Behaviour and Genetics of Social Insects Laboratory, School of Biological Sciences, University of Sydney, , Sydney, New South Wales 2006, Australia, Honey Bee Research Section, ARC-Plant Protection Research Institute, , Private Bag X5017, Stellenbosch 7599, South Africa, Department of Biology, Harvey Mudd College, , 301 Platt Boulevard, Claremont, CA 91001, USA.
Proc Biol Sci. 2013 Nov 27;281(1775):20132388. doi: 10.1098/rspb.2013.2388. Print 2014 Jan 22.
Apis mellifera capensis is unique among honeybees in that unmated workers can produce pseudo-clonal female offspring via thelytokous parthenogenesis. Workers use this ability to compete among themselves and with their queen to be the mother of new queens. Males could therefore enhance their reproductive success by imprinting genes that enhance fertility in their daughter workers. This possibility sets the scene for intragenomic conflict between queens and drones over worker reproductive traits. Here, we show a strong parent-of-origin effect for ovary size (number of ovarioles) in reciprocal crosses between two honeybee subspecies, A. m. capensis and Apis mellifera scutellata. In this cross, workers with an A. m. capensis father had 30% more ovarioles than genotypically matched workers with an A. m. scutellata father. Other traits we measured (worker weight at emergence and the presence/absence of a spermatheca) are influenced more by rearing conditions than by parent-of-origin effects. Our study is the first to show a strong epigenetic (or, less likely, cytoplasmic maternal) effect for a reproductive trait in the honeybee and suggests that a search for parent-of-origin effects in other social insects may be fruitful.
开普熊蜂是所有蜜蜂中独一无二的，因为未交配的工蜂可以通过孤雌生殖产生拟克隆的雌性后代。工蜂利用这种能力相互竞争，并与蜂王竞争成为新蜂王的母亲。因此，雄蜂可以通过印记增强其女儿工蜂生育能力的基因来提高其繁殖成功率。这种可能性为蜂王和雄蜂之间在工蜂生殖特征上的种内冲突创造了条件。在这里，我们展示了两个蜜蜂亚种，开普熊蜂和 Apis mellifera scutellata 之间的正反交中卵巢大小（卵巢小管数量）的强烈母源效应。在这种杂交中，具有开普熊蜂父亲的工蜂比具有 Apis mellifera scutellata 父亲的同工蜂多出 30%的卵巢小管。我们测量的其他特征（出蜂时的工蜂体重和是否有精囊）受饲养条件的影响大于母源效应的影响。我们的研究首次在蜜蜂中显示出一个与繁殖特征相关的强烈的表观遗传（或更不可能的细胞质母性）效应，并表明在其他社会性昆虫中寻找母源效应可能会有收获。
