Profiles in genetics: George Wells Beadle and the origins of the gene-enzyme concept.

Beadle's success in establishing biochemical genetics on a firm foundation was due to a combination of several circumstances. These include the following: 1. Apt timing of his work, which Garrod's work clearly lacked, was important. Geneticists were receptive to his ideas and conclusions. As Beadle (1967, 1974) himself acknowledged, much ground was prepared earlier by Garrod and Haldane, who discussed gene action in terms of biochemical reactions, although it was largely ignored. The physiology of gene action was discussed and speculated on to a great extent in the preceding years by Bridges, Goldschmidt, Muller, and Wright. 2. Beadle's selection of Neurospora was most appropriate. It was a haploid organism (with no complications of dominance and recessivity) that could be grown and manipulated easily for isolating mutants to study their segregation and recombination within a short time. Its cytogenetics and the method of growing on chemically defined media were already worked out. It was devoid of the long generation time and more complex sex cycle (among other problems) that complicated the biochemical study of higher plants (e.g., Primula), which Haldane and Scott-Moncrieff had attempted earlier. 3. Beadle's striking ability to shift from one organism to another--from corn to Drosophila to Neurospora--must be acknowledged. He saw the limitations of existing methods and had the courage and skill to move on to more successful methods: from conventional breeding to tissue transplants to microbiological techniques. 4. Beadle's own curiosity about the biochemical nature of gene action and his good fortune in having had such outstanding teachers as Emerson, as well as his ability to collaborate with Ephrussi and Tatum, contributed largely to his success.     

Anti-inflammatory activity of dimethyl octenol and oleanene tetrol isolated from <Emphasis Type="Italic">Trianthema decandra</Emphasis> L.

Dimethyl octenol from chloroform extract and oleanene tetrol from water extract of Trianthema decandra (TD) were isolated and characterized by using HPLC, UV, FT-IR, NMR, LC–MS and CHNS, their structure were elucidated from their respective spectral data. The anti-inflammatory activity of chloroform extract, water extract, dimethyl octenol and oleanene tetrol of T. decandra were studied and underlying cellular and molecular mechanisms of action were investigated in vitro and in vivo using macrophage-like cell line (RAW264.7 cells) and type II collagen induced arthritis mice models. Nitric oxide production was inhibited and TNF-α secretion was supressed in stimulated RAW cells treated with the chloroform extract and dimethyl octenol of T. decandra. Further, the chloroform and water extract, dimethyl octenol and oleanene tetrol inhibited protein denaturation and stabilized HRBC membranes in vitro. Reduction in inflammation as a measure of paw diameter was recorded in all the treated animals when compared to control animals. Catalase, peroxidase and glutathione peroxidase levels significantly increased in the joint tissue of treated groups. The possible mechanism of action of these compounds was studied using in silico molecular docking methods with phospholipase A₂ (PLA₂), cycloxygenase-1 (COX-1) and cycloxygenase-2 (COX-2) as targets. Among the three target proteins, the inhibition of the inflammatory protein PLA₂ and COX-2 towards dimethyl octenol and oleanene tetrol respectively. Our results contribute towards confirmation of the traditional use of TD and its compounds for the therapy of rheumatoid arthritis and other inflammatory joint disorders.     

The origins of human gene mapping. With particular reference to the contributions of J. B. S. Haldane

Methods in human gene mapping, including those developed by Bell and Haldane, Morton, and the more recent ones using somatic cell fusion, restriction fragment length polymorphism (RFLP), and multipoint linkage, are briefly reviewed.     

Sewall Wright (1889-1988)

The genetic contributions of Sewall Wright is briefly reviewed with special reference to J.B.S. Haldane's work. These include his work in population genetics, statistics, and animal breeding.