Mustonen Marina, Haimi Jari, Kesäniemi Jenni, Högmander Harri, Knott K Emily
University of Jyvaskyla, Department of Biological and Environmental Science, University of Jyvaskyla, Jyvaskyla, Finland.
University of Oulu, Department of Ecology, University of Oulu, Oulu, Finland.
PLoS One. 2017 Apr 6;12(4):e0174960. doi: 10.1371/journal.pone.0174960. eCollection 2017.
Gene expression is highly plastic, which can help organisms to both acclimate and adapt to changing environments. Possible variation in gene expression among individuals with the same genotype (among clones) is not widely considered, even though it could impact the results of studies that focus on gene expression phenotypes, for example studies using clonal lines. We examined the extent of within and between clone variation in gene expression in the earthworm Dendrobaena octaedra, which reproduces through apomictic parthenogenesis. Five microsatellite markers were developed and used to confirm that offspring are genetic clones of their parent. After that, expression of 12 genes was measured from five individuals each from six clonal lines after exposure to copper contaminated soil. Variation in gene expression was higher over all genotypes than within genotypes, as initially assumed. A subset of the genes was also examined in the offspring of exposed individuals in two of the clonal lines. In this case, variation in gene expression within genotypes was as high as that observed over all genotypes. One gene in particular (chymotrypsin inhibitor) also showed significant differences in the expression levels among genetically identical individuals. Gene expression can vary considerably, and the extent of variation may depend on the genotypes and genes studied. Ensuring a large sample, with many different genotypes, is critical in studies comparing gene expression phenotypes. Researchers should be especially cautious inferring gene expression phenotypes when using only a single clonal or inbred line, since the results might be specific to only certain genotypes.
基因表达具有高度可塑性，这有助于生物体适应和应对不断变化的环境。即使同一基因型个体（克隆体之间）的基因表达可能存在差异会影响聚焦于基因表达表型的研究结果，例如使用克隆系的研究，但这种差异并未得到广泛关注。我们研究了通过无融合孤雌生殖进行繁殖的八毛枝蚓（Dendrobaena octaedra）基因表达在克隆体内部和克隆体之间的差异程度。开发了五个微卫星标记并用于确认后代是其亲本的基因克隆体。之后，在暴露于铜污染土壤后，从六个克隆系的五个个体中分别测量了12个基因的表达。如最初所设想的那样，所有基因型之间的基因表达差异高于基因型内部的差异。还在两个克隆系中对暴露个体的后代中的一部分基因进行了检测。在这种情况下，基因型内部的基因表达差异与所有基因型之间观察到的差异一样高。特别是一个基因（胰凝乳蛋白酶抑制剂）在基因相同的个体之间也表现出表达水平的显著差异。基因表达可能有很大差异，差异程度可能取决于所研究的基因型和基因。在比较基因表达表型的研究中，确保有大量包含许多不同基因型的样本至关重要。研究人员在仅使用单个克隆系或近交系推断基因表达表型时应格外谨慎，因为结果可能仅特定于某些基因型。
