Douglas A E., Wilkinson T L.
Department of Biology, University of York, PO Box 373, York, UK
J Insect Physiol. 1998 Jul;44(7-8):629-635. doi: 10.1016/s0022-1910(98)00030-4.
The symbiotic bacteria Buchnera in aphids are borne in cells, called bacteriocytes, in the insect haemocoel. The number and median volume of bacteriocytes in pre-reproductive adult insects varied significantly among 14 parthenogenetic clones of the pea aphid Acyrthosiphon pisum. After logarithmic transformation of the data, the relationship of both number and median volume of bacteriocytes with aphid weight for the clones could be described by common regression lines with slopes significantly greater than zero. The allometric slope for median bacteriocyte volume was calculated as 1.06, by model I regression and 1.94 by model II regression; and the equivalent values of the allometric slope for total volume of bacteriocytes were 1.51 and 2.50, suggesting that the total volume of bacteriocytes increases disproportionately with aphid body weight. The partial correlation coefficient between the number and median volume of bacteriocytes was +0.07, with body weight held constant. It is proposed that the regulation of number and size of bacteriocytes is not linked and that bacteriocytes may not exhibit compensatory changes in size, in response to alteration in number. Experimental manipulation of the rates of bacteriocyte differentiation and division could therefore perturb the total volume of the symbiosis, on which aphid pests depend for normal growth and reproduction.
蚜虫体内的共生细菌布赫纳氏菌存在于昆虫血腔中被称为含菌细胞的细胞内。在豌豆蚜豆蚜的14个孤雌生殖克隆中，未成熟成年昆虫的含菌细胞数量和中位数体积差异显著。对数据进行对数转换后，克隆的含菌细胞数量和中位数体积与蚜虫体重之间的关系可以用斜率显著大于零的共同回归线来描述。通过模型I回归计算，含菌细胞中位数体积的异速生长斜率为1.06，通过模型II回归计算为1.94；含菌细胞总体积的异速生长斜率的等效值为1.51和2.50，这表明含菌细胞的总体积随蚜虫体重不成比例地增加。在体重保持不变的情况下，含菌细胞数量和中位数体积之间的偏相关系数为+0.07。有人提出，含菌细胞数量和大小的调节没有联系，含菌细胞可能不会因数量的改变而表现出大小的补偿性变化。因此，对含菌细胞分化和分裂速率的实验操作可能会扰乱共生体的总体积，而蚜虫害虫的正常生长和繁殖依赖于共生体的总体积。
