Kraaijeveld A R, Limentani E C, Godfray H C
NERC Centre for Population Biology, Department of Biology, Imperial College at Silwood Park, Ascot, Berkshire, UK.
Proc Biol Sci. 2001 Feb 7;268(1464):259-61. doi: 10.1098/rspb.2000.1354.
Drosophila melanogaster can be artificially selected for increased resistance against parasitoid wasps that attack the larvae. Lines selected for greater resistance are poorer larval competitors under conditions of resource scarcity. Here we investigated the mechanistic basis of this apparent trade-off. We found that resistant lines have approximately twice the density of haemocytes (blood cells) than that of controls. Haemocytes are involved in encapsulation, the chief cellular immune defence against parasitoids. We have previously shown that resistant lines feed more slowly than controls and hypothesize that limiting resources are being switched from trophic to defensive functions.
黑腹果蝇可以通过人工选择来提高对攻击幼虫的寄生蜂的抵抗力。在资源稀缺的条件下，选择出的抵抗力更强的品系是较差的幼虫竞争者。在这里，我们研究了这种明显权衡的机制基础。我们发现，抗性品系的血细胞（血细胞）密度大约是对照品系的两倍。血细胞参与包囊形成，这是针对寄生蜂的主要细胞免疫防御。我们之前已经表明，抗性品系的进食速度比对照品系慢，并推测有限的资源正从营养功能转向防御功能。
