An assessment of the immune costs associated with meiotic drive elements in Drosophila.
An assessment of the immune costs associated with meiotic drive elements in Drosophila.
复制标题
与果蝇减数分裂驱动元件相关的免疫成本的评估。
DOI：
10.1098/rspb.2019.1534
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Unckless,RobertL
中科院分区：
文献类型：
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作者：
Lea,JennaKay;Unckless,RobertL
大多数生物体都在不断适应病原体和寄生虫，这些病原体和寄生虫利用它们的宿主来谋取自己的利益。基因组内寄生虫或自私的遗传因素研究较少，但可能更普遍。这些因素包括转座因子、自私的B染色体和减数分裂驱动因子，它们促进自身复制而不考虑对宿主的适应性影响。因此，基因组内寄生虫对宿主也是一种持续的进化压力。杀死配子的减数分裂驱动元件通常与大的染色体倒位有关，这减少了驱动和野生型染色体之间的重组。这种减少的重组被认为降低了驱动染色体上选择的效力，并允许有害突变的积累。我们测试了配子杀伤减数分裂驱动染色体是否与三种果蝇对两种细菌病原体的免疫防御能力降低有关。我们发现在减数分裂驱动系中免疫防御能力降低的证据很少。一条携带黑腹果蝇常染色体分离扭曲体的细胞系确实表现出防御能力降低，但我们无法将这种防御能力降低归因于基因型或免疫基因表达差异。我们的研究结果表明，尽管杀死配子的减数分裂驱动染色体可能积累有害突变，但这些突变不会导致免疫防御能力降低。
Most organisms are constantly adapting to pathogens and parasites that exploit their host for their own benefit. Less studied, but perhaps more ubiquitous, are intragenomic parasites or selfish genetic elements. These include transposable elements, selfish B chromosomes and meiotic drivers that promote their own replication without regard to fitness effects on hosts. Therefore, intragenomic parasites are also a constant evolutionary pressure on hosts. Gamete-killing meiotic drive elements are often associated with large chromosomal inversions that reduce recombination between the drive and wild-type chromosomes. This reduced recombination is thought to reduce the efficacy of selection on the drive chromosome and allow for the accumulation of deleterious mutations. We tested whether gamete-killing meiotic drive chromosomes were associated with reduced immune defence against two bacterial pathogens in three species ofDrosophila. We found little evidence of reduced immune defence in lines with meiotic drive. One line carrying theDrosophila melanogasterautosomal Segregation Distorter did show reduced defence, but we were unable to attribute that reduced defence to either genotype or immune gene expression differences. Our results suggest that though gamete-killing meiotic drive chromosomes probably accumulate deleterious mutations, those mutations do not result in reduced capacity for immune defence.