Honeybee Research Institute, Jiangxi Agricultural University, Nanchang, Jiangxi, China.
PLoS One. 2011 Apr 26;6(4):e18808. doi: 10.1371/journal.pone.0018808.
Young larvae of the honey bee (Apis mellifera) are totipotent; they can become either queens (reproductives) or workers (largely sterile helpers). DNA methylation has been shown to play an important role in this differentiation. In this study, we examine the contributions of diet and cell size to caste differentiation.
METHODOLOGY/PRINCIPAL FINDINGS: We measured the activity and gene expression of one key enzyme involved in methylation, Dnmt3; the rates of methylation in the gene dynactin p62; as well as morphological characteristics of adult bees developed either from larvae fed with worker jelly or royal jelly; and larvae raised in either queen or worker cells. We show that both diet type and cell size contributed to the queen-worker differentiation, and that the two factors affected different methylation sites inside the same gene dynactin p62.
CONCLUSIONS/SIGNIFICANCE: We confirm previous findings that Dnmt3 plays a critical role in honey bee caste differentiation. Further, we show for the first time that cell size also plays a role in influencing larval development when diet is kept the same.
年幼的蜜蜂幼虫（Apis mellifera）是全能的；它们可以成为蜂王（生殖）或工蜂（主要是不育的帮手）。已经表明，DNA 甲基化在这种分化中起着重要作用。在这项研究中，我们研究了饮食和细胞大小对职分化的贡献。
方法/主要发现：我们测量了参与甲基化的一个关键酶 Dnmt3 的活性和基因表达；dynactin p62 基因的甲基化率；以及由喂食工蜂或蜂王浆的幼虫或在蜂王或工蜂细胞中饲养的幼虫发育而成的成年蜜蜂的形态特征。我们表明，饮食类型和细胞大小都促成了蜂王-工蜂的分化，这两个因素影响了 dynactin p62 基因内的不同甲基化位点。
结论/意义：我们证实了之前的发现，即 Dnmt3 在蜜蜂的职分化中起着关键作用。此外，我们首次表明，当饮食保持不变时，细胞大小也会影响幼虫的发育。
