Kurtz Joachim
Institut für Evolutionsbiologie und Okologie, Rheinische Friedrich-Wilhelms-Universität, 53121 Bonn, Germany.
Microsc Res Tech. 2002 Jun 15;57(6):456-68. doi: 10.1002/jemt.10099.
An in vitro phagocytosis assay, adjusted to as little as 1 microL of insect hemolymph, enables the microscopic determination of phagocytosis for single individuals of small insects. Even repeated determination over the lifetime of individuals is possible. This method makes it feasible to study individual variation in invertebrate phagocytic capacity. Possible sources of such variation are reviewed in this article: genetic differences, development, aging, reproduction, presence of parasites, and diverse environmental influences are natural sources of individual variation in phagocytosis. However, the methods used for phagocytosis and microscopic evaluation are also (unwelcome) sources of variation. To optimize incubation time for in vitro phagocytosis, time courses were determined. Furthermore, the reliability of visual counting and image analysis for the microscopic quantification of phagocytosis are compared. The influences of larval development and adult aging on phagocytosis by Panorpa vulgaris hemocytes are subsequently demonstrated. During development, a decrease in hemocyte numbers but a simultaneous increase in the proportion of phagocytosing hemocytes was observed when larvae reached pupation. On the other hand, adults showed a dramatic decrease in phagocytic capacity with age, while cell numbers remained fairly constant. The results show that individual variation in phagocytosis can be determined accurately in small invertebrates and related to its causes. This might be especially interesting in the context of studies relating individual immunocompetence to ecology, life history variation, and behavior.
一种体外吞噬试验，可将样本量调整至低至1微升昆虫血淋巴，能够通过显微镜确定小型昆虫单个个体的吞噬作用。甚至在个体的整个生命周期内进行反复测定也是可行的。该方法使得研究无脊椎动物吞噬能力的个体差异成为可能。本文综述了这种差异的可能来源：遗传差异、发育、衰老、繁殖、寄生虫的存在以及各种环境影响，都是吞噬作用中个体差异的自然来源。然而，用于吞噬作用和显微镜评估的方法也是（不受欢迎的）差异来源。为了优化体外吞噬作用的孵育时间，确定了时间进程。此外，还比较了视觉计数和图像分析对吞噬作用进行显微镜定量的可靠性。随后展示了幼虫发育和成虫衰老对普通蝎蛉血细胞吞噬作用的影响。在发育过程中，当幼虫化蛹时，观察到血细胞数量减少，但同时吞噬血细胞的比例增加。另一方面，成虫的吞噬能力随着年龄的增长而急剧下降，而细胞数量保持相当稳定。结果表明，在小型无脊椎动物中可以准确测定吞噬作用的个体差异，并找出其原因。在将个体免疫能力与生态学、生活史变异和行为相关联的研究背景下，这可能特别有趣。
