Department of Biology, Utah State University, Logan, UT 84322, USA.
Department of Zoology, Stockholm University, 114 19 Stockholm, Sweden.
Genes (Basel). 2020 Apr 8;11(4):400. doi: 10.3390/genes11040400.
Genes that affect adaptive traits have been identified, but our knowledge of the genetic basis of adaptation in a more general sense (across multiple traits) remains limited. We combined population-genomic analyses of evolve-and-resequence experiments, genome-wide association mapping of performance traits, and analyses of gene expression to fill this knowledge gap and shed light on the genomics of adaptation to a marginal host (lentil) by the seed beetle . Using population-genomic approaches, we detected modest parallelism in allele frequency change across replicate lines during adaptation to lentil. Mapping populations derived from each lentil-adapted line revealed a polygenic basis for two host-specific performance traits (weight and development time), which had low to modest heritabilities. We found less evidence of parallelism in genotype-phenotype associations across these lines than in allele frequency changes during the experiments. Differential gene expression caused by differences in recent evolutionary history exceeded that caused by immediate rearing host. Together, the three genomic datasets suggest that genes affecting traits other than weight and development time are likely to be the main causes of parallel evolution and that detoxification genes (especially cytochrome P450s and beta-glucosidase) could be especially important for colonization of lentil by .
已经确定了影响适应性特征的基因，但我们对更广泛意义上（跨多个特征）的适应性遗传基础的了解仍然有限。我们结合了进化和测序实验的群体基因组分析、表型全基因组关联映射以及基因表达分析，以填补这一知识空白，并阐明通过种子象鼻虫适应边缘宿主（小扁豆）的基因组学。使用群体基因组学方法，我们在适应小扁豆的过程中检测到重复系之间等位基因频率变化的适度平行性。从小扁豆适应的每条系衍生的作图群体揭示了两个宿主特异性表型（体重和发育时间）的多基因基础，这些表型的遗传力较低至中等。我们发现，与实验过程中等位基因频率变化相比，这些系之间基因型-表型关联的平行性证据较少。由于最近进化历史的差异导致的差异基因表达超过了由于直接饲养宿主导致的差异基因表达。这三个基因组数据集表明，除了体重和发育时间之外，影响特征的基因很可能是平行进化的主要原因，解毒基因（特别是细胞色素 P450 和β-葡萄糖苷酶）可能对小扁豆的定殖特别重要。
