The ecological genetics of growth in Drosophila 6. The genetic correlation between the duration of the larval period and body size in relation to larval diet.

作者：Forbes W. Robertson · 发表于：Genetics Research · 年份：1963 · DOI：10.1017/s001667230000344x · 被引用次数：169 · 研究领域：Insect Utilization and Effects、Silkworms and Sericulture Research、Insect Resistance and Genetics

1. The low but regular positive correlation between body-size and the duration of the larval period in populations ofD. melanogasterhas been studied by selecting for large size or shorter development time on aseptic defined diets deficient in RNA and comparing the results with parallel selection on unrestricted yeast diets or on media in which RNA is not a limiting factor. 2. There is a striking contrast according to the nature of the diet during selection. On unrestricted diets and where RNA is adequate there is little or no evidence of correlation between the two characters, but on low RNA media there is a striking correlation whether selection is for large body size or shorter development time. 3. This contrast is accounted for in terms of particular changes in larval growth which can be divided into a first stage of growth to a critical size in the early 3rd instar and a second stage thereafter. The duration of the first stage can be greatly prolonged by inadequate diet but the duration of the later stage appears to be virtually unaffected by such variation although the amount of growth and hence final body-size, may be drastically reduced. The different diets which lead to presence or absence of correlation have enabled selection either to extend the growing period, so that the critical stage is reached later at a larger larval size, or to accelerate the growth rate in the later stage. 4. Variation in the final stage of growth predominates on unrestricted diets and is re...