient with septic arthritis was also shown to have a buoyant density of human DNA as well as being of considerable size variation. In addition, this synovial fluid contained antibody to DNA and evidence of DNA:anti-DNA complexes, suggesting that immune complexes composed of human DNA and antibody may be involved in the pathogenesis of the arthritis. Also described are preliminary experiments characterizing the conformation of the DNA present in DNA:anti-DNA immune complexes.

Animals↗

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The association between inversion In(3R)Payne and clinally varying traits in Drosophila melanogaster.

In Drosophila melanogaster, inversion In(3R)Payne increases in frequency towards low latitudes and has been putatively associated with variation in size and thermal resistance, traits that also vary clinally. To assess the association between size and inversion, we obtained isofemale lines of inverted and standard karyotype of In(3R)Payne from the ends of the Australian D. melanogaster east coast cline. In the northern population, there was a significant association between In(3R)Payne and body size, with standard lines from this population being relatively larger than inverted lines. In contrast, the inversion had no influence on development time or cold resistance. We strengthened our findings further in a separate study with flies from populations from the middle of the cline as well as from the cline ends. These flies were scored for wing size and the presence of In(3R)Payne using a molecular marker. In females, the inversion accounted for around 30% of the size difference between cline ends, while in males the equivalent figure was 60%. Adaptive shifts in size but not in the other traits are therefore likely to have involved genes closely associated with In(3R)Payne. Because the size difference between karyotypes was similar in different populations, there was no evidence for coadaptation within populations.

Acclimatization↗