There are many differences in external morphology and internal physiology between the Apis mellifera queen bee and worker bee, some of which are relevant to beekeeping production. These include reproductive traits, body size, royal jelly secreting properties, and visual system development, among others. The identification of candidate genes that control the differentiation of these traits is critical for selective honeybee breeding programs. In this study, we compared the genomic methylation of queen bee and worker bee larvae at 3, 4, and 5 days of age by whole-genome bisulfite sequencing, and found that the basic characteristics of genomic methylation in queen and worker larvae were the same. There were approximately 49 million cytosines in the Apis larvae genome, of which about 90,000 were methylated. Methylated CpG sites accounted for 99% of the methylated cytosines, and methylation mainly occurred in exons. However, methylation levels of queen and worker larvae showed different trends with age: the methylation level of queen larvae varied with age in an inverted parabola, while the corresponding trend for worker larvae with resembled an exponential curve with a platform. The methylation level of queen larvae was higher than that of worker larvae at 3 days of age, lower than that of worker larvae at 4 days of age, and similar to that of worker larvae at 5 days old. The top 10 differentially methylated genes (DMGs) and 13 caste-specific methylated genes were listed, and correlations with caste determination were speculated. We additionally screened 38 DMGs between queen larvae and worker larvae involved in specific organ differentiation as well as reproduction, morphology, and vision differentiation during caste determination. These genes are potential molecular markers for selective breeding of A. mellifera to improve fecundity, royal jelly production, body size, and foraging, and represent candidate genes for investigating specialized functional segregation during the process of caste differentiation.

两者之间在外部形态和内部生理上有许多差异。 蜜蜂女王蜂和工蜂，其中一些与养蜂生产有关。其中包括生殖特征，体型，蜂王浆分泌特性和视觉系统发育等。确定控制这些性状分化的候选基因对于选择性蜜蜂育种计划至关重要。在这项研究中，我们通过全基因组亚硫酸氢盐测序对皇后蜂和工蜂幼虫在3、4和5天的基因组甲基化进行了比较，发现皇后蜂和工蜂幼虫的基因组甲基化的基本特征相同。大约有4900万个胞嘧啶蜜蜂幼虫基因组，其中约90,000被甲基化。甲基化的CpG位点占甲基化胞嘧啶的99％，而甲基化主要发生在外显子中。然而，皇后和幼虫的甲基化水平随年龄呈现出不同的趋势：倒立抛物线中，皇后幼虫的甲基化水平随年龄而变化，而工龄幼虫的相应趋势类似于具有平台的指数曲线。3天龄皇后幼虫的甲基化水平高于工龄幼虫，在4天龄时其甲基化水平低于工龄幼虫，与5天龄的工龄幼虫相似。列出了排名前10位的差异甲基化基因（DMG）和13个种姓特异性甲基化基因，并推测了与种姓测定的相关性。我们还筛选了38个DMG，它们在种姓确定期间涉及特定器官分化以及生殖，形态和视力分化的皇后幼虫和工人幼虫之间。这些基因是选择性育种的潜在分子标记。蜜蜂 来提高繁殖力，蜂王浆的产生，体重和觅食，并代表候选基因用于研究种系分化过程中的特殊功能隔离。