TY - JOUR
T1 - The relationship between life span and adult body size is highly strain-specific in Drosophila melanogaster
AU - Khazaeli, Aziz A.
AU - Van Voorhies, Wayne
AU - Curtsinger, James W
PY - 2005/5
Y1 - 2005/5
N2 - Among mammals, body size and life span tend to vary inversely within species, but the pattern is less clear in invertebrates. Here, we report on survival and weight of male flies from 29 laboratory strains of Drosophila melanogaster. Natural variation in body mass was enhanced by rearing larvae under normal and limited food conditions. Strain, weight, and larval treatment have significant effects on survival, but higher order interactions are also significant, indicating strain specificity. For pooled data the overall relationship between mass and life span is slight, positive, and statistically significant, but mass explains ≤1% of the variation in survival. This result is opposite to the common prediction of an inverse relationship between longevity and body size. Effects of artificially reduced body size vary substantially in both sign and magnitude from strain to strain, though long-lived strains generally retain their enhanced survival characteristics. Within-line regressions of life span on mass also vary dramatically from strain to strain; in Canton-S, the most extreme case, mass explains >40% of the variation in survival. For long-lived 'O' lines reared under normal larval conditions, smaller flies live 16% longer than larger flies; the latter are significantly underrepresented in the most advanced age class. We conclude that the body size-life span relationship is highly strain-specific; that inconsistencies in the literature probably reflect real biological variation; and that variation in body size can be a significant source of experimental noise in survival studies.
AB - Among mammals, body size and life span tend to vary inversely within species, but the pattern is less clear in invertebrates. Here, we report on survival and weight of male flies from 29 laboratory strains of Drosophila melanogaster. Natural variation in body mass was enhanced by rearing larvae under normal and limited food conditions. Strain, weight, and larval treatment have significant effects on survival, but higher order interactions are also significant, indicating strain specificity. For pooled data the overall relationship between mass and life span is slight, positive, and statistically significant, but mass explains ≤1% of the variation in survival. This result is opposite to the common prediction of an inverse relationship between longevity and body size. Effects of artificially reduced body size vary substantially in both sign and magnitude from strain to strain, though long-lived strains generally retain their enhanced survival characteristics. Within-line regressions of life span on mass also vary dramatically from strain to strain; in Canton-S, the most extreme case, mass explains >40% of the variation in survival. For long-lived 'O' lines reared under normal larval conditions, smaller flies live 16% longer than larger flies; the latter are significantly underrepresented in the most advanced age class. We conclude that the body size-life span relationship is highly strain-specific; that inconsistencies in the literature probably reflect real biological variation; and that variation in body size can be a significant source of experimental noise in survival studies.
KW - Body size
KW - Drosophila melanogaster
KW - Extreme old age
KW - Life history
KW - Life span
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U2 - 10.1016/j.exger.2005.02.004
DO - 10.1016/j.exger.2005.02.004
M3 - Article
C2 - 15919589
AN - SCOPUS:20144386009
VL - 40
SP - 377
EP - 385
JO - Experimental Gerontology
JF - Experimental Gerontology
SN - 0531-5565
IS - 5
ER -