Population and landscape genomics of rapidly evolving gene motifs and introgressive hybridization and their role in adaptation

我们目前正处于全球变暖的时期，这对世界各地的物种分布产生了巨大的影响。许多物种的北部范围边界正在发生地理扩张，而其南部外围分布的范围边缘则受到生境不适宜以及人为活动和生物压力增加导致的隔离加剧的影响。此外，杂交的显著增加是由于以前孤立的物种之间更多的二次接触。这些分布变化和物种相互作用将对生物多样性和生态过程产生深远的影响。了解长期遗传变异和基因组要素如何在较高的变化率下运作，以及杂交如何促进适应性，对于确定野生动物种群的“响应能力”或“适应潜力”将是重要的。以快速变化的基因基序为目标以适应环境变化的速度是重要的第一步，编码三核苷酸重复序列（最常与人类遗传疾病相关）实际上可能是重要的自然因素，可以在选择中跟上当代气候变化的步伐，并在新环境中重新分配范围。在飞鼠（Glaucomys）和鹿鼠（Peromyscus）的综合研究中，应用于表征这些重复序列的新一代测序平台的进展将有助于我们了解与这些可变编码重复基序相关的适应基因组学。此外，这些物种经历了最近的杂交，从而可以评估每个属中南方和北方物种之间的基因转移。通过对驯化水貂与野生水貂种群的比较研究，以及对养殖水貂与野生水貂进行杂交的地区的研究，将进一步评估这些重复基元的潜在动态性质，这些基元在圈养环境中经历了重大的选择压力变化，随后逃离并重新进入自然环境，并与当地自然种群杂交。对这些“模式”物种的分子遗传学研究将为快速进化的基因组元素和杂交能力在促进种群适应不断变化的当地环境方面的作用提供重要的见解。这项研究对政府研究人员、政策制定者和工业界来说非常重要，可以更全面地了解未来野生动物物种和濒危物种的大规模重新分布所需要的缓解措施，而不仅仅是当前的环境景观“快照”。鉴于加拿大自然资源工业的日益发展，这将产生更有效的管理战略，以维持自然人口的适应潜力。**

We are currently in a period of global warming that is having dramatic effects on species distributions worldwide. Geographic expansions of northern range boundaries are occurring for many species, while the range margins at their southern peripheral distribution are impacted by less suitable habitat and increased isolation resulting from anthropogenic activities and increased biotic stress. Furthermore, notable increases in hybridization are resulting from more secondary contact between previously isolated species. These distributional changes and species interactions will have profound effects on biodiversity and ecological processes. Understanding how standing genetic variation and genomic elements operating at higher rates of change, and hybridization all contribute to adaptability will be important to determining a wildlife population's "response capacity" or "adaptive potential". Targeting gene motifs that may rapidly change to key up with the rate of environmental change is an important first step and coding trinucleotide repeats, most commonly associated with human genetic diseases, may in fact be important natural agents under selection that can keep pace with the contemporary climate change and range redistribution into novel environments. The advancement of next-generation sequencing platforms applied to characterizing these repeats in comprehensive studies of flying squirrels (Glaucomys) and deer mice (Peromyscus) will contribute to our understanding of the genomics of adaptation associated with these variable coding repeat motifs. Furthermore, these species have undergone very recent hybridization, thereby allowing an assessment of the transfer of genes between the southern and northern species within each genera. A study on domesticated mink compared to wild populations, as well as areas where escape farmed mink and wild mink interbreed, will further assess the potential dynamic nature of these repeat motifs having experienced significant shifts in selection pressures in captivity, with subsequent escape and re-entry into natural surroundings and interbreeding with natural local populations. A molecular genetic study of these "model" species will provide important insight into the role rapidly evolving genomic elements and the capacity of hybridization have on facilitating a populations ability to adapt to changing local environments. This research is important for government researchers, policy makers as well as industry to more fully understand the mitigation that will be required with significant range re-distribution of wildlife species and species-at-risk in the future, and not just the current "snapshot" of the environmental landscape. This will yield more effective management strategies to maintain the adaptive potential of natural populations given the increasing development of natural resource industries in Canada. **