Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, N-1432 Aas, Norway.
J Insect Sci. 2007;7:1-14. doi: 10.1673/031.007.5201.
Vitellogenin is a yolk precursor protein in most oviparous females. In the advanced eusocial honeybee, Apis mellifera (Hymenoptera: Apidae), vitellogenin has recently attracted much interest as this protein, in addition to a classical function in oocyte development in the reproductive queen caste, has evolved functions in the facultatively sterile female worker caste not documented in other species. However, research on the spatial dynamics of vitellogenin in various tissues is not easily performed with available tools. Here we present an immunogold staining procedure that visualizes honeybee vitellogenin in resin embedded tissue. To establish the protocol, we used ovaries of worker bees from colonies with and without a queen. Under the first condition, vitellogenin is assumed not to be present in the workers' ovaries. Under the second condition, the ovaries of worker bees become vitellogenic, with abundant opportunities for detection of complex patterns of vitellogenin uptake and storage. By use of this experimental setup, the staining method is shown to be both sensitive and specific. To demonstrate the functional significance of the protocol, it was subsequently used to identify vitellogenin protein in the hypopharyngeal glands (brood food producing head glands) of nursing worker bees and in adjacent head fat body cells for the first time. Localization of vitellogenin in these tissues supports previously hypothesized roles of vitellogenin in social behavior. This protocol thus provides deeper insights into the functions of vitellogenin in the honeybee.
卵黄原蛋白是大多数卵生雌性动物的卵黄前体蛋白。在高级真社会性蜜蜂——意大利蜜蜂（膜翅目：蜜蜂科）中，卵黄原蛋白最近引起了很大的兴趣，因为除了在生殖女王级别的卵母细胞发育中具有经典功能外，它还在兼职不育的雌性工蜂级中进化出了其他物种中没有记录的功能。然而，利用现有工具研究卵黄原蛋白在各种组织中的空间动态并不容易。在这里，我们提出了一种免疫金染色程序，可用于在树脂包埋组织中可视化蜜蜂卵黄原蛋白。为了建立该方案，我们使用了有蜂王和无蜂王的蜂群中的工蜂卵巢。在第一种情况下，假设工蜂的卵巢中不存在卵黄原蛋白。在第二种情况下，工蜂的卵巢变得卵黄生成，有大量机会检测卵黄原蛋白摄取和储存的复杂模式。通过使用这种实验设置，证明了该染色方法既敏感又特异。为了证明该方案的功能意义，我们随后首次在哺乳工蜂的下咽腺（产卵食物产生的头部腺体）和相邻的头部脂肪体细胞中鉴定出卵黄原蛋白。卵黄原蛋白在这些组织中的定位支持了卵黄原蛋白在社会行为中的先前假设作用。因此，该方案为深入了解卵黄原蛋白在蜜蜂中的功能提供了更深入的见解。
