James A C, Azevedo R B, Partridge L
Department of Biology, Galton Laboratory, University College London, United Kingdom.
Genetics. 1997 Jul;146(3):881-90. doi: 10.1093/genetics/146.3.881.
Field-collected Drosophila melanogaster from 19 populations in Eastern Australia were measured for body size traits, and the measurements were compared with similar ones on flies from the same populations reared under standard laboratory conditions. Wild caught flies were smaller, and latitudinal trends in size were greater. Reduced size was caused by fewer cells in the wing, and the steeper cline by greater variation in cell area. The reduction in size in field-collected flies may therefore have been caused by reduced nutrition, and the steeper cline may have been caused by an environmental response to latitudinal variation in temperature. No evidence was found for evolution of size traits in response to laboratory culture. The magnitude of phenotypic plasticity in response to temperature of development time, body size, cell size and cell number was examined for six of the populations, to test for latitudinal variation in plasticity. All characters were plastic in response to temperature. Total development time showed no significant latitudinal variation in plasticity, although larval development time showed a marginally significant effect, with most latitudinal variation at intermediate rearing temperatures. Neither thorax length nor wing size and its cellular components showed significant latitudinal variation in plasticity.
对从澳大利亚东部19个种群野外采集的黑腹果蝇进行了体型特征测量，并将测量结果与在标准实验室条件下饲养的来自相同种群的果蝇的类似测量结果进行了比较。野外捕获的果蝇体型较小，且体型的纬度趋势更大。体型减小是由于翅膀中的细胞数量减少，而更陡峭的渐变是由于细胞面积的更大变化。因此，野外采集的果蝇体型减小可能是由于营养减少所致，而更陡峭的渐变可能是由于对温度纬度变化的环境反应所致。未发现体型特征因实验室培养而发生进化的证据。对其中六个种群的发育时间、体型、细胞大小和细胞数量对温度的表型可塑性程度进行了研究，以测试可塑性的纬度变化。所有特征对温度都具有可塑性。总发育时间在可塑性方面未表现出显著的纬度变化，尽管幼虫发育时间表现出微弱的显著影响，在中等饲养温度下纬度变化最大。胸长、翅大小及其细胞成分在可塑性方面均未表现出显著的纬度变化。
