Nutrition is important in honey bee (Apis mellifera L.) colony decline. While the honey bee is incapable of converting dietary plant sterols to cholesterol, the sterol 24-methylenecholesterol has been previously shown to be selectively transferred from worker honey bees to developing brood in both laboratory and field studies. The importance of 24-methylenecholesterol to honey bee development and nutrition is unknown. This selective transfer suggests either (i) honey bees concentrate 24-methylenecholesterol in their tissues by selectively excreting other sterols in their feces (hypothesis 1), or (ii) some other metabolic/physiological mechanism exists to segregate/sequester 24-methylencholesterol for transfer to brood (hypothesis 2). The objective of this study was to determine if any C28 and C29 sterols other than 24-methylenecholesterol were selectively excreted in the feces by the honey bee (hypothesis 1), thereby concentrating the relative percentages of 24-methylenecholesterol in worker bee tissue, and thereby partially explaining the mechanism of selective sterol transfer in honey bees. We conducted the study by confining worker honey bees in a small cage with glass sides to facilitate the collection of honey bee feces. After four days, the neutral sterols were identified and the percentages of these sterols were determined from the pollen the honey bees presumably consumed prior to confinement, from the tissues of the confined worker bees, and from their feces. There was no apparent excessive excretion of other C28 and C29 phytosterols such as campesterol, sitosterol and isofucosterol and stigmasterol in honey bee feces, suggesting that hypothesis 2 (above) needs investigation.

中文翻译：

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蜜蜂（Apis mellifera）粪便中的中性甾醇

营养对于蜜蜂 (Apis mellifera L.) 群体衰退很重要。虽然蜜蜂无法将膳食植物甾醇转化为胆固醇，但先前已表明，在实验室和实地研究中，甾醇 24-亚甲基胆固醇可选择性地从工蜂转移到发育中的幼蜂。24-亚甲基胆固醇对蜜蜂发育和营养的重要性尚不清楚。这种选择性转移表明 (i) 蜜蜂通过选择性排泄粪便中的其他甾醇来在其组织中浓缩 24-亚甲基胆固醇（假设 1），或 (ii) 存在一些其他代谢/生理机制来分离/隔离 24-亚甲基胆固醇以进行转移育雏（假设2）。本研究的目的是确定蜜蜂是否有选择地将除 24-亚甲基胆固醇以外的任何 C28 和 C29 甾醇从粪便中排出（假设 1），从而浓缩了工蜂组织中 24-亚甲基胆固醇的相对百分比，从而部分解释了蜜蜂中选择性甾醇转移的机制。我们将工蜂关在一个带有玻璃边的小笼子里，以促进蜜蜂粪便的收集，从而进行了这项研究。四天后，中性甾醇被鉴定出来，这些甾醇的百分比是根据蜜蜂在禁闭前可能消耗的花粉、被禁闭的工蜂的组织和它们的粪便确定的。其他 C28 和 C29 植物甾醇如菜油甾醇、