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J B Gibson

Publications and source records attributed to J B Gibson.

At least 73 records · Page 4Linked to original sources
PubMed1984

Variation in the biochemical properties of the Drosophila alcohol dehydrogenase allozymes.

Thirteen Drosophila Adh variants have been characterized with respect to gene expression, substrate preference, thermostability, and specific activity. The results suggest that the variants may be grouped into two biochemical classes, typified by the properties of the two most common enzyme forms, ADH-F and ADH-S. Membership of these classes cannot be predicted from electrophoretic mobility, nor is any simple classification possible with regard to the characteristics of level of gene expression (in terms of ADH activity or ADH protein) or thermostability of the gene product.

Alcohol Dehydrogenase↗
PubMed1984

Selective effects of the genetic background and ethanol on the alcohol dehydrogenase polymorphism in Drosophila melanogaster.

Eight freshly caught Australasian mass collections ranging in Adh F frequency from 4 to 96 per cent were each divided into eight selection lines. Two selection lines from each base population were put on one of four types of medium-standard food supplemented with 0 per cent, 3 per cent, 6 per cent or 9 per cent ethanol. After 30 generations the tolerance of 6 per cent and 9 per cent selection lines on a test dose of 9 per cent ethanol was greater than that of the 0 per cent lines on this dose. The tolerance of the 3 per cent lines on this dose was less than that of the 0 per cent lines. There were no significant differences in the tolerance responses across the eight base populations but in only one did Adh frequencies diverge among the four ethanol selection environments: F frequencies in the Brisbane 9 per cent lines were higher than in the Brisbane 0 per cent, 3 per cent and 6 per cent lines. Although the selection affecting Adh did not generally differ among the four selection environments, it differed highly significantly among the eight base populations. The equilibrium F frequencies predicted from the maximum likelihood estimates of the selection coefficients were in close agreement with the frequencies observed in the original collections. The only aspect of the coefficients which was consistent across base populations was FS heterozygote superiority.

Alcohol Oxidoreductases↗
PubMed1984

Kimura's disease: a clinico-pathological study of 21 cases and its distinction from angiolymphoid hyperplasia with eosinophilia.

Kimura's disease is a chronic inflammatory condition producing subcutaneous tumour-like nodules chiefly in the head and neck region. It is characterized histologically by lymphoid follicles, intense aggregations of eosinophils, vascular proliferation and fibrosis. Superficial lymph nodes and parotid glands are sometimes involved. The lesions may persist unchanged for years and new ones are apt to occur. Recurrences are also common. There are no systemic manifestations apart from peripheral blood eosinophilia. The lesion has been recognised as a distinct clinicopathological entity in the Far East for over 40 years. We describe 21 cases of Kimura's disease and discuss its relationship to angiolymphoid hyperplasia with eosinophilia. Although the pathogenesis and etiology of both these lesions are unknown we believe that there are sufficient significant clinical and pathological differences to justify their separation.

Adolescent↗
PubMed1982

Measuring selection coefficients affecting the alcohol dehydrogenase polymorphism in Drosophila melanogaster.

This paper describes a perturbation experiment on the frequency of the F and S Alcohol dehydrogenase (Adh) alleles of D. melanogaster. Fifty-four iso-female lines set up from three wild populations and with initial F frequencies of either 0.25, 0.50 or 0.75 were maintained on standard laboratory food medium at 22 degrees. At generations 4, 12 and 20 the lines were again scored for Adh gene frequencies. Maximum likelihood procedures were used to estimate selection coefficients for the Adh genotypes. An analysis of deviance was used to compare the coefficients against expectations under the hypotheses of neutrality and of constant values for the three base populations, and for the three initial gene frequency classes. Highly-significant departures from neutrality were observed; over all 54 lines, the set of relative fitnesses for S/S:F/S:F/F was estimated as 1.00:1.08:1.08. In addition, there were significant differences between lines in the outcome of selection which were not attributable to differences between base populations or initial F frequencies. These residual between-line differences, as well as some between-generation, within-line differences are discussed in terms of linkage disequilibria with background genes and electrophoretically cryptic variation at the Adh locus.

