The isolation of polygenic factors controlling bristle score in Drosophila melanogaster. I. Allocation of third chromosome sternopleural bristle effects to chromosome sections.
A single third chromosome C, with a high sternopleural bristle score, had been extracted from an artificial selection line. C was divided into five chromosomal sections by recombination with a multiply marked third chromosome ruseca, which had a low sternopleural bristle score. A nonuniform distribution of sternopleural bristle effect with physical length of chromosome was observed. The second section (26-44 cM) of C carried the most sternopleural bristle effect (10 bristles when homozygous), the first (0-26 cM) and third (44-62 cM) also carried significant sternopleural bristle effects (six and five bristles, respectively). The fourth section (62-71 cM) carried a small but significant effect (less than one bristle) while the fifth section (71-101 cM) carried little effect when alone (less than one bristle), though it did carry effects which had an epistatic interaction with those of the first and second sections.
Shrimpton
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AE
Department of Genetics, University of Edinburgh, Edinburgh EH9 3JN, Scotland.
Robertson
A
A