Institut für Biologie/Zoologie, Molekulare Ökologie, Martin-Luther-Universität Halle -Wittenberg, Hoher Weg 4, 06099, Halle (Saale), Germany; Honeybee Research Institute, Jiangxi Agricultural University, 330045, Nanchang, China.
Anim Genet. 2014 Apr;45(2):267-73. doi: 10.1111/age.12114. Epub 2013 Dec 10.
Nosema is a microsporidian parasite of the honeybee, which infects the epithelial cells of the gut. In Denmark, honeybee colonies have been selectively bred for the absence of Nosema over decades, resulting in a breeding line that is tolerant toward Nosema infections. As the tolerance toward the Nosema infection is a result of artificial selection, we screened chromosome 14 for a selective sweep with microsatellite markers, where a major quantitative trait locus (QTL) had been identified to be involved in the reduction in Nosema spores in the honeybees. By comparing the genetic variability of 10 colonies of the selected honeybee strain with a population sample from 22 unselected colonies, a selective sweep was revealed within the previously identified QTL region. The genetic variability of the swept loci was not only reduced in relation to the flanking markers on chromosome 14 within the selected strain but also significantly reduced compared with the same region in the unselected honeybees. This confirmed the results of the previous QTL mapping for reduced Nosema infections. The success of the selective breeding may have driven the selective sweep found in our study.
微孢子虫是一种寄生在蜜蜂肠道上皮细胞的寄生虫。在丹麦，经过几十年的选择性繁殖，已经培育出了对微孢子虫没有感染的蜜蜂品种，这种品种对微孢子虫感染具有耐受性。由于这种对微孢子虫感染的耐受性是人工选择的结果，我们使用微卫星标记在第 14 号染色体上筛选了一个选择清除区，其中一个主要的数量性状基因座（QTL）已被确定与减少蜜蜂体内的微孢子虫孢子有关。通过比较 10 个经过选择的蜜蜂品系的遗传变异性与 22 个未经选择的品系的群体样本，在先前确定的 QTL 区域内发现了一个选择清除区。被清除的基因座的遗传变异性不仅相对于选择菌株中第 14 号染色体上的侧翼标记减少，而且与未经选择的蜜蜂的同一区域相比也显著减少。这证实了先前对减少微孢子虫感染的 QTL 作图的结果。选择性繁殖的成功可能导致了我们研究中发现的选择清除。