Alcohol Oxidoreductases↗
PubMed1981

Serum alpha-fetoprotein in rats after ligation of the common bile duct: relation to ductular cell (oval cell) proliferation.

Serum AFP levels were measured by radio-immunoassay in rats at various periods after ligation and section of the common bile duct and after sham-ligation. Transient elevations of serum AFP reaching statistically significant levels occurred at 3 to 10 days, 17 days and 28 days after ligation of the common bile duct but not in sham-operated rats. The peak elevations of serum AFP followed waves of mitosis in both the ductular cells and the hepatocytes as measured by autoradiography. Proliferation of hepatocytes, however, remained minor when compared to ductular cell multiplication. Ultra-structural and histochemical studies of the liver clearly distinguished ductular (oval) cells from hepatocytes and provided no evidence of transition from ductular cells to hepatocytes. Our findings suggest that ductular cell proliferation in the rat induced by ligation of the common bile duct may produce elevations in the serum AFP.

Animals↗
PubMed1981

Latitudinal relationships of esterase-6 and phosphoglucomutase gene frequencies in Drosophila melanogaster.

Geographic variation in Esterase-6 (Est-6) and Phosphoglucomutase (Pgm) gene frequencies in Australasian populations of Drosophila melanogaster are compared with analogous data collated from 16 previous reports for North America and Europe/Asia. A large-scale latitudinal cline is found on all three zoogeographic zones for Est-6 and overall, Est-61.00 frequency increases from about 20 per cent around 20 degrees latitude to about 80 per cent approaching 50 degrees latitude. In contrast, there is no consistent evidence for the latitudinal cline in Pgm gene frequencies in any of the three zones with Pgm1.00 frequency generally about 85 per cent and Pgm1.20 and Pgm0.70 frequencies each between 5 per cent and 10 per cent. The consistent Est-6 clines are attributed to latitudinal selection gradients but not consistent correlations are found between Est-6 gene frequencies and maximum or minimum temperature or rainfall which might be associated with these gradients. The directions of the Est-6 clines in fact run counter to expectations based on the in vitro thermostabilities of the respective allozymes.

Animals↗
PubMed1981

An electrophoretically cryptic alcohol dehydrogenase variant in Drosophila melanogaster. III. Biochemical properties and comparison with common enzyme forms.

The biochemical properties of the heat-stable alcohol dehydrogenase variant ADH-FCh.D. have been investigated and compared with those of the two common enzyme forms ADH-F and ADH-S. The results show that ADH-F and ADH-S differ with respect to substrate specificity, their response to high concentrations of secondary alcohols and their apparent Michaelis constants for three alcohols in two different buffer systems. In all these tests the enzyme ADH-FCh.D. resembles ADH-S much more closely than ADH-F. It is concluded that if natural selection is to distinguish between the alleles AdhS and AdhFCh.D. then it most probably does so on the basis of the superior thermostability of ADH-FCh.D. The biochemical properties of all three enzymes are discussed in relation to the role of alcohol dehydrogenase in the exploitation of alcohol by D. melanogaster.

Alcohol Dehydrogenase↗
PubMed1981

Structural analysis of an electrophoretically cryptic alcohol dehydrogenase variant from an Australian population of Drosophila melanogaster.

The existence of geographically widespread clines in genetic polymorphisms is persuasive evidence that the distribution of such genetic variance is determined by natural selection. However, when comparing clines it is important to be certain that identical structural genes are involved. We report a structural difference (proline-214 to serine) between the product of AdhF and an electrophoretically cryptic heat-stable variant isolated from an Australian natural population, ADH-FCh.D. ("fast" Chateau Douglas). The biochemical properties of this new variant must be taken into consideration when attempting to formulate a causal explanation of the maintenance of the three identified Adh alleles. Our data also show that the products of an AdhF and an AdhS allele in Drosophila melanogaster in an Australian population are identical over 70% of their amino acid sequences with their North American counterparts.

Alcohol Oxidoreductases↗